JP2021150305A - Photoelectric conversion element, photoelectric conversion module, electronic device, and power supply module - Google Patents

Abstract

To provide a photoelectric conversion element and the like that can obtain a high output.SOLUTION: A photoelectric conversion element includes a first electrode, an electron-transporting layer, a photoelectric conversion layer, a hole-transporting layer, and a second electrode. The electron-transporting layer contains an electron-transporting material. The electron-transporting layer contains, on the electron-transporting material in a surface on the photoelectric conversion layer side, at least one of a phosphonic acid compound, a boronic acid compound, a sulfonic acid compound, a silyl halide compound and an alkoxysilyl compound. At least one of an organic salt and an inorganic salt is contained between the photoelectric conversion layer and the hole-transporting layer.SELECTED DRAWING: Figure 1

Description

The present invention relates to photoelectric conversion elements, photoelectric conversion modules, electronic devices, and power supply modules.

In recent years, solar cells using photoelectric conversion elements are expected to be widely applied not only from the viewpoint of replacing fossil fuels and measures against global warming, but also as self-supporting power sources that do not require battery replacement or power supply wiring. In addition, solar cells as a self-sustaining power source are attracting a great deal of attention as one of the energy harvesting technologies required for IoT (Internet of Things) devices and artificial satellites.

Examples of solar cells include organic solar cells such as dye-sensitized solar cells, organic thin-film solar cells, and perovskite solar cells, in addition to inorganic solar cells using silicon and the like, which have been widely used in the past. Since the perovskite solar cell can be manufactured by using a conventional printing means without using an electrolytic solution containing an organic solvent or the like, it is advantageous in terms of improving safety and suppressing manufacturing cost.

Further, with respect to an organic thin film solar cell and a perovskite solar cell, it is known that a plurality of spatially divided photoelectric conversion elements are electrically connected so as to form a series circuit to increase the output voltage. (See, for example, Patent Document 1).

An object of the present invention is to provide a photoelectric conversion element capable of obtaining a high output.

In order to achieve the above object, the following solutions are adopted in the present invention.
In a photoelectric conversion element having a first electrode, an electron transport layer, a photoelectric conversion layer, a hole transport layer, and a second electrode,
The electron transport layer contains an electron transport material and
The electron transporting layer contains at least one of a phosphonic acid compound, a boronic acid compound, a sulfonic acid compound, a halogenated silyl compound, and an alkoxysilyl compound on the electron transporting material on the surface of the photoelectric conversion layer side. death,
A photoelectric conversion element comprising at least one of an organic salt and an inorganic salt between the photoelectric conversion layer and the hole transport layer.

According to the present invention, it is possible to provide a photoelectric conversion element capable of obtaining a high output.

FIG. 1 is a schematic view of an example of a solar cell as an embodiment of a photoelectric conversion element. FIG. 2 is a block diagram of a mouse for a personal computer as an example of the electronic device of the present invention. FIG. 3 is a schematic external view showing an example of the mouse shown in FIG. FIG. 4 is a block diagram of a keyboard for a personal computer as an example of the electronic device of the present invention. FIG. 5 is a schematic external view showing an example of the keyboard shown in FIG. FIG. 6 is a schematic external view showing another example of the keyboard shown in FIG. FIG. 7 is a block diagram of a sensor as an example of the electronic device of the present invention. FIG. 8 is a block diagram of a turntable as an example of the electronic device of the present invention. FIG. 9 is a block diagram showing an example of the electronic device of the present invention. FIG. 10 is a block diagram showing an example in which a power supply IC is further incorporated in the electronic device shown in FIG. FIG. 11 is a block diagram showing an example in which a power storage device is further incorporated in the electronic device shown in FIG. FIG. 12 is a block diagram showing an example of the power supply module of the present invention. FIG. 13 is a block diagram showing an example in which a power storage device is further incorporated in the power supply module shown in FIG.

(Photoelectric conversion element)
The photoelectric conversion element means an element capable of converting light energy into electric energy or converting electric energy into light energy, and is applied to solar cells, photodiodes, and the like.
The photoelectric conversion element in the present invention has at least a first electrode, an electron transport layer, a photoelectric conversion layer, a hole transport layer, and a second electrode, and further has other members, if necessary. ..

<First electrode>
The shape and size of the first electrode are not particularly limited and may be appropriately selected depending on the intended purpose.

The structure of the first electrode is not particularly limited and may be appropriately selected depending on the intended purpose, and may be a one-layer structure or a structure in which a plurality of materials are laminated.

The material of the first electrode is not particularly limited as long as it has conductivity, and can be appropriately selected depending on the intended purpose. Examples thereof include transparent conductive metal oxide, carbon, and metal.

Examples of the transparent conductive metal oxide include indium tin oxide (hereinafter referred to as “ITO”), fluorine-doped tin oxide (hereinafter referred to as “FTO”), and antimony-doped tin oxide (hereinafter referred to as “ATO”). ), Niobdo-doped tin oxide (hereinafter referred to as "NTO"), aluminum-doped zinc oxide (hereinafter referred to as "AZO"), indium-zinc oxide, niob-titanium oxide and the like.
Examples of carbon include carbon black, carbon nanotubes, graphene, fullerenes and the like.
Examples of the metal include gold, silver, aluminum, nickel, indium, tantalum, titanium and the like.
These may be used alone or in combination of two or more. Among these, a transparent conductive metal oxide having high transparency is preferable, and ITO, FTO, ATO, NTO, and AZO are more preferable.

The average thickness of the first electrode is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 nm or more and 100 μm or less, and more preferably 50 nm or more and 10 μm or less. When the material of the first electrode is carbon or metal, the average thickness of the first electrode is preferably an average thickness that can obtain translucency.

The first electrode can be formed by a known method such as a sputtering method, a vapor deposition method, or a spray method.

Further, the first electrode is preferably formed on the substrate, and an integrated commercially available product in which the first electrode is formed on the substrate in advance can be used.
Examples of the integrated commercial product include FTO-coated glass, ITO-coated glass, zinc oxide: aluminum-coated glass, FTO-coated transparent plastic film, ITO-coated transparent plastic film, and the like. Other integrated commercial products include, for example, transparent electrodes in which tin oxide or indium oxide is doped with cations or anions having different valences, or metals having a structure such as a mesh or stripe that can transmit light. Examples thereof include a glass substrate provided with electrodes.
These may be used individually by 1 type, or may be mixed or laminated in combination of 2 or more types. Further, a metal lead wire or the like may be used in combination for the purpose of lowering the electrical resistance value.
Further, in order to appropriately process the electrodes in the integrated commercially available product to produce a photoelectric conversion module described later, a substrate on which a plurality of first electrodes are formed may be produced.

Examples of the material of the metal lead wire include aluminum, copper, silver, gold, platinum, nickel and the like.
The metal lead wire can be used in combination by forming the metal lead wire on the substrate by, for example, a vapor deposition method, a sputtering method, a crimping method, etc., and providing an ITO or FTO layer on the substrate, or by providing the metal lead wire on the ITO or FTO.

<Electron transport layer>
The electron transport layer means a layer that transports electrons generated in the photoelectric conversion layer described later to the first electrode. Therefore, the electron transport layer is preferably arranged adjacent to the first electrode.

The shape and size of the electron transport layer are not particularly limited, and can be appropriately selected depending on the intended purpose.

Further, the structure of the electron transport layer may be a single layer or a multilayer in which a plurality of layers are laminated.

The electron transport layer contains an electron transport material.
The electron transport material is not particularly limited and may be appropriately selected depending on the intended purpose, but a semiconductor material is preferable.

The semiconductor material is not particularly limited, and known materials can be used. Examples thereof include a simple substance semiconductor and a compound having a compound semiconductor.
Examples of the elemental semiconductor include silicon and germanium.
Examples of the compound semiconductor include metallic chalcogenide.
Examples of metal chalcogenides include metal oxides (oxide semiconductors), metal sulfides, metal seleniums, and metal tellurides.
Examples of metal oxides (oxide semiconductors) include oxides such as titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, and tantalum.
Examples of metal sulfides include sulfides such as cadmium, zinc, lead, silver, antimony, and bismuth.
Examples of metal selenium products include selenium products such as cadmium and lead.
Examples of tellurides of metals include tellurides such as cadmium.
Examples of other compound semiconductors include phosphides such as zinc, gallium, indium and cadmium, gallium arsenic, copper-indium-selenium and copper-indium-sulfide.
Among these, metal oxides (oxide semiconductors) are preferable, and it is more preferable to contain at least one of titanium oxide, zinc oxide, tin oxide, and niobide oxide, and it is particularly preferable to contain tin oxide.
These may be used alone or in combination of two or more. The crystal type of the semiconductor material is not particularly limited and may be appropriately selected depending on the intended purpose, and may be single crystal, polycrystalline, or amorphous.

The electron transport layer contains at least one compound of a phosphonic acid compound, a boronic acid compound, a sulfonic acid compound, a halogenated silyl compound, and an alkoxysilyl compound on the electron transport material on the surface on the photoelectric conversion layer side. do. The electron transport layer can be expected to control the physical characteristics of the interface by containing these compounds on the electron transport material on the surface of the photoelectric conversion layer side. In other words, by coating the electron transport material on the surface of the electron transport layer on the photoelectric conversion layer side with these compounds, it can be expected that the interfacial resistance is reduced and the electron transfer is smooth.
These compounds may be bound to the electron transport material. Examples of the bond include a covalent bond and an ionic bond.

The compound is at least one of a phosphonic acid compound, a boronic acid compound, a sulfonic acid compound, a halogenated silyl compound, and an alkoxysilyl compound.
The compound preferably has a nitrogen atom from the viewpoint of compatibility with the perovskite layer.

The phosphon compound is not particularly limited as long as it is a compound containing a phosphonic acid group, and can be appropriately selected depending on the intended purpose. Specific examples will be described later.

The boronic acid compound is not particularly limited as long as it is a compound containing a boronic acid group, and can be appropriately selected depending on the intended purpose. Specific examples will be described later.

The sulfonic acid compound is not particularly limited as long as it is a compound containing a sulfonic acid group, and can be appropriately selected depending on the intended purpose. Specific examples will be described later.

The silyl halide compound is not particularly limited as long as it is a compound containing a silyl halide group, and can be appropriately selected depending on the intended purpose. Specific examples will be described later.

The alkoxysilyl compound is not particularly limited as long as it is a compound containing an alkoxysilyl group, and can be appropriately selected depending on the intended purpose. Specific examples will be described later.

The molecular weight of the compound is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include 100 or more and 500 or less.

前記一般式（１）において、Ｒ_１、及びＲ_２は、水素原子、アルキル基、アリール基、又はヘテロ環を表し、同一であっても異なっていてもよい。Ｒ_３は、アルキレン基、アリーレン基、又は２価のヘテロ環を表し、Ｒ_４は、ホスホン酸基、ボロン酸基、スルホン酸基、ハロゲン化シリル基、又はアルコキシシリル基を表す。Ｒ_１又はＲ_２と、Ｒ_３と、Ｎとは、一緒になって環構造を形成していてもよい。 The compound is represented by, for example, the following general formula (1).

In the general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group, an aryl group, or a heterocycle, and may be the same or different. R ₃ represents an alkylene group, an arylene group, or a divalent heterocycle, and R ₄ represents a phosphonic acid group, a boronic acid group, a sulfonic acid group, a silyl halide group, or an alkoxysilyl group. R ₁ or R ₂ , R ₃ and N may be combined to form a ring structure.

Examples of the compound include the following compounds.

The average thickness of the electron transport layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 5 nm or more and 1 μm or less, and more preferably 10 nm or more and 700 nm or less.

