JP2010087029A - Surface-modifying method, and organic thin film forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming an organic thin film by efficiently modifying the surface of an inorganic compound with the use of a specified organic compound in a solution process. <P>SOLUTION: In an inorganic compound surface-modifying method and an organic thin film-forming method, the monomolecular film of a compound having two or more functional groups to be expressed by a general expression (1) is formed on the most upper surface layer of the inorganic compound, and then, some or all of functional groups to be expressed by the general expression (1), which are not coupled with the inorganic compound, are converted into hydrogen atoms in the compound. (In the expression, R indicates a substituent, and n indicates an integer of 1 or 2). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for modifying the surface of an inorganic compound with a specific organic compound, and a method for forming an organic thin film on the inorganic compound.

  In recent years, research on single-layer films (Self-Assembled Monolayer; hereinafter referred to as “SAM”) formed by chemisorption of organic molecules and multilayer films (Self-Assembled Multilayer) formed by stacking SAMs has made significant progress. However, it has been attracting attention from both basic and applied aspects. The SAM is a monomolecular film formed by so-called self-assembly / self-assembly, and is a molecular aggregate formed on a solid surface in the process of chemical adsorption of organic molecules. Due to the interaction between the adsorbed molecules, the constituent molecules of the aggregate are densely assembled, and a highly regular structure of molecular orientation and arrangement is spontaneously formed.

  Engineering applications of micropatterning using SAM are being studied, and can be used for etching masks of metals, semiconductors, and inorganic oxides. Taking advantage of these features, micropatterned SAMs are also used in the construction of organic electronic devices, the production of biofunctional molecular arrays with selective placement of DNA and proteins, and in cell culture experiments conducted in structurally regulated growth spaces. Therefore, application development to biofunctional microdevices such as biochips is expected (see, for example, Non-Patent Documents 1 and 2).

  Conventionally known combinations of functional groups of organic molecules that form SAMs and substrates are shown in Table 1 below (for example, see Non-Patent Document 3).

Among the substrates, particularly important in organic electronics is SAM with a silicon substrate and its thermal oxide film. Among Table 1 above, surface treatment with surface oxide films and organosilane molecules has been extensively studied (see, for example, Non-Patent Document 4).
In recent years, many SAMs of organic phosphonic acids and oxide films (silicon dioxide SiO ₂ ) have been reported (see, for example, Non-Patent Document 5). Figure 1 shows a schematic diagram of the SAM with the organic phosphonic acid oxide film (silicon dioxide SiO _2).

On the other hand, there is almost no literature reported that sulfonic acid and its derivatives and oxide films (titanium dioxide TiO ₂ ) form SAM, and only Non-Patent Document 6 describes SAM having the following structure. .

Moreover, although it is not possible to find a document in which sulfonic acid and its derivatives and silicon dioxide are reported to form SAM, silanol does not cause dehydration condensation with p-toluenesulfonic acid at a high yield as shown in the following scheme. It has been known for a long time (for example, see Non-Patent Document 7).

  Furthermore, it has been reported that silicon phthalocyanine having a hydroxy group as an axial ligand causes dehydration condensation with paratoluenesulfonic acid in a high yield (see, for example, Non-Patent Document 8).

  By the way, an information terminal that can be used anytime and anywhere is demanded in the ubiquitous information society. For this reason, flexible, lightweight, and inexpensive electronic devices are desired, but conventional electronic devices using inorganic semiconductor materials such as silicon cannot sufficiently meet these demands. Therefore, in recent years, research on electronic devices using organic semiconductor materials that can meet these demands has been actively conducted (see, for example, Non-Patent Documents 9 and 10).

By using an organic semiconductor material as a photoelectric conversion material, an organic photoelectric conversion element such as an optical sensor (for example, see Patent Documents 1 to 3) or an organic thin film solar cell (for example, see Non-Patent Documents 11 and 12). Is obtained. These devices are easier to manufacture than devices using inorganic semiconductor materials such as silicon. Especially when organic semiconductor materials that can be deposited by wet processes are used, large-area devices can be fabricated at low temperature and low cost. I have the potential to do it.
The organic thin film photoelectric conversion element reported to date has the highest efficiency, and is a blend of P3HT (poly (3-hexylthiophene)) and PCBM ([6,6] -phenyl-C61-butyric acid methyl ester). It is an element using a film as a photoelectric conversion layer (see, for example, Non-Patent Documents 11 and 12). In this blend film, there are many contact interfaces between P3HT, which is a p-type material, and PCBM, which is an n-type material, so that charge separation occurs with high efficiency. In addition, they are phase-separated to form minute domains, and the generated charges are taken out from the respective electrodes through the domains connected in a daisy chain. However, charge transport depends on the charge transport path formed by chance, and there is a problem in reproducibility and durability. Therefore, there is a need for a method for forming a composite structure of a p-type material and an n-type material that can achieve both charge separation and charge transport at a high level.

  In addition, high molecular organic semiconductor materials typified by P3HT (poly (3-hexylthiophene)) are distributed in molecular weight, which cannot be purified by sublimation or recrystallization and are difficult to purify, compared to low molecular organic semiconductor materials. However, materials such as pentacene and phthalocyanine, which exhibit high charge transportability in low-molecular organic semiconductor materials, generally have low solubility and crystallinity. Therefore, there is a problem that the suitability for coating film formation is low. There have been reports of examples of devices fabricated by applying low molecular weight organic semiconductor materials by introducing appropriate substituents, but photoelectric conversion can be achieved by applying a mixed solution of p-type materials and n-type materials consisting of low molecules. When a layer is produced, a p-type material and an n-type material are generally mixed at a molecular level, and a charge transport path is not formed well. Therefore, it is difficult to obtain a high-performance element (for example, non-patent See reference 13.). On the other hand, it is difficult to apply the upper layer without damaging the lower layer, and it is necessary to prepare either the upper layer or the lower layer by a vacuum deposition method. (For example, see Non-Patent Document 14.) Therefore, development of an organic thin film photoelectric conversion element that can be produced by a solution coating method using a low molecular weight compound and exhibits high efficiency is demanded.

For organic semiconductors and the like, it is generally known that the molecular arrangement of the outermost layer of the substrate and the molecular number layer has an important influence on the mobility. That is, the arrangement of organic molecules on SiO ₂ is important.

Furthermore, in recent years, attention has been focused on a material structure that should be called an organic-inorganic hybrid as an organic thin film solar cell. This is a method in which either a p-type material or an n-type material is an organic material, and the other is an inorganic material. Particularly well known is a combination in which a metal oxide such as TiO ₂ or ZnO is used as the n-type material and an organic material is used as the p-type material (see, for example, Non-Patent Document 15).

  However, the so-called organic-inorganic hybrid material has poor compatibility between the organic material and the inorganic material. Therefore, when the organic-inorganic hybrid material is used even in the thin film solar cell system, the mutual distance is long and the charge separation performance is low. Decreasing has been a problem. In order to improve the charge separation performance, it is better that the number of interfaces is larger. However, when a film in which a p-type material and an n-type material are mixed at the molecular level is manufactured, charge recombination occurs, so that charge transport ability is increased. descend. That is, charge separation and charge transport are in a trade-off relationship, and it is required that the distance between them is close while maintaining a certain domain size.

