JP2010235908A - Dye, photoelectric conversion element using the same, and photoelectrochemical cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye-sensitized cell having high conversion efficiency using an inexpensive organic dye. <P>SOLUTION: A dye has a structure expressed by general formula (1) in a molecule, wherein A<SP>1</SP>is a six-membered or seven-membered nitrogen-containing heterocycle formed by connecting with a benzene ring, L<SP>1</SP>is an electron transfer connecting group containing at least one heterocycle selected from among a thiophene ring, a furan ring, a pyrrole ring, a selenophene ring and a heterocycle formed by the ring-fusing of these, R<SP>1</SP>and R<SP>3</SP>are independently a hydrogen atom or a substituent respectively, R<SP>2</SP>is a hydrogen atom or a substituent, B<SP>1</SP>is a methylene group substituted by a heterocyclic acid nucleus or an electron withdrawing group, B<SP>1</SP>has at least one acid group, and n1 is an integer of 1 to 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a dye, a photoelectric conversion element sensitized with the dye, and a photoelectrochemical cell (a dye-sensitized solar cell) using the same.

  Photoelectric conversion elements are used in various optical sensors, copying machines, solar cells, and the like. Various types of photoelectric conversion elements have been put to practical use, such as those using metals, semiconductors, organic pigments and dyes, or combinations thereof. Above all, solar cells using non-depleting solar energy do not require fuel, and full-scale practical use is expected as inexhaustible clean energy. In this respect, silicon solar cells have been researched and developed for a long time. Despite the progress of popularization due to policy considerations in each country, silicon is an inorganic material, and its throughput and molecular modifications are naturally limited.

  Research on dye-sensitized solar cells has been vigorously conducted as a next-generation technology for solving the above-described problems. In particular, Greatzel et al. Of Lausanne University of Technology in Switzerland developed a dye-sensitized solar cell in which a dye composed of a ruthenium complex was fixed on the surface of a porous titanium oxide thin film, and realized a conversion efficiency comparable to that of amorphous silicon. Attracted attention from researchers.

  Patent Documents 1 to 3 disclose dye-sensitized photoelectric conversion elements using semiconductor fine particles sensitized with a dye, to which this technique is applied. This has the advantage that the device can be manufactured in a relatively simple process. However, ruthenium complex dyes used as sensitizing dyes are extremely expensive. Ruthenium is also concerned about availability, and it is still not enough to respond in earnest as a technology to support the next generation of clean energy. R & D for practical use has just begun. For these reasons, it is desired to develop photoelectric conversion elements that are sensitized by inexpensive organic materials with low resource constraints and have sufficient conversion efficiency, and reports using organic dyes as sensitizers have been reported. (See Patent Document 4).

US Pat. No. 5,463,057 US Pat. No. 5,525,440 JP 7-249790 A JP 2008-135197 A

  An object of the present invention is to provide a photoelectrochemical cell having high conversion efficiency using an inexpensive dye.

As a result of intensive studies, the inventor has found that a specific dye absorbs sunlight in a wide wavelength region, which is a factor affecting conversion efficiency, and high electron injection efficiency into the light receiving electrode, or It has been found that a photoelectrochemical cell having high conversion efficiency can be provided by satisfying both of these conditions and using this as a sensitizing dye. The present invention has been made based on this finding.
The object of the present invention has been achieved by the following means.

[一般式（１）中、Ａ¹は、ベンゼン環と連結して形成される六員環又は七員環の含窒素複素環を表す。Ｌ¹はチオフェン環、フラン環、ピロール環、セレノフェン環及びこれらが縮環した複素環の中から選ばれた少なくとも１種の複素環を含む電子伝達性連結基を表す。Ｒ^１、Ｒ^３はそれぞれ独立に、水素原子又は置換基を表す。Ｒ^２は水素原子又は置換基を表す。Ｂ¹は複素環酸性核、または電子求引性基で置換されたメチレン基を表し、Ｂ¹は少なくとも一つの酸性基を有する。n１は１〜１２の整数を表す。]
＜２＞前記一般式（１）で表される色素が、下記一般式（２）で表されることを特徴とする＜１＞記載の色素、

[一般式（２）中、Ｘはベンゼン環と連結して六員環又は七員環の含窒素複素環を形成するのに必要な非金属原子群を表す。Ｌ^１、Ｒ¹、Ｒ^２、Ｒ^３、Ｂ^１及びｎ１は、一般式（１）におけるものと同義である。Ｒ^４〜Ｒ^７はそれぞれ独立に、水素原子又は置換基を表す。ｎ２は１又は２の整数を示す。]
＜３＞前記一般式（２）中、Ｘがベンゼン環と連結して七員環の含窒素複素環を形成する非金属原子群であることを特徴とする＜２＞記載の色素、
＜４＞Ｂ^１が下記一般式（３）または一般式（４）で表されることを特徴とする＜１＞〜＜３＞のいずれか１項に記載の色素、

［一般式（３）においてＲ^７、Ｒ^９は、それぞれ独立に、脂肪族基、芳香族基または複素環基である（少なくとも１つの官能基は酸性基を有していてもよい）。ｍは０又は１を示す。一般式（３）における炭素−炭素二重結合は、Ｅ型又はＺ型のいずれであってもよい。一般式（３）中のＲ^８は硫黄原子または一般式（５）を表し、一般式（５）における炭素−炭素二重結合は、Ｅ型又はＺ型のいずれであってもよい。
一般式（４）におけるＲ^１０、Ｒ^１１は、それぞれ独立に、シアノ基又は酸性基を表し、互いに同一でも異なっていてもよい。一般式（４）における炭素−炭素二重結合は、Ｅ型又はＺ型のいずれであってもよい。
一般式（５）におけるＲ^１２、Ｒ^１３は、それぞれ独立に、シアノ基又は酸性基を表し、互いに同一でも異なっていてもよい。一般式（５）における炭素−炭素二重結合は、Ｅ型Ｚ型のいずれであってもよい。］
＜５＞前記一般式（３）で表される色素が、下記一般式（６）で表されることを特徴とする＜４＞記載の色素、

［一般式（６）においてＲ^９は、脂肪族基、芳香族基または複素環基である（酸性基を有していてもよい）。］
＜６＞前記Ｂ^１が下記一般式（７）で表されることを特徴とする＜１＞〜＜３＞のいずれか１項に記載の色素、

［一般式（７）においてＲ^７は、脂肪族基、芳香族基または複素環基である（酸性基を有していてもよい）。］
＜７＞前記Ｂ^１が下記一般式（８）で表されることを特徴とする＜１＞〜＜３＞のいずれか１項に記載の色素、

＜８＞受光電極が、＜１＞〜＜７＞のいずれか１項に記載の色素によって増感される半導体微粒子を含有することを特徴とする光電変換素子、
＜９＞受光電極と対極との間に絶縁性の多孔体を有することを特徴とする＜８＞記載の光電変換素子、
＜１０＞γ−ブチロラクトンを電解液中に含む、＜８＞又は＜９＞記載の光電変換素子、及び
＜１１＞＜８＞〜＜１０＞のいずれか１項に記載の光電変換素子を用いた光電気化学電池。 <1> a dye having a structure represented by the following general formula (1) in the molecule;

[In the general formula (1), A ¹ represents a nitrogen-containing heterocyclic six-membered ring or seven-membered ring formed by linking with the benzene ring. L ¹ represents an electron-transporting linking group containing at least one heterocyclic ring selected from a thiophene ring, a furan ring, a pyrrole ring, a selenophene ring, and a heterocyclic ring condensed with these. R ¹ and R ³ each independently represents a hydrogen atom or a substituent. R ² represents a hydrogen atom or a substituent. B ¹ represents a heterocyclic acidic nucleus or a methylene group substituted with an electron withdrawing group, and B ¹ has at least one acidic group. n1 represents an integer of 1 to 12. ]
<2> The dye according to <1>, wherein the dye represented by the general formula (1) is represented by the following general formula (2):

[In General Formula (2), X represents a nonmetallic atom group required in order to connect with a benzene ring and to form a 6-membered ring or a 7-membered nitrogen-containing heterocyclic ring. L ¹ , R ¹ , R ² , R ³ , B ¹ and n1 have the same meaning as in general formula (1). R ^{4 to} R ⁷ each independently represents a hydrogen atom or a substituent. n2 represents an integer of 1 or 2. ]
<3> The dye according to <2>, wherein, in the general formula (2), X is a nonmetallic atom group that forms a seven-membered nitrogen-containing heterocycle by linking with a benzene ring,
<4> ^{B 1} is represented by the following general formula (3) or by being represented by the general formula (4), characterized in <1> according to any one of to <3> dye,

[In General Formula (3), R ⁷ and R ⁹ are each independently an aliphatic group, an aromatic group, or a heterocyclic group (at least one functional group may have an acidic group). m represents 0 or 1; The carbon-carbon double bond in general formula (3) may be either E-type or Z-type. R ⁸ in general formula (3) represents a sulfur atom or general formula (5), and the carbon-carbon double bond in general formula (5) may be either E-type or Z-type.
R ¹⁰ and R ¹¹ in the general formula (4) each independently represent a cyano group or an acidic group, and may be the same as or different from each other. The carbon-carbon double bond in the general formula (4) may be either E-type or Z-type.
R ¹² and R ¹³ in the general formula (5) each independently represent a cyano group or an acidic group, and may be the same as or different from each other. The carbon-carbon double bond in the general formula (5) may be any of E type and Z type. ]
<5> The dye according to <4>, wherein the dye represented by the general formula (3) is represented by the following general formula (6):

[In General Formula (6), R ⁹ is an aliphatic group, an aromatic group or a heterocyclic group (may have an acidic group). ]
<6> wherein B ¹ is characterized by being represented by the following general formula (7) <1> according to any one of to <3> dye,

[In General Formula (7), R ⁷ is an aliphatic group, an aromatic group or a heterocyclic group (may have an acidic group). ]
<7> The dye according to any one of <1> to <3>, wherein B ¹ is represented by the following general formula (8):

<8> A photoelectric conversion element, wherein the light-receiving electrode contains semiconductor fine particles sensitized by the dye according to any one of <1> to <7>.
<9> The photoelectric conversion element according to <8>, having an insulating porous body between the light receiving electrode and the counter electrode,
<10> The photoelectric conversion element according to <8> or <9>, which contains γ-butyrolactone in the electrolytic solution, and the photoelectric conversion element according to any one of <11>, <8> to <10>. Had a photoelectrochemical cell.

  The dye of the present invention has high photoelectric conversion efficiency when used as a sensitizing dye for a photoelectric conversion element or a photoelectrochemical cell, has good characteristics, and does not require the use of ruthenium as the sensitizing dye.

It is sectional drawing shown typically about one embodiment of the photoelectric conversion element of this invention.

As a result of intensive studies, the present inventors have found that a pigment (pigment compound) having high photoelectric conversion efficiency and excellent durability can be obtained by introducing the following design concept. The present inventors have found that a photoelectric conversion element containing semiconductor fine particles sensitized by the dye and a photoelectrochemical cell configured with the photoelectric conversion element have high photoelectric conversion efficiency, thereby completing the present invention. It was.
<Design concept 1> In order to promote delocalization of the cation radical, a one-electron oxidation state of the dye was stabilized by introducing a donor site having a wide conjugated system.
<Design concept 2> It is considered that high conversion efficiency can be obtained by expanding the absorption range of the dye and improving the efficiency of electron injection from the dye into titanium oxide. For this purpose, either an acceptor structure having a high absorption range expansion effect, an acceptor structure having a high electron injection efficiency, or a combination of both structures was used.
<Design concept 3> The conventional dye may cover only about 1/3 of the total surface area of titanium oxide, and the amount of adsorption can be improved by controlling the dye arrangement in the adsorption state. It is done. Therefore, the present inventors introduced a structure that actively promotes the J-association of the dye. The structure that actively promotes J-association is a molecular structure in which a hydrophobic high-affinity group such as a long-chain alkyl group or an aryl group is arranged at a position opposite to the anchor portion such as a COOH group. In addition, the dye molecule has high planarity and has a substituent that protrudes three-dimensionally from the plane in the center of the molecular conjugate plane, or by having the same effect by twisting the molecule, Brickstone. It means a structure that promotes the arrangement of a structure, a staircase structure, or a Ladder structure.

Hereinafter, the coloring matter of the present invention will be described.
In the general formula (1), A ¹ is a six-membered or seven-membered nitrogen-containing heterocycle formed by linking with a benzene ring. The atom forming the six-membered or seven-membered nitrogen-containing heterocycle represented by A ¹ is preferably formed of at least one selected from a carbon atom, a sulfur atom, and an oxygen atom in addition to a nitrogen atom. A 6-membered or 7-membered nitrogen-containing heterocycle. More preferred examples include a 6-membered or 7-membered nitrogen-containing heterocycle formed of at least one selected from a carbon atom and a sulfur atom in addition to a nitrogen atom. Particularly preferred are 7-membered nitrogen-containing heterocycles formed by only carbon atoms in addition to nitrogen atoms. A ¹ may be condensed or may be substituted. Furthermore, you may have a substituent. Examples of the condensed ring include a benzene ring, a pyridine ring, a pyrrole ring, a furan ring, and a thiophene ring.

L ¹ is an electron-transporting linking group containing at least one heterocyclic ring selected from a thiophene ring, a furan ring, a pyrrole ring, a selenophene ring, and a heterocyclic ring condensed with these. Preferably, it is an electron transfer linking group containing at least one heterocyclic ring selected from a thiophene ring, a pyrrole ring or a heterocyclic ring condensed with these, more preferably a thiophene ring or a condensed heterocyclic thereof. An electron transporting linking group containing at least one heterocyclic ring selected from the ring. Examples of the condensed ring include a benzene ring, a pyridine ring, a pyrrole ring, a furan ring, and a thiophene ring.

In the general formula (1), R ¹ and R ³ each independently represents a hydrogen atom or a substituent. Preferably, R ¹ and R ³ each independently represents at least one substituent selected from a hydrogen atom, an alkyl group, an alkoxy group, and an aryl group. More preferably, it is at least one selected from an alkyl group, an alkoxy group, and an aryl group. Particularly preferred is at least one selected from an alkyl group and an aryl group, and more preferred is an alkyl group.
When R ¹ _and R ³ represent an alkyl group, preferred alkyl groups include linear, branched, and cyclic substituted or unsubstituted alkyl groups. They are alkyl groups (preferably alkyl groups having 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, t-butyl, n-hexyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl), a cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably a carbon number) 5 to 30 substituted or unsubstituted bicycloalkyl groups, that is, monovalent groups in which one hydrogen atom is removed from a bicycloalkane having 5 to 30 carbon atoms, for example, bicyclo [1,2,2] heptane-2 -Yl, bicyclo [2,2,2] octane-3-yl) and more ring structures Tricyclo structure is intended to encompass such. More preferable alkyl groups include alkyl groups having 1 to 30 carbon atoms (for example, methyl, ethyl, n-propyl, isopropyl, t-butyl, n-hexyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl) or a cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), particularly preferably carbon. Examples thereof include an alkyl group of 1 to 20, for example, methyl, ethyl, n-propyl, isopropyl, t-butyl, n-hexyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl and 2-ethylhexyl.
When R ¹ and R ³ represent an aryl group, preferred aryl groups include phenyl, naphthyl, thienyl, furyl, pyryl or a group in which these are condensed, and particularly preferably phenyl, thienyl or these in a condensed ring. Group. Examples of the condensed ring include a benzene ring, a pyridine ring, a pyrrole ring, a furan ring, and a thiophene ring.
When R ¹ and R ³ represent an alkoxy group, preferred alkoxy groups include substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms such as methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, 2-methoxyethoxy is mentioned, More preferably, a C1-C20 substituted or unsubstituted alkoxy group, for example, methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, 2-methoxyethoxy is mentioned. Particularly preferred is a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms.

R ² represents a hydrogen atom or a substituent. Preferably, it is a hydrogen atom. When R ² represents a substituent, examples of the substituent groups include groups represented by the substituent W described below, preferably as a substituent, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aromatic group , Heterocyclic group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, Amino group, acylamino group), aminocarbonylamino group, alkoxycarbonylamino group), aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, mercapto group, alkylthio group, arylthio group), heterocyclic thio Group, sulfamoyl group Sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group (acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl and heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyloxy group) Group, phosphinylamino group, silyl group, more preferably alkyl group, alkenyl group, alkynyl group, aromatic group, heterocyclic group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryl Oxy group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, Ryl group, particularly preferably alkyl group, alkenyl group, alkynyl group, aromatic group, heterocyclic group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, alkylthio group, arylthio group , A heterocyclic thio group.

B ¹ represents a heterocyclic acidic nucleus or a methylene group substituted with an electron withdrawing group, and B ¹ has at least one acidic group. As a heterocyclic acid nucleus, T.P. H. "The Theory of the photographic process. Forth edition." By James. The heterocyclic acid nucleus is preferably rhodanine, hydantoin, thiohydantoin, barbituric acid, thiobarbituric acid, pyrazolidinedione, pyrazolone, indandione, isoxazolone, more preferably rhodanine, hydantoin, thiohydantoin, barbitur Acid, thiobarbituric acid, particularly preferably rhodanine.

When B ¹ is a methylene group substituted with an electron withdrawing group, examples of the electron withdrawing group include substituents having the following effects.
In general, an electron withdrawing group attenuates the electron density at a specific position of the molecule. The electron withdrawing property or electron donating property cannot be explained simply by the difference in electronegativity. In other words, since the induced effect and the mesomery effect act in a complex manner, the appearance changes depending on the presence of aromaticity, conjugated system, and topological positional relationship. Hammett's rule is known as an empirical rule for quantitatively evaluating and predicting these effects based on the acid dissociation constants of para- and meta-substituted benzoic acids. In the case of an inductive effect, an electron withdrawing property is represented as an -I effect, and an electron donating property is represented as a + I effect. An atom having a higher electronegativity than carbon exhibits an -I effect. An anion shows a + I effect, and a cation shows a -I effect. In the case of the mesomery effect, the electron withdrawing property is represented as -M effect, and the electron donating property is represented as + M effect. Examples of electron withdrawing groups include the following.
Induced effect (-I effect)
_{^{· -O + R 2> -N +}} R 3
_{^{· -N + R 3> -P +}} R 3> ...
_{^{· -O + R 2> -S +}} R 2> ...
_{^{· -N + R 3> -NO 2}} > -SO 2 R> -SOR
· _-SO 2 R> _-SO 3 R
· ^-N + _R 3> -NR ₂
· ^-O + _R 2> -OR
· ^-S + _R 2> -SR
-F>-Cl>-Br> -I
・ = O> = NR> = CR ₂
・ = O> -OR
・ ≡N> ≡CR
· ≡N> = NR> -NR _{2
· -C≡CR> -CR = CR 2>} -CR 2 CR 3
Mesomery effect (-M effect)
_{^{· = N + R 3> =}} NR
・ = O> = NR> = CR ₂・ = S> = O> ≡N

  The electron withdrawing group is preferably a cyano group, a nitro group, a sulfonyl group, a sulfoxy group, an acyl group, an alkoxycarbonyl group or a carbamoyl group, more preferably a cyano group, a nitro group or a sulfonyl group, particularly preferably a cyano group. .

In the present invention, in the general formula (1), the methylene group substituted with a heterocyclic acidic nucleus or an electron withdrawing group represented by B ¹ has at least one acidic group. An acidic group is a group in which the pKa of the most acidic hydrogen atom constituting the group is 13 or less. Examples of acidic groups include carboxylic acid groups, sulfonic acid groups, phosphonic acid groups, phenolic hydroxyl groups, alkylsulfonylcarbamoyl groups, and phosphoric acid groups, preferably carboxylic acid groups, sulfonic acid groups, phosphonic acid groups, and phenols. A hydroxyl group, more preferably a carboxylic acid group or a sulfonic acid group, particularly preferably a carboxylic acid group.
In the general formula (1), n1 represents an integer of 1 to 12. n1 is preferably an integer of 1 to 10, more preferably an integer of 2 to 8, and particularly preferably an integer of 2 to 6.

