WO2012070390A1

WO2012070390A1 - Organic photoelectric conversion element

Info

Publication number: WO2012070390A1
Application number: PCT/JP2011/075884
Authority: WO
Inventors: 上谷　保則; 吉村　研
Original assignee: 住友化学株式会社
Priority date: 2010-11-26
Filing date: 2011-11-02
Publication date: 2012-05-31
Also published as: TW201229087A; JP5834819B2; JP2012126895A

Abstract

A high-molecular compound comprising repeating units represented by formula (1) and repeating units represented by formula (2) exhibits high absorbance in a long-wavelength region and is therefore useful for an organic photoelectric conversion element. In formula (1), R is a hydrogen atom, a fluorine atom, optionally fluorine-substituted alkyl, optionally fluorine -substituted alkoxy, optionally substituted aryl, optionally substituted heteroaryl, or a group represented by formula (3) [wherein m1 is an integer of 0 to 6, m2 is an integer of 0 to 6, R' is optionally fluorine-substituted alkyl, optionally substituted aryl, or optionally substituted heteroaryl, and a hydrogen atom in the (CH₂)_m1 or (CH₂)_m2 moiety may be replaced by a fluorine atom]; and the four R groups may be the same or different from each other. In formula (2), R is as defined above.

Description

Organic photoelectric conversion element

The present invention relates to a polymer compound and an organic photoelectric conversion element using the same.

Organic semiconductor materials are expected to be applied to organic photoelectric conversion elements such as organic solar cells and optical sensors. In particular, when a polymer compound is used as the organic semiconductor material, the functional layer can be manufactured by an inexpensive coating method. In order to improve various characteristics of the organic photoelectric conversion element, use of organic semiconductor materials that are various polymer compounds for the organic photoelectric conversion element has been studied. As an organic semiconductor material, for example, 9,9-dioctylfluorene-2,7-diboronic acid ester and 5,5 ″ ″-dibromo-3 ″, 4 ″ -dihexyl-α-pentathiophene are polymerized. A polymer compound has been proposed (USP-7803885).
However, the polymer compound does not sufficiently absorb light having a long wavelength.

The present invention provides a polymer compound having a large absorbance of light having a long wavelength.
That is, the present invention provides the formula (1)

[In the formula, R represents a hydrogen atom, a fluorine atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aryl group, or an optionally substituted heteroaryl. Group or formula (3)

(In the formula, m1 represents an integer of 0 to 6, and m2 represents an integer of 0 to 6. R ′ represents an alkyl group which may be substituted with fluorine, an aryl group which may be substituted, or a substituted group. A hydrogen atom in the formula represented by (CH ₂ ) _m1 or (CH ₂ ) _m2 may be fluorine-substituted). The four Rs may be the same or different from each other. ]
And a repeating unit represented by formula (2)

[Wherein R represents the same meaning as described above. ]
The high molecular compound containing the repeating unit represented by these is provided.
As more specific examples of the polymer compound, R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 20 carbon atoms that may be fluorine-substituted, or a carbon atom having 1 to 20 carbon atoms that may be fluorine-substituted. An alkoxy group or an optionally substituted phenyl group, wherein the substituent of the phenyl group includes a halogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms. .
The present invention also provides an organic photoelectric conversion element having a pair of electrodes and a functional layer provided between the electrodes, wherein the functional layer includes an electron-accepting compound and the polymer compound.

FIG. 1 is a graph showing an absorption spectrum of the polymer compound 1.
FIG. 2 is a diagram showing an absorption spectrum of the polymer compound 2. As shown in FIG.