The surface of the electron transport layer on the photoelectric conversion layer side is preferably as smooth as possible. The smaller the roughness factor is preferable as one index indicating smoothness, but the roughness factor on the photoelectric conversion layer side of the electron transport layer is preferably 20 or less, and more preferably 10 or less in relation to the average thickness of the electron transport layer. .. The lower limit of the roughness factor is not particularly limited and may be appropriately selected depending on the intended purpose, and examples thereof include 1 and more.
The roughness factor is the ratio of the actual surface area to the apparent surface area, and is also called Wenzel's roughness factor. The actual surface area can be obtained by measuring, for example, the BET specific surface area, and the roughness factor can be obtained by dividing the value by the apparent surface area.

The method for producing the thin film of the electron transport material in the electron transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method of forming a thin film of the electron transport material in vacuum (vacuum film formation). Method), wet film forming method and the like.
Examples of the vacuum film forming method include a sputtering method, a pulse laser deposition method (PLD method), an ion beam sputtering method, an ion assist method, an ion plating method, a vacuum deposition method, an atomic layer deposition method (ALD method), and the like. Examples include a chemical vapor deposition method (CVD method).
Examples of the wet film forming method include a sol-gel method. The sol-gel method is a method in which a gel is prepared from a solution through a chemical reaction such as hydrolysis, polymerization, or condensation, and then heat treatment is performed to promote densification. When the sol-gel method is used, the method for applying the sol solution is not particularly limited and can be appropriately selected depending on the intended purpose. For example, a dip method, a spray method, a wire bar method, a spin coating method, or a roller coating method can be used. The method, the blade coating method, the gravure coating method, and the wet printing method include a letterpress, offset, gravure, intaglio, rubber plate, screen printing, and the like. The temperature during the heat treatment after applying the sol solution is preferably 80 ° C. or higher, more preferably 100 ° C. or higher.

The method for imparting the compound onto the electron transport material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, after applying the solution containing the compound on the thin film of the electron transport material. Examples include a method of drying.
The coating method is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a dip method, a spray method, a wire bar method, a spin coating method, a roller coating method, a blade coating method, a gravure coating method and the like can be used. Can be mentioned.
The temperature during the drying treatment after the solution is applied is preferably 40 ° C. or higher, more preferably 50 ° C. or higher.

<Photoelectric conversion layer>
The photoelectric conversion layer is not particularly limited as long as it is a layer that performs photoelectric conversion, and can be appropriately selected depending on the intended purpose. Examples thereof include a perovskite layer and a bulk heterojunction layer.

<< Perovskite layer >>
The perovskite layer means a layer containing a perovskite compound and absorbing light to sensitize an electron transport layer. Therefore, the perovskite layer is preferably arranged adjacent to the electron transport layer.

The shape and size of the perovskite layer are not particularly limited and may be appropriately selected depending on the intended purpose.

The perovskite compound is a composite substance of an organic compound and an inorganic compound, and is represented by the following general formula (2).
X _α Y _β M _γ・ ・ ・ General formula (2)
In the above general formula (2), the ratio of α: β: γ is 3: 1: 1, and β and γ represent integers larger than 1. Further, for example, X can be a halogen ion, Y can be an ion of an organic compound having an amino group, M can be a metal ion, or the like.

The X in the general formula (2) is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include halogen ions such as chlorine, bromine and iodine. These may be used alone or in combination of two or more.

As Y in the above general formula (2), if it is an organic cation, it is an alkylamine compound ion such as methylamine, ethylamine, n-butylamine, formamidine, and if it is an inorganic alkali metal cation, it is cesium, potassium, rubidium or the like. Can be mentioned. These may be used individually by 1 type, may be used in combination of 2 or more type, and may be used in combination of an inorganic alkali metal cation and an organic cation, respectively. In the case of a perovskite compound of lead-methylammonium halide, when the halogen ion is Cl, the peak λmax of the light absorption spectrum is about 350 nm, when it is Br, it is about 410 nm, and when it is I, it is about 540 nm. Since it shifts to the side, the available spectral width (band range) is different.

The M in the general formula (2) is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include metal ions such as lead, indium, antimony, tin, copper and bismuth. These may be used alone or in combination of two or more.

Further, the perovskite layer preferably shows a layered perovskite structure in which a layer made of a metal halide and a layer in which organic cation molecules are arranged are alternately laminated.

The method for forming the perovskite layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a solution in which a metal halide and an alkylamine halide or cesium halide are dissolved or dispersed is applied. There is a method of drying after the process.
As a method for forming the perovskite layer, for example, a solution in which a metal halide is dissolved or dispersed is applied, dried, and then immersed in a solution in which an alkylamine halide is dissolved to form a perovskite compound. Examples include a stepwise precipitation method.
Further, as a method for forming the perovskite layer, for example, while applying a solution in which a metal halide and an alkylamine halide are dissolved or dispersed, a poor solvent (solvent having low solubility) for the perovskite compound is added to precipitate crystals. There is a method of making it. In addition, as a method for forming the perovskite layer, for example, a method of depositing a metal halide in a gas filled with methylamine or the like can be mentioned.
Among these, a method of precipitating crystals by adding a poor solvent for the perovskite compound while applying a solution in which a metal halide and an alkylamine halide are dissolved or dispersed is preferable.

The method for applying the solution is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a dipping method, a spin coating method, a spray method, a dip method, a roller method and an air knife method. Further, as a method of applying the solution, for example, a method of precipitating in a supercritical fluid using carbon dioxide or the like may be used.

The perovskite layer may also contain a sensitizing dye.
The method for forming the perovskite layer containing the sensitizing dye is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method of mixing the perovskite compound and the sensitizing dye, or after forming the perovskite layer. Then, a method of adsorbing the sensitizing dye and the like can be mentioned.

The sensitizing dye is not particularly limited as long as it is a compound photoexcited by the excitation light used, and can be appropriately selected depending on the intended purpose.
Examples of the sensitizing dye include a metal complex compound, a coumarin compound, a polyene compound, an indolin compound, a thiophene compound, a cyanine dye, a merocyanine dye, a 9-arylxanthene compound, a triarylmethane compound, a phthalocyanine compound, and a porphyrin compound. ..
Examples of the metal complex compound include JP-A-7-500630, JP-A-10-233238, JP-A-2000-26487, JP-A-2000-323191, JP-A-2001-59062 and the like. Examples thereof include the described metal complex compounds.
Examples of the coumarin compound include JP-A-10-93118, JP-A-2002-164809, JP-A-2004-954450, J. Am. Phys. Chem. C, 7224, Vol. Examples thereof include the coumarin compound described in 111 (2007) and the like.
Examples of the polyene compound include JP-A-2004-95450, Chem. Commun. , 4887 (2007) and the like.
Examples of the indoline compound include JP-A-2003-264010, JP-A-2004-63274, JP-A-2004-115636, JP-A-2004-200068, JP-A-2004-235502, J. Mol. Am. Chem. Soc. , 12218, Vol. 126 (2004), Chem. Commun. , 3036 (2003), Angew. Chem. Int. Ed. , 1923, Vol. Examples thereof include the indoline compound described in 47 (2008) and the like.
Examples of the thiophene compound include J. cerevisiae. Am. Chem. Soc. , 16701, Vol. 128 (2006), J. Mol. Am. Chem. Soc. , 14256, Vol. Examples thereof include the thiophene compound described in 128 (2006) and the like.
Examples of the cyanine dye are described in JP-A-11-86916, JP-A-11-214730, JP-A-2000-106224, JP-A-2001-76773, JP-A-2003-7359, and the like. Cyanine pigment and the like can be mentioned.
Examples of the merocyanine dye are described in JP-A-11-214731, JP-A-11-238905, JP-A-2001-52766, JP-A-2001-76775, JP-A-2003-7360 and the like. Examples include merocyanine pigments.
Examples of the 9-arylxanthene compound include the 9-arylxanthene compounds described in JP-A-10-92477, JP-A-11-273754, JP-A-11-273755, JP-A-2003-31273, and the like. And so on.
Examples of the triarylmethane compound include the triarylmethane compounds described in JP-A-10-93118, JP-A-2003-31273, and the like.
Examples of the phthalocyanine compound and the porphyrin compound include JP-A-9-199744, JP-A-10-233238, JP-A-11-204821, JP-A-11-265738, J. Am. Phys. Chem. , 2342, Vol. 91 (1987), J. Mol. Phys. Chem. B, 6272, Vol. 97 (1993), Electrical. Chem. , 31, Vol. 537 (2002), JP-A-2006-032260, J. Mol. Porphyrins Phthalocyanines, 230, Vol. 3 (1999), Angew. Chem. Int. Ed. , 373, Vol. 46 (2007), Langmuir, 5436, Vol. Examples thereof include the phthalocyanine compound and the porphyrin compound described in 24 (2008) and the like.
Among these, metal complex compounds, indoline compounds, thiophene compounds, and porphyrin compounds are preferable.

<< Bulk Heterojunction Layer >>
The bulk heterojunction layer contains an electron donating organic material and an electron attracting organic material.
In the bulk heterojunction layer, an electron donating organic material (P-type organic semiconductor) and an electron attracting organic material (N-type organic semiconductor) are mixed to produce a bulk heterojunction which is a nano-sized PN junction. By doing so, a current can be obtained by utilizing the photocharge separation that occurs at the junction surface.

<<< Electron-donating organic material (P-type organic semiconductor) >>>
Examples of the P-type organic semiconductor include polythiophene or a derivative thereof, an arylamine derivative, a stilben derivative, oligothiophene or a derivative thereof, a phthalocyanine derivative, porphyrin or a derivative thereof, polyphenylene vinylene or a derivative thereof, polythienylene vinylene or a derivative thereof, and the like. Examples thereof include conjugated polymers such as benzodithiophene derivatives and diketopyrrolopyrrole derivatives and low molecular weight compounds. These may be used alone or in combination of two or more.

Among these, polythiophene, which is a conductive polymer having π-conjugation, or a derivative thereof is preferable. The polythiophene and its derivative are advantageous in that excellent stereoregularity can be ensured and the solubility in a solvent is relatively high.

The polythiophene and its derivative are not particularly limited as long as they are compounds having a thiophene skeleton, and can be appropriately selected depending on the intended purpose. For example, polyalkylthionaphthenes such as polyalkylthiophene typified by poly-3-hexylthiophene, poly-3-hexylisothionaphthene, poly-3-octylisothionaphthene, and poly-3-decylisothionaphthene; Examples include polyethylene dioxythiophene.

In recent years, PTB7 (poly ({4,8-bis [(2-ethylhexyl) oxy] benzo [1,2-b: 4,] which is a copolymer composed of benzodithiophene, carbazole, benzothiadiazole and thiophene) 5-b'] dithiophene-2,6-diyl} {3-fluoro-2-[(2-ethylhexyl) carbonyl] thieno [3,4-b] thiophenezyl})), PCDTBT (poly [N-9'') Derivatives such as -heptadecanyl-2,7-carbazole-alto-5,5- (4', 7'-di-2-thienyl-2', 1', 3'-benzothiadiazole)]) are excellent photoelectrics. It is mentioned as a compound which can obtain conversion efficiency.

Further, not only a conjugate polymer but also a small molecule compound in which an electron donating unit and an electron attracting unit are bonded is known to have excellent photoelectric conversion efficiency, and can be used in the present invention (also used in the present invention). See, for example, ACSApl. Polymer. Interfaces 2014, 6, 803-810).
Among the small molecule compounds as the electron-donating organic material, the compound represented by the following general formula (A) is preferable.