The general formula (1) is more preferably represented by the general formula (2).
In the general formula (2), X represents a nonmetallic atom group necessary for forming a six-membered or seven-membered nitrogen-containing group by linking with a benzene ring. Here, the nonmetallic atom group refers to an atomic group in which at least one selected from the group consisting of a carbon atom, an oxygen atom, a nitrogen atom and a sulfur atom is bonded.
The atom forming the six-membered or seven-membered nitrogen-containing heterocycle represented by X is preferably at least one selected from the group consisting of a carbon atom, a sulfur atom, and an oxygen atom in addition to a nitrogen atom. Mention may be made of the six-membered or seven-membered nitrogen-containing heterocycle formed. More preferred examples include a six-membered or seven-membered nitrogen-containing heterocycle formed by at least one atom selected from a carbon atom and a sulfur atom in addition to a nitrogen atom. Particularly preferred is a seven-membered nitrogen-containing heterocyclic ring formed by at least one atom selected from a carbon atom and a sulfur atom in addition to a nitrogen atom. More preferred examples include a seven-membered nitrogen-containing heterocycle formed by a carbon atom and a sulfur atom in addition to a nitrogen atom.
X may be condensed or substituted. Furthermore, you may have a substituent. Examples of the condensed ring include a benzene ring, a pyridine ring, a pyrrole ring, a furan ring, and a thiophene ring.

In the general formula (2), R ^{4 to} R ⁷ represent at least one substituent selected from a hydrogen atom, an alkyl group, an alkoxy group, and an aryl group. R ^{4 to} R ⁷ are preferably a hydrogen atom or an alkyl group.
When R ^{4 to} R ⁷ represent an alkyl group, a preferred alkyl group represents a linear, branched, or cyclic substituted or unsubstituted alkyl group. They are alkyl groups (preferably alkyl groups having 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, t-butyl, n-hexyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl), a cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably a carbon number) 5 to 30 substituted or unsubstituted bicycloalkyl groups, that is, monovalent groups in which one hydrogen atom is removed from a bicycloalkane having 5 to 30 carbon atoms, for example, bicyclo [1,2,2] heptane-2 -Yl, bicyclo [2,2,2] octane-3-yl) and more ring structures Rishikuro structure is intended to encompass such. More preferable alkyl groups include alkyl groups having 1 to 30 carbon atoms (for example, methyl, ethyl, n-propyl, isopropyl, t-butyl, n-hexyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl) or a cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), particularly preferably carbon. Examples thereof include an alkyl group of 1 to 20, for example, methyl, ethyl, n-propyl, isopropyl, t-butyl, n-hexyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl and 2-ethylhexyl.
When R ^{3 to} R ⁷ represent an aryl group, preferred aryl groups include phenyl, naphthyl, thienyl, furyl, pyryl, or a group in which these are condensed, and particularly preferably phenyl, thienyl, or these in a condensed ring. Group. Examples of the condensed ring include a benzene ring, a pyridine ring, a pyrrole ring, a furan ring, and a thiophene ring.
When R ^{3 to} R ⁷ represent an alkoxy group, preferred alkoxy groups include substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms such as methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, 2-methoxyethoxy is mentioned, More preferably, a C1-C20 substituted or unsubstituted alkoxy group, for example, methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, 2-methoxyethoxy is mentioned. Particularly preferred is a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms.
In the general formula (2), n2 represents an integer of 1 or 2. Preferably, 2.

In the general formula (1) and (2), preferably when B ¹ is a group represented by the above general formula (3) or general formula (4).
In the general formula (3), R ⁷ and R ⁹ are each independently an aliphatic group, an aromatic group or a heterocyclic group (at least one functional group may have the acidic group described above). ). An aliphatic group and an aromatic group are preferable. More preferred are aliphatic groups and aromatic groups, and particularly preferred are aliphatic groups.
Examples of the aliphatic group include an alkyl group (for example, methyl, ethyl, n-propyl, isopropyl, t-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl), a cycloalkyl group (preferably A substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms (eg, cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl). Preferred aliphatic groups are alkyl groups and alkenyl groups having 1 to 30 carbon atoms, more preferably 1 to 25 carbon atoms, and particularly preferably 1 to 20 carbon atoms, which may have a substituent.
Examples of aromatic groups include benzene ring, furan ring, pyrrole ring, pyridine ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyrazole ring, isoxazole ring, isothiazole ring, pyrimidine ring, pyrazine ring or these condensed. These are cyclic rings, which may be substituted. A benzene ring, a pyrrole ring, a pyridine ring, and a thiophene ring are preferable, and a benzene ring and a thiophene ring are more preferable. Particularly preferred is a benzene ring. These may be substituted.
As the heterocyclic group, a 3- to 6-membered substituted or unsubstituted heterocyclic group, more preferably a 5- or 6-membered unsubstituted heterocyclic group, particularly preferably a 6-membered heterocyclic group (for example, piperidine, Morpholine). These may have a substituent.
In the general formula (3), m represents 0 or 1. Preferably it is 1.

The carbon-carbon double bond in general formula (3) may be either E-type or Z-type. R ⁸ in the general formula (3) represents a sulfur atom or the general formula (5), and the carbon-carbon double bond in the general formula (5) may be either E type or Z type. R ¹² and R ¹³ in the general formula (5) each independently represent a cyano group or an acidic group, and may be the same as or different from each other. Further, the carbon-carbon double bond in the general formula (5) may be any of E type and Z type.

R ¹⁰ and R ¹¹ in the general formula (4) each independently represent a cyano group or an acidic group, and may be the same or different from each other. The carbon-carbon double bond in the general formula (4) may be either E-type or Z-type.

The general formula (3) is preferably represented by the general formula (6). In the general formula (6), R ⁹ is an aliphatic group, an aromatic group, or a heterocyclic group (which may have an acidic group).

In the general formula (1) or (2), B ¹ is preferably represented by the general formula (7). In the general formula (7), R ⁷ is an aliphatic group, an aromatic group or a heterocyclic group (which may have an acidic group).
In the general formula (1) or (2), B ¹ is preferably represented by the general formula (8).

Examples of the substituent in the present invention (hereinafter referred to as “substituent W”) include those shown below.
・ Halogen atoms (for example, fluorine atom, chlorine atom, bromine atom, iodine atom),
-Alkyl group [Represents a linear, branched, or cyclic substituted or unsubstituted alkyl group. They are alkyl groups (preferably alkyl groups having 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, t-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl). A cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably having 5 to 30 carbon atoms). A substituted or unsubstituted bicycloalkyl group, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms, for example, bicyclo [1,2,2] heptan-2-yl, bicyclo [2,2,2] octane-3-yl), a tricyclo structure with more ring structures Domo is intended to cover. An alkyl group (for example, an alkyl group of an alkylthio group) in the substituents described below also represents such an alkyl group. ],
-Alkenyl group [Represents a linear, branched, or cyclic substituted or unsubstituted alkenyl group. They are alkenyl groups (preferably substituted or unsubstituted alkenyl groups having 2 to 30 carbon atoms, such as vinyl, allyl, prenyl, geranyl, oleyl), cycloalkenyl groups (preferably substituted or substituted groups having 3 to 30 carbon atoms). An unsubstituted cycloalkenyl group, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms (for example, 2-cyclopenten-1-yl, 2-cyclohexen-1-yl), Bicycloalkenyl group (a substituted or unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a bicycloalkene having one double bond. For example, bicyclo [2,2,1] hept-2-en-1-yl, bicyclo 2,2,2] oct-2-en-4-yl).
An alkynyl group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, such as ethynyl, propargyl, trimethylsilylethynyl group, aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, For example, phenyl, p-tolyl, naphthyl, m-chlorophenyl, o-hexadecanoylaminophenyl),
Aromatic groups (for example, benzene ring, furan ring, pyrrole ring, pyridine ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyrazole ring, isoxazole ring, isothiazole ring, pyrimidine ring, pyrazine ring or these A ring fused with
A heterocyclic group (preferably a monovalent group obtained by removing one hydrogen atom from a 5- or 6-membered substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, more preferably a carbon number of 3 To 30- or 5-membered aromatic heterocyclic group such as 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl),
・ Cyano group, ・ Hydroxyl group, ・ Nitro group, ・ Carboxyl group,
An alkoxy group (preferably a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, such as methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, 2-methoxyethoxy),
An aryloxy group (preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, such as phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy, 2-tetradecanoylamino Phenoxy),
A silyloxy group (preferably a silyloxy group having 3 to 20 carbon atoms, such as trimethylsilyloxy, t-butyldimethylsilyloxy),
A heterocyclic oxy group (preferably a substituted or unsubstituted heterocyclic oxy group having 1 to 30 carbon atoms, 1-phenyltetrazole-5-oxy, 2-tetrahydropyranyloxy),
An acyloxy group (preferably a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms, such as formyloxy, acetyloxy, Pivaloyloxy, stearoyloxy, benzoyloxy, p-methoxyphenylcarbonyloxy),
A carbamoyloxy group (preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms such as N, N-dimethylcarbamoyloxy, N, N-diethylcarbamoyloxy, morpholinocarbonyloxy, N, N-di -N-octylaminocarbonyloxy, Nn-octylcarbamoyloxy),
An alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, such as methoxycarbonyloxy, ethoxycarbonyloxy, t-butoxycarbonyloxy, n-octylcarbonyloxy),
Aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, such as phenoxycarbonyloxy, p-methoxyphenoxycarbonyloxy, pn-hexadecyloxyphenoxycarbonyloxy ),
Amino groups (preferably amino groups, substituted or unsubstituted alkylamino groups having 1 to 30 carbon atoms, substituted or unsubstituted anilino groups having 6 to 30 carbon atoms, such as amino, methylamino, dimethylamino, anilino N-methyl-anilino, diphenylamino),
Acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms, such as formylamino, acetylamino Pivaloylamino, lauroylamino, benzoylamino, 3,4,5-tri-n-octyloxyphenylcarbonylamino),
Aminocarbonylamino group (preferably substituted or unsubstituted aminocarbonylamino having 1 to 30 carbon atoms, such as carbamoylamino, N, N-dimethylaminocarbonylamino, N, N-diethylaminocarbonylamino, morpholinocarbonylamino) ,
An alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms such as methoxycarbonylamino, ethoxycarbonylamino, t-butoxycarbonylamino, n-octadecyloxycarbonylamino, N-methyl- Methoxycarbonylamino),
An aryloxycarbonylamino group (preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms, such as phenoxycarbonylamino, p-chlorophenoxycarbonylamino, mn-octyloxyphenoxycarbonylamino) ,
A sulfamoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms, such as sulfamoylamino, N, N-dimethylaminosulfonylamino, Nn-octylaminosulfonyl amino),
Alkyl and arylsulfonylamino groups (preferably substituted or unsubstituted alkylsulfonylamino having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonylamino having 6 to 30 carbon atoms, such as methylsulfonylamino, butylsulfonylamino, Phenylsulfonylamino, 2,3,5-trichlorophenylsulfonylamino, p-methylphenylsulfonylamino),
・ Mercapto group,
An alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, such as methylthio, ethylthio, n-hexadecylthio),
An arylthio group (preferably a substituted or unsubstituted arylthio having 6 to 30 carbon atoms, such as phenylthio, p-chlorophenylthio, m-methoxyphenylthio),
A heterocyclic thio group (preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms, such as 2-benzothiazolylthio, 1-phenyltetrazol-5-ylthio),
A sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms, such as N-ethylsulfamoyl, N- (3-dodecyloxypropyl) sulfamoyl, N, N-dimethylsulfamoyl, N -Acetylsulfamoyl, N-benzoylsulfamoyl, N- (N′-phenylcarbamoyl) sulfamoyl),
・ Sulfo group,
Alkyl and arylsulfinyl groups (preferably substituted or unsubstituted alkylsulfinyl groups having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfinyl groups having 6 to 30 carbon atoms, such as methylsulfinyl, ethylsulfinyl, phenylsulfinyl, p -Methylphenylsulfinyl),
Alkyl and arylsulfonyl groups (preferably substituted or unsubstituted alkylsulfonyl groups having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonyl groups having 6 to 30 carbon atoms such as methylsulfonyl, ethylsulfonyl, phenylsulfonyl, p- Methylphenylsulfonyl),
Acyl group (preferably formyl group, substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, substituted or unsubstituted carbon group having 4 to 30 carbon atoms A heterocyclic carbonyl group bonded to a carbonyl group at a carbon atom, for example, acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyloxyphenylcarbonyl, 2-pyridylcarbonyl, 2-furylcarbonyl),
Aryloxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms, such as phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, pt-butylphenoxycarbonyl) ,
An alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, n-octadecyloxycarbonyl),
A carbamoyl group (preferably a substituted or unsubstituted carbamoyl having 1 to 30 carbon atoms such as carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N, N-di-n-octylcarbamoyl, N- ( Methylsulfonyl) carbamoyl),
Aryl and heterocyclic azo groups (preferably substituted or unsubstituted arylazo groups having 6 to 30 carbon atoms, substituted or unsubstituted heterocyclic azo groups having 3 to 30 carbon atoms, such as phenylazo, p-chlorophenylazo, 5 -Ethylthio-1,3,4-thiadiazol-2-ylazo),
An imide group (preferably N-succinimide, N-phthalimide),
A phosphino group (preferably a substituted or unsubstituted phosphino group having 2 to 30 carbon atoms, such as dimethylphosphino, diphenylphosphino, methylphenoxyphosphino),
A phosphinyl group (preferably a substituted or unsubstituted phosphinyl group having 2 to 30 carbon atoms, such as phosphinyl, dioctyloxyphosphinyl, diethoxyphosphinyl),
A phosphinyloxy group (preferably a substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms, such as diphenoxyphosphinyloxy, dioctyloxyphosphinyloxy),
A phosphinylamino group (preferably a substituted or unsubstituted phosphinylamino group having 2 to 30 carbon atoms, such as dimethoxyphosphinylamino, dimethylaminophosphinylamino),
A silyl group (preferably a substituted or unsubstituted silyl group having 3 to 30 carbon atoms, for example, trimethylsilyl, t-butyldimethylsilyl, phenyldimethylsilyl).
In addition, the substituent may be further substituted. In that case, the above-mentioned substituent W can be mentioned as an example of a substituent.

  Although the preferable specific example of the pigment | dye (dye compound) of this invention is shown below, this invention is not limited to these.

  The dye of the present invention has a maximum absorption wavelength in a solution of preferably 350 to 1000 nm, more preferably 370 to 700 nm, and particularly preferably 390 to 650 nm.

  As shown in FIG. 1, the preferable embodiment of the photoelectric conversion element of this invention is demonstrated with reference to drawings. The photoelectric conversion element 10 includes a conductive support 1, a semiconductor film (photosensitive layer) 2 sensitized with a dye placed on the conductive support 2, a hole transport layer 3, and a counter electrode 4. The conductive support 1 provided with a semiconductor film (not shown separately) functions as a working electrode in the photoelectric conversion element 10. The photoelectric conversion element 10 can be used as a battery for working in the external circuit 6 and can be operated as a photoelectrochemical cell (not shown).

The light receiving electrode 5 is an electrode composed of a conductive support 1 and a layer (photosensitive layer) 2 of semiconductor fine particles 22 adsorbed with a dye 21 coated on the conductive support. In the present embodiment, the light receiving electrode 5 is shown as including the electrolyte 23, but may be regarded as not including this. The photosensitive layer 2 is designed according to the purpose, and may be a single layer structure or a multilayer structure. The dye in one photosensitive layer may be one kind or a mixture of various kinds, but at least one of them uses the dye of the present invention. Light incident on the photosensitive layer 2 excites the dye. The excited dye has electrons with high energy, and these electrons are passed from the dye 21 to the conduction band of the semiconductor fine particles 22 and reach the conductive support 1 by diffusion. At this time, the molecule of the dye 21 is an oxidant, but the electrons on the electrode return to the dye oxidant while working in the external circuit, and the light receiving electrode 5 serves as the negative electrode of the battery. work.
In the present invention, the materials used for the photoelectric conversion element and the photoelectrochemical cell and the method for producing each member may be the usual ones of this type. For example, US Pat. No. 5,463,057, US Pat. No. 5,525,440, JP-A-7-249790, JP-A-2004-220974, and JP-A-2008-135197 can be referred to. Hereinafter, an outline of main members will be described.

Next, the photoelectrochemical cell of the present invention will be described in detail.
The configuration of the photoelectrochemical cell of the present invention comprises a transparent substrate and a counter substrate as an outermost layer, and a transparent conductive film, a light receiving electrode, a charge transfer layer, a counter electrode, and a conductive layer are disposed between the two substrates from the transparent substrate side. It has been done. The space portion between the light receiving electrode and the counter electrode is preferably filled with an insulating porous body. In particular, a layer filled with an insulating porous material is preferably provided between the light receiving electrode and the charge transfer layer. Andrew Key, Michael Greatzel, “Low cost photovoltaic moduls based on dyssensed titanium dioxide and carbon powder” by Andrew Greyzel. 44, Elsevier Science, 1996, p. 99-117. In the three-layer module disclosed therein, the layer filled with this insulating porous body is called a separator.
As the insulating porous material used as the space filler or the separator, for example, particles such as glass beads and silicon dioxide (silica) can be used. Preferably, sintered silicon dioxide particles are preferred. The insulating porous body is preferably one that can be formed by coating and sintering from the viewpoint of cost reduction. Specifically, an insulating porous body in which silica particles are sintered is preferable. The reason why a porous body obtained by sintering silica particles is preferable is that the porous body has good transparency because it has a low refractive index and low light scattering. The porous body preferably has an average particle size of 5 to 150 nm in order to ensure good transparency.

  The light receiving electrode is an electrode composed of a conductive support and a layer of semiconductor fine particles (photosensitive layer) adsorbed with a dye coated on the conductive support. The photosensitive layer is designed according to the purpose, and may be a single layer structure or a multilayer structure. The dyes in one photosensitive layer may be one kind or a mixture of various kinds, but at least one of them is a dye having at least one structure represented by any one of the general formulas (I) to (VII). is there. Light incident on the photosensitive layer excites the dye. The excited dye has electrons with high energy, and these electrons are transferred from the dye to the conduction band of the semiconductor fine particles, and further reach the conductive support by diffusion. At this time, the dye molecule is an oxidant, but the electrons on the electrode return to the dye oxidant while working in the external circuit, and the dye-sensitized photoelectric conversion element is the negative electrode of this battery. Work as.

  The conductive support is a support made of glass or plastic having a conductive film layer on the surface, such as a metal having a conductive property in itself. As the support, in addition to glass and plastic, ceramic (Japanese Patent Laid-Open No. 2005-135902) or conductive resin (Japanese Patent Laid-Open No. 2001-160425) may be used. On the support, a surface may be provided with a light management function. For example, an antireflection film in which high refractive films and low refractive index oxide films described in JP-A-2003-123859 are alternately laminated, and JP-A-2002 The light guide function described in -260746 is raised.

It is preferable to provide a function of blocking ultraviolet light on the support. For example, the method of making the fluorescent material which can change the ultraviolet light of Unexamined-Japanese-Patent No. 2001-185242 into visible light exist in a transparent support body or the surface of a transparent support body is mentioned. Another preferred method is a method using an ultraviolet absorber. As preferred embodiments, for example, disclosed in JP-A-11-345991, JP-A-2002-25634, JP-A-2003-21769, JP-A-2004-227843, JP-A-2004-349129, JP-A-2002-134178, and JP-A-2003-1000035. Things.
The functions described in JP-A-11-250944, JP-A-2003-308892, and JP-A-2003-282163 may be provided on the support.