JP 2003-234460 A JP 2003-332551 A JP 2005-268609 A Supervised by Takahiro Seki, “Integrated membranes of functional materials and application development”, CM Publishing Supervised by Toyoki Kunitake, “Self-Organized Nanomaterials”, Frontier Publishing Chemical Reviews, 2005, 105, 1103. Nagata, Shinya, “Functional Materials”, September 2007, Vol.27, No.9, p.18 J. Am. Chem. Soc., 2003, Vol.125, p.16074-16080. Applied Surface Science, 1998, Vol.125, p.85-92. Zeitschrift. Naturforsch. B Anorg. Chem. Org. Chem., 1980, Vol.35, p.31-34. Inorg. Chem., 2001, Vol.40, p.932-939. Chemical Reviews, 2007, Vol.107, p.1296-1323. Organic Field-Effect Transistors, 2007, CRC Press, pages 159-228 Organic Photovoltaics, 2005, Taylor & Francis, pp. 49-104 Chemical Reviews, 2007, Vol.107, p.1324-1338. Materials Today, 2007, Vol. 10, p.34-41. "The latest collection of functional pigments," 2007, Technical Information Association, pages 320-328 Inorganica. Chimica. Acta, 2008, Vol.361, p.581.

  The present invention has been made in view of the above technical background, and an object of the present invention is to provide a method for forming an organic thin film by efficiently modifying the surface of an inorganic compound with a specific organic compound by a solution process. There is.

Therefore, as a result of intensive studies, the inventor formed a SAM on the surface of an inorganic compound using a specific organic compound having solubility suitable for a solution process, and applied an external stimulus such as heat to the surface. The inventors have found that the elimination reaction of substituents can proceed rapidly, the surface of the inorganic compound can be efficiently modified to form an organic thin film, and the present invention has been completed.
The problems of the present invention have been solved by the following means.

（式中、Ｒは置換基を表し、ｎは１又は２の整数を表す。）
［２］前記無機化合物が金属酸化物であることを特徴とする［１］項に記載の方法。
［３］前記一般式（１）で表される官能基を有する化合物を、水または有機溶媒に溶解させて前記無機化合物上に塗布し、前記無機化合物と共有結合を形成させることを特徴とする［１］又は［２］項に記載の方法。
［４］前記一般式（１）で表される官能基を有する化合物が、前記一般式（１）で表される官能基が、連結基を介してもしくは直接、π共役系化合物残基に連結してなることを特徴とする［１］〜［３］のいずれか１項に記載の方法。 [1] A monomolecular film of a compound having two or more functional groups represented by the following general formula (1) is formed on the outermost surface layer of the inorganic compound, and then the compound is bonded to the inorganic compound in the following general formula A method for surface modification of an inorganic compound, wherein a part or all of the functional group represented by the formula (1) is converted to a hydrogen atom.

(In the formula, R represents a substituent, and n represents an integer of 1 or 2.)
[2] The method according to item [1], wherein the inorganic compound is a metal oxide.
[3] The compound having the functional group represented by the general formula (1) is dissolved in water or an organic solvent and coated on the inorganic compound to form a covalent bond with the inorganic compound. The method according to item [1] or [2].
[4] In the compound having the functional group represented by the general formula (1), the functional group represented by the general formula (1) is linked to a π-conjugated compound residue via a linking group or directly. The method according to any one of [1] to [3], wherein

（式中、Ｒは置換基を表し、ｎは１又は２の整数を表す。）
［６］前記無機化合物が金属酸化物であることを特徴とする［５］項に記載の方法。
［７］前記一般式（１）で表される官能基を有する化合物を、水または有機溶媒に溶解させて前記無機化合物上に塗布し、前記無機化合物と共有結合を形成させることを特徴とする［５］又は［６］項に記載の方法。
［８］前記一般式（１）で表される官能基を有する化合物が、前記一般式（１）で表される官能基が、連結基を介してもしくは直接、π共役系化合物残基に連結してなることを特徴とする［５］〜［７］のいずれか１項に記載の方法。
［９］［５］〜［８］のいずれか１項に記載の方法により得られた有機薄膜を含む有機電子デバイス。 [5] A monomolecular film of a compound having two or more functional groups represented by the following general formula (1) is formed on the outermost surface layer of the inorganic compound, and then the following general compound not bonded to the inorganic compound in the compound A method for producing an organic thin film, wherein a part or all of the functional group represented by the formula (1) is converted into a hydrogen atom.

(In the formula, R represents a substituent, and n represents an integer of 1 or 2.)
[6] The method according to item [5], wherein the inorganic compound is a metal oxide.
[7] The compound having the functional group represented by the general formula (1) is dissolved in water or an organic solvent and coated on the inorganic compound to form a covalent bond with the inorganic compound. The method according to item [5] or [6].
[8] In the compound having the functional group represented by the general formula (1), the functional group represented by the general formula (1) is linked to a π-conjugated compound residue via a linking group or directly. The method according to any one of [5] to [7], wherein
[9] An organic electronic device comprising an organic thin film obtained by the method according to any one of [5] to [8].

  According to the present invention, by using an organic compound having a specific substituent as a precursor, an inorganic compound can be easily formed on a substrate by a solution process, and the obtained film can be externally exposed to heat or the like. By applying a stimulus, the elimination reaction of the substituent efficiently proceeds, the surface of the inorganic compound is efficiently modified, and an organic thin film can be formed. The obtained organic semiconductor film has high chemical stability and semiconductor operation stability, exhibits good semiconductor characteristics, and can be used for organic electronic devices.

Hereinafter, the present invention will be described in detail.
The inorganic compound surface modification method and the organic thin film production method of the present invention are dye compounds having two or more functional groups represented by the following general formula (1) (hereinafter referred to as “organic compounds used in the present invention”). Is used to form a monomolecular film on the outermost layer of the inorganic compound, and then the hydrogen is removed by removing part or all of the functional group represented by the general formula (1) that is not bonded to the inorganic compound in the compound. It is converted into atoms.

[Organic compounds used in the present invention]
(Functional group represented by general formula (1))
First, the functional group represented by the following general formula (1) will be described.

  In the general formula (1), R represents a substituent, and n represents an integer of 1 or 2.

  Examples of the substituent represented by R include halogen atoms, alkyl groups (including cyclic structures such as cycloalkyl groups and bicycloalkyl groups), and alkenyl groups (including cyclic structures such as cycloalkenyl groups and bicycloalkenyl groups). .), Alkynyl group, aryl group, heterocyclic group, cyano group, hydroxy group, nitro group, carboxy group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy Group, aryloxycarbonyloxy group, amino group (including anilino group), acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino group, Mercapto group, Alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl or heterocyclic azo group , Imide group, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, and silyl group.