However, in the general formula (A), n represents an integer of 1 to 3.
R ₁ represents any of an n-butyl group, an n-hexyl group, an n-octyl group, an n-decyl group, and an n-dodecyl group.
R ₂ represents an oxygen atom having an alkyl group having 6 to 22 carbon atoms, a sulfur atom with an alkyl group having 6 to 22 carbon atoms, carbon atoms having an alkyl group having 6 to 22 carbon atoms, or the following general formula (B) Represents a group represented by. Among them, an oxygen atom having an alkyl group having 6 to 20 carbon atoms, a sulfur atom having an alkyl group having 6 to 20 carbon atoms, a carbon atom having an alkyl group having 6 to 20 carbon atoms, or a table represented by the following general formula (B). Is preferred.

However, in the general formula (B), R ₃ and R ₄ represent a hydrogen atom or an alkyl group having 6 to 12 carbon atoms.
R ₅ represents a branched alkyl group having 6 to 22 carbon atoms. Of these, an alkyl group having 6 to 12 carbon atoms which may be branched is preferable.

More specifically, as the small molecule compound as the electron-donating organic material, a compound represented by the following general formula (C) is preferable.

However, in the general formula (C), R ₃ and R ₄ represent a hydrogen atom or an alkyl group having 6 to 12 carbon atoms, and are preferably a hydrogen atom or an alkyl group having 6 to 10 carbon atoms.
R ₅ represents a branched alkyl group having 6 to 22 carbon atoms, and is preferably a branched alkyl group having 6 to 12 carbon atoms.

Here, specific examples of the compound represented by the general formula (C) are shown below, but the present invention is not limited thereto.

<<< Electron-Attractive Organic Material (N-Type Organic Semiconductor) >>>
Examples of the electron-attracting organic material include an imide derivative, a fullerene, and a fullerene derivative. Among these, fullerene derivatives are preferable from the viewpoint of charge separation and charge transport.

As the fullerene derivative, an appropriately synthesized derivative may be used, or a commercially available product may be used. For example, PC71BM (phenyl C71 butyrate methyl ester, manufactured by Frontier Carbon Co., Ltd.), PC61BM (phenyl C61 butyrate methyl ester) may be used. , Frontier Carbon Co., Ltd.), PC85BM (Phenyl C85 Methyl Butyrate, Frontier Carbon Co., Ltd.), ICBA (Fullerene Inden 2 Derivative, Frontier Carbon Co., Ltd.) and the like. In addition, a furaropyrrolidine-based fullerene derivative represented by the following general formula (D) can be mentioned.

However, in the general formula (D), Y ₁ and Y ₂ may be the same or different, and may have a hydrogen atom, an alkyl group which may have a substituent, and an alkenyl which may have a substituent. It represents any of a group, an alkynyl group which may have a substituent, an aryl group which may have a substituent, and an aralkyl group which may have a substituent.
It should _{be noted that Y 1} and Y ₂ are not hydrogen atoms at the same time.

Ar represents an aryl group which may have a substituent.
Specific examples of the aryl group include a phenyl group, a naphthyl group, an anthralyl group, a phenanthryl group and the like. Among these, a phenyl group is preferable.

As the substituent of the aryl group having a substituent represented by Ar, it is preferable to remove an oxygen atom. Examples of the substituent include an aryl group, an alkyl group, a cyano group, an alkoxy group, an alkoxycarbonyl group and the like.
Among these substituents, examples of the aryl group include a phenyl group and the like.
Examples of the alkyl group portion of the alkyl group and the alkoxy group include an alkyl group having 1 to 22 carbon atoms, as in the case of the alkyl group represented _{by Y 1} and Y _{2 described later.}
The number of these substituents and the substitution position are not particularly limited, but for example, 1 to 3 substituents can be present at any position of the aryl group represented by Ar.

Among the groups represented by Y ₁ and Y ₂ , the alkyl group is preferably an alkyl group having 1 to 22 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, and an alkyl group having 6 to 12 carbon atoms. Is particularly preferable. These alkyl groups may be linear or branched, but are particularly preferably linear.
The alkyl group may further contain one or two or more different elements such as S and O in the carbon chain.

Among the groups represented by Y ₁ and Y ₂ , the alkenyl group is preferably an alkenyl group having 2 to 10 carbon atoms, and particularly preferable specific examples are a vinyl group, a 1-propenyl group, an allyl group and an isopropenyl. A linear or branched alkenyl group having 2 to 4 carbon atoms such as a group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-methyl-2-propenyl group, a 1,3-butadienyl group, etc. Can be mentioned.

Among the groups represented by Y ₁ and Y ₂ , the alkynyl group preferably has an alkynyl group having 1 to 10 carbon atoms, and as particularly preferable specific examples, an ethynyl group, a 1-propynyl group, a 2-propynyl group, 1 Examples thereof include a linear or branched alkynyl group having 2 to 4 carbon atoms such as a methyl-2-propynyl group, a 1-butynyl group, a 2-butynyl group and a 3-butynyl group.

Among the groups represented by Y ₁ and Y ₂ , examples of the aryl group include a phenyl group, a naphthyl group, an anthralyl group, and a phenanthryl group.

Among the groups represented by Y ₁ and Y ₂ , the aralkyl group includes an aralkyl group having 7 to 20 carbon atoms such as 2-phenylethyl, benzyl, 1-phenylethyl, 3-phenylpropyl and 4-phenylbutyl. And so on.

As described above, the alkyl group, alkenyl group, alkynyl group, aryl group, and aralkyl group of the groups represented by _{Y 1} and Y _{2 include the case where they have a substituent and the case where they do not have a substituent.}
Examples of the substituent that the group represented by Y ₁ and Y ₂ can have include an alkyl group, an alkoxycarbonyl group, a polyether group, an alkanoyl group, an amino group, an aminocarbonyl group, an alkoxy group, an alkylthio group and a group. -CONHCOR'(where R'is an alkyl group in the formula), group: -C (= NR')-R "(where R'and R" are alkyl groups in the formula), group: -NR'= CR "R'" (where R', R "and R'" are alkyl groups in the formula) and the like.

Among these substituents, examples of the polyether group include _{a group represented by the formula: Y 3-} (OY ₄ ) n-O-. Here, Y ₃ represents a monovalent hydrocarbon group such as an alkyl group, and Y ₄ represents a divalent aliphatic hydrocarbon group.
In the polyether group represented by the above formula, specific examples of the repeating unit represented by _{− (OY 4} ) _{n − are − (OCH 2} ) _n −, − (OC ₂ H ₄ ) _n −, − ( OC ₃ H ₆ ) _{Alkoxy chains such as n} − and the like can be mentioned. The number of repetitions n of these repeating units is preferably 1 to 20, more preferably 1 to 5. The repeating unit represented by − (OY ₄ ) _n − may include not only the same repeating unit but also two or more different repeating units. Of the repeating units described above, _-OC 2 _{H 4} - and _-OC 3 _{H 6} - For, may be either straight-chain and branched-chain.

Further, among the above-mentioned substituents, an alkyl group, an alkoxycarbonyl group, an alkanoyl group, an alkoxy group, an alkylthio group, a polyether group, a group: -CONHCOR', a group: -C (= NR')-R ", and Group: The alkyl group moiety (R', R ") in -NR'= CR" R'" is preferably an alkyl group having 1 to 22 carbon atoms, and an alkyl having 1 to 12 carbon atoms, similar to the above-mentioned alkyl group. A group is more preferable, and an alkyl group having 6 to 12 carbon atoms is particularly preferable.

As the amino group portion of the amino group and the aminocarbonyl group, an amino group in which one or two or more alkyl groups having 1 to 20 carbon atoms are bonded is particularly preferable.

Among the fullerene derivatives represented by the general formula (D), as an example of a compound having suitable performance, Ar is a phenyl group having a substituent or no substituent, and Y ₁ One of and Y ₂ is a hydrogen atom, and the other is an alkyl group having an alkoxycarbonyl group as a substituent, an alkyl group having an alkoxy group as a substituent, an alkyl group having a polyether group as a substituent, and a substituent. Examples thereof include a compound having an alkyl group having an amino group, or a compound having a substituent or a phenyl group having no substituent.

Among such compounds, as an example of a compound having particularly excellent performance, Ar has a phenyl group, a cyano group, an alkoxy group, an alcoholiccarbonyl group, or an alkyl group as a substituent, or has a substituent. Not a phenyl group, _one of Y 1 and Y ₂ is a hydrogen atom, the other is an alkyl group having an alkoxycarbonyl group as a substituent, an alkyl group having an alkoxy group as a substituent, and a poly as a substituent. Examples thereof include an alkyl group having an ether group, a phenyl group, a phenyl group having an alkyl group as a substituent, a phenyl group having an alkoxycarbonyl group as a substituent, and a compound having a phenyl group having an alkoxy group as a substituent.

These compounds contain groups having appropriate polarity on the pyrrolidine skeleton and have good self-assembling properties, so that they have an appropriate layer separation structure when forming a photoelectric conversion layer having a bulk heterojunction structure. It is possible to form a photoelectric conversion part having a bulk heterojunction structure having the above. As a result, it is considered that the electron mobility and the like are improved and high conversion efficiency is exhibited.

As the most preferable compound, Ar is a phenyl group, _{either Y 1} or Y ₂ is a hydrogen atom, the other is an unsubstituted alkyl group (alkyl group having 4 to 6 carbon atoms), and an unsubstituted phenyl. A compound that is a group, a 1-naphthyl group, or a 2-naphthyl group.

The method for forming the bulk heterojunction layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, spin coating coating, blade coating coating, slit die coating coating, screen printing coating, bar coater coating, and mold coating , Print transfer method, immersion pulling method, inkjet method, spray method, vacuum deposition method and the like. From these, it can be appropriately selected according to the characteristics of the organic material thin film to be produced, such as thickness control and orientation control.

For example, when the spin coating is applied, the concentrations of the P-type organic semiconductor and the N-type organic semiconductor are preferably 5 mg / mL or more and 40 mg / mL or less. By setting this concentration, a homogeneous organic material thin film can be easily produced.

In order to remove the organic solvent from the produced organic material thin film, the annealing treatment may be performed under reduced pressure or under an inert atmosphere (under a nitrogen or argon atmosphere). The temperature of the annealing treatment is preferably 40 ° C. or higher and 300 ° C. or lower, and more preferably 50 ° C. or higher and 200 ° C. or lower. Further, by performing the annealing treatment, the effective area in which the laminated layers permeate and contact each other at the interface is increased, and the short-circuit current can be increased. The annealing treatment may be performed after the electrodes are formed.

The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, methanol, ethanol, butanol, toluene, xylene, o-chlorophenol, acetone, ethyl acetate, ethylene glycol, tetrahydrofuran, dichloromethane, chloroform, dichloroethane, chlorobenzene, dichlorobenzene, trichlorobenzene, chloronaphthalene, dimethylformamide, dimethyl sulfoxide, Examples thereof include N-methylpyrrolidone and γ-butyrolactone. These may be used alone or in combination of two or more. Among these, chlorobenzene, chloroform and orthodichlorobenzene are preferable.

Further, in order to control the phase separation structure of the P-type organic semiconductor and the N-type organic semiconductor, an additive of 0.1% by mass or more and 10% by mass or less may be added to the organic solvent. Examples of the additive include diiodoalkane (1,8-diiodooctane, 1,6-diiodohexane, 1,10-diiododecane, etc.) and alkanedithiol (1,8-octanedithiol, 1,6--. Hexanedithiol, 1,10-decandithiol, etc.), 1-chloronaphthalene, polydimethylsiloxane derivative and the like.