  Preferred conductive films include metals (eg, platinum, gold, silver, copper, aluminum, rhodium, indium, etc.), carbon, or conductive metal oxides (indium-tin composite oxide, tin oxide doped with fluorine, etc.) ). Examples of preferred conductive film modes and methods include JP-A No. 2003-151355, JP-A No. 2004-31174, JP-A No. 2004-31175, JP-A No. 2004-31176, JP-A No. 2005-85699, JP-A No. 2005-85670, and JP-A No. 2005. 116391, JP2003-323818, JP2004165080, and JP2005141981.

The thickness of the conductive film layer is preferably 0.01 to 30 μm, more preferably 0.03 to 25 μm, and particularly preferably 0.05 to 20 μm.
The lower the surface resistance of the conductive support, the better. The range of the surface resistance is preferably 50 Ω / cm ² or less, more preferably 10 Ω / cm ² or less. Although there is no restriction | limiting in particular in this lower limit, Usually, it is about 0.1 ohm / cm < ² >.

  Since the resistance value of the conductive film increases as the cell area increases, a collecting electrode may be provided. Preferred shapes and materials of the current collecting electrodes are disclosed in JP-A-11-266028, JP-A-2005-108467, JP-A-2003-203681, JP-A-2004-146425, JP-A-2004-128267, JP-A-2004-164970, JP-A-2004. -327226, JP-A-2004-164950, JP-A-2005-78857, JP-A-2005-197176, JP-A-2004-164950, JP-A-2000-285777, JP-A-2002-314108, and JP-A-2003-123858.

As described in JP-A-2000-285974, a gas barrier film and / or an ion diffusion preventing film may be disposed between the support and the transparent conductive film. As the gas barrier layer, either a resin film (for example, Japanese Patent Laid-Open No. 2000-282163, Japanese Patent Laid-Open No. 2005-14086) or an inorganic film (Japanese Patent Laid-Open No. 2005-142886) may be used.
Moreover, you may provide a transparent electrode and a porous semiconductor electrode photocatalyst content layer like Unexamined-Japanese-Patent No. 2005-142084 or 2005-142085.

  The transparent conductive layer may have a laminated structure. As a preferable method, for example, in addition to the method described in JP-A No. 2003-323818 in which FTO is laminated on ITO, JP-A No. 2005-44544, JP-A No. 2005-142888, and JP-A No. 2005-19205. JP-A-2004-241228 and JP-A-2004-319872.

It is preferable that the conductive support is substantially transparent. Substantially transparent means that the light transmittance is 10% or more, preferably 50% or more, particularly preferably 80% or more. As the transparent conductive support, a glass or plastic coated with a conductive metal oxide is preferable. The coating amount of the conductive metal oxide at this time is preferably 0.1 to 100 g per 1 m ² of a glass or plastic support. When a transparent conductive support is used, light is preferably incident from the support side.

  The semiconductor fine particles are preferably metal chalcogenide (for example, oxide, sulfide, selenide, etc.) or perovskite fine particles. Preferred examples of the metal chalcogenide include titanium, tin, zinc, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, tantalum oxide, cadmium sulfide, cadmium selenide, and the like. . Preferred perovskites include strontium titanate and calcium titanate. Of these, titanium oxide, zinc oxide, tin oxide, and tungsten oxide are particularly preferable.

  As a method for producing semiconductor fine particles, for example, preferably as a method for producing titania nanoparticles, a method by flame hydrolysis of titanium tetrachloride (Japanese Patent Publication No. 06-511113), a combustion method of titanium tetrachloride (Japanese Patent Laid-Open No. 2003-327432), Hydrolysis of stable chalcogenide complexes (Japanese Patent Laid-Open No. 2001-85076), hydrolysis of orthotitanic acid (Japanese Patent Laid-Open No. 2004-161589, Japanese Patent Laid-Open No. 2004-238213), soluble portion after formation of semiconductor fine particles from soluble portion and insoluble portion For dissolution and removal of water (JP 2002-246620), hydrothermal synthesis of an aqueous peroxide solution (JP 2003-92154), or manufacturing method of core / shell structure titanium oxide fine particles by sol-gel method (JP 2004-10403) ).

  Examples of the crystal structure of titania include anatase type, brookite type, and rutile type, and anatase type and brookite type are preferable. Preferred examples include those described in JP-A Nos. 11-339867, 2001-43907, and 2001-43907. Further, examples of preferable physical properties of titanium oxide include the examples described in EP 1338563, US 2004/0161380, US 6075203, US 6444189, US 6720202, CN 1540772, JP 2001-283542, and JP 2001-212457.

  Titania nanotubes, nanowires, and nanorods may be mixed with titania fine particles or used as a semiconductor electrode. Preferred examples include Japanese Patent Laid-Open Nos. 2003-168495, 2003-251194, 2004-175586, and 2004. Examples include those described in JP-A-175875, JP-A No. 2004-175588, JP-A No. 2004-31354, JP-A No. 2004-31355, JP-A No. 2004-319661, and JP-A No. 2005-162584.

  Titania may be doped with a nonmetallic element or the like. Preferred examples include JP-A 2000-235874, JP-A 2003-252624, JP-A 2002-25637, JP-A 2003-187881, JP-A 2003-187882, JP-A 2003-179244, JP-A 2004-87148, JP-A 2004. -119279, JP2005-93944, JP2005-64493, JP2003-257507, and JP2003-323920. In addition to the dopant, an additive to the titania may be used as a binder for improving necking or an additive on the surface for preventing reverse electron transfer. Examples of preferable additives include ITO, SnO particles (JP-A-11-283682, JP-A-2001-345125), whiskers (JP-A-2003-163037), fibrous graphite / carbon nanotubes (JP-A-2003-163037), oxidation Zinc necking binder (Japanese Patent Laid-Open No. 2003-273381), fibrous materials such as cellulose (Japanese Patent Laid-Open No. 2003-123861), metal (Japanese Patent Laid-Open No. 2000-285975, Japanese Patent Laid-Open No. 2001-35551), organic silicon (Japanese Patent Laid-Open No. 2000-294304) , Dodecylbenzenesulfonic acid (JP 2000-260493), charge transfer bonding molecules such as silane compounds (JP 2000-323192, JP 2001-102103), potential gradient dendrimers (JP 2004-213908), and the like. It is done.

  For the purpose of removing surface defects on titania, titania may be acid-base or redox treated before dye adsorption. Examples of acid-base treatment include, for example, JP 2000-101106 A, JP 2002-293541 A, JP 2003-297441 A, JP 2003-297442 A, JP 2004-235240 A, and the like. Further, as described in JP-A-08-81222, JP-A-2000-285980, JP-A-2004-158243, JP-A-2004-247104, etc., etching, oxidation treatment, hydrogen peroxide treatment, dehydrogenation treatment, UV-ozone, You may process by oxygen plasma etc.

  As the semiconductor electrode, a composite electrode such as titanium oxide and tin oxide (TiO2 / SnO2) may be used. As a mixed electrode of titania, for example, JP 2000-119393, JP 2004-95387, JP 2001-155791, JP 2003-272723, JP 05-504023, JP 2000-114563, JP 2002-75476, JP 2002-8741, CN 1350334, JP 2003-272724, JP 2003-308891, JP 2005-174934, JP JP-A No. 2001-358348, JP-A No. 2003-123862, JP-A No. 2004-103420, JP-A No. 2005-39013, and JP-A No. 2003-317815. As mixed electrodes other than titania, for example, JP 2001-185243, JP 2003-282164, JP 2003-289151, JP 2003-321299, JP 2002-93471, JP 2002-141115, JP 2002-184476, JP 2002-356400, JP 2002-246623, JP 2002-246624, JP 2002-261303, JP 2003-243053, JP 2004-6235, JP 2003-323920, JP 2004-277197, JP 2004-210605, JP 2005-135798, JP 2005-135799, JP 2001-196105, JP 2002-100418, JP 2002-100419, JP 2002-280084, JP 2003-272. 24, JP 2004-124124, JP-A 09-237641, JP-A 11-273755, include JP 2004-247105.

  The semiconductor electrode may be a tandem type in order to increase the utilization rate of incident light. Examples of preferable tandem configuration examples include Japanese Patent Laid-Open No. 2002-90989, Japanese Patent Laid-Open No. 2002-222971, Japanese Patent Laid-Open No. 2003-168497, Japanese Patent Laid-Open No. 2003-249275, 2005-166313, Japanese Patent Laid-Open No. 11-273353, Japanese Patent Laid-Open No. 2002-167808, Examples described in JP-A-2005-129259, JP-A-2002-231324, JP-A-2005-158620, JP-A-2005-158621, JP-A-2005-191137, JP-A-2003-333757 are included.

  The particle diameters of these semiconductor fine particles are 0.001 to 1 μm as primary particles, and 0.01 to 100 μm as the average particle diameter of the dispersion in terms of the average particle diameter when the projected area is converted into a circle. It is preferable.

  As a method of coating the semiconductor fine particles on the conductive support, a method of coating a dispersion or colloidal solution of semiconductor fine particles on the conductive support, or a method of coating the semiconductor fine particle precursor described in Japanese Patent No. 2664194 with the conductive support. As a general method, (1) a wet method such as a method for obtaining a semiconductor fine particle film by applying it on the surface and hydrolyzing with moisture in the air can be cited. As a manufacturing method of the wet method, as a method of preparing a dispersion of semiconductor fine particles, a method of pulverizing with a mortar, a method of dispersing while pulverizing using a mill, or a method of precipitating fine particles in a solvent when synthesizing a semiconductor Examples of the method are as follows. Preferably, JP-A Nos. 11-144772, JP-A 2005-1000079, EP 1300957, JP-A 2002-324591, JP-A 2002-145615, JP-A 2003-176130, and JP-A 2004-2004 are preferable. 79610. (1) As a dispersion medium of the coating liquid of the wet method, water or various organic solvents (for example, methanol, ethanol, t-butanol, dichloromethane, acetone, acetonitrile, ethyl acetate, etc.) can be mentioned. 06-511113, CN144292, JP11-11912, JP2000-294814, JP2000-319018, JP2000-319018, JP2000-319018, JP2002-145614, JP2002-75477, JP 2004-193321, WO02 / 067357, JP2004-207205, JP2004-111348, JP2004-186144, JP2003-282162, JP2005-142011, JP2005-174695, JP2005-8550. JP-A-11-343118, JP-A-11-354169, JP-A-2000-106222, JP-A-2003-246621, JP-A-2003-51345, JP-A-2004-158551, JP-A-2001-358348, JP-A-2003-217893, and the like. Can be mentioned. . During dispersion, a polymer, surfactant, acid, chelating agent, or the like may be used as a dispersion aid as necessary.

Examples of the method for coating the semiconductor fine particles on the conductive support include (1) a wet method, (2) a dry method, and (3) other methods.
(2) Preferably, the dry method is disclosed in JP 2000-231943, JP 2002-170602, JP 2001-345124, JP 2003-197280, JP 2003-123854, JP 2003-123852, JP 2003-123853. JP-A-2005-39013, JP-A-2004-39286, JP-A-2005-104760.
(3) As other methods, preferably, JP-A No. 2002-134435, US 2004/0123896, JP-A No. 2004-327265, JP-A No. 342397, JP-A No. 2003-500787, JP-A No. 2005-85491, JP-A No. 2003-98977, JP JP 2002-299665, JP 2003-243053, JP 2004-253331, JP 11-310898, JP 2003-257507, JP 2003-323920, US 2004/0084080, US 2004/0121068, JP 2004-319873, Special Examples include Kaihei 10-112337, JP-A-11-6098, JP-A 2000-178791, JP-A 2000-178792, JP-A 2004-103420, and JP-A 2003-301283.

  Light scattering inside the semiconductor electrode layer. A light management function for efficiently performing reflection may be provided. Preferably, JP 2002-93476, JP 2004-296373, JP 2002-352868, JP 2003-142170, JP 2003-59549, JP 2002-289274, JP 2002-222968, JP 2003-217688. , JP 2004-172110, JP 2003-303629, JP 2004-343071, JP 2005-116302, JP 09-259943, JP 10-255863, JP 2003-142171, JP 2002-110261, and JP2004-311197 is mentioned.

  It is preferable to form a short-circuit prevention layer between the transparent conductive film and the oxide semiconductor layer in order to prevent reverse current due to direct contact between the electrolyte and the electrode. Preferred examples include JP 06-507999, JP 06-51113, JP 2000-178792, JP 11-312541, JP 2000-285974, JP 2000-285799, JP 2001-143771, JP 2001156314. , JP 2001-307785, JP 2002-151168, JP 2002-75471, JP 2003-163359, JP 2003-163360, JP 2003-123856, WO 03/038909, JP 2002-289270, JP 2002. -393939, JP 2003-297443, JP 2004-87622, JP 2003-331934, JP 2003-243054, JP 2004-319130, JP 2004-36369, JP 2005-719. 6, JP 2005-108807, JP 2005-108836, include JP 2005-142087.

  In order to prevent contact between the photoelectrode and the counter electrode, it is preferable to use a spacer or a separator. Preferable examples include JP-A-2001-283941, JP-A-2003-18783, JP-A-2000-294306, JP-A-2002-175844, JP-A-2002367686, and JP-A-2004-253333.

  The semiconductor fine particles preferably have a large surface area so that many dyes can be adsorbed. For example, in a state where the semiconductor fine particles are coated on the support, the surface area is preferably 10 times or more, more preferably 100 times or more the projected area. Although there is no restriction | limiting in particular in this upper limit, Usually, it is about 5000 times. Preferred examples of the structure of the semiconductor fine particles include JP 2001-93591 A, JP 2001-257010 A, JP 2001-196106 A, JP 2001-273936 A, and EP 1207572.

In general, as the thickness of the semiconductor fine particle layer increases, the amount of dye that can be supported per unit area increases, so that the light absorption efficiency increases. However, the diffusion distance of the generated electrons increases, and the loss due to charge recombination also increases. The preferred thickness of the semiconductor fine particle layer varies depending on the use of the device, but is typically 0.1 to 100 μm. When using as a photoelectrochemical cell, it is preferable that it is 1-50 micrometers, and it is more preferable that it is 3-30 micrometers. The semiconductor fine particles may be fired at a temperature of 100 to 800 ° C. for 10 minutes to 10 hours in order to adhere the particles to each other after being applied to the support. When glass is used as the support, the film forming temperature is preferably 400 to 600 ° C.
When using a plastic as a support, it is preferable to form a film at 300 ° C. or lower, and more preferably 200 ° C. or lower. As a method for forming a film at 200 ° C. or lower, any of (1) wet method, (2) dry method, and (3) electrophoresis method (including electrodeposition method) may be used, preferably (1) wet method, Or (2) dry method, more preferably (1) wet method.

The wet method is a method of forming a film on a plastic film by applying a semiconductor layer or a precursor thereof wet, etc., and further activating it. For example, a semiconductor disclosed in JP-A-10-290018 A method of heating a mixture of conductive compounds at a low temperature, a method using a precursor (for example, (NH4) 2TiF6 disclosed in JP-A-2001-110462, titanium peroxide disclosed in JP-A-2001-247314, JP-A-11- 219734 disclosed metal alkoxides, metal complexes, metal organic acid salts).
A method of applying a slurry containing a metal organic oxide (such as alkoxide) disclosed in JP 2005-520314 and forming a semiconductor film by heat treatment, light treatment, etc., and an inorganic precursor disclosed in JP 2003-28847A And the method of identifying the pH of the slurry and the properties of the dispersed titania particles disclosed in JP-A-2005-056627.
A binder may be added to these slurries. Examples of the binder include cellulose disclosed in JP2003-109678A or JP2003-123861A, fluoropolymer disclosed in JP2003-272722A, and JP2004-47261A. The disclosed crosslinked rubber, polybutyl titanate disclosed in JP-T-2005-516365, carboxymethyl cellulose disclosed in JP-A-2005-135798, and the like.

  As a technique related to the formation of a semiconductor or a precursor layer thereof, there are a method of hydrophilizing by a physical method such as corona discharge, plasma, UV disclosed in JP-A No. 2003-308890, an alkali (JP-A No. 2004-119120) and polyethylene dioxy. Examples thereof include chemical treatment with thiophene and polystyrene sulfonic acid (Japanese Patent Laid-Open No. 2005-169228), and formation of an interlayer film for bonding such as polyaniline disclosed in Japanese Patent Laid-Open No. 2003-297443.

  Moreover, the method of processing after application | coating may be taken and a preferable method includes UV irradiation, a heating, a plasma, a micro group, electricity supply, infrared irradiation, a chemical process etc., for example. Processing pressure may be applied after application, and examples of methods for applying pressure include JP-T-2003-500857, JP-A-2002-93475, JP-A-2003-282160, and JP-A-2004-214129. Examples of light irradiation include JP-A No. 2001-357896, JP-A No. 11-219734, JP-A No. 2004-314313, JP-A No. 2005-142446, and JP-A No. 2001-247314. Examples of plasma / micro / conduction include JP 2002-353453, JP 2003-308893, JP 2004-265562, JP 2004-327369, JP 2004-342319, JP 2005-116415, JP 2005. -139498, and JP-A-2004-273770. Examples of the chemical treatment include JP 2001-357896, JP 2002-280327, JP 2003-281947, JP 2005-520314, and JP 2003-297442.

Examples of the dry method include vapor deposition, sputtering, and aerosol deposition method, and preferably disclosed in JP-A-2005-39013, JP-A-2004-074609, JP-A-32655481, JP-A-2003-100309, and JP-A-2004-39286. A method is mentioned.
Moreover, you may use the electrophoresis method and electrodeposition method of Unexamined-Japanese-Patent No. 2002-100146 and Unexamined-Japanese-Patent No. 2004-31354.

  Alternatively, a method in which a DSC is once created on a heat-resistant substrate and then transferred to a plastic film may be used. Preferably, after a semiconductor layer / conductive layer is formed on a sacrificial substrate containing an inorganic salt that can be removed with ultraviolet light and an aqueous solvent disclosed in JP-A-2002-184475, a method of transferring via EVA disclosed in JP-A-2002-184475, For example, a method of removing the sacrificial substrate after transfer to the organic substrate.

The coating amount of the semiconductor fine particles per 1 m ² of the support is preferably 0.5 to 500 g, more preferably 5 to 100 g.

  In order to adsorb the dye to the semiconductor fine particles, a method of immersing well-dried semiconductor fine particles in a dye solution for a long time is general. The dye solution may be heated to 50 ° C. to 100 ° C. as necessary. The adsorption of the dye may be performed before or after application of the semiconductor fine particles. Further, the semiconductor fine particles and the pigment may be applied and adsorbed simultaneously. Unadsorbed dye is removed by washing. When baking a coating film, it is preferable to adsorb | suck a pigment | dye after baking. It is particularly preferable that the dye is quickly adsorbed after the baking and before water adsorbs on the surface of the coating film. One type of dye may be adsorbed or a mixture of several types may be used. In the case of mixing, the dyes of the present invention may be mixed, U.S. Pat. Nos. 4,927,721, 4,684,537, 5,844,365, 5,350,644, 5,463,057, 5,525,440, and JP-A-7- You may mix the complex pigment | dye described in 249790 gazette, and the pigment | dye of this invention. The dye to be mixed is selected so as to make the wavelength range of photoelectric conversion as wide as possible.

The total amount of the dye used is preferably 0.01 to 100 mmol, more preferably 0.1 to 50 mmol, and particularly preferably 0.1 to 10 mmol per 1 m ² of the support. In this case, the amount of the dye of the present invention is preferably 5 mol% or more.

  Further, the adsorption amount of the dye to the semiconductor fine particles is preferably 0.001 to 1 mmol, more preferably 0.1 to 0.5 mmol, with respect to 1 g of the semiconductor fine particles.

  By using such a dye amount, a sensitizing effect in a semiconductor can be sufficiently obtained. On the other hand, when the amount of the dye is small, the sensitizing effect is insufficient, and when the amount of the dye is too large, the dye not attached to the semiconductor floats and causes the sensitizing effect to be reduced.