  More specifically, examples of the substituent represented by R include a halogen atom (for example, a chlorine atom, a bromine atom, an iodine atom), an alkyl group [representing a linear, branched, cyclic substituted or unsubstituted alkyl group. . These are alkyl groups (preferably alkyl groups having 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, t-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, 2-ethylhexyl). A cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably having 5 to 30 carbon atoms). A substituted or unsubstituted bicycloalkyl group, that is, a monovalent group obtained by removing one hydrogen atom from a C 5-30 bicycloalkane, for example, bicyclo [1,2,2] heptan-2-yl, bicyclo [2,2,2] octane-3-yl), and tricyclo structures with more ring structures It is intended to free. An alkyl group (for example, an alkyl group of an alkylthio group) in the substituents described below also represents such an alkyl group. ],

Alkenyl group [represents a linear, branched or cyclic substituted or unsubstituted alkenyl group. They are alkenyl groups (preferably substituted or unsubstituted alkenyl groups having 2 to 30 carbon atoms, such as vinyl, allyl, prenyl, geranyl, oleyl), cycloalkenyl groups (preferably substituted or unsubstituted 3 to 30 carbon atoms). An unsubstituted cycloalkenyl group, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms (for example, 2-cyclopenten-1-yl, 2-cyclohexen-1-yl), Bicycloalkenyl group (Substituted or unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a bicycloalkene having one double bond. For example, bicyclo [2,2,1] hept-2-en-1-yl, bicyclo [2,2 2] is intended to encompass oct-2-en-4-yl). ],

Alkynyl group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, such as ethynyl, propargyl, trimethylsilylethynyl group, aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms such as Phenyl, p-tolyl, naphthyl, m-chlorophenyl, o-hexadecanoylaminophenyl), a heterocyclic group (preferably a 5- or 6-membered substituted or unsubstituted aromatic or non-aromatic heterocyclic compound A monovalent group in which one hydrogen atom is removed from, and more preferably a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms, such as 2-furyl, 2-thienyl, 2 -Pyrimidinyl, 2-benzothiazolyl), cyano group, hydroxy group, nitro group, carboxy group,

An alkoxy group (preferably a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, for example, methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, 2-methoxyethoxy), an aryloxy group (preferably A substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, such as phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy, 2-tetradecanoylaminophenoxy), silyloxy group (preferably Is a silyloxy group having 3 to 20 carbon atoms, such as trimethylsilyloxy, t-butyldimethylsilyloxy, a heterocyclic oxy group (preferably a substituted or unsubstituted heterocyclic oxy group having 2 to 30 carbon atoms, 1- Phenyltetrazol-5-oxy, 2-tetrahydropyranyl Ii) acyloxy group (preferably formyloxy group, substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms, such as formyloxy, acetyl Oxy, pivaloyloxy, stearoyloxy, benzoyloxy, p-methoxyphenylcarbonyloxy),

A carbamoyloxy group (preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms such as N, N-dimethylcarbamoyloxy, N, N-diethylcarbamoyloxy, morpholinocarbonyloxy, N, N-di- n-octylaminocarbonyloxy, Nn-octylcarbamoyloxy), alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, such as methoxycarbonyloxy, ethoxycarbonyloxy, t- Butoxycarbonyloxy, n-octylcarbonyloxy), aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, such as phenoxycarbonyloxy, p Methoxyphenoxy carbonyloxy, p-n-hexadecyloxycarbonyl phenoxycarbonyloxy),

An amino group (preferably an amino group, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted anilino group having 6 to 30 carbon atoms, such as amino, methylamino, dimethylamino, anilino, N-methyl-anilino, diphenylamino), acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms) Groups such as formylamino, acetylamino, pivaloylamino, lauroylamino, benzoylamino, 3,4,5-tri-n-octyloxyphenylcarbonylamino), aminocarbonylamino groups (preferably substituted with 1 to 30 carbon atoms) Or unsubstituted aminocarbonylamino, eg , Carbamoylamino, N, N-dimethylaminocarbonyl amino, N, N-diethylamino carbonylamino, morpholinocarbonylamino),

An alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms such as methoxycarbonylamino, ethoxycarbonylamino, t-butoxycarbonylamino, n-octadecyloxycarbonylamino, N-methyl-methoxy; Carbonylamino), aryloxycarbonylamino group (preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms, such as phenoxycarbonylamino, p-chlorophenoxycarbonylamino, m- (n-octyloxy) ) Phenoxycarbonylamino), a sulfamoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms such as sulfamoylamino, N, N-dimethylamino) Sulfonylamino, N-n-octylaminosulfonylamino),

Alkyl or arylsulfonylamino group (preferably substituted or unsubstituted alkylsulfonylamino having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonylamino having 6 to 30 carbon atoms, such as methylsulfonylamino, butylsulfonylamino, phenyl Sulfonylamino, 2,3,5-trichlorophenylsulfonylamino, p-methylphenylsulfonylamino), mercapto group, alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms such as methylthio, ethylthio, n-hexadecylthio), an arylthio group (preferably a substituted or unsubstituted arylthio having 6 to 30 carbon atoms, such as phenylthio, p-chlorophenylthio, m-methoxyphenylthio), a heterocyclic thio group (preferably Substituted or unsubstituted heterocyclic thio group prime 2-30, for example, 2-benzothiazolylthio, 1-phenyl-5-ylthio),

Sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms such as N-ethylsulfamoyl, N- (3-dodecyloxypropyl) sulfamoyl, N, N-dimethylsulfamoyl, N- Acetylsulfamoyl, N-benzoylsulfamoyl, N- (N′-phenylcarbamoyl) sulfamoyl), sulfo group, alkyl or arylsulfinyl group (preferably a substituted or unsubstituted alkylsulfinyl group having 1 to 30 carbon atoms) 6-30 substituted or unsubstituted arylsulfinyl groups such as methylsulfinyl, ethylsulfinyl, phenylsulfinyl, p-methylphenylsulfinyl), alkyl or arylsulfonyl groups (preferably substituted or unsubstituted having 1 to 30 carbon atoms) Substitutional alk Sulfonyl groups, 6-30 substituted or unsubstituted arylsulfonyl group, e.g., methylsulfonyl, ethylsulfonyl, phenylsulfonyl, p- methylphenyl sulfonyl),

Acyl group (preferably formyl group, substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, substituted or unsubstituted carbon group having 4 to 30 carbon atoms Heterocyclic carbonyl groups bonded to the carbonyl group by atoms, for example, acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyloxyphenylcarbonyl, 2-pyridylcarbonyl, 2-furylcarbonyl), aryl An oxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms such as phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, pt-butylphenoxycarbonyl), alkoxy Carbonyl group ( Preferably, it is a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms such as methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, n-octadecyloxycarbonyl), carbamoyl group (preferably having 1 to 30 carbon atoms). Substituted or unsubstituted carbamoyl, such as carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N, N-di-n-octylcarbamoyl, N- (methylsulfonyl) carbamoyl),

An aryl or heterocyclic azo group (preferably a substituted or unsubstituted arylazo group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic azo group having 3 to 30 carbon atoms, such as phenylazo, p-chlorophenylazo, 5- Ethylthio-1,3,4-thiadiazol-2-ylazo), an imide group (preferably N-succinimide, N-phthalimide), a phosphino group (preferably a substituted or unsubstituted phosphino group having 2 to 30 carbon atoms, For example, dimethylphosphino, diphenylphosphino, methylphenoxyphosphino), phosphinyl group (preferably a substituted or unsubstituted phosphinyl group having 2 to 30 carbon atoms, such as phosphinyl, dioctyloxyphosphinyl, diethoxyphosphini ), A phosphinyloxy group (preferably having 2 carbon atoms) 30 substituted or unsubstituted phosphinyloxy groups, for example, diphenoxyphosphinyloxy, dioctyloxyphosphinyloxy), phosphinylamino groups (preferably substituted or unsubstituted having 2 to 30 carbon atoms) Phosphinylamino group such as dimethoxyphosphinylamino, dimethylaminophosphinylamino), silyl group (preferably a substituted or unsubstituted silyl group having 3 to 30 carbon atoms such as trimethylsilyl, t-butyldimethyl Silyl, phenyldimethylsilyl).