The average thickness of the photoelectric conversion layer is preferably 50 nm or more and 400 nm or less, and more preferably 60 nm or more and 250 nm or less. When the average thickness is 50 nm or more, the light absorption by the photoelectric conversion layer is small and the carrier generation is not insufficient, and when the average thickness is 400 nm or less, the transport efficiency of the carriers generated by the light absorption is further lowered. There is no such thing.

<Organic salt, inorganic salt>
The photoelectric conversion element contains at least one salt of an organic salt and an inorganic salt between the photoelectric conversion layer and the hole transport layer.
It can be expected that the photoelectric conversion element contains the salt between the photoelectric conversion layer and the hole transport layer to control the physical characteristics of the interface.
When the photoelectric conversion layer is a perovskite layer, the salt is preferably a salt different from the salt constituting the perovskite layer.

The salt is not particularly limited and may be appropriately selected depending on the intended purpose. However, when a perovskite compound is used in the photoelectric conversion layer, the cation may have a halogen atom in terms of compatibility. preferable. Examples of the halogen atom include chlorine, iodine and bromine.

The organic salt is preferably an amine hydrohalide from the viewpoint of compatibility, especially when a perovskite compound is used in the photoelectric conversion layer.
The inorganic salt is preferably a halide of an alkali metal from the viewpoint of compatibility, especially when a perovskite compound is used in the photoelectric conversion layer. Examples of the alkali metal include lithium, sodium, potassium, rubidium, cesium and the like.

Examples of the amine halide hydride include n-butylamine hydrobromide, n-butylamine iodide, n-hexylamine hydrobromide, and n-hexylamine iodide. , N-decylamine hydrobromide, n-octadecylamine hydroiodide, pyridine hydrobromide, aniline hydroiodide, hydrazinedi hydrobromide, ethylenediamine diiohydrate, 2- Phenylethylamine hydroiodide, phenylenediamine dihydrochloride, diphenylamine hydrobromide, diphenylamine hydroiodide, benzylamine iodide, 4-diphenylaminophenethylamine hydroiodide, etc. Can be mentioned.
Examples of the alkali metal halide include cesium iodide, cesium bromide, rubidium iodide, potassium iodide and the like.

The method of arranging at least one of an organic salt and an inorganic salt between the photoelectric conversion layer and the hole transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, photoelectric conversion Examples thereof include a method in which a solution containing the salt is applied onto the layer, dried, and then a hole transport layer is formed on the layer. Examples of the solution include an aqueous solution and an alcohol solution.
The coating method is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a dip method, a spray method, a wire bar method, a spin coating method, a roller coating method, a blade coating method, a gravure coating method and the like can be used. Can be mentioned.
The temperature at the time of the drying treatment after applying the solution is not particularly limited and can be appropriately selected depending on the intended purpose.

Further, the organic salt and the inorganic salt do not need to be uniformly distributed at the interface between the perovskite layer and the hole transport layer, and may be locally present in a plurality of regions (island-like or the like). Further, it may be distributed in the perovskite layer or the hole transport layer by reacting with the perovskite compound of the perovskite layer and the hole transport material of the hole transport layer. That is, it is sufficient that there is a region in which the organic salt and the inorganic salt are present between the perovskite layer in which the organic salt and the inorganic salt are not present and the whole transport layer in which the organic salt and the inorganic salt are not present.

<Hall transport layer>
The hole transport layer means a layer that transports holes (holes) generated in the photoelectric conversion layer to a second electrode described later. Therefore, it is preferable that the hole transport layer is arranged adjacent to the photoelectric conversion layer via the salt.

The hole transport layer includes, for example, a solid hole transport material and optionally other materials.
The solid hole-transporting material (hereinafter, may be simply referred to as “hole-transporting material”) is not particularly limited as long as it has the property of transporting holes, and may be appropriately selected according to the purpose. However, it is preferable to contain an organic compound.

When an organic compound is used as the hole transporting material, the hole transport layer contains, for example, a plurality of types of compounds.

Examples of the organic compound include polymer materials.
The polymer material used for the hole transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a polythiophene compound, a polyphenylene vinylene compound, a polyfluorene compound, a polyphenylene compound, a polyarylamine compound, and a polythiadiazole can be selected. Examples include compounds.
Examples of the polythiophene compound include poly (3-n-hexylthiophene), poly (3-n-octyloxythiophene), poly (9,9'-dioctyl-fluorene-co-bithiophene), and poly (3,3'. ''-Gidodecyl-quarterthiophene), poly (3,6-dioctylthiophene [3,2-b] thiophene), poly (2,5-bis (3-decylthiophen-2-yl) thieno [3,2- b] Thiophene), poly (3,4-didecylthiophene-cothieno [3,2-b] thiophene), poly (3,6-dioctylthiophene [3,2-b] thiophene-cothieno [3] , 2-b] thiophene), poly (3,6-dioctylthiophene [3,2-b] thiophene-co-thiophene) or poly (3,6-dioctylthiophene [3,2-b] thiophene-co-bithiophene) ) Etc. can be mentioned.
Examples of the polyphenylene vinylene compound include poly [2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene vinylene] and poly [2-methoxy-5- (3,7-dimethyloctyloxy) -1. , 4-Phenylene vinylene] or poly [(2-methoxy-5- (2-ethylphenyloxy) -1,4-phenylene vinylene) -co- (4,4'-biphenylene-vinylene)] and the like. ..
Examples of the polyfluorene compound include poly (9,9'-zidodecylfluorenyl-2,7-diyl) and poly [(9,9-dioctyl-2,7-dibiphenylene fluorene) -alt-co-. (9,10-anthracene)], poly [(9,9-dioctyl-2,7-divinylenefluorene) -alt-co- (4,4'-biphenylene)], poly [(9,9-dioctyl-) 2,7-Divinylenefluorene) -alt-co- (2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene)] or poly [(9,9-dioctyl-2,7-diyl) -Co- (1,4- (2,5-dihexyloxy) benzene)] and the like can be mentioned.
Examples of the polyphenylene compound include poly [2,5-dioctyloxy-1,4-phenylene] and poly [2,5-di (2-ethylhexyloxy-1,4-phenylene]].
Examples of the polyarylamine compound include poly [(9,9-dioctylfluorenyl-2,7-diyl) -alt-co- (N, N'-diphenyl) -N, N'-di (p-). Hexylphenyl) -1,4-diaminobenzene], poly [(9,9-dioctylfluorenyl-2,7-diyl) -alt-co- (N, N'-bis (4-octyloxyphenyl) benzidine) -N, N'-(1,4-diphenylene)], poly [(N, N'-bis (4-octyloxyphenyl) benzidine-N, N'-(1,4-diphenylene)], poly [( N, N'-bis (4- (2-ethylhexyloxy) phenyl) benzidine-N, N'-(1,4-diphenylene)], poly [phenylimino-1,4-phenylene vinylene-2,5-dioctyl Oxy-1,4-phenylene vinylene-1,4-phenylene], poly [p-triluimino-1,4-phenylene vinylene-2,5-di (2-ethylhexyloxy) -1,4-phenylene vinylene-1, 4-Phenylene], poly [4- (2-ethylhexyloxy) phenylimino-1,4-biphenylene] and the like can be mentioned.
Examples of the polythiadiazole compound include poly [(9,9-dioctylfluorenyl-2,7-diyl) -alt-co- (1,4-benzo (2,1', 3) thiadiazole]] and poly ( Examples thereof include 3,4-didecylthiophene-co- (1,4-benzo (2,1', 3) thiadiazole).
Among these, a polythiophene compound and a polyarylamine compound are preferable in consideration of carrier mobility and ionization potential, and further, a polymer compound having a repeating structure represented by the following general formula (3) is preferably used.

_{Ar 1} in the above general formula (3) represents an aryl group. Examples of the aryl group include a phenyl group, a 1-naphthyl group, a 9-anthrasenyl group and the like. The aryl group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, an aryl group and the like. Ar ₂ , Ar ₃ and Ar ₄ independently represent an arylene group, a divalent heterocyclic group and the like. Examples of the arylene group include 1,4-phenylene, 1,1'-biphenylene, 9,9'-di-n-hexylfluorene and the like. Examples of the divalent heterocyclic group include 2,5-thiophene and the like. Independently, R _{1 to} R ₄ include a hydrogen atom, an alkyl group, an aryl group and the like. Examples of the alkyl group include a methyl group and an ethyl group. Examples of the aryl group include a phenyl group and a 2-naphthyl group. The alkyl group and the aryl group may have a substituent.

Specific examples of the polymer compound having a repeating structure represented by the general formula (3) include, but are not limited to, the following (B-01) to (B-20). ..

The hole transport layer may contain not only the above polymer compound but also a small molecule compound alone or a mixture of a small molecule and a polymer.
The chemical structure of the low molecular weight hole transporting material is not particularly limited, and for example, an oxadiazole compound, a triphenylmethane compound, a pyrazoline compound, a hydrazone compound, a tetraarylbenzidine compound, a stillben compound, a spirobifluorene compound, a thiophene oligomer, etc. Can be mentioned.
Examples of the oxadiazole compound include oxadiazole compounds shown in Japanese Patent Publication No. 34-5466, Japanese Patent Application Laid-Open No. 56-123544 and the like.
Examples of the triphenylmethane compound include the triphenylmethane compound shown in Japanese Patent Publication No. 45-555.
Examples of the pyrazoline compound include pyrazoline compounds shown in Japanese Patent Publication No. 52-4188 and the like.
Examples of the hydrazone compound include hydrazone compounds shown in Japanese Patent Publication No. 55-42380.
Examples of the tetraarylbenzidine compound include tetraarylbenzidine compounds shown in JP-A-54-58445 and the like.
Examples of the stilbene compound include stilbene compounds shown in JP-A-58-65440 and JP-A-60-98437.
Examples of the spirobifluorene compound include JP-A-2007-115665, JP-A-2014-72327, JP-A-2001-2570112, WO2004 / 063283, WO2011 / 03450, and WO2011 / 45321. , WO2013 / 042699, and spirobifluorene compounds shown in WO2013 / 121835.
Examples of the thiophene oligomer include thiophene oligomers shown in JP-A-2-2508881 and JP-A-2013-033868.

When a high molecular weight compound and a low molecular weight compound are mixed, the difference in ionization potential between them is preferably 0.2 eV or less. The ionization potential is the energy required to extract one electron from a molecule, and is expressed in units of electron volt (eV). The method for measuring the ionization potential is not particularly limited, but the measurement by photoelectron spectroscopy is preferable.

The other material contained in the hole transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include additives and oxidizing agents.

The additive is not particularly limited and may be appropriately selected depending on the intended purpose. For example, iodine, lithium iodide, sodium iodide, potassium iodide, cesium iodide, calcium iodide, copper iodide, etc. Metal iodides such as iron iodide or silver iodide, quaternary ammonium salts such as tetraalkylammonium iodide or pyridinium iodide, lithium bromide, sodium bromide, potassium bromide, cesium bromide or calcium bromide, etc. Metal bromide, quaternary ammonium compounds such as tetraalkylammonium bromide or pyridinium bromide, bromine salts, metal chlorides such as copper chloride or silver chloride, metal acetates such as copper acetate, silver acetate or palladium acetate, copper sulfate or Metal sulfates such as zinc sulfate, metal complexes such as ferrocyanate-ferricate or ferrocene-ferricinium ion, sulfur compounds such as polysodium sulfide or alkylthiol-alkyldisulfide, viologen dyes, hydroquinone and the like, pyridine, Basic compounds such as 4-t-butylpyridine or benzimidazole can be mentioned.