  Further, a colorless compound may be co-adsorbed for the purpose of reducing the interaction between dyes such as association. Examples of the hydrophobic compound to be co-adsorbed include steroid compounds having a carboxyl group (for example, cholic acid and pivaloyl acid).

  After adsorbing the dye, the surface of the semiconductor fine particles may be treated with amines. Preferred amines include 4-tert-butyl pyridine, polyvinyl pyridine and the like. These may be used as they are in the case of a liquid, or may be used by dissolving in an organic solvent.

  Hereinafter, the charge transfer layer and the counter electrode will be described in detail. The charge transfer layer is a layer having a function of replenishing electrons to the oxidant of the dye, and is provided between the light receiving electrode and the counter electrode. Typical examples include a liquid in which a redox couple is dissolved in an organic solvent, a so-called gel electrolyte in which a polymer matrix is impregnated with a liquid in which a redox pair is dissolved in an organic solvent, and a molten salt containing the redox couple. .

  Examples of the redox pair include a combination of iodine and iodide (for example, lithium iodide, tetrabutylammonium iodide, tetrapropylammonium iodide, etc.), alkyl viologen (for example, methyl viologen chloride, hexyl viologen bromide, benzyl viologen tetrafluoro). Borate) and its reduced form, a combination of polyhydroxybenzenes (for example, hydroquinone, naphthohydroquinone, etc.) and its oxidized form, a combination of divalent and trivalent iron complexes (for example, red blood salt and yellow blood salt) Etc. Of these, a combination of iodine and iodide is preferred. Examples of organic solvents for dissolving them include aprotic polar solvents (for example, acetonitrile, propylene carbonate, ethylene carbonate, dimethylformamide, dimethyl sulfoxide, sulfolane, 1,3-dimethylimidazolinone, 3-methyloxazolidinone, etc.) -110262-disclosed water-containing electrolyte, JP-A 2000-36332, JP-A 2000-243134, and re-published electrolyte solvent disclosed in WO / 00-54361, etc., include acetonitrile, methoxypropionitrile, propylene carbonate, γ- Butyrolactone is preferred.

  As an additive to the electrolyte, in addition to the aforementioned 4-tert-butylpyridine, pyridine and pyridine compounds disclosed in JP-A-2003-331986, aminopyridine-based compounds described in JP-A-2004-47229, JP-A-2004-171821, and the like Benzimidazole compounds disclosed in JP-A-2004-273272, aminotriazole-based compounds and aminothiazole-based compounds disclosed in JP-A-2005-38711, imidazole-based compounds disclosed in JP-A-2005-108663, quinoline-based compounds (JP-A-2005-135782) , An aminotriazine compound (JP 2005-183166), a urea derivative (JP 2003-168493), an amide compound (JP 2004-103404), a pyrimidine compound (JP 2004-247158), and nitrogen There heterocycle (JP 2005-166612, JP 2005-166613, and JP 2005-16615) can be mentioned.

  In order to improve efficiency, a method of controlling the water content of the electrolytic solution may be used. Preferred methods for controlling the moisture include a method for controlling the concentration (JP 2000-323189 A, JP 2001-76774 A), a method in which a dehydrating agent is allowed to coexist (JP 2002-237335, JP 2002-237335), and the like. It is done.

  As disclosed in Japanese Patent Application Laid-Open No. 2004-235011, an inclusion compound of iodine and cyclodextrin may be used to reduce the toxicity of iodine. Conversely, as disclosed in Japanese Patent Application Laid-Open No. 2003-25709, a method of constantly supplying water is used. May be. As disclosed in Japanese Patent No. 3462115, a cyclic amidine may be used, an antioxidant (Japanese Patent Laid-Open No. 2004-39292), a hydrolysis inhibitor (Japanese Patent Laid-Open No. 2004-111276), a decomposition inhibitor (Japanese Patent Laid-Open No. 2004-111277), and iodine. Zinc halide (JP 2004-152613 A)

  A molten salt may be used as the electrolyte, and preferable molten salts include ionic liquids containing imidazolium or triazolium type cations (Japanese Patent Application Laid-Open Nos. 09-507334, 08-259543, 2003-031270, and JP-A-2003-031270). 2005-112733, JP-A-2005-116367, JP-A-2005-112733, JP-A-2003-68374, JP-A-2003-92153, JP-A-2004-241378, JP-A-2005-85587, JP-A-2004-87387), oxazolium-based ( JP 2000-53662), Pyridinium (JP 2000-58891, JP 2001-23705, JP 2001-167630, JP 2001-256828, JP 2001-266862), Guanidium (JP 2001-35253) , And These combinations (JP 2000-90991, JP 2001-35552) can be mentioned. These cationic systems may be combined with specific anions. For example, JP 2002-75442, JP 2001-75443, JP 2002-170426, JP 2002-298913, JP 2002-367426, JP 2003 -01148 and the like. Additives may be added to these molten salts. Preferred additives include JP-A-2001-67931, JP-A-2001-160427, JP-A-2002-289267, JP-A-2002-289268, JP-A-2000-90991. , JP-A 2000-1000048, JP-A 2001-283943) and the like. You may have a liquid crystalline substituent like Unexamined-Japanese-Patent No. 2002-319314 or 2002-343440. Moreover, you may use the quaternary ammonium salt type molten salt as described in Unexamined-Japanese-Patent No. 2005-104845, Unexamined-Japanese-Patent No. 2005-104848, Unexamined-Japanese-Patent No. 2005-179254, etc.

  As molten salts other than these, for example, Japanese Patent Application Laid-Open No. 2005-139100, Japanese Patent Application Laid-Open No. 2005-145927, and lithium iodide and at least one other lithium salt (for example, lithium acetate, lithium perchlorate, etc.) are mixed with polyethylene oxide. By doing so, the thing which provided the fluidity | liquidity at room temperature etc. are mentioned. In this case, the amount of the polymer added is 1 to 50% by mass. Moreover, (gamma) -butyrolactone may be contained in electrolyte solution, and thereby the diffusion efficiency of iodide ion becomes high and conversion efficiency improves.

  The electrolyte may be quasi-solidified by adding a gelling agent to an electrolyte solution composed of an electrolyte and a solvent for gelation. Examples of the gelling agent include organic compounds having a molecular weight of 1000 or less (Japanese Patent Laid-Open Nos. 11-185836, 2000-36608, 2000-58140), Si-containing compounds having a molecular weight in the range of 500-5000 (Japanese Patent Laid-Open No. 2003-203520), Specific examples include organic salts (Japanese Patent Laid-Open No. 2003-203520), sorbitol derivatives (Japanese Patent Laid-Open No. 2003-346828), and polyvinyl pyridine (Japanese Patent Laid-Open No. 2004-227920, Japanese Patent Laid-Open No. 2005-093370) made of a specific acidic compound and a basic compound.

Alternatively, a method of trapping a matrix polymer, a crosslinkable polymer compound or monomer, a crosslinking agent, an electrolyte, and a solvent in the polymer may be used.
The matrix polymer is preferably a polymer having a nitrogen-containing heterocyclic ring in the repeating unit of the main chain or side chain, and a crosslinked product obtained by reacting these with an electrophilic compound (Japanese Patent Laid-Open Nos. 11-126917 and 2000- 86724), a polymer having a triazine structure, a polymer having a ureido structure (Japanese Patent Laid-Open No. 2000-251532), a liquid crystal compound (Japanese Patent Laid-Open No. 2000-319260, Japanese Patent Laid-Open No. 2002-246066), a high polymer having an ether bond Molecules (JP 2000-150006, JP 2002-63813, JP 2001-338700, JP 2002-75480), polyvinylidene fluoride (2003-303628), methacrylate / acrylate (JP 2001-28276, JP 2001-210390), thermosetting resin 2-336314, JP 2002-305041), crosslinked polysiloxane (JP 2002-216861), PVA (JP 2002-175841), inclusion compounds such as polyalkylene glycol and dextrin (JP 2004-327271), Examples include a system to which oxygen or a sulfur-containing polymer (Japanese Patent Application Laid-Open No. 2005-108845) is added, a natural polymer (Japanese Patent Application Laid-Open No. 2005-71688), and the like. Alkali-swelling polymers (Japanese Patent Laid-Open No. 2002-175482), polymers having a compound capable of forming a charge transfer complex between a cation moiety and iodine in one polymer (Japanese Patent Laid-Open No. 2005-63791) and the like are added to these. May be.
As the matrix polymer, a system containing a cross-linked polymer obtained by reacting a functional group such as a hydroxyl group, an amino group, or a carboxyl group with one or more functional isocyanate as one component may be used. Examples thereof include JP 2000-228234, JP 2002-184478, JP 2002-289271, and JP 2003-303630). In addition, a crosslinking polymer (Japanese Patent Application Laid-Open No. 2003-86258) in which a cross-linked polymer composed of a hydrosilyl group and a double bond compound (Japanese Patent Application Laid-Open No. 2003-59548), polysulfonic acid, polycarboxylic acid, or the like is reacted with a divalent or higher-valent metal ion compound. May be used.

  As a solvent that can be preferably used in combination with the above quasi-solid electrolyte, a specific phosphoric acid ester (JP 2000-1000048, JP 2003-16833), a mixed solvent containing ethylene carbonate (JP 2004-87202) And solvents having a specific dielectric constant (Japanese Patent Application Laid-Open No. 2004-335366), and solvents described in Japanese Patent Application Laid-Open Nos. 2003-16833 and 2003-264011.

The liquid electrolyte solution may be retained in the solid electrolyte membrane or in the pores, and preferably as a method therefor, a conductive polymer membrane (JP-A-11-339866), a fibrous solid (JP-A-2000-357544), a filter, etc. Solid on cloth (Japanese Patent Laid-Open No. 2001-345125).
A specific combination of the gel electrolyte and the conductive resin counter electrode disclosed in JP-A-2003-157914 may be used.

  A solid charge transport system such as a p-type semiconductor or a hole transport material may be used instead of the liquid electrolyte and the quasi-solid electrolyte. As a P-type semiconductor, CuI (Japanese Patent Laid-Open No. 2001-156314, Japanese Patent Laid-Open No. 2001-185743, Japanese Patent Laid-Open No. 2001-185743, Japanese Patent Laid-Open No. 2001-230434, Japanese Patent Laid-Open No. 2003-234485, Japanese Patent Laid-Open No. 2003-234485, Japanese Patent Laid-Open No. 2003-243681 is preferable. , JP2003-234486), CuSCN, and p-SbAl (JP2003-258284). As a method for producing these hole transport materials, Japanese Patent Application Laid-Open Nos. 2003-331938, 2001-168359, 2001-196612, 2001-257370, 2002-246623, 2002-246624, and JP2003-289151A is mentioned.

  An organic hole transport material may be used as the solid charge transport layer. As the hole transport layer, polythiophene (JP 2000-106223, JP 2003-364304), polyaniline (JP 2003-264304), polypyrrole (JP 2000-106224, JP 2003-264304), and polysilane (special Spiro compounds that share a central element with a tetrahedral structure such as C and Si, and conductive polymers such as KOKAI 2001-53555 and JP 2001-203377) (Special Tables H11-513522, Special Tables) 2001-525108), aromatic amine derivatives such as triarylamine (JP-A-11-144773, JP-A-11-339868, JP-A-2003-123856, JP-A-2003-197942, JP-A-2004-356281), triphenylene derivatives (special Kaihei 11-17648 ), Nitrogen-containing heterocyclic derivative (JP-2001-85077, JP-2001-85713), liquid crystalline cyano derivatives (patent 3,505,381) and the like.

  Since the redox couple becomes an electron carrier, a certain concentration is required. The preferred concentration is 0.01 mol / l or more in total, more preferably 0.1 mol / l, and particularly preferably 0.3 mol / l or more. The upper limit in this case is not particularly limited, but is usually about 5 mol / l.

  The counter electrode functions as a positive electrode of the photoelectrochemical cell. The counter electrode is usually synonymous with the conductive support described above, but the support is not necessarily required in a configuration in which the strength is sufficiently maintained. However, having a support is advantageous in terms of hermeticity. Examples of the material for the counter electrode include platinum, carbon, conductive polymer, and the like. Preferred examples include platinum (Japanese Patent Laid-Open No. 2001-102102), carbon (Japanese Patent Laid-Open No. 2002-298936, Japanese Patent Laid-Open No. 2003-297446, Japanese Patent Laid-Open No. 2004-127747, Japanese Patent Laid-Open No. 2004-152747, Japanese Patent Laid-Open No. 2004-165015, Japanese Patent Laid-Open No. 2004-2004. 11112, JP2004-241228, JP2004-319872), and conductive polymers (JP2003-317814, JP2004-319131, JP2005-116301), JP2001-43908, JP You may use what is shown by the example of 2003-142168, Unexamined-Japanese-Patent No. 2004-127849, and Unexamined-Japanese-Patent No. 2004-152747.

  As the structure of the counter electrode, a structure having a high current collecting effect is preferable. Preferred examples include JP-A-10-505192, JP-A-2004-296669, JP-A-2005-11609, JP-A-2005-141996, JP-A-2005-142090, JP-A-2005-158470, JP-A-2000-348784, JP-A-2005. -158379, JP-A 2000-294305, JP-A 2001-243959, JP-A 2004-241228, JP-A 2004-296203, JP-A 2004-319872, and JP-A 2005-197097.

The conductive support is a support made of glass or plastic having a conductive film layer on the surface, such as a metal having a conductive property in itself. As the support, in addition to glass and plastic, ceramic (Japanese Patent Laid-Open No. 2005-135902) or conductive resin (Japanese Patent Laid-Open No. 2001-160425) may be used. On the support, the surface may be provided with a light management function. For example, an antireflection film in which high refractive films and low refractive index oxide films described in JP-A-2003-123859 are alternately laminated, and JP-A-2002 -The light guide function described in 260746 is raised.
It is preferable that the conductive support is substantially transparent. Substantially transparent means that the light transmittance is 10% or more, preferably 50% or more, particularly preferably 80% or more. As the transparent conductive support, a glass or plastic coated with a conductive metal oxide is preferable. The coating amount of the conductive metal oxide at this time is preferably 0.1 to 100 g per 1 m ² of a glass or plastic support. When a transparent conductive support is used, light is preferably incident from the support side.

  A gas barrier film and / or an ion diffusion preventing film may be disposed between the support and the transparent conductive film (Japanese Patent Laid-Open No. 2000-285974). Moreover, you may provide a transparent electrode and a porous semiconductor electrode photocatalyst content layer (Unexamined-Japanese-Patent No. 2005-142084). The transparent conductive layer may have a laminated structure, and as a preferable method, for example, an FTO (fluorine-doped tin oxide) film may be laminated on an ITO (indium tin oxide) film described in JP-A-2003-323818.

It is preferable that the conductive support has a function of blocking ultraviolet light. For example, the method of making the fluorescent material which can change the ultraviolet light of Unexamined-Japanese-Patent No. 2001-185242 into visible light exist in a transparent support body or the surface of a transparent support body etc. is employable. Preferred conductive films include metals (eg, platinum, gold, silver, copper, aluminum, rhodium, indium, etc.), carbon, or conductive metal oxides (indium-tin composite oxide, tin oxide doped with fluorine, etc.) ). Examples of preferred conductive film modes and methods include those described in JP-A No. 2003-151355.
The thickness of the conductive film layer is preferably 0.01 to 30 μm, more preferably 0.03 to 25 μm, and particularly preferably 0.05 to 20 μm.

The lower the surface resistance of the conductive support, the better. The range of the surface resistance is preferably 50 Ω / cm ² or less, more preferably 10 Ω / cm ² or less. Although there is no restriction | limiting in particular in this lower limit, Usually, it is about 0.1 ohm / cm < ² >.
Since the resistance value of the conductive film increases as the electrode area increases, a collecting electrode described in JP-A-11-266028 may be disposed.

  The semiconductor fine particles are preferably metal chalcogenide (for example, oxide, sulfide, selenide, etc.) or perovskite fine particles. Preferred examples of the metal chalcogenide include titanium, tin, zinc, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, tantalum oxide, cadmium sulfide, cadmium selenide, and the like. . Preferred perovskites include strontium titanate and calcium titanate. Of these, titanium oxide, zinc oxide, tin oxide, and tungsten oxide are particularly preferable.

  As a method for producing semiconductor fine particles, for example, preferably as a method for producing titania nanoparticles, a method by flame hydrolysis of titanium tetrachloride, a combustion method of titanium tetrachloride, hydrolysis of a stable chalcogenide complex, hydrolysis of orthotitanic acid, Examples include a method in which semiconductor fine particles are formed from a soluble portion and an insoluble portion, and then the soluble portion is dissolved and removed, a hydrothermal synthesis of an aqueous peroxide solution, or a method of producing core / shell structured titanium oxide fine particles by a sol-gel method. it can.

  Examples of the crystal structure of titania include anatase type, brookite type, and rutile type, and anatase type and brookite type are preferable. Preferred examples include those described in JP-A-11-339867. Titania nanotubes, nanowires, and nanorods may be mixed with titania fine particles or used as a semiconductor electrode (Japanese Patent Laid-Open No. 2003-168495). As the semiconductor electrode, a composite electrode such as titanium oxide and tin oxide may be used. Examples of the mixed electrode of titania include those described in JP-A-2000-119393. Examples of mixed electrodes other than titania include those described in JP-A-2001-185243. The semiconductor electrode may be a tandem type in order to increase the utilization rate of incident light.

Titania may be doped with a nonmetallic element or the like. In addition to dopants to titania, ITO particles, SnO particles, whiskers, fibrous graphite / carbon nanotubes, cellulose, etc. to the surface to prevent necking and binders to prevent reverse electron transfer Fibrous materials, metals, organic silicon, dodecylbenzenesulfonic acid and the like can be added.
For the purpose of removing surface defects on titania, titania may be subjected to acid-base or oxidation-reduction treatment before dye adsorption (Japanese Patent Laid-Open No. 2000-101106). Further, etching, oxidation treatment, hydrogen peroxide treatment, dehydrogenation treatment, UV-ozone, oxygen plasma, or the like may be used.

  The particle diameters of the semiconductor fine particles are 0.001 to 1 μm as primary particles and 0.01 to 100 μm as the average particle diameter of the dispersion in terms of the average particle diameter when the projected area is converted into a circle. preferable.

As a method of coating the semiconductor fine particles on the conductive support, a method of coating a dispersion or colloidal solution of the semiconductor fine particles on the conductive support, a method of coating the precursor of the semiconductor fine particles on the conductive support, and air. Examples include wet methods such as a method of obtaining a semiconductor fine particle film by hydrolysis with moisture in it. Examples of the method for preparing a dispersion of semiconductor fine particles include a method of pulverizing in a mortar, a method of dispersing while pulverizing using a mill, or a method of depositing fine particles in a solvent and using them as they are when a semiconductor is synthesized. . Examples of the dispersion medium include water or various organic solvents (for example, methanol, ethanol, dichloromethane, acetone, acetonitrile, ethyl acetate, etc.). During dispersion, a polymer, surfactant, acid, chelating agent, or the like may be used as a dispersion aid as necessary.
After coating the semiconductor fine particles on the conductive support, for example, ultraviolet irradiation, heating, plasma irradiation, microwave irradiation, energization, infrared irradiation, energization, chemical treatment, and the like can be performed. Examples of the dry method include vapor deposition, sputtering, and aerosol deposition method. In addition, an electrophoresis method or an electrodeposition method may be used.

  In addition, the semiconductor fine particles can be coated on the conductive support by a method (Japanese Patent Laid-Open No. 2002-184475) of once forming a semiconductor fine particle layer on a heat-resistant substrate and then transferring it to a plastic film. Another example is a method in which a semiconductor fine particle layer is formed on a sacrificial substrate containing an inorganic salt that can be removed with ultraviolet rays or an aqueous solvent, and then transferred to an organic substrate, and then the sacrificial substrate is removed (Japanese Patent Laid-Open No. 2003-98977).