Hereinafter, the present invention will be described in detail.
The polymer compound of the present invention includes a repeating unit represented by the formula (1) and a repeating unit represented by the formula (2).
In formula (1) and formula (2), the alkyl group represented by R is a chain or cyclic group, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec- Examples thereof include a butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, an isooctyl group, a decyl group, a dodecyl group, a pentadecyl group, and an octadecyl group. A hydrogen atom in the alkyl group may be substituted with a fluorine atom. Examples of the alkyl group substituted with a fluorine atom include a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group, a perfluorohexyl group, and a perfluorooctyl group.
In the formulas (1) and (2), the alkoxy group represented by R is a chain or cyclic group, for example, methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, sec -Butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, cyclohexyloxy group, heptyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, 3,7-dimethyloctyloxy group Can be mentioned. A hydrogen atom in the alkoxy group may be substituted with a fluorine atom. Examples of the alkoxy group substituted with a fluorine atom include a trifluoromethoxy group, a pentafluoroethoxy group, a perfluorobutoxy group, a perfluorohexyloxy group, and a perfluorooctyloxy group.
In formula (1) and formula (2), the aryl group represented by R is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon. The aryl group includes a group containing a benzene ring, a group containing a condensed ring having aromaticity, a group having a structure in which two or more benzene rings or a condensed ring having aromaticity are directly bonded, and two or more benzenes A group having a structure in which a ring or a condensed ring having aromaticity is bonded via a group such as vinylene is included. The number of carbon atoms of the aryl group is preferably 6 to 60, and more preferably 6 to 30. Examples of the aryl group include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group. The aryl group may have a substituent. Examples of the substituent that the aryl group may have include a halogen atom such as a fluorine atom, an alkyl group having 1 to 20 carbon atoms, and an alkoxy group having 1 to 20 carbon atoms.
In formula (1) and formula (2), examples of the heteroaryl group represented by R include a chenyl group, a pyrrolyl group, a furyl group, a pyridyl group, a quinolyl group, and an isoquinolyl group. The heteroaryl group may have a substituent. Examples of the substituent that the heteroaryl group may have include a halogen atom such as a fluorine atom, an alkyl group having 1 to 20 carbon atoms, and an alkoxy group having 1 to 20 carbon atoms.
In the group represented by the formula (3), m1 represents an integer of 0 to 6, and m2 represents an integer of 0 to 6. R ′ represents an alkyl group which may be substituted with fluorine, an aryl group which may be substituted or a heteroaryl group which may be substituted. Definitions and specific examples of the optionally substituted alkyl group represented by R ′, the optionally substituted aryl group, and the optionally substituted heteroaryl group are as follows: The definition and specific examples of the alkyl group which may be substituted, the aryl group which may be substituted and the heteroaryl group which may be substituted are the same. (CH ₂ ) _m1 Or (CH ₂ ) _m2 The hydrogen atom in the formula represented by may be fluorine-substituted. That is, CH ₂ Is CHF or CF ₂ It may be replaced by a group represented by
In the formulas (1) and (2), when R is an alkyl group or an alkoxy group, the alkyl group or the alkoxy group has 1 to 20 carbon atoms from the viewpoint of the solubility of the polymer compound in the solvent. Preferably, it is 2-18, more preferably 3-12.
Examples of the repeating unit represented by the formula (1) include the following repeating units.

Examples of the repeating unit represented by the formula (2) include the following repeating units.

The total of the amount of the repeating unit represented by the formula (1) and the amount of the repeating unit represented by the formula (2) contained in the polymer compound of the present invention is an organic having a functional layer containing the polymer compound. From the viewpoint of increasing the photoelectric conversion efficiency of the photoelectric conversion element, it is preferably 20 to 100 mol%, more preferably 30 to 100 mol%, based on the total amount of repeating units contained in the polymer compound. preferable. The amount of the repeating unit represented by the formula (1) contained in the polymer compound of the present invention is preferably 10 to 50 mol% with respect to the total amount of the repeating units contained in the polymer compound, More preferably, it is 15 to 50 mol%. The amount of the repeating unit represented by the formula (2) contained in the polymer compound of the present invention is preferably 10 to 50 mol% with respect to the total amount of repeating units contained in the polymer compound, More preferably, it is 15 to 50 mol%.
The polymer compound of the present invention may have a repeating unit other than the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2). Examples of the repeating unit other than the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) include an arylene group and a heteroarylene group, and the repeating unit represented by the formula (1) and the formula ( And a heteroarylene group not containing the repeating unit represented by 2). Examples of the arylene group include a phenylene group, a naphthalenediyl group, an anthracenediyl group, a pyrenediyl group, and a fluorenediyl group. Examples of the heteroarylene group include a flangyl group, a pyrrole diyl group, a pyridinediyl group, and the like. The heteroarylene group may have a substituent, and examples of the substituent include a halogen atom, an alkyl group having 1 to 20 carbon atoms, and an alkoxy group having 1 to 20 carbon atoms.
A preferred embodiment of the polymer compound of the present invention is represented by the formula (4)