In addition, an oxidant can be added. The type of oxidizing agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, tris (4-bromophenyl) hexachloroantimonate, silver hexafluoroantimonate, nitrosonium tetrafluovorate, etc. Examples include silver nitrate, cobalt complex, 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate and the like. It is not necessary for the oxidant to oxidize the entire hole-transporting material, and it is effective if a part of the material is oxidized. Further, the oxidizing agent may or may not be taken out of the system after the reaction.
Since the hole transport layer contains an oxidizing agent, a part or all of the hole transport material can be converted into a radical cation, so that the conductivity is improved and the durability and stability of the output characteristics can be improved. Become.

The average thickness of the hole transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. However, on the photoelectric conversion layer, 0.01 μm or more and 20 μm or less is preferable, and 0.1 μm or more and 10 μm or less is more preferable. It is preferable, and more preferably 0.2 μm or more and 2 μm or less.

The hole transport layer can be formed directly on the photoelectric conversion layer. The method for producing the hole transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of forming a thin film in vacuum such as vacuum deposition and a wet film forming method. Among these, the wet film forming method is particularly preferable in terms of manufacturing cost and the like, and the method of coating on the photoelectric conversion layer is more preferable.
The wet film forming method is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a dip method, a spray method, a wire bar method, a spin coating method, a roller coating method, a blade coating method, and a gravure coating method. And so on. Further, as the wet printing method, for example, a method such as letterpress, offset, gravure, intaglio, rubber plate, or screen printing may be used.

Further, the hole transport layer may be formed, for example, by forming a film in a supercritical fluid or a subcritical fluid having a temperature and pressure lower than the critical point.
A supercritical fluid exists as a non-aggregating high-density fluid in a temperature and pressure region exceeding the limit (critical point) at which a gas and a liquid can coexist, does not aggregate even when compressed, is above the critical temperature, and has a critical pressure. It means a fluid that is a fluid in the above state. The supercritical fluid is not particularly limited and may be appropriately selected depending on the intended purpose, but a fluid having a low critical temperature is preferable.
The subcritical fluid is not particularly limited as long as it exists as a high-pressure liquid in the temperature and pressure regions near the critical point, and can be appropriately selected depending on the intended purpose. A fluid listed as a supercritical fluid can also be suitably used as a subcritical fluid.

Examples of the supercritical fluid include carbon monoxide, carbon dioxide, ammonia, nitrogen, water, alcohol solvent, hydrocarbon solvent, halogen solvent, ether solvent and the like.
Examples of the alcohol solvent include methanol, ethanol, n-butanol and the like.
Examples of the hydrocarbon solvent include ethane, propane, 2,3-dimethylbutane, benzene, toluene and the like. Examples of the halogen solvent include methylene chloride, chlorotrifluoromethane and the like.
Examples of the ether solvent include dimethyl ether and the like.
These may be used alone or in combination of two or more.
Among these, carbon dioxide is preferable because it has a critical pressure of 7.3 MPa and a critical temperature of 31 ° C., so that a supercritical state can be easily created, and it is nonflammable and easy to handle.

The critical temperature and critical pressure of the supercritical fluid are not particularly limited and can be appropriately selected depending on the intended purpose. The critical temperature of the supercritical fluid is preferably -273 ° C. or higher and 300 ° C. or lower, and more preferably 0 ° C. or higher and 200 ° C. or lower.

Furthermore, in addition to supercritical fluids and subcritical fluids, organic solvents and entrainers can also be used in combination. By adding an organic solvent and an entrainer, the solubility in a supercritical fluid can be adjusted more easily.
The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a ketone solvent, an ester solvent, an ether solvent, an amide solvent, a halogenated hydrocarbon solvent and a hydrocarbon solvent.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone and the like.
Examples of the ester solvent include ethyl formate, ethyl acetate, n-butyl acetate and the like.
Examples of the ether solvent include diisopropyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, dioxane and the like.
Examples of the amide solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like.
Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, 1-chloronaphthalene and the like. ..
Examples of the hydrocarbon solvent include n-pentane, n-hexane, n-octane, 1,5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-xylene, m-xylene, p-xylene, and the like. Ethylbenzene, cumene and the like can be mentioned.
These may be used alone or in combination of two or more.

Further, the hole transporting material may be laminated on the photoelectric conversion layer, and then a press treatment step may be performed. By performing the press treatment, the hole transportable material comes into close contact with the photoelectric conversion layer, so that the power generation efficiency may be improved.
The press processing method is not particularly limited and may be appropriately selected depending on the intended purpose. A press molding method using a flat plate as represented by an IR (infrared spectroscopy) tablet molding machine, a roller or the like was used. The roll press method and the like can be mentioned.
The pressure during the press treatment ^{is preferably 10 kgf / cm 2} or more, and more preferably 30 kgf / cm ² or more.
The press processing time is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 hour or less. Further, heat may be applied during the pressing process.

During the pressing process, a mold release agent may be sandwiched between the press machine and the electrodes.
The release agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoride ethylene hexafluoride propylene copolymer, perfluoroalkoxy Fluororesin, polyvinylidene fluoride, ethylene tetrafluoride ethylene copolymer, ethylene chlorotrifluorinated ethylene copolymer, fluororesin such as polyvinyl fluoride and the like can be mentioned. These may be used alone or in combination of two or more.

<Membrane containing metal oxide>
A film containing a metal oxide may be provided between the hole transport layer and the second electrode after the press treatment step and before the second electrode is provided.
The metal oxide is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include molybdenum oxide, tungsten oxide, vanadium oxide and nickel oxide. These may be used alone or in combination of two or more. Of these, molybdenum oxide is preferable.
The method of providing the film containing the metal oxide on the hole transport layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method of forming a thin film in vacuum such as sputtering or vacuum deposition A wet film forming method and the like can be mentioned.

As a wet film forming method for forming a film containing a metal oxide, a method of preparing a paste in which a metal oxide powder or a sol is dispersed and applying the paste on the hole transport layer is preferable.
The wet film forming method is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a dip method, a spray method, a wire bar method, a spin coating method, a roller coating method, a blade coating method, and a gravure coating method. And so on. Further, as the wet printing method, for example, a method such as letterpress, offset, gravure, intaglio, rubber plate, or screen printing may be used.

The average thickness of the film containing the metal oxide is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.1 nm or more and 50 nm or less, and more preferably 1 nm or more and 10 nm or less.

<Second electrode>
The second electrode is preferably formed on the hole transport layer or on a film containing a metal oxide. Further, as the second electrode, the same one as that of the first electrode can be used.
The shape, structure, and size of the second electrode are not particularly limited and may be appropriately selected depending on the intended purpose.
Examples of the material of the second electrode include metals, carbon compounds, conductive metal oxides, and conductive polymers.
Examples of the metal include platinum, gold, silver, copper and aluminum.
Examples of the carbon compound include graphite, fullerene, carbon nanotube, graphene and the like.
Examples of the conductive metal oxide include ITO, FTO, ATO and the like.
Examples of the conductive polymer include polythiophene and polyaniline.
These may be used alone or in combination of two or more.

The second electrode can be formed by appropriately applying a method such as coating, laminating, vacuum deposition, CVD, or bonding on the hole transport layer depending on the type of material used and the type of hole transport layer.

Further, in the photoelectric conversion element, it is preferable that at least one of the first electrode and the second electrode is substantially transparent. For example, it is preferable to make the first electrode transparent so that the incident light is incident from the first electrode side. In this case, it is preferable to use a material that reflects light for the second electrode, and a metal, glass on which a conductive oxide is vapor-deposited, plastic, a metal thin film, or the like is preferably used. It is also an effective means to provide an antireflection layer on the electrode on the incident light side.

Here, an example of the photoelectric conversion element will be described with reference to the drawings.
FIG. 1 is a schematic view of an example of a solar cell as an embodiment of a photoelectric conversion element.
The solar cell 50 of FIG. 1 has a first electrode 2, a dense electron transport layer 3, a perovskite layer 5 which is a photoelectric conversion layer, a hole transport layer 6, and a second electrode 7.
The first electrode 2 is in contact with the dense electron transport layer 3.
The dense electron transport layer 3 is in contact with the perovskite layer 5.
The perovskite layer 5 is in contact with the hole transport layer 6 via a salt (not shown).
The hole transport layer 6 is in contact with the second electrode 7.

(Photoelectric conversion module)
The photoelectric conversion module of the present invention comprises a plurality of photoelectric conversion elements of the present invention electrically connected in series or in parallel.
The photoelectric conversion module preferably has, for example, a plurality of photoelectric conversion elements of the present invention on a substrate, and further has a second substrate and a sealing member different from the above-mentioned substrate, and other members as needed. Have.
Examples of the photoelectric conversion module include a photoelectric conversion module.

The photoelectric conversion module is a photoelectric conversion module in which a plurality of photoelectric conversion elements of the present invention are provided on a substrate, and hole transport layers are continuous with each other in at least two photoelectric conversion elements adjacent to each other. It is preferable that the first electrode, the electron transport layer, and the photoelectric conversion layer in at least two photoelectric conversion elements adjacent to each other are separated by a hole transport layer. In such a photoelectric conversion module, since the electron transport layer and the photoelectric conversion layer are cut off, the recombination of electrons due to diffusion is reduced, so that after being exposed to high-intensity light for a long period of time, However, it is possible to maintain power generation efficiency.

<Board>
The shape, structure, and size of the substrate are not particularly limited, and can be appropriately selected depending on the intended purpose. In the following, the above-mentioned substrate may be referred to as a first substrate.
As the material of the first substrate, a material having translucency and insulation is preferable. Examples of such a material include glass, plastic film, ceramic and the like. Among these, when a step of firing is included when forming the electron transport layer, a material having heat resistance to the firing temperature is preferable. Further, as the first substrate, one having flexibility is preferable.

<Second board>
The second substrate is arranged to face the first substrate so as to sandwich the plurality of photoelectric conversion elements of the present invention.
The shape, structure, and size of the substrate are not particularly limited, and can be appropriately selected depending on the intended purpose.
The material of the second substrate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include glass, plastic film, metal leaf and ceramic.

An uneven portion may be formed at the joint portion between the second substrate and the sealing member described later in order to improve the adhesion.
The method for forming the uneven portion is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a sandblasting method, a waterblasting method, a chemical etching method, a laser processing method, and a method using abrasive paper. Be done.
As a method of increasing the adhesion between the second substrate and the sealing member, for example, a method of removing organic substances on the surface of the second substrate or a method of improving the hydrophilicity of the second substrate may be used. The means for removing organic substances on the surface of the second substrate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include UV ozone cleaning and oxygen plasma treatment.

<Sealing member>
The sealing member is arranged between the first substrate and the second substrate to seal the photoelectric conversion element.
The material of the sealing member is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a cured product of an acrylic resin and a cured product of an epoxy resin.
As the cured product of the acrylic resin, any known material can be used as long as the monomer or oligomer having an acrylic group in the molecule is cured.
As the cured product of the epoxy resin, any known material can be used as long as the monomer or oligomer having an epoxy group in the molecule is cured.

Examples of the epoxy resin include an aqueous dispersion type, a solvent-free type, a solid type, a heat-curable type, a curing agent mixed type, and an ultraviolet curable type. Among these, the thermosetting type and the ultraviolet curable type are preferable, and the ultraviolet curable type is more preferable. Even if it is an ultraviolet curable type, it is possible to heat it, and it is preferable to heat it even after it is cured by ultraviolet rays.

Examples of the epoxy resin include bisphenol A type, bisphenol F type, novolak type, cyclic aliphatic type, long chain aliphatic type, glycidylamine type, glycidyl ether type, glycidyl ester type and the like. These may be used alone or in combination of two or more.

It is preferable to mix a curing agent and various additives with the epoxy resin, if necessary.