  It is preferable to form a short-circuit prevention layer between the transparent conductive film and the oxide semiconductor layer in order to prevent reverse current due to direct contact between the electrolyte and the electrode. In order to prevent contact between the photoelectrode and the counter electrode, it is preferable to use a separator. As the separator, an insulating porous material is preferably used. For example, particles such as glass beads and silicon dioxide (silica) can be used. Preferably, sintered silicon dioxide particles are preferred. The insulating porous body is preferably one that can be formed by coating and sintering from the viewpoint of cost reduction. Specifically, an insulating porous body in which silica particles are sintered is preferable. The reason why a porous body obtained by sintering silica particles is preferable is that the porous body has good transparency because it has a low refractive index and low light scattering. The porous body preferably has an average particle size of 5 to 150 nm in order to ensure good transparency.

The semiconductor fine particles preferably have a large surface area so that many dyes can be adsorbed. For example, in a state where the semiconductor fine particles are coated on the support, the surface area thereof is preferably 10 times or more, more preferably 100 times or more the projected area. Although there is no restriction | limiting in particular in this upper limit, Usually, it is about 5000 times. In general, as the thickness of the semiconductor fine particle layer increases, the amount of dye that can be supported per unit area increases, so that the light absorption efficiency increases. However, the diffusion distance of the generated electrons increases, and the loss due to charge recombination also increases. The preferred thickness of the semiconductor fine particle layer varies depending on the use of the device, but is typically 0.1 to 100 μm. When using as a photoelectrochemical cell, it is preferable that it is 1-50 micrometers, and it is more preferable that it is 3-30 micrometers. The semiconductor fine particles may be fired at a temperature of 100 to 800 ° C. for 10 minutes to 10 hours in order to adhere the particles to each other after being applied to the support.
The coating amount of the semiconductor fine particles per 1 m ² of the support is preferably 0.5 to 500 g, more preferably 5 to 100 g.
When glass is used as the support, the film forming temperature is preferably 400 to 600 ° C. When using a plastic as a support body, it is preferable to form into a film at 300 degrees C or less, and 200 degrees C or less is still more preferable. As a method for forming a film at 200 ° C. or lower, any of the above-described wet method, dry method, and electrophoresis method (including electrodeposition method) may be used, but a wet method is preferable.

  In order to adsorb the dye to the semiconductor fine particles, a method of immersing well-dried semiconductor fine particles in a dye solution for a long time is general. The dye solution may be heated to 50 ° C. to 100 ° C. as necessary. The adsorption of the dye may be performed before or after application of the semiconductor fine particles. Further, the semiconductor fine particles and the pigment may be applied and adsorbed simultaneously. Unadsorbed dye is removed by washing. When baking a coating film, it is preferable to adsorb | suck a pigment | dye after baking. It is particularly preferable that the dye is quickly adsorbed after the baking and before water adsorbs on the surface of the coating film. One type of dye may be adsorbed or a mixture of several types may be used. In the case of mixing, dyes having at least one structure represented by the general formula (1) may be mixed, US Pat. Nos. 4,927,721 and 4,684,537, and JP-A-7-249790. The complex dye described in the publication may be mixed with the dye of the present invention. The dye to be mixed is selected so as to make the wavelength range of photoelectric conversion as wide as possible.

The total amount of the dye used is preferably 0.01 to 100 mmol, more preferably 0.1 to 50 mmol, and particularly preferably 0.1 to 10 mmol per 1 m ² of the support. In this case, the amount of the dye of the present invention is preferably 5 mol% or more. Further, the adsorption amount of the dye to the semiconductor fine particles is preferably 0.001 to 1 mmol, more preferably 0.1 to 0.5 mmol, with respect to 1 g of the semiconductor fine particles. By using such a dye amount, a sensitizing effect in a semiconductor can be sufficiently obtained. On the other hand, when the amount of the dye is small, the sensitizing effect is insufficient, and when the amount of the dye is too large, the dye not attached to the semiconductor floats and causes the sensitizing effect to be reduced. Further, a colorless compound may be co-adsorbed for the purpose of reducing the interaction between dyes such as association. Examples of the hydrophobic compound to be co-adsorbed include steroid compounds having a carboxyl group (for example, cholic acid and pivaloyl acid).

  After adsorbing the dye, the surface of the semiconductor fine particles may be treated with amines. Preferred amines include 4-tert-butyl pyridine, polyvinyl pyridine and the like. These may be used as they are in the case of a liquid, or may be used by dissolving in an organic solvent. The charge transfer layer is a layer having a function of replenishing electrons to the oxidant of the dye, and is provided between the light receiving electrode and the counter electrode. Typical examples include a liquid in which a redox couple is dissolved in an organic solvent, a so-called gel electrolyte in which a polymer matrix is impregnated with a liquid in which a redox pair is dissolved in an organic solvent, and a molten salt containing the redox couple. .

  Examples of the redox pair include a combination of iodine and iodide (for example, lithium iodide, tetrabutylammonium iodide, tetrapropylammonium iodide, etc.), alkyl viologen (for example, methyl viologen chloride, hexyl viologen bromide, benzyl viologen tetrafluoro). Borate) and its reduced form, a combination of polyhydroxybenzenes (for example, hydroquinone, naphthohydroquinone, etc.) and its oxidized form, a combination of divalent and trivalent iron complexes (for example, red blood salt and yellow blood salt) Etc. Of these, a combination of iodine and iodide is preferred. As the organic solvent for dissolving them, an aprotic polar solvent (for example, acetonitrile, propylene carbonate, ethylene carbonate, dimethylformamide, dimethyl sulfoxide, sulfolane, 1,3-dimethylimidazolinone, 3-methyloxazolidinone, etc.) is preferable. Examples of the polymer used for the matrix of the gel electrolyte include polyacrylonitrile and polyvinylidene fluoride. Examples of the molten salt include those imparted with fluidity at room temperature by mixing polyethylene oxide with lithium iodide and at least one other lithium salt (such as lithium acetate and lithium perchlorate). It is done. In this case, the amount of the polymer added is 1 to 50% by mass. Moreover, (gamma) -butyrolactone may be contained in electrolyte solution, and thereby the diffusion efficiency of iodide ion becomes high and conversion efficiency improves.

As an additive to the electrolyte, in addition to the aforementioned 4-tert-butylpyridine, an aminopyridine compound, a benzimidazole compound, an aminotriazole compound and an aminothiazole compound, an imidazole compound, an aminotriazine compound, a urea derivative, Amide compounds, pyrimidine-based compounds and nitrogen-free heterocycles can be added.
In order to improve efficiency, a method of controlling the water content of the electrolytic solution may be used. Preferred methods for controlling moisture include a method for controlling the concentration and a method in which a dehydrating agent is allowed to coexist. In order to reduce the toxicity of iodine, an inclusion compound of iodine and cyclodextrin may be used, and conversely, a method of constantly supplying water may be used. Cyclic amidine may be used, and an antioxidant, hydrolysis inhibitor, decomposition inhibitor, and zinc iodide may be added.

A molten salt may be used as the electrolyte, and preferred molten salts include ionic liquids containing imidazolium or triazolium type cations, oxazolium-based, pyridinium-based, guanidinium-based, and combinations thereof. These cationic systems may be combined with specific anions. Additives may be added to these molten salts. It may have a liquid crystal substituent. Further, a quaternary ammonium salt-based molten salt may be used.
As a molten salt other than these, for example, flowability at room temperature was imparted by mixing polyethylene oxide with lithium iodide and at least one other lithium salt (for example, lithium acetate, lithium perchlorate, etc.). And the like.

  The electrolyte may be quasi-solidified by adding a gelling agent to an electrolyte solution composed of an electrolyte and a solvent to cause gelation. Examples of the gelling agent include organic compounds having a molecular weight of 1000 or less, Si-containing compounds having a molecular weight in the range of 500 to 5000, organic salts made of specific acidic compounds and basic compounds, sorbitol derivatives, and polyvinylpyridine.

Alternatively, a method of trapping a matrix polymer, a crosslinkable polymer compound or monomer, a crosslinking agent, an electrolyte, and a solvent in the polymer may be used.
As the matrix polymer, a polymer having a nitrogen-containing heterocyclic ring in the main chain or side chain repeating unit, a crosslinked product obtained by reacting these with an electrophilic compound, a polymer having a triazine structure, or having a ureido structure Polymers, liquid crystalline compounds, ether-bonded polymers, polyvinylidene fluorides, methacrylates / acrylates, thermosetting resins, crosslinked polysiloxanes, PVA, inclusion compounds such as polyalkylene glycol and dextrin, Examples include systems to which oxygen or sulfur-containing polymers are added, natural polymers, and the like. An alkali swelling polymer, a polymer having a compound capable of forming a charge transfer complex between a cation moiety and iodine in one polymer, or the like may be added to these.
As the matrix polymer, a system containing a cross-linked polymer obtained by reacting a functional group such as a hydroxyl group, an amino group, or a carboxyl group with one or more functional isocyanate as one component may be used. Further, a crosslinking method in which a crosslinked polymer composed of a hydrosilyl group and a double bond compound, polysulfonic acid, polycarboxylic acid, or the like is reacted with a divalent or higher-valent metal ion compound may be used.

  Examples of the solvent that can be preferably used in combination with the quasi-solid electrolyte include a specific phosphate ester, a mixed solvent containing ethylene carbonate, and a solvent having a specific dielectric constant. The liquid electrolyte solution may be held in a solid electrolyte membrane or pores, and preferred methods thereof include conductive polymer membranes, fibrous solids, and cloth solids such as filters.

  A solid charge transport layer such as a p-type semiconductor or a hole transport material may be used instead of the above liquid electrolyte and quasi-solid electrolyte. An organic hole transport material may be used as the solid charge transport layer. The hole transport layer is preferably a spiro, which is a conductive polymer such as polythiophene, polyaniline (Japanese Patent Laid-Open No. 2003-264304), polypyrrole, and polysilane, and two rings share a central element having a tetrahedral structure such as C and Si. Examples thereof include aromatic amine derivatives such as compounds, triarylamines, triphenylene derivatives, nitrogen-containing heterocyclic derivatives, and liquid crystalline cyano derivatives.

  Since the redox couple becomes an electron carrier, a certain concentration is required. The preferred concentration is 0.01 mol / l or more in total, more preferably 0.1 mol / l, and particularly preferably 0.3 mol / l or more. The upper limit in this case is not particularly limited, but is usually about 5 mol / l.

  The counter electrode functions as a positive electrode of the photoelectrochemical cell. The counter electrode is usually synonymous with the conductive support described above, but the support is not necessarily required in a configuration in which the strength is sufficiently maintained. Examples of the material for the counter electrode include platinum, carbon, and conductive polymer. As the structure of the counter electrode, a structure having a high current collecting effect is preferable.

In order for light to reach the photosensitive layer, at least one of the conductive support and the counter electrode must be substantially transparent. In the photoelectrochemical cell of the present invention, the conductive support is preferably transparent, and sunlight is preferably incident from the support side. In this case, it is more preferable that the counter electrode has a property of reflecting light. As the counter electrode of the photoelectrochemical cell, glass or plastic on which metal or conductive oxide is vapor-deposited is preferable, and glass on which platinum is vapor-deposited is particularly preferable. In the photoelectrochemical cell, it is preferable to seal the side surface of the cell with a polymer, an adhesive, or the like in order to prevent the constituents from evaporating. The characteristics of the photoelectrochemical cell of the present invention thus obtained are generally as follows. When the AM 1.5G is 100 mW / cm ² , the open circuit voltage is 0.01 to 1.5 V, and the short circuit current density is 0.001 to 20 mA. / Cm ² , form factor 0.1-0.9, conversion efficiency 0.001-25%.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these.

(Synthesis example)
(Preparation of Illustrative Dye A-1)
Exemplified dye A-1 was prepared according to the method of the following scheme.

(1) Preparation of Compound A-1a 5,0.0 g of 10,11-dihydro-5H-dibenz [b, f] azepine was dissolved in 130 ml of DMF with stirring at room temperature and then ice-cooled, and 18.4 g of 50-70% sodium hydride. Was added in four portions and stirred at an internal temperature of 5 ° C. or lower for 0.5 hours. Thereto, 70.3 g of 1-iodoethane was dropped over 20 minutes, and the remaining amount was washed with 20 ml of DMF. Thereafter, the temperature was raised to room temperature, and the reaction was performed for 2.5 hours. After completion of the reaction, water was added dropwise to the reaction solution, followed by extraction with ethyl acetate. After separation, the ethyl acetate layer was washed with 1N hydrochloric acid, aqueous sodium bicarbonate, and water in that order, and pre-dried with anhydrous sodium sulfate. After removing magnesium sulfate, the mixture is concentrated, and the crude product is purified by column chromatography (solvent: hexane) to give compound A-1a.
41.7 g was obtained.

(2) Preparation of Compound A-1b 10.0 g of Compound A-1a was stirred and dissolved in 180 ml of DMF at room temperature and then ice-cooled. To this solution, 10.1 g of N-bromosuccinimide was added in four portions and stirred as it was for 1 hour. After completion of the reaction, the reaction solution was extracted with an aqueous sodium thiosulfate solution and ethyl acetate, separated, and then washed with water added to the ethyl acetate layer. After separation, the ethyl acetate layer was pre-dried with anhydrous sodium sulfate, filtered and concentrated. The crude product was roughly purified by column chromatography (solvent: hexane) and further purified by liquid chromatography.
6.5 g was obtained.

(3) Preparation of Compound A-1c 1.21 g of Compound A-1b, 2.25 g of 4-hexyl-2-boronic acid ester, and 6 ml of a 10 wt% sodium carbonate solution were dissolved in 40 ml of DME, and the system was purged with nitrogen. To this solution, 234 mg of tetrakis (triphenylphosphine) palladium was added and heated under reflux for 3.5 hours. After cooling to room temperature, it was diluted with ethyl acetate, the organic layer was washed twice with water and dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure to obtain a crude product. This crude product was purified by column chromatography (solvent: ethyl acetate / hexane = 1/15) to obtain 1.54 g of A-1c.

(4) Preparation of Compound A-1d 0.39 g of Compound A-1c was dissolved in 10 ml of DMF and cooled on ice. To this solution, a Vilsmeier reagent prepared in advance from 1.32 ml of DMF and 0.34 ml of phosphorus oxychloride was added dropwise and stirred at room temperature for 1 hour. Thereafter, the temperature was raised to 70 ° C., and further stirred for 1 hour and 20 minutes.
After completion of the reaction, the reaction solution was added into a 14 wt% sodium acetate aqueous solution and stirred at room temperature for 30 minutes. This solution was extracted twice with ethyl acetate, and the ethyl acetate extracts were combined and washed with water. After drying with magnesium sulfate, the solvent was distilled off under reduced pressure to obtain a compositional organism. This crude product was roughly purified by column chromatography (solvent: ethyl acetate / hexane = 1/10) and further purified by liquid chromatography to obtain 0.28 g of A-1d.

(5) Preparation of Compound A-1 0.20 g of Compound A-1d was dissolved in 3.5 ml of acetonitrile and 3 ml of toluene. To this solution, 81.5 mg of cyanoacetic acid and 2 ml of piperidine were added, followed by heating and stirring at 70 ° C. for 8.5 hours. After cooling, dichloromethane was added to the reaction solution, the organic layer was washed twice with dilute hydrochloric acid and water and dried over sodium sulfate, and then the solvent was distilled off under reduced pressure to obtain a crude product. The crude product was recrystallized from methanol / dichloromethane and subjected to crude purification, and then purified by column chromatography (solvent: dichloromethane → dichloromethane / methanol = 10/1).
0.12 g was obtained.
When the UV / VIS spectrum of this compound was measured as an ethanol solution, the maximum absorption wavelength was 437.5 nm.

(Preparation of Exemplified Dye A-4)
Exemplified dye A-4 was prepared according to the method of the following scheme.

(6) Preparation of Compound A-4a 0.7 g of Compound A-1d was dissolved in 10 ml of DMF with stirring at room temperature and then cooled with ice. To this solution, 0.265 g of N-bromosuccinimide was added in portions and stirred as it was for 1 hour. After completion of the reaction, the reaction solution was extracted with an aqueous sodium thiosulfate solution and ethyl acetate, separated, and then washed with water added to the ethyl acetate layer. After separation, the ethyl acetate layer was pre-dried with anhydrous sodium sulfate, filtered and concentrated. The crude product was roughly purified by column chromatography (solvent: hexane) and then further purified by liquid chromatography. A-4d
0.51 g was obtained.

  By repeating the Suzuki coupling reaction shown in the paragraph (0076) and the bromination reaction shown in the paragraph (0079), an azepine derivative in which two hexyl-substituted thiophene rings represented by A-4b are bonded, A- An azepine derivative in which three hexyl-substituted thiophene rings represented by 4d are bonded and an azepine derivative in which four hexyl-substituted thiophene rings represented by A-4f are bonded can be synthesized.

(7) Preparation of Compound A-4 0.21 g of Compound A-4g was dissolved in 3.5 ml of acetonitrile, 3 ml of benzene and 0.2 ml of DMF. To this solution, 42.1 mg of cyanoacetic acid, 0.6 ml of piperidine and 42.5 mg of ammonium acetate were added, and the mixture was heated to reflux for 33 hours with a Dean-Stark apparatus. After cooling, dichloromethane was added to the reaction solution, the organic layer was washed twice with dilute hydrochloric acid and water and dried over sodium sulfate, and then the solvent was distilled off under reduced pressure to obtain a crude product. The crude product was roughly purified by column chromatography (solvent: dichloromethane → dichloromethane / methanol = 20/1) and then purified by liquid chromatography. A-4
0.11 g was obtained.
When the UV / VIS spectrum of this compound was measured as an ethanol / THF mixed solution (3: 2, volume ratio), the maximum absorption wavelength was 450.5 nm.

  Other compounds were prepared in the same manner.

Example 1
(Preparation of photoelectric conversion element)
The photoelectric conversion element shown in FIG. 1 was produced as follows.
On the glass substrate, tin oxide doped with fluorine was formed as a transparent conductive film by sputtering, and this was scribed with a laser to divide the transparent conductive film into two parts. Among these, anatase-type titanium oxide particles were sintered on one conductive film to produce a light receiving electrode. Thereafter, a dispersion containing silica particles and rutile in a ratio of 40:60 (mass ratio) was applied and sintered on the light receiving electrode to form an insulating porous body. Next, a carbon electrode was formed as a counter electrode.
Next, it was immersed in the ethanol solution (3 * 10 < ^-4 > mol / l) of the sensitizing dye described in Table 1 for 48 hours. The glass dyed with the sensitizing dye was immersed in a 10% ethanol solution of 4-tert-butylpyridine for 30 minutes, then washed with ethanol and naturally dried. The thickness of the photosensitive layer thus obtained was 10 μm, and the coating amount of semiconductor fine particles was 20 g / m ² . The coating amount of the sensitizing dye was appropriately selected from the range of 0.1 to 10 mmol / m ² according to the kind of the sensitizing dye.
As the electrolytic solution, a methoxypropionitrile solution of dimethylpropylimidazolium iodide (0.5 mol / l) and iodine (0.1 mol / l) was used.

(Measurement of maximum absorption wavelength of sensitizing dye)
The maximum absorption wavelength of the sensitizing dye used was measured. A spectrophotometer (U-4100, manufactured by Hitachi High-Tech) was used, and ethanol was used as the solution.

(Measurement of photoelectric conversion efficiency)
Simulated sunlight containing no ultraviolet rays was generated by passing the light of a 500 W xenon lamp (manufactured by Ushio) through an AM1.5G filter (manufactured by Oriel) and a sharp cut filter (KenkoL-42, trade name). The intensity of this light was 89 mW / cm ² . The produced photoelectric conversion element was irradiated with this light, and the generated electricity was measured with a current-voltage measuring device (Caseley 238 type, trade name). The result of having measured the conversion efficiency of the photoelectrochemical cell calculated | required by this was shown to the following Tables 1-3. As a result, conversion efficiency of 5% or more was evaluated as ◎, 2% or more and less than 5% as ◯, 0.5% or more and less than 2% as △, and less than 0.5% as x. .