  Among the above-mentioned substituents, those having a hydrogen atom may be substituted with the above-mentioned group after removing this. Examples of such a substituent include an alkylcarbonylaminosulfonyl group, an arylcarbonylaminosulfonyl group, an alkylsulfonylaminocarbonyl group, and an arylsulfonylaminocarbonyl group. More specific examples include methylsulfonylaminocarbonyl, p-methylphenylsulfonylaminocarbonyl, acetylaminosulfonyl, and benzoylaminosulfonyl groups. R may be further substituted with a substituent.

  Here, examples of R include a hydroxy group, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a carboxyl group, and a silyl group. Preferred are a hydroxy group, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, and a heterocyclic group, and particularly preferred are a hydroxy group, a linear or branched alkyl group having 1 to 30 carbon atoms, and 6 to 18 carbon atoms. Of the aryl group.

  In the general formula (1), n represents an integer of 1 or 2, and most preferably 2.

  The functional group represented by the general formula (1) is most preferably a functional group represented by the following general formula (2) or (3).

  In the present invention, the metal salt of the functional group is not preferable because it inhibits the formation of a monomolecular film of the compound and the functional group is difficult to be replaced with a hydrogen atom. This is because the metal salt substituent of sulfonic acid and sulfinic acid does not undergo dehydration condensation with the hydroxyl group on the outermost layer of the substrate, and sulfur trioxide or sulfur dioxide is eliminated from the metal salt substituent of sulfonic acid and sulfinic acid. This compound is considered to be difficult to desorb because the energy level is higher than that of the compound after desorption of sulfonic acid and sulfinic acid.

  The organic compound used in the present invention is a dye compound having two or more functional groups represented by the general formula (1). Preferably, the functional group represented by the general formula (1) is a linking group. Or directly or directly linked to a π-conjugated compound residue.

(Linking group)
The linking group is preferably divalent. Specific examples of preferred linking groups include alkylene groups (including cycloalkylene groups), alkenylene groups (including cycloalkenylene groups), alkynylene groups, arylene groups, heterocyclic linking groups (including heteroarylene groups), and carbonyl linkages. Group (—C (═O) —), thiocarbonyl linking group (—C (═S) —), oxygen atom linking group (—O—), nitrogen atom linking group (—N (R ^a ) —, where R ^a is the same as R in the general formula (1)), sulfur atom linking group (—S—), silylene group (—Si (R ^b ) (R ^c ) —, wherein R ^b and R ^c are , Each of which is the same as R in the general formula (1) and may be bonded to each other to form a ring), and a linking group composed of a combination thereof. In the present invention, the cycloalkylene group includes a bicycloalkynylene group and a tricyclo structure having more ring structures, and the cycloalkenylene group includes a bicycloalkenylene group and a tricyclo structure having more ring structures. Etc. are also included.
The linking group is more preferably a divalent group obtained by removing one hydrogen atom from the monovalent substituent described above for R. Specific examples of preferred linking groups include divalent groups in which one hydrogen atom has been removed from a monovalent substituent such as an aryl group, heterocyclic group, aryloxy group, heterocyclic oxy group, arylthio group, and heterocyclic thio group. And most preferably a heterocyclic group, an aryloxy group, a heterocyclic oxy group, an arylthio group, or a divalent group obtained by removing one hydrogen atom from a heterocyclic thio group.

(Π-conjugated compound)
As the π-conjugated compound in the present invention, any compound having a wide π-conjugated plane may be used, but a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, Triazole ring, oxazole ring, thiazole ring, furan ring, thiophene ring, more preferably aromatic such as benzene ring, pyridine ring, pyrazine ring, pyrrole ring, pyrazole ring, imidazole ring, oxazole ring, thiazole ring, thiophene ring The structure is preferably a structure in which two or more aromatic hydrocarbon rings or aromatic heterocycles are condensed and / or covalently linked.
Specific examples of the π-conjugated compound in the present invention include condensed polycyclic compounds such as tetracene, pentacene, triphenylene, and hexabenzocoronene, heterocyclic oligomers such as quarterthiophene and sexithiophene, phthalocyanines, porphyrins, and the like. .

  From the viewpoint of chemical stability, semiconductor operation stability, and semiconductor characteristics of the compound, the organic compound used in the present invention is particularly preferably a phthalocyanine compound represented by the following general formula (P). Here, the phthalocyanine compound refers to a compound having a phthalocyanine skeleton, and is a derivative in which a substituent is bonded to phthalocyanine.

(In the formula, Q represents an atomic group necessary to form an aromatic hydrocarbon ring or an aromatic heterocycle. Plural Qs may be the same or different. R ² represents a substituent. If .m an integer of 1 to 16 is 2 or more, the plurality of -SO ₂ R ² groups may.-SO ₂ R ² groups be the same or different, aromatic hydrocarbon formed by Q Substituted with a hydrogen atom in a ring or aromatic heterocycle.)

In the general formula (P), Q represents an atomic group necessary for forming an aromatic hydrocarbon ring or an aromatic heterocycle. A plurality of Q may be the same or different. Here, the aromatic hydrocarbon ring or aromatic heterocycle is preferably a 4- to 10-membered ring, more preferably a 5- to 7-membered ring, still more preferably a 5- or 6-membered ring, and particularly preferably a 6-membered ring.
Although the hetero atom contained in the aromatic heterocycle formed by Q is not particularly limited, nitrogen, oxygen, sulfur, selenium, silicon, germanium or phosphorus is preferable, nitrogen, oxygen or sulfur is more preferable, and nitrogen is particularly preferable. The number of heteroatoms contained in one aromatic heterocycle formed by Q is not particularly limited, but is preferably 1 to 3.

Specific examples of the aromatic hydrocarbon ring or aromatic heterocycle formed by Q include benzene ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, pyrrole ring, pyrazole ring, imidazole ring, triazole ring, oxazole ring. Oxadiazole ring, thiazole ring, thiadiazole ring, furan ring, thiophene ring, selenophene ring, silole ring, germol ring, phosphole ring and the like.
The aromatic hydrocarbon ring or aromatic heterocycle formed by Q may have a substituent, and as the substituent, those exemplified above for R can be applied.