(In the formula, R represents the same meaning as described above.)
It is a high molecular compound containing the repeating unit represented by these.
The weight average molecular weight in terms of polystyrene of the polymer compound of the present invention is preferably 10 ³ ~ 10 ⁸ And more preferably 10 ³ ~ 10 ⁷ And more preferably 10 ³ ~ 10 ⁶ It is.
The polymer compound of the present invention is preferably a conjugated polymer compound. Here, the conjugated polymer compound means a compound in which atoms constituting the main chain of the polymer compound are substantially conjugated.
The polymer compound of the present invention may be produced by any method. For example, after synthesizing a monomer having a functional group suitable for the polymerization reaction to be used, the monomer is dissolved in an organic solvent, if necessary, , And can be synthesized by polymerization using a known aryl coupling reaction using a catalyst, a ligand and the like. The monomer can be synthesized with reference to, for example, methods disclosed in USP 2008/145571 and JP-A-2006-335933.
Examples of the polymerization by the aryl coupling reaction include polymerization by Stille coupling reaction, polymerization by Suzuki coupling reaction, polymerization by Yamamoto coupling reaction, and polymerization by Kumada-Tamao coupling reaction.
Polymerization by Stille coupling reaction is required using palladium complexes such as palladium [tetrakis (triphenylphosphine)], [tris (dibenzylideneacetone)] dipalladium, palladium acetate, bis (triphenylphosphine) palladium dichloride as catalysts. Depending on the ligand, ligands such as triphenylphosphine, tri (2-methylphenyl) phosphine, tri (2-methoxyphenyl) phosphine, diphenylphosphinopropane, tri (cyclohexyl) phosphine, tri (tert-butyl) phosphine A monomer having an organic tin residue and a monomer having a halogen atom such as a bromine atom, an iodine atom or a chlorine atom, or a sulfonate group such as a trifluoromethanesulfonate group or a p-toluenesulfonate group. A polymerization reaction of a monomer having a group. The details of the polymerization by the Stille coupling reaction are described in, for example, Angewante Chemie International Edition, 2005, Vol. 44, p. 4442-4489.
Polymerization by Suzuki coupling reaction uses a palladium complex or nickel complex as a catalyst in the presence of an inorganic base or an organic base, and a ligand is added as necessary to have a boronic acid residue or a boric acid ester residue. Polymerization in which a monomer is reacted with a monomer having a halogen atom such as a bromine atom, an iodine atom or a chlorine atom, or a monomer having a sulfonate group such as a trifluoromethanesulfonate group or a p-toluenesulfonate group.
Examples of the inorganic base include sodium carbonate, potassium carbonate, cesium carbonate, tripotassium phosphate, and potassium fluoride. Examples of the organic base include tetrabutylammonium fluoride, tetrabutylammonium chloride, tetrabutylammonium bromide, and tetraethylammonium hydroxide. Examples of the palladium complex include palladium [tetrakis (triphenylphosphine)], [tris (dibenzylideneacetone)] dipalladium, palladium acetate, and bis (triphenylphosphine) palladium dichloride. Examples of the nickel complex include bis (cyclooctadiene) nickel. Examples of the ligand include triphenylphosphine, tri (2-methylphenyl) phosphine, tri (2-methoxyphenyl) phosphine, diphenylphosphinopropane, tri (cyclohexyl) phosphine, and tri (tert-butyl) phosphine. It is done.
Details of the polymerization by the Suzuki coupling reaction are described in, for example, Journal of Polymer Science: Part A: Polymer Chemistry (Part A: Polymer Chemistry), 2001, Vol. 39, p. 1533-1556.
Polymerization by Yamamoto coupling reaction uses a catalyst and a reducing agent to react monomers having halogen atoms, monomers having sulfonate groups such as trifluoromethanesulfonate groups, or monomers having halogen atoms and monomers having sulfonate groups. Polymerization.
Catalysts include nickel zero-valent complexes such as bis (cyclooctadiene) nickel and ligands such as bipyridyl, [bis (diphenylphosphino) ethane] nickel dichloride, [bis (diphenylphosphino) propane] nickel. A catalyst comprising a nickel complex other than a nickel zero-valent complex such as dichloride and a ligand such as triphenylphosphine, diphenylphosphinopropane, tri (cyclohexyl) phosphine, tri (tert-butyl) phosphine, if necessary. . Examples of the reducing agent include zinc and magnesium. Polymerization by the Yamamoto coupling reaction may be performed using a dehydrated solvent in the reaction, may be performed in an inert atmosphere, or may be performed by adding a dehydrating agent to the reaction system.
Details of the polymerization by Yamamoto coupling are described in, for example, Macromolecules, 1992, Vol. 25, p. 1214-1223.
Polymerization by Kumada-Tamao coupling reaction uses a nickel catalyst such as [bis (diphenylphosphino) ethane] nickel dichloride, [bis (diphenylphosphino) propane] nickel dichloride, a compound having a magnesium halide group and a halogen atom. Polymerization to react with the compound having For the reaction, a dehydrated solvent may be used for the reaction, the reaction may be performed in an inert atmosphere, or a dehydrating agent may be added to the reaction system.