As sample number 92, the following sensitizing dye A described in WO2007 / 119525 was used.

As shown in Table 1, the electrochemical cell produced using the dye of the present invention has A3-A6, B2-B6, C3-C6, D3-D6, F1, F2, G1, M2-M4, N1-N4, O1, P1, Q1, R1-R4, S1, S2, T2, T3, U1-U3, V1, Z2-Z4, α2-α4, β2-β4, γ2, γ3 were used. In the case, the conversion efficiency showed a high value of 5% or more. Even when a dye having another disclosed structure was used, the conversion efficiency was 2% or more and less than 5%, which was a usable level.
On the other hand, in the comparative example of sample number 92, the conversion efficiency was 0.5% or more and less than 2%, which was insufficient for use in an electrochemical cell.

(Example 2)
An ITO film was produced on a glass substrate, and an FTO film was laminated thereon to produce a transparent conductive film. Then, a transparent electrode plate was obtained by forming an oxide semiconductor porous film on the transparent conductive film. And the photoelectrochemical cell was produced using the transparent electrode plate, and conversion efficiency was measured. The method is as follows (1)-(5).

(1) Preparation of raw material solution for ITO (indium-tin-oxide) film Indium (III) tetrahydrate 5.58 g and tin (II) chloride dihydrate 0.23 g were dissolved in 100 ml of ethanol. Thus, a raw material compound solution for the ITO film was obtained.

(2) Preparation of raw material solution for FTO (fluorine-doped tin oxide) film 0.701 g of tin (IV) chloride pentahydrate was dissolved in 10 ml of ethanol, and 0.592 g of a saturated aqueous solution of ammonium fluoride was added thereto. This mixture was subjected to an ultrasonic cleaning machine for about 20 minutes and completely dissolved to obtain a raw material compound solution for an FTO film.

(3) Preparation of ITO / FTO transparent conductive film The surface of a heat-resistant glass plate having a thickness of 2 mm was chemically washed and dried, and then this glass plate was placed in a reactor and heated with a heater. When the heating temperature of the heater reached 450 ° C., the raw material compound solution for ITO film obtained in (1) was adjusted from a nozzle having a diameter of 0.3 mm to a pressure of 0.06 MPa and a distance to the glass plate of 400 mm, 25 Sprayed for a minute.
After the spraying of the raw material compound solution for ITO film, 2 minutes passed (ethanol was sprayed on the glass substrate surface during this period to suppress the rise of the substrate surface temperature), and the heating temperature of the heater became 530 ° C. Occasionally, the FTO membrane raw material compound solution obtained in (2) was sprayed for 2 minutes 30 seconds under the same conditions. As a result, a transparent electrode plate was obtained in which an ITO film having a thickness of 530 nm and an FTO film having a thickness of 170 nm were sequentially formed on the heat-resistant glass plate.
For comparison, similarly, a transparent electrode plate in which only a 530 nm thick ITO film is formed on a heat resistant glass plate having a thickness of 2 mm and a transparent electrode plate in which only a 180 nm thick FTO film is similarly formed are formed. Each was produced.
These three kinds of transparent electrode plates were heated in a heating furnace at 450 ° C. for 2 hours.

(4) Production of photoelectrochemical cell Next, a photoelectrochemical cell having the structure shown in FIG. 2 of Japanese Patent No. 4260494 was produced using the above three types of transparent electrode plates. The oxide semiconductor porous film 15 is formed by dispersing fine particles of titanium oxide having an average particle diameter of about 230 nm in acetonitrile to form a paste, applying the paste to the transparent electrode 11 to a thickness of 15 μm by a bar coating method, and drying 450 The oxide semiconductor porous film 15 was loaded with the dyes listed in Table 2 by baking at 1 ° C. for 1 hour.
Further, a conductive substrate in which an ITO film and an FTO film were laminated on a glass plate was used for the counter electrode 16, and an electrolytic solution made of a non-aqueous solution of iodine / iodide was used for the electrolyte layer 17. The planar dimension of the photoelectrochemical cell was 25 mm × 25 mm.

(5) Evaluation of photoelectrochemical cell About this photoelectrochemical cell, artificial sunlight (AM1.5) was irradiated and the electric power generation efficiency was calculated | required. The results are shown in Table 4. As a result, conversion efficiency of 5% or more was indicated as ◎, 2% or more and less than 5% as ◯, 0.5% or more and less than 2% as △, and less than 0.5% as x. .
Sample No. using sensitizing dye A In Samples 11 to 13, the conversion efficiency is low, whereas Sample No. using the exemplified dye of the present invention. It turned out that a favorable result is shown in 1-9. In a photoelectrochemical cell using a laminate of an ITO film and an FTO film as a transparent electrode plate, the conversion efficiency is particularly high as compared with the case of using only an ITO film or only an FTO film. This dye was found to be highly effective.

Example 3
A collecting electrode was arranged on the FTO film to produce a photoelectrochemical cell, and the conversion efficiency was evaluated. Evaluation was made into two types, test cell (i) and test cell (iv), as follows.

(Test cell (i))
The surface of a heat-resistant glass plate of 100 mm × 100 mm × 2 mm was chemically washed and dried, then placed in a reactor and heated with a heater, and then the FTO (fluorine-doped tin oxide) film used in Example 2 The raw material compound solution was sprayed from a nozzle having a diameter of 0.3 mm at a pressure of 0.06 MPa and a distance to the glass plate of 400 mm for 25 minutes to prepare a glass substrate with an FTO film. On the surface, grooves having a depth of 5 μm were formed in a lattice circuit pattern by an etching method. After pattern formation by photolithography, etching was performed using hydrofluoric acid. A metal conductive layer (seed layer) was formed thereon by sputtering in order to enable plating formation, and a metal wiring layer 3 was further formed by additive plating. The metal wiring layer 3 was formed in a convex lens shape from the surface of the transparent substrate 2 to a height of 3 μm. The circuit width was 60 μm. From this, an FTO film having a thickness of 400 nm was formed as the shielding layer 5 by the SPD method to obtain an electrode substrate (i). The cross-sectional shape of the electrode substrate (i) was as shown in FIG. 2 in JP-A No. 2004-146425.
A titanium oxide dispersion having an average particle size of 25 nm was applied and dried on the electrode substrate (i), and heated and sintered at 450 ° C. for 1 hour. This was immersed in an ethanol solution of the dye shown in Table 3 for 40 minutes to carry the dye. It arrange | positioned facing a platinum sputter | spatter FTO board | substrate through a 50-micrometer-thick thermoplastic polyolefin resin sheet, the resin sheet part was heat-melted, and the bipolar plate was fixed.
A methoxyacetonitrile solution containing 0.5M iodide and 0.05M iodine as the main components was injected from the electrolyte solution inlet previously opened on the platinum sputter electrode side, and filled between the electrodes. It was. Further, the peripheral portion and the electrolyte solution injection port were finally sealed using an epoxy-based sealing resin, and a silver paste was applied to the current collecting terminal portion to obtain a test cell (i). The photoelectric conversion characteristics of the test cell (i) were evaluated using pseudo sunlight of AM1.5. The results are shown in Table 3.

(Test cell (iv))
A glass substrate with a 100 × 100 mm FTO film was prepared in the same manner as in the test cell (i). A metal wiring layer 3 (gold circuit) was formed on the FTO glass substrate by additive plating. The metal wiring layer 3 (gold circuit) was formed in a lattice shape on the substrate surface, and had a circuit width of 50 μm and a circuit thickness of 5 μm. On this surface, an FTO film having a thickness of 300 nm was formed as a shielding layer 5 by the SPD method to obtain a test cell (iv). When the cross section of the electrode substrate (iv) was confirmed using SEM-EDX, there was a sneaking in which seems to be caused by the skirting of the plating resist at the bottom of the wiring, and the shadow portion was not covered with FTO.
A test cell (iv) was produced in the same manner as the test cell (i) using the electrode substrate (iv). The photoelectric conversion characteristics of the test cell (iv) were evaluated by AM1.5 artificial sunlight, and the results are shown in Table 5. As a result, conversion efficiency of 5% or more was indicated as ◎, 2% or more and less than 5% as ◯, 0.5% or more and less than 2% as △, and less than 0.5% as x. .

  From Table 5, when the pigment | dye of this invention was used, the conversion efficiency in the case of test cell (i) showed a high value with 5% or more. Even when the test cell (iv) was used, the value was almost the same as when the test cell (i) was used with the sensitizing dye A.

Example 4
Tests were conducted on a method for producing peroxotitanic acid and titanium oxide fine particles and a method for producing an oxide semiconductor film using the peroxotitanic acid and titanium oxide fine particles, and a photoelectrochemical cell was produced and evaluated.

(Photovoltaic cell (A))
(1) Preparation of coating solution (A) for forming an oxide semiconductor film 5 g of titanium hydride is suspended in 1 liter of pure water, 400 g of 5 mass% hydrogen peroxide solution is added over 30 minutes, and then 80 A solution of peroxotitanic acid was prepared by dissolution by heating to ° C. 90% by volume is taken from the total amount of this solution, adjusted to pH 9 by adding concentrated aqueous ammonia, placed in an autoclave, hydrothermally treated at 250 ° C. for 5 hours under saturated vapor pressure, and titania colloidal particles (A) Was prepared. The obtained titania colloidal particles were anatase type titanium oxide having high crystallinity by X-ray diffraction.
Next, the obtained titania colloidal particles (A) was concentrated to 10 wt%, the peroxotitanic acid solution were mixed, the titanium of the mixed solution TiO ₂ terms, TiO ₂ mass of 30 mass% Then, hydroxypropylcellulose was added as a film formation aid so that a coating solution for forming a semiconductor film was prepared.

(2) Production of Oxide Semiconductor Film (A) Next, the coating solution was applied onto a transparent glass substrate on which fluorine-doped tin oxide was formed as an electrode layer, dried naturally, and subsequently 6000 mJ using a low-pressure mercury lamp. The peroxoacid was decomposed by irradiating with / cm ² of ultraviolet rays, and the coating film was cured. The coating film was heated at 300 ° C. for 30 minutes to decompose and anneal the hydroxypropyl cellulose to form an oxide semiconductor film (A) on the glass substrate.

(3) Adsorption of dye to oxide semiconductor film (A) Next, an ethanol solution having a concentration of 3 × 10 ⁻⁴ mol / liter of the dye of the present invention was prepared as a spectral sensitizing dye. This dye solution was applied onto the metal oxide semiconductor film (A) with a 100 rpm spinner and dried. This coating and drying process was performed five times.

(4) Preparation of electrolyte solution In a mixed solvent having a volume ratio of acetonitrile and ethylene carbonate of 1: 5, tetrapropylammonium iodide is adjusted to a concentration of 0.46 mol / liter and iodine to a concentration of 0.07 mol / liter. To prepare an electrolyte solution.

(5) Production of photoelectric cell (A) The glass substrate produced in (2) on which the oxide semiconductor film (A) adsorbing the dye was formed was used as one electrode, and the other electrode was fluorine-doped. A transparent glass substrate formed with tin oxide as an electrode and carrying platinum on it is placed facing it, the sides are sealed with resin, the electrolyte solution (4) is sealed between the electrodes, and the electrodes are lead between Photoelectric cells (A) were prepared by connecting with wires.

(6) Evaluation of Photoelectric Cell (A) Photoelectric cell (A) was irradiated with light of 100 W / m ² with a solar simulator, measured η (conversion efficiency), and the results are shown in Table 6. Indicated.

(Photovoltaic cell (B))
An oxide semiconductor film (A) except that after irradiation with ultraviolet rays decomposes the peroxo acid and hardens the film, ion irradiation with Ar gas (manufactured by Nissin Electric: ion implantation apparatus, irradiation with 200 eV for 10 hours) is performed. ), An oxide semiconductor film (B) was formed.
Similarly to the oxide semiconductor film (A), the dye was adsorbed to the oxide semiconductor film (B).
Thereafter, a photoelectric cell (B) was prepared in the same manner as in Example 1, and η was measured. The results are shown in Table 6.

(Photovoltaic cell (C))
18.3 g of titanium tetrachloride was diluted with pure water to obtain an aqueous solution containing 1.0% by mass in terms of TiO ₂ . While stirring this aqueous solution, 15% by mass of aqueous ammonia was added to obtain a white slurry having a pH of 9.5. This slurry was washed by filtration to obtain a 10.2% by mass hydrated titanium oxide gel cake in terms of TiO ₂ . This cake was mixed with 400 g of a 5 mass% hydrogen peroxide solution, and then heated to 80 ° C. to dissolve to prepare a peroxotitanic acid solution. 90% by volume was taken from the total amount of this solution, and concentrated ammonia water was added to adjust the pH to 9, and the mixture was placed in an autoclave and subjected to hydrothermal treatment at 250 ° C. for 5 hours under saturated vapor pressure to conduct titania colloidal particles (C ) Was prepared.
Next, an oxide semiconductor film (C) is formed in the same manner as the oxide semiconductor film (A) using the peroxotitanic acid solution and titania colloidal particles (C) obtained above, and a metal oxide semiconductor film In the same manner as (A), the dye of the present invention was adsorbed as a spectral sensitizing dye.
Thereafter, a photoelectric cell (C) was prepared by the same method as that for the photoelectric cell (A), and η was measured. The results are shown in Table 6.

(Photovoltaic cell (D))
18.3 g of titanium tetrachloride was diluted with pure water to obtain an aqueous solution containing 1.0% by mass in terms of TiO ₂ . While stirring this, 15% by mass of ammonia water was added to obtain a white slurry having a pH of 9.5. This slurry was filtered and washed, suspended in pure water to obtain a 0.6 mass% hydrated titanium oxide gel slurry as TiO ₂ , adjusted to pH 2 by adding hydrochloric acid thereto, put in an autoclave, and stirred at 180 ° C. for 5 hours. The titania colloidal particles (D) were prepared by performing hydrothermal treatment for a period of time under saturated vapor pressure.
Next, titania colloidal particles (D) are concentrated to 10% by mass, and hydroxypropyl cellulose is added as a film forming aid so as to be 30% by mass in terms of TiO ₂ to form a semiconductor film. A coating solution was prepared. Next, the coating solution is applied onto a transparent glass substrate on which fluorine-doped tin oxide is formed as an electrode layer, dried naturally, and subsequently irradiated with 6000 mJ / cm ² of ultraviolet rays using a low-pressure mercury lamp to form a film. Cured. Furthermore, it heated at 300 degreeC for 30 minute (s), decomposed | disassembled and annealed hydroxypropyl cellulose, and formed the oxide semiconductor film (D).
Next, the dye of the present invention was adsorbed as a spectral sensitizing dye in the same manner as the oxide semiconductor film (A). Then, the photoelectric cell (D) was created by the method similar to a photoelectric cell (A), and (eta) was measured. The results are shown in Table 6. As a result, conversion efficiency of 5% or more was indicated as ◎, 2% or more and less than 5% as ◯, 0.5% or more and less than 2% as △, and less than 0.5% as x. .

  From Table 6, in the case of the pigment | dye of this invention, when test cell (A)-(C) was used, it turned out that conversion efficiency is especially high. Even when the test cell (D) was used, when the dye of the present invention was used, a higher conversion efficiency was shown than in the comparative example.

(Example 5)
Titanium oxide was prepared or synthesized by changing the method, an oxide semiconductor film was produced from the obtained titanium oxide, and a photoelectrochemical cell was evaluated.

(1) Preparation of titanium oxide by heat treatment Using commercially available anatase-type titanium oxide (trade name ST-01, manufactured by Ishihara Sangyo Co., Ltd.), this is heated to about 900 ° C. and converted to blue-kite type titanium oxide. Further, it was heated to about 1,200 ° C. to obtain a rutile type titanium oxide. The obtained blue kite type titanium oxide was designated as titanium oxide 1.

(2) Synthesis of titanium oxide by wet method (titanium oxide 2 (blue kite type))
954 ml of distilled water is charged into a reaction vessel equipped with a reflux condenser and heated to 95 ° C. While maintaining the stirring speed at about 200 rpm, 46 ml of an aqueous solution of titanium tetrachloride (Ti content: 16.3 mass%, specific gravity 1.59, purity 99.9%) was added to this distilled water at a speed of about 5.0 ml / min. It was dripped at the reaction tank. At this time, care was taken not to lower the temperature of the reaction solution. As a result, the titanium tetrachloride concentration was 0.25 mol / liter (2% by mass in terms of titanium oxide). In the reaction tank, the reaction liquid started to become cloudy immediately after dropping, but kept at the same temperature. After the dropping, the temperature was further raised and heated to near the boiling point (104 ° C.). The reaction was terminated.
The sol obtained by the reaction was filtered, and then powdered using a vacuum dryer at 60 ° C. As a result of quantitative analysis of this powder by X-ray diffractometry, the ratio of (peak intensity of the blue kite type 121 surface) / (peak intensity at the position where the three overlap) is 0.38, (rutile type main peak intensity) / The ratio (peak intensity at the position where the three lines overlap) was 0.05. From these, the titanium oxide had a crystallinity of about 70.0% by mass for the brookite type, about 1.2% by mass for the rutile type, and about 28.8% by mass for the anatase type. Further, when the fine particles were observed with a transmission electron microscope, the average particle diameter of the primary particles was 0.015 μm.

(Titanium oxide 3 (Blue Kite type))
An aqueous solution of titanium trichloride (Ti content: 28% by mass, specific gravity 1.5, purity 99.9%) was diluted with distilled water to give a solution of 0.25 mol / L in terms of titanium concentration. At this time, it was ice-cooled so as not to increase the liquid temperature and kept at 50 ° C. or lower. Next, 500 ml of this solution was put into a reaction tank equipped with a reflux condenser, and ozone gas with a purity of 80% was bubbled from the ozone gas generator at 1 L / min while heating at 85 ° C. to carry out an oxidation reaction. This state was maintained for 2 hours to complete the reaction. The obtained sol was filtered and vacuum-dried to obtain a powder. As a result of quantitative analysis of this powder by X-ray diffractometry, the ratio of (peak intensity on the surface of the blue kite type 121) / (peak intensity at the position where the three overlap) is 0.85, (rutile main peak intensity) / The ratio (peak intensity at the position where the three lines overlap) was 0. From these, the titanium dioxide was about 98% by mass for the blue kite type, 0% by mass for the rutile type, 0% by mass for the anatase type, and about 2% was amorphous. Further, when the fine particles were observed with a transmission electron microscope, the average particle diameter of the primary particles was 0.05 μm.

(Production and evaluation of dye-sensitized photoelectric conversion device)
A photoelectric conversion element having the configuration shown in FIG.
A glass substrate was coated with fluorine-doped tin oxide to form a conductive transparent electrode. A paste using each titanium oxide particle as a raw material was formed on the electrode surface, applied to a thickness of 50 μm by a bar coating method, and then baked at 500 ° C. to form a thin layer having a thickness of about 20 μm. Next, a 3 × 10 −4 molar ethanol solution of RuL ₂ (SCN) ₂ (L = 2,2′-bipyridyl-4,4′-dicarboxylate), which is a ruthenium complex, was prepared. A glass substrate on which a thin layer of titanium oxide was formed was immersed and held at room temperature for 12 hours. As a result, the complex was deposited on a thin layer of titanium oxide.

  A photoelectric conversion element having a configuration shown in FIG. 1 of JP-A-2000-340269 was prepared using an iodine salt of tetrapropylammonium as an electrolytic solution and an acetonitrile solution of lithium iodide and using platinum as a counter electrode. For photoelectric conversion, light from a 160-w high-pressure mercury lamp (the infrared part was cut by a filter) was applied to the above-mentioned element, and the conversion efficiency at that time was measured. The results are shown in Table 7. As a result, conversion efficiency of 5% or more was indicated as ◎, 2% or more and less than 5% as ◯, 0.5% or more and less than 2% as △, and less than 0.5% as x. .

  From Table 7, it was found that the dye of the present invention has high conversion efficiency even when the titanium oxide is changed.