  The aromatic hydrocarbon ring or aromatic heterocycle formed by Q may further form a condensed ring with another ring. Examples of the condensed ring include a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, and a pyridazine ring. , Pyrrole ring, pyrazole ring, imidazole ring, triazole ring, oxazole ring, oxadiazole ring, thiazole ring, thiadiazole ring, furan ring, thiophene ring, selenophene ring, silole ring, germol ring, phosphole ring and the like. The above substituent and condensed ring may further have a substituent and may be further condensed with another ring. As the substituent, those described above as R can be applied.

  The aromatic hydrocarbon ring or aromatic heterocycle formed by Q is preferably a benzene ring, pyridine ring, pyrazine ring, pyrimidine ring, triazine ring, pyrrole ring, pyrazole ring, imidazole ring, triazole ring, oxazole ring, thiazole. Ring, furan ring, thiophene ring, more preferably benzene ring, pyridine ring, pyrazine ring, pyrrole ring, pyrazole ring, imidazole ring, oxazole ring, thiazole ring, thiophene ring, more preferably benzene ring, A pyridine ring, a pyrazine ring, a pyrazole ring, an imidazole ring, and a thiophene ring are preferable, and a benzene ring, a pyridine ring, and a pyrazine ring are particularly preferable.

In the general formula (P), the —SO ₂ R ² group may be bonded anywhere in the molecule, but is preferably a hydrogen atom in the aromatic hydrocarbon ring or aromatic heterocycle formed by Q Replace. R ² has the same meaning as R in the general formula (1), and the preferred range is also the same.

In the general formula (P), m represents an integer of 1 to 16. When m is 2 or more, the plurality of —SO ₂ R ² groups may be the same or different. m is preferably an integer of 1 to 8, more preferably an integer of 1 to 4.

In the general formula (P), M represents a metal atom or a hydrogen atom. When M represents a hydrogen atom, two hydrogen atoms are each bonded to any two nitrogen atoms of N ^{1 to} N ⁴ .
When M represents a metal atom, any metal may be used as long as it forms a stable complex, and Li, Na, K, Be, Mg, Ca, Ba, Al, Si, Hg, Cr, Fe, Co Ni, Cu, Zn, Ge, Pd, Cd, Sn, Pt, Pb, Sr, V, Mn, Ti, In, or Ga can be used. In addition, a substituent may be bonded to the metal atom, and as the substituent, those mentioned above for R can be used. In addition to single metal atoms, trivalent or higher-valent metal atoms and other elements that are divalent by bonding with other elements, such as AlCl, Ti = O, V = O, SiCl _{2 and the} like are also included. It is.
Preferably Mg as M, Ca, AlCl, an _{SiCl 2, Fe, Co, Ni} , Cu, Zn, Pd, Sn, SnCl 2, Pt, Pb, V = O, Mn , or Ti = O, more preferably Fe , Co, Ni, Cu or Zn, particularly preferably Cu or Zn. In addition, the case where M is a hydrogen atom is also preferable, and the general formula (P) in the case where M is a hydrogen atom is represented by the following general formula (P ′).

In Formula (P '), Q, R 2 and m, Q in each of the general formula (P), have the same meanings as R ² and m, the preferable range is also the same.

(Existence of isomers)
Generally, in a phthalocyanine compound having a plurality of substituents, there may exist positional isomers having different positions to which the substituents are bonded. The organic compound used in the present invention is not an exception, and in some cases, several kinds of positional isomers can be considered. In the present invention, the phthalocyanine compound may be used as a single compound or as a mixture of positional isomers. When used as a mixture of regioisomers, the number of regioisomers mixed, the substitution position of the substituent in each regioisomer, and the mixing ratio of regioisomers may be arbitrary.

(Preferred specific example)
Although the preferable specific example of a compound represented by the said General formula (1) is given to the following, this invention is not limited to these.
Specific examples of phthalocyanine compounds are shown in Tables 2 to 6, respectively. In Tables 2 to 6, the * mark of the substituent represents a binding site to the phthalocyanine compound represented by the following general formula (1-A). In Tables 2 to 6, for example, the notation “R ^α1 / R ^α2 ” represents the meaning of “R ^α1 or R ^α2 ”. Therefore, a compound having this notation is a mixture of substitutional isomers. It is. Further, when R ^{α1 to} R ^α8 or R ^{β1 to} R ^β8 are unsubstituted, that is, when a hydrogen atom is bonded, the notation is omitted. Bu represents a butyl group, and Me represents a methyl group.

(Synthesis method)
The phthalocyanine ring formation reaction of the phthalocyanine compound in the present invention is described by Shigeyoshi Shigeyoshi, Kobayashi Nagao, edited by "Phthalocyanine-Chemistry and Function-" (IPC, 1997), pages 1 to 62, Takahashi Ryo, Sakamoto Keiichi, This can be carried out according to pages 29 to 77 of “Phthalocyanine as a functional dye” edited by Eiko Okumura (IPC, 2004).

  Typical methods for synthesizing phthalocyanine compounds include the Weiler method, phthalonitrile method, lithium method, subphthalocyanine method, and chlorinated phthalocyanine method described in these documents. In the present invention, the phthalonitrile method can be preferably used. Specifically, it is preferable to perform a phthalocyanine ring formation reaction using a compound having a functional group represented by the general formula (1) such as t-butylsulfonylphthalonitrile as a raw material. Any reaction conditions may be used in the phthalocyanine ring formation reaction. In the ring formation reaction, it is preferable to add various metals to be the central metal of phthalocyanine, but a desired metal may be introduced after the synthesis of a phthalocyanine compound having no central metal. Any solvent may be used as the reaction solvent, but a solvent having a high boiling point is preferable. Further, an acid or a base may be used for promoting the ring formation reaction. Optimum reaction conditions vary depending on the structure of the target phthalocyanine compound, but can be set with reference to specific reaction conditions described in the above-mentioned documents.

  As raw materials used for the synthesis of the phthalocyanine compound, derivatives such as phthalic anhydride, phthalimide, phthalic acid and salts thereof, phthalic acid diamide, phthalonitrile, 1,3-diiminoisoindoline can be used. These raw materials may be synthesized by any known method.

  Moreover, the organic compound used for this invention can also be prepared with reference to description, such as Unexamined-Japanese-Patent No. 2005-119165.

(purity)
As will be described later, the organic thin film (organic semiconductor thin film) obtained by the method of the present invention can be used in an organic electronic device. In an organic electronic device, a condition for exhibiting high carrier mobility is that an organic semiconductor material has high purity. If even a small amount of impurities are contained in the organic semiconductor film, the impurities serve as carrier traps or cause defects in the crystal structure, which causes a decrease in mobility. Therefore, from this point of view, it is desirable that the impurity concentration is low, preferably 10% or less, more preferably 1% or less. The purity of the material can be examined, for example, by liquid chromatography (HPLC).