In the polymerization by the aryl coupling reaction, a solvent is usually used. The solvent may be selected in consideration of the polymerization reaction used, the solubility of the monomer and polymer, and the like. Specifically, tetrahydrofuran, toluene, 1,4-dioxane, dimethoxyethane, N, N-dimethylacetamide, N, N-dimethylformamide, an organic solvent such as a mixed solvent obtained by mixing two or more of these solvents, an organic solvent Examples thereof include a solvent having two phases of a phase and an aqueous phase. The solvent used in the Stille coupling reaction is preferably an organic solvent such as tetrahydrofuran, toluene, N, N-dimethylformamide, a mixed solvent obtained by mixing two or more of these solvents, or a solvent having two phases of an organic solvent phase and an aqueous phase. . The solvent used for the Stille coupling reaction is preferably deoxygenated before the reaction in order to suppress side reactions. Solvents used in the Suzuki coupling reaction are organic solvents such as tetrahydrofuran, toluene, 1,4-dioxane, dimethoxyethane, N, N-dimethylacetamide, N, N-dimethylformamide, and mixed solvents in which two or more of these solvents are mixed. A solvent and a solvent having two phases of an organic solvent phase and an aqueous phase are preferred. The solvent used for the Suzuki coupling reaction is preferably deoxygenated before the reaction in order to suppress side reactions. The solvent used for the Yamamoto coupling reaction is an organic solvent such as tetrahydrofuran, toluene, 1,4-dioxane, dimethoxyethane, N, N-dimethylacetamide, N, N-dimethylformamide, or a mixed solvent in which two or more of these solvents are mixed. A solvent is preferred. The solvent used for the Yamamoto coupling reaction is preferably deoxygenated before the reaction in order to suppress side reactions.
Among the polymerizations by the aryl coupling reaction, from the viewpoint of reactivity, a method of polymerizing by a Stille coupling reaction, a method of polymerizing by a Suzuki coupling reaction, a method of polymerizing by a Yamamoto coupling reaction are preferable, and a Stille coupling reaction More preferred are a method of polymerizing, a method of polymerizing by a Suzuki coupling reaction, and a method of polymerizing by a Yamamoto coupling reaction using a nickel zero-valent complex.
The lower limit of the reaction temperature of the aryl coupling reaction is preferably −100 ° C., more preferably −20 ° C., and particularly preferably 0 ° C. from the viewpoint of reactivity. The upper limit of the reaction temperature is preferably 200 ° C., more preferably 150 ° C., and particularly preferably 120 ° C. from the viewpoint of the stability of the monomer and the polymer compound.
In the polymerization by the aryl coupling reaction, a known method can be used as a method for removing the polymer compound of the present invention from the reaction solution after completion of the reaction. For example, the polymer compound of the present invention can be obtained by adding a reaction solution to a lower alcohol such as methanol, filtering the deposited precipitate, and drying the filtrate. When the purity of the obtained polymer compound is low, it can be purified by recrystallization, continuous extraction with a Soxhlet extractor, column chromatography, or the like.
When the polymer compound of the present invention is used for the production of an organic photoelectric conversion element, if a polymerization active group remains at the terminal of the polymer compound, characteristics such as durability of the organic photoelectric conversion element may be deteriorated. It is preferable to protect the terminal of the polymer compound with a stable group.
Examples of the stable group for protecting the terminal include an alkyl group, an alkoxy group, a fluoroalkyl group, a fluoroalkoxy group, an aryl group, an arylamino group, and a monovalent heterocyclic group. Examples of the arylamino group include a phenylamino group and a diphenylamino group. Examples of the monovalent heterocyclic group include a chenyl group, a pyrrolyl group, a furyl group, a pyridyl group, a quinolyl group, and an isoquinolyl group. Further, the polymerization active group remaining at the terminal of the polymer compound may be replaced with a hydrogen atom instead of a stable group. From the viewpoint of enhancing hole transportability, it is preferable that the stable group for protecting the terminal is a group imparting electron donating properties such as an arylamino group. When the polymer compound is a conjugated polymer compound, the end of a group having a conjugated bond in which the conjugated structure of the main chain of the polymer compound and the conjugated structure of a stable group protecting the end are continuous is also protected. It can preferably be used as a stable group. Examples of the group include an aryl group and a monovalent heterocyclic group having aromaticity.
When the polymer compound of the present invention is produced using Stille coupling, for example, the formula (5)