The curing agent is not particularly limited and may be appropriately selected depending on the intended purpose, and is classified into, for example, amine-based, acid anhydride-based, polyamide-based, and other curing agents.
Examples of the amine-based curing agent include aliphatic polyamines such as diethylenetriamine and triethylenetetramine, and aromatic polyamines such as metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone.
Examples of the acid anhydride-based curing agent include phthalic anhydride, tetra and hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, hetic anhydride, dodecenyl succinic anhydride and the like. ..
Examples of other curing agents include imidazoles, polyethercaptans, and the like. These may be used alone or in combination of two or more.

The additive is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a filler, a gap agent, a polymerization initiator, a desiccant (moisture absorbent), a curing accelerator, and a coupling agent. , Flexible agents, colorants, flame retardant aids, antioxidants, organic solvents and the like. Among these, fillers, gap agents, curing accelerators, polymerization initiators and desiccants (moisture absorbents) are preferable, and fillers and polymerization initiators are more preferable.

By including a filler as an additive, it suppresses the infiltration of water and oxygen, further reduces volume shrinkage during curing, reduces the amount of outgas during curing or heating, improves mechanical strength, and provides thermal conductivity. Effects such as control of fluidity can be obtained. Therefore, including a filler as an additive is very effective in maintaining a stable output in various environments.

Further, regarding the output characteristics of the photoelectric conversion element and its durability, not only the influence of invading moisture and oxygen but also the influence of outgas generated when the sealing member is cured or heated cannot be ignored. In particular, the influence of outgas generated during heating has a great influence on the output characteristics in high temperature environment storage.
By containing a filler, a gap agent, and a desiccant in the sealing member, these themselves can suppress the infiltration of water and oxygen, and the amount of the sealing member used can be reduced, so that the effect of reducing outgas can be obtained. Can be done. Inclusion of a filler, a gap agent, and a desiccant in the sealing member is effective not only at the time of curing but also at the time of storing the photoelectric conversion element in a high temperature environment.

The filler is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an inorganic type such as crystalline or amorphous silica, talc, alumina, aluminum nitride, silicon nitride, calcium silicate, calcium carbonate and the like. Examples include fillers. These may be used alone or in combination of two or more.
The average primary particle size of the filler is preferably 0.1 μm or more and 10 μm, and more preferably 1 μm or more and 5 μm or less. When the average primary particle size of the filler is within the above-mentioned preferable range, the effect of suppressing the invasion of water and oxygen can be sufficiently obtained, the viscosity becomes appropriate, and the adhesion to the substrate and the defoaming property are improved. However, it is also effective for controlling the width of the sealing portion and workability.
The content of the filler is preferably 10 parts by mass or more and 90 parts by mass or less, and more preferably 20 parts by mass or more and 70 parts by mass or less with respect to the entire sealing member (100 parts by mass). When the content of the filler is within the above-mentioned preferable range, the effect of suppressing the infiltration of water and oxygen is sufficiently obtained, the viscosity is appropriate, and the adhesion and workability are also good.

The gap agent is also called a gap control agent or a spacer agent. By including a gap agent as an additive, it becomes possible to control the gap of the sealing portion. For example, when a sealing member is provided on a first substrate or a first electrode and a second substrate is placed on the sealing member for sealing, the sealing member is mixed with a gap agent. As a result, the gap of the sealing portion is aligned with the size of the gap agent, so that the gap of the sealing portion can be easily controlled.
The gap agent is not particularly limited as long as it is granular and has a uniform particle size and has high solvent resistance and heat resistance, and can be appropriately selected depending on the intended purpose. As the gap agent, one having a high affinity with the epoxy resin and having a spherical particle shape is preferable. Specifically, glass beads, silica fine particles, organic resin fine particles and the like are preferable. These may be used alone or in combination of two or more.
The particle size of the gap agent can be selected according to the gap of the sealing portion to be set, but is preferably 1 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less.

The polymerization initiator is not particularly limited as long as it uses heat or light to initiate polymerization, and can be appropriately selected depending on the intended purpose. Examples thereof include a thermal polymerization initiator and a photopolymerization initiator. Be done.

The thermal polymerization initiator is a compound that generates active species such as radicals and cations by heating, and is, for example, an azo compound such as 2,2'-azobisisobutyronitrile (AIBN) or benzoyl peroxide (BPO). Peroxides such as. As the thermal cationic polymerization initiator, a benzenesulfonic acid ester, an alkylsulfonium salt, or the like is used.
On the other hand, as the photopolymerization initiator, in the case of an epoxy resin, a photocationic polymerization initiator is preferably used. When a photocationic polymerization initiator is mixed with an epoxy resin and light irradiation is performed, the photocationic polymerization initiator is decomposed to generate an acid, and the acid causes the epoxy resin to polymerize, and the curing reaction proceeds. The photocationic polymerization initiator has the effects of less volume shrinkage during curing, no oxygen inhibition, and high storage stability.

Examples of the photocationic polymerization initiator include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, metatheron compounds, silanol-aluminum complexes and the like.
Further, as the polymerization initiator, a photoacid generator having a function of generating an acid by irradiating with light can also be used. The photoacid generator acts as an acid that initiates cationic polymerization, and examples thereof include onium salts such as ionic sulfonium salts and iodonium salts, which are composed of a cationic portion and an anionic portion. These may be used alone or in combination of two or more.

The amount of the polymerization initiator added may vary depending on the material used, but is preferably 0.5 parts by mass or more and 10 parts by mass or less, and 1 part by mass or more and 5 parts by mass with respect to the entire sealing member (100 parts by mass). Less than a part is more preferable. When the addition amount is within the above-mentioned preferable range, the curing proceeds appropriately, the residual uncured matter can be reduced, and the outgas can be prevented from becoming excessive.

A desiccant, also called a hygroscopic agent, is a material having a function of physically or chemically adsorbing and absorbing moisture. By containing it in a sealing member, moisture resistance can be further enhanced and the influence of outgas can be reduced. ..
The desiccant is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably in the form of particles, for example, calcium oxide, barium oxide, magnesium oxide, magnesium sulfate, sodium sulfate, calcium chloride, etc. Examples thereof include inorganic water-absorbing materials such as silica gel, molecular sieve, and zeolite. Among these, zeolite having a large amount of moisture absorption is preferable. These may be used alone or in combination of two or more.

The curing accelerator, also called a curing catalyst, is a material that accelerates the curing rate, and is mainly used for thermosetting epoxy resins.
The curing accelerator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, DBU (1,8-diazabicyclo (5,4,0) -undesen-7) or DBN (1,5-). Tertiary amines or tertiary amine salts such as diazabicyclo (4,3,0) -nonen-5), imidazoles such as 1-cyanoethyl-2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole, Examples thereof include phosphine such as triphenylphosphine and tetraphenylphosphonium / tetraphenylborate, or phosphonium salts. These may be used alone or in combination of two or more.

The coupling agent is not particularly limited as long as it is a material having an effect of enhancing the molecular binding force, and can be appropriately selected depending on the intended purpose. Examples thereof include a silane coupling agent, and more specifically, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-phenyl-γ -Aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- Examples include silane coupling agents such as mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, and 3-methacryloxypropyltrimethoxysilane. Be done. These may be used alone or in combination of two or more.

Further, as the sealing member, an epoxy resin composition commercially available as a sealing material, a sealing material, an adhesive or the like is known, and it can be effectively used in this embodiment as well. Among them, there are epoxy resin compositions developed and commercially available for applications such as solar cells and organic EL devices, which can be particularly effectively used in the present embodiment. Examples of commercially available epoxy resin compositions include TB3118, TB3114, TB3124, TB3125F (manufactured by ThreeBond Co., Ltd.), WorldRock5910, WorldRock5920, WorldRock8723 (manufactured by Kyoritsu Kagaku Co., Ltd.), and WB90US (P) (manufactured by Moresco). Can be mentioned.

A sheet-shaped sealing material can be used as the sealing member.
The sheet-shaped encapsulant is a sheet in which an epoxy resin layer is formed in advance, and glass, a film having a high gas barrier property, or the like is used for the sheet. The sealing member and the second substrate can be formed at one time by pasting the sheet-shaped sealing material on the second substrate and then curing the sheet-like sealing material. Depending on the formation pattern of the epoxy resin layer formed on the sheet, a structure having a hollow portion can be formed.

The method for forming the sealing member is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the dispensing method, the wire bar method, the spin coating method, the roller coating method, the blade coating method, the gravure coating method and the like. Can be mentioned. Further, as a method for forming the sealing member, for example, a method such as letterpress, offset, gravure, intaglio, rubber plate, or screen printing may be used.
Further, a passivation layer may be provided between the sealing member and the second electrode. The passivation layer is not particularly limited as long as the sealing member is arranged so as not to be in contact with the second electrode, and can be appropriately selected depending on the intended purpose. For example, aluminum oxide, silicon nitride, silicon oxide, etc. Can be mentioned.

<Other parts>
The other members are not particularly limited and may be appropriately selected depending on the intended purpose.

The photoelectric conversion module of the present invention can be applied to a power supply device by combining it with a circuit board or the like that controls the generated current. Examples of devices that use a power supply device include an electronic desk calculator and a wristwatch. Further, a power supply device having the photoelectric conversion element of the present invention can be applied to a mobile phone, an electronic organizer, an electronic paper, or the like. Further, the power supply device having the photoelectric conversion element of the present invention can be used as an auxiliary power source for prolonging the continuous use time of a rechargeable or dry battery type electric appliance, or as a power source that can be used even at night by combining with a secondary battery or the like. Can be used. Further, it can be used for IoT devices, artificial satellites, etc. as a self-supporting power source that does not require battery replacement or power supply wiring.

(Electronics)
The electronic device of the present invention includes a photoelectric conversion module of the present invention, an apparatus operated by electric power generated by the photoelectric conversion of the photoelectric conversion module, and further includes other apparatus as needed.

(Power supply module)
The power supply module of the present invention includes a photoelectric conversion module of the present invention, a power supply IC (Integrated Circuit), and further has other devices as needed.

Next, a specific embodiment of the photoelectric conversion module of the present invention and an electronic device having a device operated by the electric power obtained by generating electric power thereof will be described.

FIG. 2 is a block diagram of a mouse for a personal computer as an example of the electronic device of the present invention.
As shown in FIG. 2, the photoelectric conversion module, the power supply IC, and the power storage device are combined, and the supplied power is connected to the power supply of the mouse control circuit. As a result, the power storage device can be charged when the mouse is not in use, and the mouse can be operated with the electric power, and a mouse that does not require wiring or battery replacement can be obtained. In addition, the weight can be reduced by eliminating the need for batteries, which is effective.

FIG. 3 is a schematic external view showing an example of the mouse shown in FIG.
As shown in FIG. 3, the photoelectric conversion module, the power supply IC, and the power storage device are mounted inside the mouse, but the upper part of the photoelectric conversion element is covered with a transparent housing so that the photoelectric conversion element of the photoelectric conversion module is exposed to light. It has been It is also possible to mold the entire mouse housing with a transparent resin. The arrangement of the photoelectric conversion element is not limited to this, and for example, even if the mouse is covered with a hand, it can be arranged at a position where light is irradiated, which may be preferable.

Next, the photoelectric conversion module of the present invention and another embodiment of the electronic device having the device operated by the electric power obtained by generating electricity thereof will be described.

FIG. 4 is a block diagram of a keyboard for a personal computer as an example of the electronic device of the present invention.
As shown in FIG. 4, the photoelectric conversion element of the photoelectric conversion module, the power supply IC, and the power storage device are combined, and the supplied power is connected to the power supply of the keyboard control circuit. As a result, the power storage device can be charged when the keyboard is not in use, and the keyboard can be operated with the electric power, and a keyboard that does not require wiring or battery replacement can be obtained. In addition, the weight can be reduced by eliminating the need for batteries, which is effective.