[Inorganic compounds]
There is no restriction | limiting in particular as an inorganic compound used for this invention. For example, metal / compound semiconductors (Au, Ag, Cu, Pt, Pd, Hg, Fe, GaAs, InP, Si, CdS, CdSe, ZnS, ZnSe, SnSe, FeS ₂ , PbS, InP, GaAs, CuInS ₂ , CuInSe ₂ etc.), oxide / oxide film _{(ZrO 2, TiSrO 3, TiO} 2, Nb 2 O 3, Al 2 O 3, AgO, CuO, Ta 2 O 5, Zr / Al 2 O 3, glass, mica, SiO _{2 , SnO 2, WO 3, GeO} 2, ZrO 2, ZnO, V 2 O 5, KTaO 3, indium tin oxide (ITO), stainless steel (SUS), lead zirconate titanate (PZT)), silicon nitride (Si ₃ N ₄ , SiN _x ) and the like are preferable.

The shape of the inorganic compound used in the present invention is not particularly limited, but is preferably plate-shaped, and in the present invention, an inorganic compound substrate is preferably used. Further, the surface treatment of the surface layer of the substrate may be performed in any manner. For example, the surface of silicon dioxide may be hydrogen-terminated silicon Si—H such as hexamethyldisilazane (HMDS), octadecyltrichlorosilane (OTS), Oxide-NH _2, etc. Etc., those having a surface treated by coating with halogenated silicon Si—X (X = Cl, Br, I, etc.), hydrogen-terminated diamond C—H or the like can be used.

In the present invention, it is particularly preferable that a hydroxyl group is present in the outermost layer of the inorganic compound substrate. Therefore, the inorganic compound is preferably a metal oxide, and an oxide / oxide film (ZrO ₂ , TiSrO ₃ , TiO ₂ , Nb ₂ O ₃ , Al ₂ O ₃ , AgO, CuO, Ta ₂ O ₅ , Zr / Al ₂ O ₃ , glass, mica, SiO ₂ , SnO ₂ , WO ₃ , GeO ₂ , ZrO ₂ , ZnO, V ₂ O ₅ , KTaO ₃ , ITO, SUS, PZT) and the like are preferably used.
In addition, for example, the surface layer of an inorganic compound substrate may be subjected to ozone treatment to expose hydroxy groups on the substrate, or a hydroxy group-containing alkanethiol SAM film may be formed on the metal surface. it can.

[Formation of monomolecular film]
In the method of the present invention, a monomolecular film of the organic compound used in the present invention is formed on the outermost layer of the inorganic compound. The monomolecular film can be formed by forming an organic compound used in the present invention on an inorganic compound substrate, and then covalently bonding the organic compound used in the present invention and the inorganic compound by heating. it can.

(Film formation method)
The organic compound used in the present invention may be formed on the inorganic compound substrate by any method, but can be formed by a vacuum process or a solution process. Specific examples of film formation by a vacuum process include physical vapor deposition methods such as vacuum deposition, sputtering, ion plating, molecular beam epitaxy (MBE), and chemical vapor deposition (CVD) such as plasma polymerization. ) Method.
Here, film formation by a solution process refers to a method in which an organic compound is dissolved in a solvent that can be dissolved and a film is formed using the solution. Specifically, casting method, blade coating method, wire bar coating method, spray coating method, dipping (dipping) coating method, bead coating method, air knife coating method, curtain coating method, ink jet method, spin coating method, Langmuir- A usual method such as a Langmuir-Blodgett (LB) method can be used. In the present invention, film formation by a solution process is more preferable, and it is particularly preferable to use a casting method, a spin coating method, a dipping (dip) coating method, or an ink jet method.

(Application conditions)
When a film is formed on a substrate using a solution process, the material for forming the layer is selected from an appropriate organic solvent (for example, hexane, octane, decane, toluene, xylene, ethylbenzene, 1-methylnaphthalene, 1,2-dichlorobenzene, etc. A hydrocarbon solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc .; a halogen such as dichloromethane, chloroform, tetrachloromethane, dichloroethane, trichloroethane, tetrachloroethane, chlorobenzene, dichlorobenzene, chlorotoluene, etc. Hydrocarbon solvents; for example, ester solvents such as ethyl acetate, butyl acetate, amyl acetate; for example, methanol, propanol, butanol, pentanol, hexanol, cyclohexanol, methyl cello Alcohol solvents such as rub, ethyl cellosolve, ethylene glycol; for example, ether solvents such as dibutyl ether, tetrahydrofuran, dioxane, anisole; for example, N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2 A polar solvent such as -pyrrolidone, 1-methyl-2-imidazolidinone, dimethyl sulfoxide, etc.) and / or water can be dissolved or dispersed to form a coating solution, and a thin film can be formed by various coating methods.
The concentration of the organic compound used in the present invention in the coating solution is preferably 0.1 to 80% by mass, more preferably 0.1 to 10% by mass, whereby a film having an arbitrary thickness can be formed. .

  The organic compound used in the present invention is particularly suitable for film formation by a solution process. In order to form a film by a solution process, it is necessary that the material is dissolved in the above-described solvent or the like, but it is not sufficient to simply dissolve the material. Usually, even a material for forming a film by a vacuum process can be dissolved in a solvent to some extent. However, in the solution process, after the material is dissolved in a solvent and applied, the solvent evaporates to form a thin film, and many materials that are not suitable for the solution process have high crystallinity. Crystallization makes it difficult to form a good thin film. The organic compound used in the present invention is also excellent in that crystallization hardly occurs.

It is also possible to use a resin binder during film formation. In this case, the material for forming the layer and the binder resin can be dissolved or dispersed in the above-mentioned appropriate solvent to form a coating solution, and a thin film can be formed by various coating methods. Examples of the resin binder include insulating polymers such as polystyrene, polycarbonate, polyarylate, polyester, polyamide, polyimide, polyurethane, polysiloxane, polysulfone, polymethyl methacrylate, polymethyl acrylate, cellulose, polyethylene, and polypropylene, and copolymers thereof. And photoconductive polymers such as polyvinyl carbazole and polysilane, and conductive polymers such as polythiophene, polypyrrole, polyaniline, and polyparaphenylene vinylene. The resin binder may be used alone or in combination. Considering the mechanical strength of the thin film, a resin binder having a high glass transition temperature is preferable, and considering the charge mobility, a resin binder, a photoconductive polymer, or a conductive polymer having a structure not containing a polar group is preferable.
It is preferable not to use a resin binder in terms of the characteristics of the organic semiconductor, but it may be used depending on the purpose. Although the usage-amount of the resin binder in this case does not have a restriction | limiting in particular, In the film | membrane consisting of the organic compound used for this invention, Preferably it is used at 0.1-30 mass%.

  In the film formation, the substrate may be heated or cooled, and the film quality and packing of molecules in the film can be controlled by changing the temperature of the substrate. Although there is no restriction | limiting in particular as temperature of a board | substrate, It is preferable that it is between 0 degreeC-200 degreeC.