(In the formula, R represents the same meaning as described above. Z represents a bromine atom, an iodine atom or a chlorine atom. The two Zs may be the same or different.)
And a compound represented by formula (6)

(Wherein R represents the same meaning as described above. Z ² Represents an organotin residue. 2 Z ² May be the same or different. )
The polymer represented by the formula can be polymerized to produce the polymer compound of the present invention.
As a compound represented by Formula (5), the following compounds are mentioned, for example.

From the viewpoint of increasing the reactivity of polymerization using Stille coupling, Z in Formula (5) is preferably a bromine atom or a chlorine atom, and more preferably a bromine atom. The compound represented by the formula (5) is, for example, Macromolecules, 2009, Vol. 42, No. 17, p. Synthesis using the method described in 6564-6571
Can do.
As a compound represented by Formula (6), the following compounds are mentioned, for example.

(Where Bu is CH ₃ (CH ₂ ) ₃ Represents a group. )
From the viewpoint of ease of synthesis of the compound represented by the formula (6), Z in the formula (6) ² -SnMe ₃ , -SnEt ₃ Or -SnBu ₃ It is preferable that Where Me is CH ₃ Represents a group, Et is CH ₃ CH ₂ Represents a group, Bu is CH ₃ (CH ₂ ) ₃ Represents a group.
The compound represented by formula (6) is prepared by, for example, reacting the compound represented by formula (7) with an organolithium compound to produce an intermediate, and then reacting the intermediate with a trialkyltin halide. Can be manufactured.

(In the formula, R represents the same meaning as described above.)
Examples of the organic lithium compound include butyl lithium (n-BuLi), sec-butyl lithium (sec-BuLi), tert-butyl lithium (tert-BuLi), and lithium diisopropylamide. Among organolithium compounds, n-BuLi is preferable. Examples of the trialkyltin halide include trimethyltin chloride, triethyl chloride, and tributyl chloride.
The reaction for producing an intermediate from a compound represented by formula (7) and an organolithium compound and the reaction for producing a compound represented by formula (6) from the intermediate and trialkyltin halide are usually carried out in a solvent. Done. As the solvent, sufficiently dehydrated tetrahydrofuran, fully dehydrated 1,4-dioxane, and sufficiently dehydrated diethyl ether are preferably used.
The temperature for reacting the organolithium compound with the compound represented by formula (7) is usually −100 to 50 ° C., preferably −80 to 0 ° C. The reaction time of the organolithium compound and the compound represented by the formula (7) is usually 1 minute to 10 hours, preferably 30 minutes to 5 hours. The amount of the organolithium compound to be reacted is usually 2 to 5 equivalents, preferably 2 to 3 equivalents, relative to the compound represented by the formula (7).
The temperature at which the intermediate and the trialkyltin halide are reacted is usually −100 to 100 ° C., preferably −80 ° C. to 50 ° C. The reaction time of the intermediate and the trialkyltin halide is usually 1 minute to 30 hours, preferably 1 to 10 hours. The amount of the trialkyltin halide to be reacted is usually 2 to 6 equivalents, preferably 2 to 3 equivalents, relative to the compound represented by the formula (7).
After the reaction, normal post-treatment can be performed to obtain the compound represented by the formula (6). For example, after the reaction is stopped by adding water, the product is extracted with an organic solvent and the solvent is distilled off. The product can be isolated and purified by a method such as fractionation by chromatography or recrystallization.
The compound represented by the formula (7) can be produced, for example, by reacting the compound represented by the formula (8) in the presence of an acid.

(Wherein R represents the same meaning as described above)
The acid used in the reaction for producing the compound represented by the formula (7) from the compound represented by the formula (8) may be Lewis acid or Bronsted acid, Hydrochloric acid, bromic acid, hydrofluoric acid, sulfuric acid, nitric acid, formic acid, acetic acid, propionic acid, oxalic acid, benzoic acid, boron fluoride, aluminum chloride, tin chloride (IV), iron chloride (II), titanium tetrachloride, Examples include benzenesulfonic acid, p-toluenesulfonic acid and mixtures of these compounds.
The reaction for producing the compound represented by formula (7) from the compound represented by formula (8) is preferably carried out in the presence of a solvent. When the reaction is carried out in the presence of a solvent, the reaction temperature is preferably from −80 ° C. to the boiling point of the solvent.
Solvents used in the reaction include saturated hydrocarbons such as pentane, hexane, heptane, octane and cyclohexane, unsaturated hydrocarbons such as benzene, toluene, ethylbenzene and xylene, carbon tetrachloride, chloroform, dichloromethane, chlorobutane, bromobutane, chloro Halogenated hydrocarbons such as pentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane, bromocyclohexane, chlorobenzene, dichlorobenzene, trichlorobenzene, methanol, ethanol, 1-propanol, 2-propanol, butanol, tert-butyl alcohol, etc. Carboxylic acids such as alcohol, formic acid, acetic acid, propionic acid, dimethyl ether, diethyl ether, methyl-tert-butyl ether, tetrahydro Orchids, tetrahydropyran, ethers such as dioxane. The solvent may be used alone or in combination.
After the reaction, normal post-treatment can be performed to obtain the compound represented by the formula (7). For example, after the reaction is stopped by adding water, the product is extracted with an organic solvent and the solvent is distilled off. The product can be isolated and purified by a method such as fractionation by chromatography or recrystallization.
The compound represented by Formula (8) is, for example, Formula (9).