(Example 6)
Photoelectrochemical cells were fabricated as semiconductor electrodes using titanium oxides having different particle sizes, and the characteristics were evaluated.
[Preparation of paste]
First, a paste for forming a semiconductor layer or a light scattering layer of a semiconductor electrode constituting the photoelectrode was prepared by the following procedure.

(Paste 1)
A titania slurry was prepared by placing spherical TiO ₂ particles (anatase type, average particle size: 25 nm, hereinafter referred to as spherical TiO ₂ particles 1) in a nitric acid solution and stirring. Next, a cellulose binder as a thickener was added to the titania slurry and kneaded to prepare a paste.

(Paste 2)
A titania slurry was prepared by placing spherical TiO ₂ particles 1 and spherical TiO ₂ particles (anatase type, average particle size: 200 nm, hereinafter referred to as spherical TiO ₂ particles 2) in a nitric acid solution and stirring. Next, a cellulose binder as a thickener was added to the titania slurry and kneaded to prepare a paste (mass of TiO ₂ particles 1: mass of TiO ₂ particles 2 = 30:70).

(Paste 3)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase type, diameter: 100 nm, aspect ratio: 5, hereinafter referred to as rod-like TiO ₂ particles 1), the mass of the rod-like TiO ₂ particles 1: the mass of the paste 1 = 10: Ninety pastes were prepared.

(Paste 4)
The paste 1, a rod-shaped TiO ₂ particles 1 were mixed, the mass rod-shaped TiO ₂ particles 1: Paste 1 Mass = 30: 70 paste was prepared.

(Paste 5)
The paste 1, a rod-shaped TiO ₂ particles 1 were mixed, the mass rod-shaped TiO ₂ particles 1: Paste 1 Mass = 50: 50 paste was prepared.

(Paste 6)
The paste 1 is mixed with plate-like mica particles (diameter: 100 nm, aspect ratio: 6, hereinafter referred to as plate-like mica particles 1), and the mass of the plate-like mica particles 1: the mass of the paste 1 = 20: 80 paste. Was prepared.

(Paste 7)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 30 nm, aspect ratio: 6.3, hereinafter referred to as rod-like TiO ₂ particles 2), the mass of the rod-like TiO ₂ particles 2: the mass of the paste 1 = 30: 70 pastes were prepared.

(Paste 8)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 50 nm, aspect ratio: 6.1, hereinafter referred to as rod-like TiO ₂ particles 3), and the mass of the rod-like TiO ₂ particles 3: the mass of the paste 1 = 30. : 70 paste was prepared.

(Paste 9)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 75 nm, aspect ratio: 5.8, hereinafter referred to as rod-like TiO ₂ particles 4), and the mass of the rod-like TiO ₂ particles 4: the mass of the paste 1 = 30. : 70 paste was prepared.

(Paste 10)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 130 nm, aspect ratio: 5.2, hereinafter referred to as rod-like TiO ₂ particles 5), and the mass of the rod-like TiO ₂ particles 5: the mass of the paste 1 = 30. : 70 paste was prepared.

(Paste 11)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 180 nm, aspect ratio: 5, hereinafter referred to as rod-like TiO ₂ particles 6), and the mass of the rod-like TiO ₂ particles 6: the mass of the paste 1 = 30: 70. A paste was prepared.

(Paste 12)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 240 nm, aspect ratio: 5, hereinafter referred to as rod-like TiO ₂ particles 7), the mass of the rod-like TiO ₂ particles 7: the mass of the paste 1 = 30: 70. A paste was prepared.

(Paste 13)
The paste 1 is mixed with rod-like TiO ₂ particles (anatase, diameter: 110 nm, aspect ratio: 4.1, hereinafter referred to as rod-like TiO ₂ particles 8), and the mass of the rod-like TiO ₂ particles 8: the mass of the paste 1 = 30. : 70 paste was prepared.

(Paste 14)
The paste 1 is mixed with rod-shaped TiO ₂ particles (anatase, diameter: 105 nm, aspect ratio: 3.4, hereinafter referred to as rod-shaped TiO ₂ particles 9), and the mass of the rod-shaped TiO ₂ particles 9: the mass of the paste 1 = 30. : 70 paste was prepared.

(Photoelectrochemical cell 1)
A photoelectrode having the same configuration as the photoelectrode 12 shown in FIG. 5 described in JP-A-2002-289274 is prepared by the following procedure, and further, using the photoelectrode, a dye-sensitized type other than the photoelectrode is used. A 10 × 10 mm scale dye-sensitized solar cell 1 having the same configuration as that of the solar cell 20 was produced.

A transparent electrode in which a fluorine-doped SnO ₂ conductive film (film thickness: 500 nm) was formed on a glass substrate was prepared. Then, the paste 2 was screen-printed on the SnO ₂ conductive film and then dried. Then, it baked on the conditions of 450 degreeC in the air. Further, by repeating this screen printing and baking using the paste 4, a semiconductor electrode having the same configuration as the semiconductor electrode 2 shown in FIG. 5 on the SnO ₂ conductive film (area of light receiving surface; 10 mm × 10 mm, layer thickness) 10 μm, layer thickness of semiconductor layer; 6 μm, layer thickness of light scattering layer; 4 μm, content of rod-like TiO ₂ particles 1 contained in the light scattering layer; 30% by mass), containing sensitizing dye A photoelectrode was prepared.

Next, the pigment | dye was made to adsorb | suck to a semiconductor electrode as follows. First, anhydrous ethanol dehydrated with magnesium ethoxide was used as a solvent, and the dye of the present invention was dissolved therein so that the concentration thereof was 3 × 10 ⁻⁴ mol / L to prepare a dye solution. Next, the semiconductor electrode was immersed in this solution, whereby the dye was adsorbed to the semiconductor electrode by about 1.5 × 10 ⁻⁷ mol / cm ² to complete the photoelectrode 10.

  Next, a platinum electrode (thickness of Pt thin film; 100 nm) having the same shape and size as the above-described photoelectrode as a counter electrode, and an iodine redox solution containing iodine and lithium iodide as an electrolyte E were prepared. Furthermore, a spacer S (trade name: “Surlin”) manufactured by DuPont having a shape corresponding to the size of the semiconductor electrode is prepared. As shown in FIG. 3 of JP-A-2002-289274, the photoelectrode 10 and the counter electrode are prepared. The photoelectrochemical cell 1 was completed by facing the CE through the spacer S and filling the above electrolyte therein.

(Photoelectrochemical cell 2)
The photoelectrode 10 shown in FIG. 1 described in JP-A No. 2002-289274 and the diagram described in JP-A No. 2002-289274 are the same as those of the photoelectrochemical cell 1 except that the semiconductor electrode is manufactured as follows. A photoelectrode and a photoelectrochemical cell 2 having the same configuration as the dye-sensitized solar cell 20 shown in FIG.

Paste 2 was used as a semiconductor layer forming paste. Then, paste 2 was screen-printed on the SnO ₂ conductive film and then dried. Then, it baked on the conditions of 450 degreeC in the air, and formed the semiconductor layer.

  Paste 3 was used as the innermost layer forming paste of the light scattering layer. The paste 5 was used as the outermost layer forming paste of the light scattering layer. Then, a light scattering layer was formed on the semiconductor layer in the same manner as in the dye-sensitized solar cell 1.

Then, on the SnO ₂ conductive film, a semiconductor electrode having the same configuration as the semiconductor electrode 2 shown in FIG. 1 described in JP-A-2002-289274 (light receiving surface area: 10 mm × 10 mm, layer thickness: 10 μm, layer thickness of the semiconductor layer) 3 μm, the thickness of the innermost layer; 4 μm, the content of rod-like TiO ₂ particles 1 contained in the innermost layer; 10% by mass, the thickness of the outermost layer; 3 μm, contained in the innermost layer The content ratio of the rod-like TiO ₂ particles 1 to be formed; 50% by mass) was formed, and a photoelectrode containing no sensitizing dye was produced. Similarly to the photoelectrochemical cell 1, the photoelectrochemical cell 2 was completed by making the photoelectrode, the counter electrode CE, and the spacer S face each other and filling the above electrolyte therein.

(Photoelectrochemical cell 3)
The light shown in FIG. 5 was prepared by the same procedure as that of the photoelectrochemical cell 1 except that the paste 1 was used as the semiconductor layer forming paste and the paste 4 was used as the light scattering layer forming paste when the semiconductor electrode was manufactured. A photoelectrode and photoelectrochemical cell 3 having the same configuration as the electrode 10 and the photoelectrochemical cell 20 shown in FIG. 3 described in JP-A-2002-289274 were produced. The semiconductor electrode has a light receiving surface area of 10 mm × 10 mm, a layer thickness of 10 μm, a semiconductor layer thickness of 5 μm, a light scattering layer thickness of 5 μm, and the rod-like TiO ₂ particles 1 contained in the light scattering layer. Content rate: 30% by mass.

(Photoelectrochemical cell 4)
In the production of the semiconductor electrode, the light shown in FIG. 5 was obtained by the same procedure as that of the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 6 was used as the light scattering layer forming paste. A photoelectrode and a photoelectrochemical cell 4 having the same configuration as the electrode 10 and the photoelectrochemical cell 20 shown in FIG. 3 described in JP-A-2002-289274 were produced. The semiconductor electrode has a light receiving surface area: 10 mm × 10 mm, layer thickness: 10 μm, semiconductor layer thickness: 6.5 μm, light scattering layer thickness: 3.5 μm, plate-like contained in the light scattering layer The content of mica particles 1 was 20% by mass.

(Photoelectrochemical cell 5)
In the production of the semiconductor electrode, the photoelectrode and the photoelectrochemistry were prepared in the same procedure as in the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 8 was used as the light scattering layer forming paste. Battery 5 was produced. The content ratio of the rod-shaped TiO ₂ particles 3 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

(Photoelectrochemical cell 6)
In the production of the semiconductor electrode, the photoelectrode and the photoelectrochemical process were performed in the same manner as in the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 9 was used as the light scattering layer forming paste. A battery 6 was produced. The content ratio of the rod-shaped TiO ₂ particles 4 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

(Photoelectrochemical cell 7)
In the production of the semiconductor electrode, the photoelectrode and the photoelectrochemistry were prepared in the same procedure as in the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 10 was used as the light scattering layer forming paste. Battery 7 was produced. The content ratio of the rod-shaped TiO ₂ particles 5 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

(Photoelectrochemical cell 8)
In the production of the semiconductor electrode, the photoelectrode and the photoelectrochemistry were prepared in the same procedure as in the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 11 was used as the light scattering layer forming paste. Battery 8 was produced. The content ratio of the rod-shaped TiO ₂ particles 6 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

(Photoelectrochemical cell 9)
In the production of the semiconductor electrode, the photoelectrode and the photoelectrochemistry were prepared in the same procedure as in the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 13 was used as the light scattering layer forming paste. A battery 9 was produced. The content ratio of the rod-shaped TiO ₂ particles 8 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

(Photoelectrochemical cell 10)
In the production of the semiconductor electrode, the photoelectrode and the photoelectrochemical process were performed in the same manner as in the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 14 was used as the light scattering layer forming paste. Battery 10 was produced. The content of the rod-like TiO ₂ particles 9 contained in the light scattering layer of the semiconductor electrode was 30% by mass.

(Photoelectrochemical cell 11)
Similar to the photoelectrochemical cell 1 except that a semiconductor electrode (light-receiving surface area: 10 mm × 10 mm, layer thickness: 10 μm) made of only the semiconductor layer using only the paste 2 was manufactured in the manufacture of the semiconductor electrode. A photoelectrode and a comparative photoelectrochemical cell 1 were prepared according to the procedure.

(Electrochemical battery 12)
In the production of the semiconductor electrode, the photoelectrode and the comparative photoelectricity were prepared in the same procedure as in the photoelectrochemical cell 1 except that the paste 2 was used as the semiconductor layer forming paste and the paste 7 was used as the light scattering layer forming paste. A chemical battery 2 was produced. The content ratio of the rod-shaped TiO ₂ particles 2 contained in the light scattering layer of the semiconductor electrode; was 30 wt%.

[Battery characteristics test]
A battery characteristic test was performed, and the conversion efficiency η was measured for the photoelectrochemical cells 1 to 12. The battery characteristic test was performed by irradiating 1000 W / m ² of pseudo-sunlight from a xenon lamp through an AM1.5 filter using a solar simulator (manufactured by WACOM, WXS-85H). Current-voltage characteristics were measured using an IV tester, and energy conversion efficiency (η /%) was determined. The results are shown in Table 8. As a result, conversion efficiency of 5% or more was indicated as ◎, 2% or more and less than 5% as ◯, 0.5% or more and less than 2% as △, and less than 0.5% as x. .

  As shown in Table 8, the dye of the present invention was found to have high conversion efficiency.

(Example 7)
A slurry obtained by adding metal alkoxide to metal oxide fine particles was applied to a conductive substrate, and then UV ozone irradiation, UV irradiation or drying was performed to produce an electrode. Then, the photoelectrochemical cell was produced and the conversion efficiency was measured.

(Metal oxide fine particles)
Titanium oxide was used as the metal oxide fine particles. As the titanium oxide, P25 powder (trade name, manufactured by Degussa) having a mass ratio of 30% rutile type and 70% anatase type and an average particle size of 25 nm was used.
(Pretreatment of metal oxide fine particle powder)
The metal oxide fine particles were previously heat-treated to remove surface organic substances and moisture. In the case of titanium oxide fine particles, the fine particles were heated in an oven at 450 ° C. in the atmosphere for 30 minutes.

(Measurement of water content in metal oxide fine particles)
When the moisture content contained in titanium oxide and P25 powder (trade name, manufactured by Degussa) stored in an environment of temperature 26 ° C. and humidity 72% is reduced by thermogravimetry and heated to 300 ° C. The amount of moisture desorbed was determined by Karl Fischer titration.

  When the amount of water desorbed when titanium oxide, P25 powder (trade name, manufactured by Degussa) was heated at 300 ° C. was quantified by Karl Fischer titration, 0.253 mg of water was contained in 0.1033 g of titanium oxide fine powder. It was included. That is, since the titanium oxide fine powder contained about 2.5 wt% of water, the metal oxide fine particle powder was heat-treated in an oven at 450 ° C. for 30 minutes before mixing with the metal alkoxide, and stored in a desiccator after cooling. Used.

(Preparation of metal alkoxide paste)
The metal alkoxide that plays a role in bonding metal oxide fine particles includes titanium (IV) tetraisopropoxide (TTIP) as a titanium raw material, zirconium (IV) tetra n-propoxide as a zirconium raw material, and niobium as a niobium raw material. (V) Pentaethoxide (all manufactured by Aldrich) was used.

The molar concentration ratio between the metal oxide fine particles and the metal alkoxide is appropriately adjusted according to the metal oxide fine particle diameter so that the amorphous layer generated by hydrolysis of the metal alkoxide is not excessively thick and the particles can be sufficiently bonded to each other. did. All metal alkoxides were 0.1M ethanol solutions. When mixing titanium oxide fine particles and titanium (IV) tetraisopropoxide (TTIP), 3.55 g of 0.1M TTIP solution was mixed with 1 g of titanium oxide fine particles. At this time, the titanium oxide concentration in the obtained paste was about 22% by mass, and the viscosity was appropriate for coating. Moreover, the titanium oxide, TTIP, and ethanol at this time were 1: 0.127: 3.42 by mass ratio, and 1: 0.036: 5.92 by molar ratio.
Similarly, a mixed paste of titanium oxide fine particles and an alkoxide other than TTIP was prepared so that the fine particle concentration was 22% by mass. In the paste using zinc oxide and tin oxide fine particles, the content was 16% by mass. In the case of zinc oxide and tin oxide, the metal alkoxide solution was mixed at a ratio of 5.25 g to 1 g of the metal oxide fine particles.

  The metal oxide fine particles and the metal alkoxide solution were stirred for 2 hours with a magnetic stirrer in a sealed container to obtain a uniform paste. As a method for applying the paste to the conductive substrate, a doctor blade method, a screen printing method, a spray coating method, or the like can be used, and an appropriate paste viscosity is appropriately selected depending on the application method. Here, a method of applying simply with a glass rod (similar to the doctor blade method) was used. In this case, the concentration of the metal oxide fine particles giving an appropriate paste viscosity was approximately in the range of 5 to 30% by mass.

  In this embodiment, the layer thickness of the amorphous metal oxide produced by the decomposition of the metal alkoxide is in the range of about 0.1 to 0.6 nm. A range of about 0.05 to 1.3 nm was suitable for room temperature film formation by this method.

(Applying paste on conductive substrate and air-drying treatment)
Two adhesive tapes as spacers on a polyethylene terephthalate (PET) film substrate (20Ω / cm ² ) with tin-doped indium oxide (ITO) conductive film or a glass substrate (10Ω / cm ² ) with fluorine-doped tin oxide (FTO) conductive film The pastes were applied in parallel at regular intervals, and each paste prepared according to the above method was uniformly applied using a glass rod.

After applying the paste and before dye adsorption, a porous film was prepared by changing the conditions for the presence or absence of UV ozone treatment, UV irradiation treatment, or drying treatment.
(Drying process)
The film after application to the conductive substrate was air-dried at room temperature in the atmosphere for about 2 minutes. During this process, the metal alkoxide in the paste was hydrolyzed by moisture in the atmosphere, and amorphous titanium oxide, zirconium oxide, and niobium oxide were formed from Ti alkoxide, Zr alkoxide, and Nb alkoxide, respectively.
Since the produced amorphous metal oxide plays a role of adhering metal oxide fine particles and the film to the conductive substrate, a porous film excellent in mechanical strength and adhesion was obtained only by air drying.

(UV ozone treatment)
NL-UV253 UV ozone cleaner manufactured by Nippon Laser Electronics Co., Ltd. was used for UV ozone treatment. The UV light source was equipped with three 4.5 W mercury lamps having emission lines at 185 nm and 254 nm, and the sample was placed horizontally at a distance of about 6.5 cm from the light source. Ozone is generated by introducing an oxygen stream into the chamber. In this example, this UV ozone treatment was performed for 2 hours. Note that no decrease in the conductivity of the ITO film and the FTO film due to this UV ozone treatment was observed.

(UV treatment)
Similarly to the UV ozone treatment, the treatment was performed for 2 hours, except that the inside of the chamber was replaced with nitrogen. No decrease in the conductivity of the ITO film and FTO film due to the UV treatment was observed.

(Dye adsorption)
The dye of the present invention was used as a sensitizing dye, and a 0.5 mM ethanol solution was prepared. In this example, the porous film produced by the above process was dried in an oven at 100 ° C. for 1 hour, then immersed in a sensitizing dye solution, and allowed to stand at room temperature for 50 minutes to adsorb the sensitizing dye on the titanium oxide surface. did. The sample after adsorption of the sensitizing dye was washed with ethanol and air-dried.

(Production of photoelectrochemical cell and evaluation of battery characteristics)
A photoelectrochemical cell was fabricated by using a conductive substrate on which a porous film after dye adsorption was formed as a photoelectrode, and an ITO / PET film or FTO / glass counter electrode in which platinum fine particles were modified by sputtering. The effective area of the photoelectrode was about 0.2 cm ² . As the electrolyte solution, 3-methoxypropionitrile containing 0.5 M LiI, 0.05 M I ₂ and 0.5 M t-butylpyridine was introduced into the gap between the two electrodes by capillary action.

The battery performance was evaluated by photocurrent action spectrum measurement under irradiation with a constant number of photons (1016 cm ⁻² ) and IV measurement under irradiation with AM1.5 simulated sunlight (100 mW / cm ² ). A CEP-2000 type spectral sensitivity measuring device manufactured by Spectrometer Co., Ltd. was used for these measurements.
The obtained output characteristic values are summarized in Table 9. As a result, conversion efficiency of 3% or more was indicated as ◎, 2% or more and less than 5% as ◯, 0.5% or more and less than 2% as △, and less than 0.5% as x. .