(Covalent bond formation)
Formation of a covalent bond between the organic compound and the inorganic compound used in the present invention is caused at 50 ° C. or higher, preferably 100 ° C. or higher. Moreover, an upper limit is 500 degrees C or less, Preferably it is 400 degrees C or less. The higher the temperature, the shorter the reaction time, and the lower the temperature, the longer the time required for the bond formation reaction. Depending on the application, the characteristics can be adjusted by partial conversion.
For heating, in addition to heating by heat transfer using a heater, irradiation with light having a wavelength absorbed by a compound such as an infrared lamp or a semiconductor laser may be used. In addition, a layer that absorbs light may be provided in the vicinity of the organic compound used in the present invention, and heating may be performed by absorbing light in this layer. Such heating is preferably performed in an inert atmosphere such as nitrogen, argon, or vacuum.

(Functional group conversion)
In the method of the present invention, a monomolecular film of the organic compound used in the present invention is formed and then heated, whereby the functional group represented by the general formula (1) not bonded to the inorganic compound substrate in the compound is formed. Part or all of the group is converted to a hydrogen atom. By removing the functional group represented by the general formula (1) and converting it to a hydrogen atom, the organic compound used in the present invention is converted into a solvent-insoluble compound. For example, when the organic compound used in the present invention is a phthalocyanine compound represented by the general formula (P), an unsubstituted phthalocyanine thin film can be formed on the substrate surface of the inorganic compound, and the substrate surface of the inorganic compound can be formed. Can be modified with unsubstituted phthalocyanine.

  The heating temperature for converting the functional group represented by the general formula (1) not bonded to the substrate of the inorganic compound into a hydrogen atom is 200 ° C. or higher, preferably 250 ° C. or higher. Moreover, an upper limit is 500 degrees C or less, Preferably it is 400 degrees C or less. The higher the temperature, the shorter the reaction time, and the lower the temperature, the longer the time required for the elimination reaction. Depending on the application, the characteristics can be adjusted by partial conversion. Heating can be performed by the same means as the formation of the covalent bond.

(Film thickness)
The organic thin film obtained by the above method is a monomolecular film. Therefore, although a film thickness changes with the organic compounds used for this invention, it is generally 0.1-100 nm, Preferably it is 1-50 nm, More preferably, it is 1-20 nm.

[Organic electronic devices]
The organic electronic device of the present invention includes an organic thin film (organic semiconductor film) obtained by the above method. Here, the organic electronic device is a device containing an organic semiconductor and having two or more electrodes, and a current flowing between the electrodes and a generated voltage are controlled by electricity, light, magnetism, chemical substances, or the like, or A device that generates light, an electric field, a magnetic field or the like by an applied voltage or current. Examples include organic photoelectric conversion elements, organic field effect transistors, organic electroluminescent elements, gas sensors, organic rectifying elements, organic inverters, information recording elements, and the like. The organic photoelectric conversion element can be used for both optical sensor applications and energy conversion applications (solar cells). Among these, an organic field effect transistor or an organic photoelectric conversion element is preferable, and an organic field effect transistor is particularly preferable.

  By using a dye compound having two or more functional groups represented by the general formula (1) as a precursor of an organic semiconductor, film formation on a substrate is easy, and external stimulation such as heat is applied to the obtained film. As a result, the elimination reaction of the substituent proceeds efficiently, and an organic semiconductor film exhibiting good semiconductor characteristics with high chemical stability and semiconductor operation stability can be obtained. The organic semiconductor film of the present invention and an electronic device (particularly, a field effect transistor (FET)) using the organic semiconductor film have high purity, high semiconductor operation stability, and good semiconductor characteristics.

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

Reference example 1
(Measurement of molecular weight)
The molecular weight of commercially available 4-substituted zinc sulfonate phthalocyanine (Exemplary Compound A-53, manufactured by Frontier Scientific, trade name: ZnPcS-834) was measured by matrix-assisted ionization-time-of-flight mass spectrometry (MALDI-TOF-MS). However, it was 895 (= [M ⁺ ]: polar negative). The MALDI-TOF-MS measurement was performed using Voyager-DE PRO (trade name) manufactured by Applied Biosystems and using α-cyano-4-hydroxycinnamic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) as a matrix.

(Measurement of mass reduction rate)
Moreover, the thermal analysis (TG / DTA measurement) was performed about this compound. TG / DTA measurement was performed by Seiko Instruments Inc. Using EXSTAR6000 (trade name), the temperature was increased at a rate of 10 ° C./min in a range of 30 ° C. to 550 ° C. under a N ₂ air flow (flow rate 200 ml / min) to obtain the mass reduction rate. The measurement results are shown in FIG. FIG. 2 is a graph showing the temperature change of the mass reduction rate.

When 4-substituted zinc phthalocyanine sulfonate (Exemplary Compound A-53) was heated at 250 ° C., it showed water solubility. The initial mass loss in TG / DTA is believed to be due to the solvent or water. Thereafter, the residue was heated to 400 ° C., and the MS spectrum of the residue was measured. As a result, the peak of the MS spectrum was changed to 576 (= [M ⁺ ]: polar positive). This means that the sulfonic acid group was eliminated and changed from a 4-substituted sulfonic acid zinc phthalocyanine to a zinc phthalocyanine pigment.

Reference example 2
For a commercially available 4-substituted sulfonic acid metal-free phthalocyanine (Exemplary Compound A-54, manufactured by Frontier Scientific, trade name: Pcs-834), the molecular weight and the mass reduction rate were measured in the same manner as in Reference Example 1. The MS spectrum was 832 (= [M ⁺ ] -1: polar negative). The measurement result of the mass reduction rate is shown in FIG.

When 4-substituted sulfonic acid metal-free phthalocyanine (Exemplary Compound A-54) was heated at 250 ° C., it showed water solubility. The initial mass loss in TG / DTA is believed to be due to the solvent or water. Thereafter, the mixture was heated to 400 ° C., and the MS spectrum of the residue was measured. As a result, the peak of the MS spectrum was changed to 514 (= [M ⁺ ]: polar positive). This means that the sulfonic acid group was eliminated and changed from a 4-substituted sulfonic acid metal-free phthalocyanine to a metal-free phthalocyanine pigment.

Reference example 3
The mass reduction rate of the commercially available 4-substituted sodium sulfonate copper phthalocyanine (manufactured by Aldrich) was measured in the same manner as in Reference Example 1. The result of measuring TG / DTA is shown in FIG.
FIG. 4 is a graph showing the TG / DTA measurement results of 4-substituted sodium sulfonate copper phthalocyanine. In FIG. 4, the top curve shows mass change (TG) with respect to temperature, the bottom curve shows heat input / output (enthalpy change) (DTA) with respect to temperature, and the middle curve shows TG. The amount of change per hour (differential value) (DTG) is shown.
From the top curve in FIG. 4, it was found that there was almost no mass loss. Moreover, it turned out that there is almost no enthalpy change from the lowermost curve in FIG. From these results, it was found that the tetrasubstituted sodium sulfonate copper phthalocyanine was less likely to detach the sulfonic acid group at 400 ° C. than the 4-substituted zinc sulfonate phthalocyanine or the 4-substituted sulfonic acid metal-free phthalocyanine. This is presumably because the energy level of the compound after elimination of sulfur trioxide from the sodium sulfonate substituent is higher than that of the compound after elimination of sulfonic acid.