Can be produced by reacting a Grignard reagent or an organolithium compound.
As the Grignard reagent used in the above reaction, methyl magnesium chloride, methyl magnesium bromide, ethyl magnesium chloride, ethyl magnesium bromide, propyl magnesium chloride, propyl magnesium bromide, butyl magnesium chloride, butyl magnesium bromide, hexyl magnesium bromide, octyl magnesium bromide, Examples include decylmagnesium bromide, allylmagnesium chloride, allylmagnesium bromide, benzylmagnesium chloride, phenylmagnesium bromide, naphthylmagnesium bromide, and tolylmagnesium bromide.
Examples of the organic lithium compound include methyl lithium, ethyl lithium, propyl lithium, butyl lithium, phenyl lithium, naphthyl lithium, benzyl lithium, and tolyl lithium.
The reaction for producing the compound represented by the formula (8) from the compound represented by the formula (9) and a Grignard reagent or an organolithium compound may be carried out in an inert gas atmosphere such as nitrogen or argon. preferable. Moreover, it is preferable to implement this reaction in presence of a solvent. When the reaction is carried out in the presence of a solvent, the reaction temperature is preferably from −80 ° C. to the boiling point of the solvent.
Solvents used in the reaction include saturated hydrocarbons such as pentane, hexane, heptane, octane and cyclohexane, unsaturated hydrocarbons such as benzene, toluene, ethylbenzene and xylene, dimethyl ether, diethyl ether, methyl-tert-butyl ether, tetrahydrofuran, And ethers such as tetrahydropyran and dioxane. These solvents may be used alone or in combination.
After the reaction, normal post-treatment can be performed to obtain the compound represented by the formula (8). For example, after the reaction is stopped by adding water, the product is extracted with an organic solvent and the solvent is distilled off. The product can be isolated and purified by a method such as fractionation by chromatography or recrystallization.
The compound represented by Formula (9) is, for example, Formula (10).