  In Table 9, the columns of “UV ozone”, “UV”, and “dry” indicate the presence / absence of UV ozone treatment, UV irradiation treatment, and drying treatment after formation of the porous film and before sensitizing dye adsorption, respectively. The processed one is “◯”, and the unprocessed one is “×”.

The column _“ Pretreatment of TiO ₂ ” in Table 9 indicates the presence or absence of pretreatment of titanium oxide fine particles (heat treatment in an oven at 450 ° C. for 30 minutes). Samples 6, 14, and 22 represent samples using a paste having a high TTIP concentration (titanium oxide: TTIP molar ratio of 1: 0.356). The other samples (samples 1-5, 7-13, 23, 24) all use a paste of titanium oxide: TTIP = 1: 0.0356.

  From the results shown in Table 9, when the dye of the present invention was used, photoelectricity was observed regardless of the presence or absence of UV ozone treatment, UV irradiation treatment, and drying treatment after the formation of the porous film and before adsorption of the sensitizing dye. It was found that the conversion efficiency of the chemical battery was high.

(Example 8)
Using acetonitrile as a solvent, an electrolyte solution was prepared in which lithium iodide 0.1 mol / l, iodine 0.05 mol / l, and dimethylpropylimidazolium iodide 0.62 mol / l were dissolved. No. shown below. 1-No. 8 benzimidazole compounds were separately added and dissolved to a concentration of 0.5 mol / l.

No. 1-No. Eight benzimidazole compound electrolyte solution was dripped at the porous titanium oxide semiconductor thin film (thickness 15 micrometers) which carry | supported the pigment | dye of this invention in electroconductive glass. A frame type spacer (thickness: 25 μm) made of a polyethylene film was placed thereon, and this was covered with a platinum counter electrode to produce a photoelectric conversion element.
The obtained photoelectric conversion element was irradiated with light having an intensity of 100 mW / cm ^{2 using} a Xe lamp as a light source. Table 10 shows the obtained open circuit voltage and photoelectric conversion efficiency. The open circuit voltage is indicated as ◎ for those with 7.0 V or more, ◯ for those with 6.5 V or more but less than 7.0 V, △ for those with 6.0 V or more but less than 6.5 V, and × for those with 6.0 V or less. . A conversion efficiency of 3% or more was indicated as ◎, 2% or more and less than 5% as 未 満, 0.5% or more and less than 2% as Δ, and less than 0.5% as ×.
Table 10 also shows the results of photoelectric conversion elements using an electrolytic solution to which no benzimidazole compound was added.

  From the results in Table 10, it can be seen that the dye of the present invention has high conversion efficiency.

Example 9
(Photoelectrochemical cell 1)
According to the following procedure, a photoelectrode having the same configuration as the photoelectrode 10 shown in FIG. 1 described in JP-A No. 2004-152613 (however, the semiconductor electrode 2 has a two-layer structure) is manufactured. A photoelectrochemical cell having the same configuration as the dye-sensitized solar cell 20 shown in FIG. 1 described in JP-A-2004-152613 except that a photoelectrode is used (the area of the light receiving surface F2 of the semiconductor electrode 2 is 1 cm ² ). Was made. For each layer of the semiconductor electrode 2 having a two-layer structure, the layer disposed on the side close to the transparent electrode 1 is referred to as “first layer”, and the layer disposed on the side close to the porous body layer PS is referred to as “second layer”. It is called “layer”.

  First, P25 and P200 using an average particle diameter of 25 nm P25 powder (trade name, manufactured by Degussa), titanium oxide particles having different particle diameters, and P200 powder (average particle diameter: 200 nm, product name, manufactured by Degussa). Of acetylacetone, ion-exchanged water, and surfactant (manufactured by Tokyo Chemical Industry Co., Ltd., commercial product) so that the total content of P15 and P200 is 15% by mass and the mass ratio of P25 and P200 is P25: P200 = 30: 70 Name; “Triton-X”) was added and kneaded to prepare a slurry for forming a second layer (hereinafter referred to as “slurry 1”).

  Next, a slurry for forming a first layer (P1 content; 15 mass%; hereinafter, “slurry 2” is prepared by the same preparation procedure as that of the slurry 1 except that only P25 is used without using P200. Was prepared).

On the other hand, a transparent electrode (thickness: 1.1 mm) in which a fluorine-doped SnO ₂ conductive film (film thickness: 700 nm) was formed on a glass substrate (transparent conductive glass) was prepared. Then, the SnO ₂ conductive film, the slurry 2 described above was coated with Bakoda, then dried. Then, it baked for 30 minutes at 450 degreeC in air | atmosphere. In this way, the first layer of the semiconductor electrode 2 was formed on the transparent electrode.

Furthermore, the second layer was formed on the first layer by repeating the same application and firing as described above using the slurry 1. In this way, the semiconductor electrode 2 (light-receiving surface area; 1.0 cm ² , the total thickness of the first layer and the second layer: 10 μm (the thickness of the first layer: 3 μm, the first layer) on the SnO ₂ conductive film No. 2 layer thickness: 7 μm)), and a photoelectrode 10 containing no sensitizing dye was prepared.

Next, an ethanol solution of the dye of the present invention (sensitizing dye concentration; 3 × 10 ⁻⁴ mol / L) was prepared as a sensitizing dye. The photoelectrode 10 was immersed in this solution and allowed to stand for 20 hours under a temperature condition of 80 ° C. As a result, a sensitizing dye was adsorbed by about 1.0 × 10 ⁻⁷ mol / cm ² inside the semiconductor electrode. Thereafter, in order to improve the open circuit voltage Voc, the semiconductor electrode after the adsorption of the ruthenium complex was immersed in an acetonitrile solution of 4-tert-butylpyridine for 15 minutes, and then dried in a nitrogen stream maintained at 25 ° C. 10 was completed.

  Next, a counter electrode CE having the same shape and size as the above photoelectrode was produced. First, an isopropanol solution of chloroplatinic acid hexahydrate was dropped on a transparent conductive glass, dried in air, and then baked at 450 ° C. for 30 minutes to obtain a platinum sintered counter electrode CE. The counter electrode CE was previously provided with a hole for injection of the electrolyte E (diameter 1 mm).

  Next, zinc iodide, 1,2-dimethyl-3-propylimidazolium iodide, iodine, and 4-tert-butylpyridine are dissolved in methoxyacetonitrile as a solvent to form a liquid electrolyte (iodide). Zinc concentration: 10 mmol / L, dimethylpropylimidazolium iodide concentration: 0.6 mol / L, iodine concentration: 0.05 mol / L, 4-tert-butylpyridine concentration: 1 mol / L).

  Next, a spacer S (trade name: “HIMILAN”, ethylene / methacrylic acid random copolymer ionomer film) manufactured by Mitsui Dupont Polychemical Co., Ltd. having a shape matched to the size of the semiconductor electrode was prepared. As shown in FIG. 1 described in 15613, the photoelectrode and the counter electrode were opposed to each other through a spacer, and each was bonded by thermal welding to obtain a battery casing (no electrolyte filled).

  Next, after injecting the liquid electrolyte into the housing from the hole of the counter electrode, the hole is closed with a member made of the same material as the spacer, and this member is thermally welded to the hole of the counter electrode to seal the hole. 1 was completed.

(Photoelectrochemical cell 2)
The photoelectrochemical cell 2 was produced in the same procedure and conditions as the photoelectrochemical cell 1 except that the concentration of zinc iodide in the liquid electrolyte was 50 mmol / L.

(Photoelectrochemical cell 3)
The photoelectrochemical cell is the same as the photoelectrochemical cell 1 except that lithium iodide is added instead of zinc iodide in the liquid electrolyte and the concentration of lithium iodide in the liquid electrolyte is 20 mmol / L. 3 was produced.

(Electrochemical battery 4)
Photoelectrochemical cell in the same procedure and conditions as in photoelectrochemical cell 1 except that lithium iodide is added instead of zinc iodide in the liquid electrolyte and the concentration of lithium iodide in the liquid electrolyte is 100 mmol / L. 4 was produced.

(Battery characteristics evaluation test)
The photoelectric conversion efficiency (η (%)) was measured for the photoelectrochemical cells 1 to 4 by the following procedure.

The battery characteristic evaluation test uses a solar simulator (trade name; “WXS-85-H type”, manufactured by Wacom), and the irradiation conditions of pseudo-sunlight from a xenon lamp light source through an AM filter (AM1.5), The measurement was performed under measurement conditions of 100 mW / cm ² (so-called “1Sun” irradiation conditions).

  About each photoelectrochemical cell, the current-voltage characteristic was measured at room temperature using the IV tester, and photoelectric conversion efficiency (eta) [%] was calculated | required from these. The obtained results are shown as “fresh” in Table 11 (1 Sun irradiation conditions). Table 11 also shows the results of durability evaluation tests examined after 300 hours of photoelectric conversion efficiency η [%] of the dye-sensitized solar cells 1 to 4 under operating conditions of 60 ° C., 1 Sun irradiation and 10Ω load. Indicated.

  As is apparent from the results shown in Table 11, the dye of the present invention was found to be excellent even when zinc iodide was added to the electrolyte.

(Example 10)
1. Preparation of Titanium Dioxide Dispersion 15 g of titanium dioxide fine particles (Nippon Aerosil Co., Ltd., Degussa P-25), water 45 g, dispersant (Aldrich, Triron X −100) 1 g and 30 g of zirconia beads having a diameter of 0.5 mm (manufactured by Nikkato Co., Ltd.) were added, and dispersion treatment was performed at 1500 rpm for 2 hours using a sand grinder mill (manufactured by Imex). Zirconia beads were filtered off from the resulting dispersion. The average particle diameter of the titanium dioxide fine particles in the obtained dispersion was 2.5 μm. The particle size was measured with a master sizer manufactured by MALVERN.

2. Preparation of Titanium Oxide Fine Particle Layer (Electrode A) Adsorbed with Dye 20 mm × 20 mm conductive glass plate coated with fluorine-doped tin oxide (Asahi Glass Co., Ltd., TCO glass-U, surface resistance: about 30Ω / m ² ) was prepared, and an adhesive tape for spacers was applied to both ends of the conductive layer side (a portion having a width of 3 mm from the end), and then the dispersion was applied onto the conductive layer using a glass rod. After application of the dispersion, the adhesive tape was peeled off and air-dried at room temperature for 1 day. Next, this semiconductor-coated glass plate was placed in an electric furnace (muffle furnace FP-32 type manufactured by Yamato Scientific Co., Ltd.) and baked at 450 ° C. for 30 minutes. The semiconductor-coated glass plate was taken out and cooled, and then immersed in an ethanol solution of the dyes shown in Table 10 (concentration: 3 × 10 ⁻⁴ mol / L) for 3 hours. The semiconductor-coated glass plate on which the dye was adsorbed was immersed in 4-tert-butylpyridine for 15 minutes, washed with ethanol, and air dried. The thickness of the thus obtained dye-sensitized titanium oxide fine particle layer is 10 [mu] m, the coating amount of titanium oxide fine particles was 20 g / m ^2. Moreover, the adsorption amount of the pigment | dye was in the range of 0.1-10 mmol / m < ² > according to the kind.

3. Production of Photoelectrochemical Battery 1 As a solvent, a mixture of acetonitrile and 3-methyl-2-oxazolidinone in a volume ratio of 90/10 was used. To this solvent, iodine and an iodine salt of 1-methyl-3-hexylimidazolium as an electrolyte salt were added to prepare a solution containing 0.5 mol / L electrolyte salt and 0.05 mol / L iodine. To this solution, (solvent + nitrogen-containing polymer compound + electrolyte salt) was added as 100% by mass, and 10% of the nitrogen-containing polymer compound (1-1) shown in Table 10 was added. Furthermore, 0.1 mol of the electrophile (2-6) was mixed with 1 mol of the electrophilic site with respect to the reactive nitrogen atom of the nitrogen-containing polymer compound to obtain a uniform reaction solution.

On the other hand, on the dye-sensitized titanium oxide fine particle layer formed on the conductive glass plate, the platinum thin film side of the counter electrode made of a glass plate on which platinum is vapor-deposited through a spacer is placed. A glass plate was fixed. The open end of the obtained assembly was immersed in the electrolyte solution, and the reaction solution was infiltrated into the dye-sensitized titanium oxide fine particle layer by capillary action.
Subsequently, it heated at 80 degreeC for 30 minute (s), and the crosslinking reaction was performed. In this way, as shown in FIG. 2 of JP 2000-323190 A, the dye-sensitized titanium oxide fine particle layer 20, the electrolyte layer 30, the platinum thin film 42, and the glass are formed on the conductive layer 12 of the conductive glass plate 10. The photoelectrochemical cell 1-1 (sample No. 1) of the present invention in which the counter electrode 40 composed of the plate 41 was sequentially laminated was obtained.
Further, by repeating the above process except that the combination of the composition of the dye and the electrolyte composition is changed as shown in Table 10, photoelectrochemical cells 1-2, 1- having different photosensitive layers 20 and / or charge transfer layers 30 are obtained. 3 was obtained.

4). Production of photoelectrochemical cells A and B (1) Photoelectrochemical cell A
An electrode A (20 mm × 20 mm) composed of a titanium oxide fine particle layer dye-sensitized with the dye of the present invention as described above was superimposed on a platinum-deposited glass plate of the same size via a spacer. Next, an electrolyte solution (iodine 0.05 mol / L using a mixture of acetonitrile and 3-methyl-2-oxazolidinone in a volume ratio of 90/10 as a solvent using a capillary phenomenon in the gap between both glass plates, lithium iodide 0 .5 mol / L solution) was infiltrated to produce photoelectrochemical cell A-1. Photoelectrochemical cells A-2 and A-3 were obtained by repeating the above steps except that the dye was changed as shown in Table 10.

(2) Photoelectrochemical cell B (electrolyte described in JP-A-9-27352)
The electrolytic solution was applied and impregnated on the electrode A (20 mm × 20 mm) composed of the titanium oxide fine particle layer dye-sensitized with the dye of the present invention as described above. The electrolyte was 1 g of hexaethylene glycol methacrylate (manufactured by Nippon Oil & Fats Chemical Co., Ltd., Bremer PE-350), 1 g of ethylene glycol, and 2-hydroxy-2-methyl-1-phenyl-propane as a polymerization initiator. It was obtained by dissolving 500 mg of lithium iodide in a mixed solution containing 20 mg of -1-one (manufactured by Ciba Geigy Japan, Darocur 1173) and vacuum degassing for 10 minutes. Next, the porous titanium oxide layer impregnated with the mixed solution is placed under a reduced pressure to remove bubbles in the porous titanium oxide layer, promote penetration of the monomer, and then polymerize by irradiation with ultraviolet light. A uniform gel of the compound was filled into the fine pores of the porous titanium oxide layer. The product thus obtained was exposed to an iodine atmosphere for 30 minutes to diffuse iodine in the polymer compound, and then a platinum-deposited glass plate was overlaid to obtain a photoelectrochemical cell B-1. Photoelectrochemical cells B-2 and B-3 were obtained by repeating the above steps except that the dye was changed as shown in Table 10.

5). Measurement of photoelectric conversion efficiency Simulated sun which does not contain ultraviolet rays by passing light of 500W xenon lamp (made by USHIO INC.) Through AM1.5 filter (made by Oriel) and sharp cut filter (Kenko L-42) It was light. The light intensity was 89 mW / cm ² .

  Alligator clips were connected to the conductive glass plate 10 and the platinum-deposited glass plate 40 of the above-described photoelectrochemical cell, and each alligator clip was connected to a current-voltage measuring device (Keutley SMU238 type). This was irradiated with simulated sunlight from the conductive glass plate 10 side, and the generated electricity was measured with a current-voltage measuring device. Table 12 summarizes the initial value (fresh) of the conversion efficiency (η) of the photoelectrochemical cell determined in this way and the rate of decrease in conversion efficiency during 300 hours of continuous irradiation.

(Remarks)
(1) Symbols of pigments are as described in the text.
(2) Nitrogen-containing polymer 1-1 represents the following compound.

(3) Electrolyte salt MHIm: 1-methyl-3-hexylimidazolium iodine salt MBIm: 1-butyl-3-methylimidazolium iodine salt (4) Solvent AN: acetonitrile.
PC: Propylene carbonate.
NMO: 3-methyl-2-oxazolidinone.
(5) Electrophile

  As is apparent from the results shown in Table 10, it was found that the dye of the present invention has high conversion efficiency and high durability even in this case.

DESCRIPTION OF SYMBOLS 1 Conductive support body 2 Photosensitive layer 21 Dye compound 22 Semiconductor fine particle 23 Electrolyte 3 Hole transport layer 4 Counter electrode 5 Photosensitive electrode 6 Circuit 10 Photoelectric conversion element

Claims (11)

A dye having a structure represented by the following general formula (1) in a molecule.

[In the general formula (1), A ¹ represents a nitrogen-containing heterocyclic six-membered ring or seven-membered ring formed by linking with the benzene ring. L ¹ represents an electron-transporting linking group containing at least one heterocyclic ring selected from a thiophene ring, a furan ring, a pyrrole ring, a selenophene ring, and a heterocyclic ring condensed with these. R ¹ and R ³ each independently represents a hydrogen atom or a substituent. R ² represents a hydrogen atom or a substituent. B ¹ represents a heterocyclic acidic nucleus or a methylene group substituted with an electron withdrawing group, and B ¹ has at least one acidic group. n1 represents an integer of 1 to 12. ] The dye represented by the general formula (1) is represented by the following general formula (2).

[In General Formula (2), X represents a nonmetallic atom group required in order to connect with a benzene ring and to form a 6-membered ring or a 7-membered nitrogen-containing heterocyclic ring. L ¹ , R ¹ , R ² , R ³ , B ¹ and n1 have the same meaning as in general formula (1). R ^{4 to} R ⁷ each independently represents a hydrogen atom or a substituent. n2 represents an integer of 1 or 2. ]   3. The dye according to claim 2, wherein in the general formula (2), X is a group of non-metallic atoms that form a seven-membered nitrogen-containing heterocycle by linking with a benzene ring. B ¹ is the following general formula (3) or general formula (4) with a dye according to any one of claims 1 to 3, characterized by being represented.

[In General Formula (3), R ⁷ and R ⁹ are each independently an aliphatic group, an aromatic group, or a heterocyclic group (at least one functional group may have an acidic group). m represents 0 or 1; The carbon-carbon double bond in general formula (3) may be either E-type or Z-type. R ⁸ in general formula (3) represents a sulfur atom or general formula (5), and the carbon-carbon double bond in general formula (5) may be either E-type or Z-type.
R ¹⁰ and R ¹¹ in the general formula (4) each independently represent a cyano group or an acidic group, and may be the same as or different from each other. The carbon-carbon double bond in the general formula (4) may be either E-type or Z-type.
R ¹² and R ¹³ in the general formula (5) each independently represent a cyano group or an acidic group, and may be the same as or different from each other. The carbon-carbon double bond in the general formula (5) may be any of E type and Z type. ] The pigment | dye represented by the said General formula (3) is represented by the following general formula (6), The pigment | dye of Claim 4 characterized by the above-mentioned.

[In General Formula (6), R ⁹ is an aliphatic group, an aromatic group or a heterocyclic group (may have an acidic group). ] The dye according to any one of claims 1 to 3, wherein the B ¹ is represented by the following general formula (7).

[In General Formula (7), R ⁷ is an aliphatic group, an aromatic group or a heterocyclic group (may have an acidic group). ] The dye according to any one of claims 1 to 3, wherein the B ¹ is represented by the following general formula (8).

  A photoelectric conversion element, wherein the light-receiving electrode contains semiconductor fine particles sensitized by the dye according to claim 1.   The photoelectric conversion element according to claim 8, further comprising an insulating porous body between the light receiving electrode and the counter electrode.   The photoelectric conversion element of Claim 8 or 9 which contains (gamma) -butyrolactone in electrolyte solution.   The photoelectrochemical cell using the photoelectric conversion element of any one of Claims 8-10.

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