Example 1
A silicon wafer with a thermal oxide film is UV ozone-treated in a solution of 0.1 g of commercially available 4-substituted zinc sulfonate phthalocyanine (Exemplary Compound A-53, manufactured by Frontier Scientific, trade name: ZnPcS-834) in 5 ml of water. The treated substrate was immersed for 5 minutes and heated at 150 ° C. for 30 minutes. Then, the thickness of the substrate washed away with water was measured using an automatic ellipsometer (DHA-XA series, trade name, manufactured by Mizoji Optical Industry Co., Ltd.), and a monolayer of 10 mm was formed on the substrate. I understood it. This was further heated at 400 ° C. for 30 minutes. Similarly, when the film thickness was measured, it was found that a monomolecular film of 8 cm was formed.
From the above results, (1) When heated at 150 ° C., the hydroxy group on SiO ₂ on the outermost layer of the substrate and the sulfonic acid group substituted with phthalocyanine form a dehydration condensation to form a covalent bond, thereby forming a monomolecular film. (2) Of the sulfonic acid groups substituted with phthalocyanine, the sulfonic acid groups not bonded to the substrate are eliminated and converted into hydrogen atoms by heating at 400 ° C., and a single molecule of unsubstituted phthalocyanine It was found that a film was formed.

Comparative Example 1
The same operation as in Example 1 was performed except that 4-substituted sodium sulfonate phthalocyanine (manufactured by Aldrich) was used instead of 4-substituted sulfonate zinc phthalocyanine (Exemplary Compound A-53). When the thickness of the substrate was measured using an automatic ellipsometer in the same manner as in Example 1, it was found that the thickness was 0 mm and no monomolecular film was formed on the substrate. This is presumably because the sodium sulfonate substituent does not undergo dehydration condensation with the hydroxy group on SiO ₂ on the outermost surface layer of the substrate, and is washed away with water even after heating.

Example 2
(Production of solar cells)
A glass substrate (2.5 cm × 2.5 cm) on which an ITO electrode was patterned was subjected to ultrasonic cleaning in isopropyl alcohol and then dried. Further, UV ozone treatment was performed for 30 minutes in order to remove organic contaminants on the surface of the ITO electrode. Next, a PEDOT (poly (3,4-ethylenedioxythiophene)) / PSS (polystyrene sulfonic acid) aqueous solution (BaytronP (standard product), Stark) is spin-coated (4000 rpm, 60 seconds) on the ITO substrate. By drying at 120 ° C. for 10 minutes, a hole transporting buffer layer having a film thickness of about 50 nm was formed. The film thickness was measured with a stylus type film thickness meter (trade name: DEKTAK 6M, manufactured by ULVAC) (hereinafter the same).

Next, a water mixed solution (15 mg + 15 mg / mL) obtained by emulsifying nanoparticles (particle size: 80 nm, manufactured by Aldrich) of the above water-soluble 4-substituted zinc sulfonate phthalocyanine (Exemplary Compound A-53) and titanium oxide with a homogenizer. By spin coating on the buffer layer at 1000 rpm, an organic semiconductor (organic photoelectric conversion layer) precursor film having a substantially uniform thickness of 200 nm or less was formed. In a nitrogen atmosphere, it was heated to 400 ° C. at 10 ° C./min, and held at 400 ° C. for 5 minutes to convert it into an organic semiconductor film, thereby producing a photoelectric conversion layer. On this photoelectric conversion layer, using a vacuum deposition apparatus (trade name: EBX-8C, manufactured by ULVAC), LiF is about 1 nm as a buffer layer and aluminum is used as a metal electrode at a vacuum degree of 2 × 10 ⁻⁴ or less. The organic photoelectric conversion element having an effective area of 0.04 cm ² was obtained by sequentially vacuum-depositing the film with a thickness of about 80 nm.

This element was irradiated with simulated sunlight of AM1.5 and 100 mW / cm ² using a solar simulator (Oriel, 150W simple type), and an electrochemical analyzer (trade name: ALS model 660B, manufactured by BAS) was used. The current-voltage characteristics were measured. As a result, photocurrent and photovoltaic power were generated, and good photoelectric conversion characteristics were exhibited. This is thought to be due to the fact that the bond between the organic-inorganic interfaces was generated by dehydration, resulting in a short distance between each other and high charge separation ability.

Comparative Example 2
An organic photoelectric conversion device in the same manner as in Example 2 except that the 4-substituted sodium sulfonate copper phthalocyanine of Reference Example 3 (manufactured by Aldrich) was used instead of the water-soluble phthalocyanine (Exemplary Compound A-53) in Example 2. Was made. The produced sample was measured for photoelectric conversion characteristics in the same manner as in Example 2, but showed no photoelectric conversion characteristics at all. This is presumably because no bond is formed at the interface and the ability to desorb substituents is low, so the distance between them is long and the charge separation ability is low.

It is a schematic diagram of the SAM with the conventional organic phosphonic acid and the oxide film (silicon dioxide SiO _2). 6 is a graph showing a temperature change of a mass reduction rate of Reference Example 1. 6 is a graph showing a temperature change of a mass reduction rate of Reference Example 2. 10 is a graph showing a TG / DTA measurement result of Reference Example 3.

Claims (9)

A monomolecular film of a compound having two or more functional groups represented by the following general formula (1) is formed on the outermost layer of the inorganic compound, and then the following general formula (1) not bonded to the inorganic compound in the compound. A method for modifying the surface of an inorganic compound, wherein a part or all of the functional group represented by formula (1) is converted to a hydrogen atom.

(In the formula, R represents a substituent, and n represents an integer of 1 or 2.)   The method according to claim 1, wherein the inorganic compound is a metal oxide.   2. The compound having a functional group represented by the general formula (1) is dissolved in water or an organic solvent and coated on the inorganic compound to form a covalent bond with the inorganic compound. Or the method of 2.   The compound having the functional group represented by the general formula (1) is formed by linking the functional group represented by the general formula (1) to a π-conjugated compound residue via a linking group or directly. The method according to any one of claims 1 to 3, wherein: A monomolecular film of a compound having two or more functional groups represented by the following general formula (1) is formed on the outermost layer of the inorganic compound, and then the following general formula (1) not bonded to the inorganic compound in the compound. A method for producing an organic thin film characterized in that part or all of the functional group represented by formula (1) is converted to a hydrogen atom.

(In the formula, R represents a substituent, and n represents an integer of 1 or 2.)   6. The method according to claim 5, wherein the inorganic compound is a metal oxide.   6. The compound having a functional group represented by the general formula (1) is dissolved in water or an organic solvent and coated on the inorganic compound to form a covalent bond with the inorganic compound. Or the method of 6.   The compound having the functional group represented by the general formula (1) is formed by linking the functional group represented by the general formula (1) to a π-conjugated compound residue via a linking group or directly. A method according to any one of claims 5 to 7, characterized in that   The organic electronic device containing the organic thin film obtained by the method of any one of Claims 5-8.

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