It can manufacture by making the compound and peroxide which are represented by these react.
Examples of the peroxide include sodium perborate, m-chloroperbenzoic acid, hydrogen peroxide, and benzoyl peroxide. Preferred are sodium perborate and m-chloroperbenzoic acid, and particularly preferred is sodium perborate.
The reaction for producing the compound represented by the formula (9) from the compound represented by the formula (10) and the peroxide is carried out in the presence of a carboxylic acid solvent such as acetic acid, trifluoroacetic acid, propionic acid and butyric acid. It is preferable.
In order to increase the solubility of the compound represented by formula (10), a mixed solvent obtained by mixing a carboxylic acid solvent with one or more solvents selected from the group consisting of carbon tetrachloride, chloroform, dichloromethane, benzene, and toluene. It is preferable to carry out the reaction. The reaction temperature is preferably 0 ° C. or higher and 50 ° C. or lower.
After the reaction, normal post-treatment can be performed to obtain the compound represented by the formula (9). For example, after the reaction is stopped by adding water, the product is extracted with an organic solvent and the solvent is distilled off. The product can be isolated and purified by methods such as chromatographic fractionation and recrystallization.
Since the polymer compound of the present invention has a high absorbance of light having a long wavelength such as 600 nm light and efficiently absorbs sunlight, an organic photoelectric conversion element manufactured using the polymer compound of the present invention has a short-circuit current. Density increases.
The organic photoelectric conversion element of the present invention has a pair of electrodes and a functional layer provided between the electrodes, and the functional layer includes an electron-accepting compound, a repeating unit represented by the formula (1), and a formula And a polymer compound containing the repeating unit represented by (2). As an electron-accepting compound, fullerene and a fullerene derivative are preferable. As a specific example of the organic photoelectric conversion element,
1. An organic photoelectric conversion element having a pair of electrodes and a functional layer between the electrodes, the functional layer containing an electron-accepting compound and a polymer compound containing a repeating unit represented by the formula (1);
2. An organic photoelectric conversion element having a pair of electrodes and a functional layer between the electrodes, the functional layer containing an electron-accepting compound and a polymer compound containing a repeating unit represented by formula (1) An organic photoelectric conversion element in which the electron-accepting compound is a fullerene derivative;
Is mentioned. In general, at least one of the pair of electrodes is transparent or translucent. Hereinafter, this case will be described as an example.
1 above. In the organic photoelectric conversion element, the amount of the electron accepting compound in the functional layer containing the electron accepting compound and the polymer compound is 10 to 1000 parts by weight with respect to 100 parts by weight of the polymer compound. It is preferably 20 to 500 parts by weight. In addition, 2. In the organic photoelectric conversion element, the amount of the fullerene derivative in the functional layer containing the fullerene derivative and the polymer compound is preferably 10 to 1000 parts by weight with respect to 100 parts by weight of the polymer compound. More preferably, it is ~ 500 parts by weight. From the viewpoint of increasing the photoelectric conversion efficiency, the amount of the fullerene derivative in the functional layer is preferably 20 to 400 parts by weight, and preferably 40 to 250 parts by weight with respect to 100 parts by weight of the polymer compound. More preferred is 80 to 120 parts by weight. From the viewpoint of increasing the short-circuit current density, the amount of the fullerene derivative in the functional layer is preferably 20 to 250 parts by weight, and preferably 40 to 120 parts by weight with respect to 100 parts by weight of the polymer compound. More preferred.
In order for the organic photoelectric conversion element to have high photoelectric conversion efficiency, a polymer compound containing the electron accepting compound and the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) is desirable. It has an absorption region that can efficiently absorb the spectrum of incident light, and the heterojunction interface contains many heterojunction interfaces in order to efficiently separate excitons, and the charge generated by the heterojunction interface It is important to have a charge transporting property for quickly transporting to the electrode.
From such a viewpoint, as the organic photoelectric conversion element, the above 1. , 2. From the standpoint of including a large number of heterojunction interfaces, the organic photoelectric conversion element is preferable. The organic photoelectric conversion element is more preferable. Further, in the organic photoelectric conversion element of the present invention, an additional layer may be provided between at least one electrode and the functional layer in the element. Examples of the additional layer include a charge transport layer that transports holes or electrons, and a buffer layer.
The organic photoelectric conversion element of the present invention is usually formed on a substrate. The substrate may be any substrate that does not chemically change when an electrode is formed and an organic layer is formed. Examples of the material for the substrate include glass, plastic, polymer film, and silicon. In the case of an opaque substrate, the opposite electrode, that is, the electrode far from the substrate is preferably transparent or translucent.
As a material for the pair of electrodes, a metal, a conductive polymer, or the like can be used. The material of one of the pair of electrodes is preferably a material having a low work function. For example, metals such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and those metals An alloy of two or more of these metals, or one or more of those metals and one or more of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, tin An alloy with metal, graphite, a graphite intercalation compound, or the like is used. Examples of the alloy include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, and calcium-aluminum alloy.
Examples of the material of the transparent or translucent electrode include a conductive metal oxide film and a translucent metal thin film. Specifically, a film formed using a conductive material made of indium oxide, zinc oxide, tin oxide, and indium tin oxide (ITO), indium zinc oxide, etc., which is a composite thereof, NESA Gold, platinum, silver, and copper are used, and ITO, indium / zinc / oxide, and tin oxide are preferable. Examples of the method for producing the electrode include a vacuum deposition method, a sputtering method, an ion plating method, a plating method, and the like. Moreover, you may use organic transparent conductive films, such as polyaniline and its derivative (s), polythiophene, and its derivative (s) as an electrode material.
As a material used for the charge transport layer as the additional layer, that is, the hole transport layer or the electron transport layer, an electron donating compound and an electron accepting compound described later can be used, respectively.
As a material used for the buffer layer as an additional layer, halides or oxides of alkali metals or alkaline earth metals such as lithium fluoride can be used. In addition, fine particles of an inorganic semiconductor such as titanium oxide can be used.
As the functional layer in the organic photoelectric conversion element of the present invention, for example, an organic thin film containing the polymer compound of the present invention and an electron-accepting compound can be used.
The organic thin film generally has a thickness of 1 nm to 100 μm, preferably 2 nm to 1000 nm, more preferably 5 nm to 500 nm, and further preferably 20 nm to 200 nm.
The organic thin film may contain the polymer compound alone or in combination of two or more. Moreover, in order to improve the hole transport property of the organic thin film, a low molecular compound and / or a high molecular compound other than the high molecular compound can be mixed and used as the electron donating compound in the organic thin film.
Examples of the electron-donating compound that the organic thin film may contain in addition to the polymer compound containing the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) include pyrazoline derivatives, aryl Amine derivatives, stilbene derivatives, triphenyldiamine derivatives, oligothiophene and derivatives thereof, polyvinylcarbazole and derivatives thereof, polysilane and derivatives thereof, polysiloxane derivatives having aromatic amines in the side chain or main chain, polyaniline and derivatives thereof, polythiophene and Examples thereof include polypyrrole and derivatives thereof, polyphenylene vinylene and derivatives thereof, and polythienylene vinylene and derivatives thereof.
Examples of the electron accepting compound include oxadiazole derivatives, anthraquinodimethane and derivatives thereof, benzoquinone and derivatives thereof, naphthoquinone and derivatives thereof, anthraquinone and derivatives thereof, tetracyanoanthraquinodimethane and derivatives thereof, and fluorenone derivatives. Diphenyldicyanoethylene and derivatives thereof, diphenoquinone derivatives, metal complexes of 8-hydroxyquinoline and derivatives thereof, polyquinoline and derivatives thereof, polyquinoxaline and derivatives thereof, polyfluorene and derivatives thereof, C ₆₀ And phenanthroline derivatives such as carbon nanotubes and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline. Fullerene and derivatives thereof are particularly preferable.
The electron-donating compound and the electron-accepting compound are relatively determined from the energy levels of these compounds.
Fullerene and its derivatives include C ₆₀ , C ₇₀ , C ₈₄ And derivatives thereof. A fullerene derivative represents a compound in which at least a part of fullerene is modified.
Examples of the fullerene derivative include a compound represented by the formula (I), a compound represented by the formula (II), a compound represented by the formula (III), and a compound represented by the formula (IV).