FIG. 5 is a schematic external view showing an example of the keyboard shown in FIG.
As shown in FIG. 5, the photoelectric conversion element, the power supply IC, and the power storage device of the photoelectric conversion module are mounted inside the keyboard, but the upper part of the photoelectric conversion element is covered with a transparent housing so that the photoelectric conversion element is exposed to light. It has been. It is also possible to mold the entire keyboard housing with transparent resin. The arrangement of the photoelectric conversion element is not limited to this. In the case of a small keyboard in which the space for incorporating the photoelectric conversion element is small, as shown in FIG. 6, it is possible and effective to embed the small photoelectric conversion element in a part of the keys.

Next, the photoelectric conversion module of the present invention and another embodiment of the electronic device having the device operated by the electric power obtained by generating electricity thereof will be described.

FIG. 7 is a block diagram of a sensor as an example of the electronic device of the present invention.
As shown in FIG. 7, the photoelectric conversion element of the photoelectric conversion module, the power supply IC, and the power storage device are combined, and the supplied power is connected to the power supply of the sensor circuit. This makes it possible to configure the sensor module without the need to connect to an external power source and to replace the battery. As sensing targets, it can be applied to various sensors such as temperature / humidity, illuminance, human sensation, CO ₂ , acceleration, UV, noise, geomagnetism, and atmospheric pressure, and is effective. As shown in FIG. 7, the sensor module is configured to periodically sense a measurement target and transmit the read data to a PC, a smartphone, or the like by wireless communication.
With the advent of the IoT (Internet of Things) society, it is expected that the number of sensors will increase rapidly. Replacing the batteries of these innumerable sensors one by one takes a lot of time and effort, which is not realistic. In addition, the sensor is located in a place where it is difficult to replace the battery, such as a ceiling or a wall, which also deteriorates workability. The ability to supply power with a photoelectric conversion element is also a great advantage. Further, the photoelectric conversion module of the present invention can obtain a high output even in low illuminance and has a small dependence on the light incident angle of the output, so that it has an advantage that the degree of freedom of installation is high.

Next, the photoelectric conversion module of the present invention and another embodiment of the electronic device having the device operated by the electric power obtained by generating electricity thereof will be described.

FIG. 8 is a block diagram of a turntable as an example of the electronic device of the present invention.
As shown in FIG. 8, the photoelectric conversion element, the power supply IC, and the power storage device are combined, and the supplied power is connected to the power supply of the turntable circuit. This makes it possible to configure the turntable without the need to connect to an external power source and to replace the battery.
Turntables are used, for example, in showcases for displaying products, but the wiring of the power supply does not look good, and the displayed items must be removed when replacing the batteries, which takes a lot of time and effort. By using the photoelectric conversion module of the present invention, such a problem can be solved and it is effective.

The photoelectric conversion module of the present invention, an electronic device having a device operated by the electric power obtained by generating electric power thereof, and a power supply module have been described above, but these are only a few, and the photoelectric conversion of the present invention is described. Modules are not limited to these uses.

<Use>
The photoelectric conversion module of the present invention can function as a self-supporting power source, and the device can be operated by using the electric power generated by the photoelectric conversion. Since the photoelectric conversion module of the present invention can generate electricity by being irradiated with light, it is not necessary to connect an electronic device to a power source or replace a battery. Therefore, it is possible to operate the electronic device even in a place where there is no power supply facility, to carry it around, and to operate the electronic device even in a place where it is difficult to replace the battery without replacing the battery. In addition, when a dry battery is used, the electronic device becomes heavier and larger in size, which may hinder installation on a wall or ceiling, or portability. However, the photoelectric conversion module of the present invention may be used. Because it is lightweight and thin, it has a high degree of freedom in installation, and it has great advantages for wearing and carrying around.

As described above, the photoelectric conversion module of the present invention can be used as a self-supporting power source and can be combined with various electronic devices. For example, electronic desk computers, wristwatches, mobile phones, electronic organizers, electronic paper and other display devices, personal computer accessories such as mice and keyboards, various sensor devices such as temperature and humidity sensors and human sensor, and transmission of beacons and GPS. It can be used in combination with many electronic devices such as machines, auxiliary lights, and remote controls.

Since the photoelectric conversion module of the present invention can generate electricity even with light of low illuminance, it can generate electricity indoors or even in a dim shadow, and therefore has a wide range of application. In addition, unlike dry batteries, there is no liquid leakage, and unlike button batteries, there is no accidental ingestion, and safety is high. Further, it can be used as an auxiliary power source for prolonging the continuous use time of rechargeable or dry battery type electric appliances. In this way, by combining the photoelectric conversion module of the present invention and the device that operates by the electric power generated by the photoelectric conversion, it is lightweight, easy to use, has a high degree of freedom of installation, does not require replacement, and is safe. It can be reborn as an electronic device that has excellent properties and is also effective in reducing the environmental burden.

FIG. 9 shows a basic configuration diagram of an electronic device in which the photoelectric conversion module of the present invention and a device operated by the electric power generated by the photoelectric conversion module are combined. This can generate electric power and extract electric power when the photoelectric conversion element is irradiated with light. The circuit of the device can be operated by its electric power.

However, since the output of the photoelectric conversion element of the photoelectric conversion module changes depending on the ambient illuminance, the electronic device shown in FIG. 9 may not be able to operate stably. In this case, as shown in FIG. 10, in order to supply a stable voltage to the circuit side, it is possible and effective to incorporate a power supply IC for the photoelectric conversion element between the photoelectric conversion element and the circuit of the device. ..
However, the photoelectric conversion element of the photoelectric conversion module can generate electricity if it is irradiated with light of sufficient illuminance, but if the illuminance sufficient to generate electricity is insufficient, the desired power cannot be obtained, which is also a drawback of the photoelectric conversion element. be. In this case, as shown in FIG. 11, by mounting a power storage device such as a capacitor between the power supply IC and the device circuit, it becomes possible to charge the power storage device with surplus power from the photoelectric conversion element, and the illuminance. Even if the value is too low or the photoelectric conversion element is not exposed to light, the power stored in the power storage device can be supplied to the device circuit, and stable operation can be performed.

In this way, in an electronic device that combines the photoelectric conversion module of the present invention and a device circuit, by combining a power supply IC and a power storage device, it can operate even in an environment without a power supply, and it is stable without battery replacement. It becomes possible to make the best use of the merit of the photoelectric conversion element.

On the other hand, the photoelectric conversion module of the present invention can also be used as a power supply module and is useful. For example, as shown in FIG. 12, when the photoelectric conversion module of the present invention and the power supply IC for the photoelectric conversion element are connected, the power generated by the photoelectric conversion of the photoelectric conversion element of the photoelectric conversion module is constant in the power supply IC. It is possible to configure a DC power supply module that can supply at the voltage level of.
Further, as shown in FIG. 13, by adding a power storage device to the power supply IC, it becomes possible to charge the power storage device with the electric power generated by the photoelectric conversion element of the photoelectric conversion module, and the illuminance is too low. It is possible to configure a power supply module capable of supplying electric power even when the photoelectric conversion element is not exposed to light.
The power supply module of the present invention shown in FIGS. 12 and 13 can be used as a power supply module without battery replacement unlike a conventional primary battery.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples. The present invention is not limited to the examples exemplified here.

<Production Example 1: Synthesis of polymer compound>
The polymer compound (B-05) represented by the following was synthesized by the following reaction.

なお、「Ｅｔ」はエチル基を表す。

In addition, "Et" represents an ethyl group.

0.66 g (2.0 mmol) of the above dialdehyde compound and 1.02 g (2.0 mmol) of diphosphonate were placed in a 100 ml four-necked flask, and 75 ml of tetrahydrofuran was added after substitution with nitrogen. ^{6.75 ml (6.75 mmol) of a 1.0 mol · dm-} 3tetrahydrofuran solution of potassium t-butoxide was added dropwise to this solution and stirred at room temperature for 2 hours, then diethyl benzylphosphonate and benzaldehyde were sequentially added, and the mixture was further stirred for 2 hours. bottom.
Approximately 1 ml of acetic acid was added to complete the reaction and the solution was washed with water. After distilling off the solvent under reduced pressure, purification was carried out by reprecipitation using tetrahydrofuran and methanol to obtain 0.95 g of the polymer compound (B-05). The polystyrene-equivalent number average molecular weight measured by gel permeation chromatography (GPC) was 8500, and the weight average molecular weight was 20,000. The ionization potential measured using the RIKEN KEIKI photoelectron spectrometer AC-2 was 5.20 eV. The ionization potentials described below are all values measured by AC-2.

(Example 1)
<Manufacturing of solar cells>
An ITO (Indium Tin Oxide) glass substrate was used as the substrate and the first electrode.

A tin oxide colloidal solution (manufactured by Alpha Acer) was applied onto an ITO glass substrate and dried by heating at 100 ° C. for 1 hour. ^{Next, a solution of 0.1 mM ethanol (where M means mol / dm 3} ) in which (1-aminoethyl) phosphonic acid (manufactured by Aldrich) was dissolved was applied onto the above-mentioned membrane by a spin coating method. It was applied and dried at 70 ° C. for 10 minutes to obtain an electron transport layer.

Next, lead iodide (II) (0.5306 g), lead (II) bromide (0.0736 g), methylamine bromide (0.0224 g), and formamidine iodide (0.1876 g) were added to N, In addition to N-dimethylformamide (0.8 ml) and dimethyl sulfoxide (0.2 ml), a solution obtained by heating and stirring at 60 ° C. is applied onto the above electron transport layer by a spin coating method while chlorobenzene. (0.3 ml) was added to form a perovskite film, which was dried at 150 ° C. for 30 minutes to prepare a perovskite layer (photoelectric conversion layer). The average thickness of the perovskite layer was set to 200 nm to 350 nm. Further, a solution of 20 mM ethanol in which -n-hexyltrimethylamine iodide was dissolved was applied onto the formed perovskite layer by spin coating.

Next, 73.6 mg of the polymer compound represented by (B-05) produced in Production Example 1 and 7.4 mg of 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate were weighed, and chlorobenzene was measured. It was dissolved in 3.0 ml. The obtained solution was applied onto the laminate obtained by the above step by a spin coating method to prepare a hole transport layer. The average thickness of the hole transport layer (the portion on the perovskite layer) was set to 50 to 120 nm.

Further, gold was vacuum-deposited at 100 nm on the above-mentioned laminate.
From the above, the solar power cell 1 was obtained.

<< Evaluation of solar cell characteristics >>
The obtained solar cell 1 is irradiated with light by a solar simulator (AM1.5, 100 mW / cm ² ), and a solar cell evaluation system (manufactured by NF Circuit Design Block Co., Ltd., trade name: As-510-PV03). The solar cell characteristics (initial characteristics) were evaluated using. The results are shown in Table 2.

(Examples 2 to 15)
A solar cell was prepared in the same manner as in Example 1 except that (1-aminoethyl) phosphonic acid and -n-hexyltrimethylamine iodide were changed to the compounds shown in Table 2. , Evaluated. The results are shown in Table 2.

In Table 2, the iodide-n-hexyltrimethylamine is n-hexylamine hydroiodide.
-N-Hexyltrimethylamine bromide is n-hexylamine hydrobromide.
Phenethylamine iodide is 2-phenylethylamine hydroiodide.

In Tables 2 and 3, the meaning of each reference numeral is as follows.
"Voc" means open circuit voltage.
"Jsc" means short circuit current density.
"FF" means Scherrer equation.
“Η” means photoelectric conversion efficiency.

(Comparative Examples 1 to 4)
A solar cell was prepared in the same manner as in Example 1 except that (1-aminoethyl) phosphonic acid and -n-hexyltrimethylamine iodide were changed to the compounds shown in Table 3. Evaluation was performed. The results are shown in Table 3.

As is clear from Examples 1 to 15 and Comparative Examples 1 and 2, phosphonic acid, sulfonic acid, silyl halide compound, or alkoxysilyl compound (hereinafter referred to as "acidic compound") is used, and an organic salt or an inorganic substance is used. By inserting the salt between the photoelectric conversion layer and the hole transport layer, it is clear that the conversion efficiency is higher than when only the acidic compound is used or when the organic salt or the inorganic salt is used alone. be. Furthermore, as is clear from Comparative Examples 3 and 4, it is also clear that the conversion efficiency is not increased even if a carboxylic acid is used as the acidic compound.
Further, as is clear from Examples 1 to 4 and Example 6, it is clear that the conversion efficiency is increased by using a compound having an amino group as the acidic compound.

ただし、前記一般式（１）中、Ｒ_１、及びＲ_２は、水素原子、アルキル基、アリール基、又はヘテロ環を表し、同一であっても異なっていてもよい。Ｒ_３は、２価のアルキレン基、２価のアリール基、又は２価のヘテロ環を表し、Ｒ_４は、ホスホン酸基、ボロン酸基、スルホン酸基、ハロゲン化シリル基、又はアルコキシシリル基を表す。Ｒ_１又はＲ_２と、Ｒ_３と、Ｎとは、一緒になって環構造を形成していてもよい。
＜４＞ 前記塩が、カチオンにハロゲン原子を有する前記＜１＞から＜３＞のいずれかに記載の光電変換素子である。
＜５＞ 前記有機塩が、アミンのハロゲン化水素酸塩であり、
前記無機塩が、アルカリ金属のハロゲン化物である前記＜１＞から＜３＞のいずれかに記載の光電変換素子である。
＜６＞ 前記光電変換層が、ペロブスカイト化合物を含有するペロブスカイト層である前記＜１＞から＜５＞のいずれかに記載の光電変換素子である。
＜７＞ 前記ペロブスカイト化合物が、下記一般式（２）で表される前記＜６＞に記載の光電変換素子である。
ＸαＹβＭγ ・・・一般式（２）
ただし、前記一般式（２）中、α：β：γの比率は、３：１：１であり、β及びγは、１より大きい整数を表す。Ｘは、ハロゲンイオン、Ｙは、アミノ基を有する有機化合物のイオン及びアルカリ金属イオンの少なくとも１つ、Ｍは、金属イオンを表す。
＜８＞ 前記ホール輸送層が、下記一般式（３）で表される繰り返し構造を有する高分子化合物を含有する前記＜１＞から＜７＞のいずれかに記載の光電変換素子である。

ただし、前記一般式（３）中、Ａｒ_１は、アリール基を表し、Ａｒ_２、Ａｒ_３及びＡｒ_４は、それぞれ独立して、アリーレン基、又は２価のヘテロ環基を表す。Ｒ_１〜Ｒ_４は、それぞれ独立して、水素原子、アルキル基、又はアリール基を表す。
＜９＞ 前記電子輸送材料が、金属酸化物である前記＜１＞から＜８＞のいずれかに記載の光電変換素子である。
＜１０＞ 前記金属酸化物が、酸化スズを含有する前記＜９＞に記載の光電変換素子である。
＜１１＞ 前記電子輸送層の光電変換層側の表面のラフネスファクターが、１０以下である前記＜１＞から＜１０＞のいずれかに記載の光電変換素子である。
＜１２＞ 前記＜１＞から＜１１＞のいずれかに記載の光電変換素子が直列又は並列に電気的に接続されたことを特徴とする光電変換モジュールである。
＜１３＞ 前記＜１２＞に記載の光電変換モジュールと、
前記光電変換モジュールが光電変換することによって発生した電力によって動作する装
置と、
を有することを特徴とする電子機器である。
＜１４＞ 前記＜１２＞に記載の光電変換モジュールと、
前記光電変換モジュールが光電変換することによって発生した電力を蓄電する蓄電池と、前記光電変換モジュールが光電変換することによって発生した電力及び／又は前記蓄電池に蓄電された電力によって動作する装置を有することを特徴とする電子機器である。
＜１５＞ 前記＜１２＞に記載の光電変換モジュールと、
電源ＩＣと、
を有することを特徴とする電源モジュールである。 Aspects of the present invention are, for example, as follows.
<1> In the photoelectric conversion element having the first electrode, the electron transport layer, the photoelectric conversion layer, the hole transport layer, and the second electrode.
The electron transport layer contains an electron transport material and
The electron transporting layer contains at least one of a phosphonic acid compound, a boronic acid compound, a sulfonic acid compound, a halogenated silyl compound, and an alkoxysilyl compound on the electron transporting material on the surface of the photoelectric conversion layer side. death,
The photoelectric conversion element is characterized by containing at least one salt of an organic salt and an inorganic salt between the photoelectric conversion layer and the hole transport layer.
<2> The photoelectric conversion element according to <1>, wherein the compound has a nitrogen atom.
<3> The compound is the photoelectric conversion element according to any one of <1> to <2> represented by the following general formula (1).

However, in the general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group, an aryl group, or a heterocycle, and may be the same or different. R ₃ represents a divalent alkylene group, a divalent aryl group, or a divalent heterocycle, and R ₄ is a phosphonic acid group, a boronic acid group, a sulfonic acid group, a silyl halide group, or an alkoxysilyl group. Represents. R ₁ or R ₂ , R ₃ and N may be combined to form a ring structure.
<4> The photoelectric conversion element according to any one of <1> to <3>, wherein the salt has a halogen atom as a cation.
<5> The organic salt is a hydrogen halide of an amine.
The photoelectric conversion element according to any one of <1> to <3>, wherein the inorganic salt is a halide of an alkali metal.
<6> The photoelectric conversion element according to any one of <1> to <5>, wherein the photoelectric conversion layer is a perovskite layer containing a perovskite compound.
<7> The perovskite compound is the photoelectric conversion element according to <6> represented by the following general formula (2).
XαYβMγ ・ ・ ・ General formula (2)
However, in the general formula (2), the ratio of α: β: γ is 3: 1: 1, and β and γ represent integers larger than 1. X represents a halogen ion, Y represents at least one of an organic compound ion having an amino group and an alkali metal ion, and M represents a metal ion.
<8> The photoelectric conversion element according to any one of <1> to <7>, wherein the hole transport layer contains a polymer compound having a repeating structure represented by the following general formula (3).

However, in the general formula (3), Ar ₁ represents an aryl group, and Ar ₂ , Ar ₃ and Ar ₄ independently represent an arylene group or a divalent heterocyclic group. R _{1 to} R ₄ independently represent a hydrogen atom, an alkyl group, or an aryl group.
<9> The photoelectric conversion element according to any one of <1> to <8>, wherein the electron transport material is a metal oxide.
<10> The photoelectric conversion element according to <9>, wherein the metal oxide contains tin oxide.
<11> The photoelectric conversion element according to any one of <1> to <10>, wherein the roughness factor of the surface of the electron transport layer on the photoelectric conversion layer side is 10 or less.
<12> The photoelectric conversion module according to any one of <1> to <11> is electrically connected in series or in parallel.
<13> The photoelectric conversion module according to <12> and
A device that operates by the electric power generated by the photoelectric conversion module
It is an electronic device characterized by having.
<14> The photoelectric conversion module according to <12> and
Having a storage battery that stores the electric power generated by the photoelectric conversion module, and / or a device that operates by the electric power generated by the photoelectric conversion and / or the electric power stored in the storage battery. It is a characteristic electronic device.
<15> The photoelectric conversion module according to <12> and
Power supply IC and
It is a power supply module characterized by having.

The photoelectric conversion element according to <1> to <11>, the photoelectric conversion module according to <12>, the electronic device according to any one of <13> to <14>, and the above-mentioned <15>. The power supply module can solve the conventional problems and achieve the object of the present invention.

2 First electrode 3 Dense electron transport layer (dense layer)
5 Perovskite layer 6 Hole transport layer 7 Second electrode 50 Solar cell

Japanese Unexamined Patent Publication No. 2016-195175

Claims (15)

In a photoelectric conversion element having a first electrode, an electron transport layer, a photoelectric conversion layer, a hole transport layer, and a second electrode,
The electron transport layer contains an electron transport material and
The electron transporting layer contains at least one of a phosphonic acid compound, a boronic acid compound, a sulfonic acid compound, a halogenated silyl compound, and an alkoxysilyl compound on the electron transporting material on the surface of the photoelectric conversion layer side. death,
A photoelectric conversion element comprising at least one of an organic salt and an inorganic salt between the photoelectric conversion layer and the hole transport layer. The photoelectric conversion element according to claim 1, wherein the compound has a nitrogen atom. The photoelectric conversion element according to any one of claims 1 to 2, wherein the compound is represented by the following general formula (1).

However, in the general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group, an aryl group, or a heterocycle, and may be the same or different. R ₃ represents an alkylene group, an arylene group, or a divalent heterocycle, and R ₄ represents a phosphonic acid group, a boronic acid group, a sulfonic acid group, a silyl halide group, or an alkoxysilyl group. R ₁ or R ₂ , R ₃ and N may be combined to form a ring structure. The photoelectric conversion element according to any one of claims 1 to 3, wherein the salt has a halogen atom as a cation. The organic salt is an amine hydrohalide,
The photoelectric conversion element according to any one of claims 1 to 3, wherein the inorganic salt is a halide of an alkali metal. The photoelectric conversion element according to any one of claims 1 to 5, wherein the photoelectric conversion layer is a perovskite layer containing a perovskite compound. The photoelectric conversion element according to claim 6, wherein the perovskite compound is represented by the following general formula (2).
XαYβMγ ・ ・ ・ General formula (2)
However, in the general formula (2), the ratio of α: β: γ is 3: 1: 1, and β and γ represent integers larger than 1. X represents a halogen ion, Y represents at least one of an organic compound ion having an amino group and an alkali metal ion, and M represents a metal ion. The photoelectric conversion element according to any one of claims 1 to 7, wherein the hole transport layer contains a polymer compound having a repeating structure represented by the following general formula (3).

However, in the general formula (3), Ar ₁ represents an aryl group, and Ar ₂ , Ar ₃ and Ar ₄ independently represent an arylene group or a divalent heterocyclic group. R _{1 to} R ₄ independently represent a hydrogen atom, an alkyl group, or an aryl group. The photoelectric conversion element according to any one of claims 1 to 8, wherein the electron transport material is a metal oxide. The photoelectric conversion element according to claim 9, wherein the metal oxide contains tin oxide. The photoelectric conversion element according to any one of claims 1 to 10, wherein the roughness factor of the surface of the electron transport layer on the photoelectric conversion layer side is 10 or less. A photoelectric conversion module according to any one of claims 1 to 11, wherein the photoelectric conversion elements are electrically connected in series or in parallel. The photoelectric conversion module according to claim 12 and
A device that operates by the electric power generated by the photoelectric conversion module
An electronic device characterized by having. The photoelectric conversion module according to claim 12 and
Having a storage battery that stores the electric power generated by the photoelectric conversion module, and / or a device that operates by the electric power generated by the photoelectric conversion and / or the electric power stored in the storage battery. Characterized electronic equipment. The photoelectric conversion module according to claim 12 and
Power supply IC and
A power supply module characterized by having.

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