(In the formulas (I) to (IV), R ^a Is a group having an alkyl group, an aryl group, a heteroaryl group or an ester structure. Multiple R ^a May be the same or different. R ^b Represents an alkyl group or an aryl group. Multiple R ^b May be the same or different. )
R ^a And R ^b The definitions and specific examples of the alkyl group, aryl group and heteroaryl group represented by are the same as the definitions and specific examples of the alkyl group, aryl group and heteroaryl group represented by R.
R ^a The group having an ester structure represented by, for example, formula (V)

(Wherein u1 represents an integer of 1 to 6, u2 represents an integer of 0 to 6, R ^c Represents an alkyl group, an aryl group or a heteroaryl group. )
The group represented by these is mentioned.
R ^c The definitions and specific examples of the alkyl group, aryl group and heteroaryl group represented by are the same as the definitions and specific examples of the alkyl group, aryl group and heteroaryl group represented by R.
C ₆₀ Specific examples of the derivatives include the following.

C ₇₀ Specific examples of the derivatives include the following.

The organic thin film may be produced by any method. For example, the organic thin film may be produced by a film formation method from a solution containing the polymer compound of the present invention, or an organic thin film may be formed by a vacuum deposition method. Good. Examples of the method for producing an organic thin film by film formation from a solution include a method of producing an organic thin film by applying the solution on one electrode and then evaporating the solvent.
The solvent used for film formation from a solution is not particularly limited as long as it dissolves the polymer compound of the present invention. Examples of the solvent include unsaturated hydrocarbons such as toluene, xylene, mesitylene, tetralin, decalin, bicyclohexyl, butylbenzene, sec-butylbenzene, and tert-butylbenzene, carbon tetrachloride, chloroform, dichloromethane, dichloroethane, and chlorobutane. , Halogenated hydrocarbons such as bromobutane, chloropentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane, bromocyclohexane, chlorobenzene, dichlorobenzene and trichlorobenzene, and ethers such as tetrahydrofuran and tetrahydropyran. The polymer compound of the present invention can usually be dissolved in the solvent in an amount of 0.1% by weight or more.
For film formation from solution, spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, flexographic method A coating method such as a printing method, an offset printing method, an inkjet printing method, a dispenser printing method, a nozzle coating method, a capillary coating method can be used, and a spin coating method, a flexographic printing method, an inkjet printing method, and a dispenser printing method are preferable.
By irradiating light such as sunlight from a transparent or translucent electrode, the organic photoelectric conversion element generates a photovoltaic force between the electrodes and can be operated as an organic thin film solar cell. It can also be used as an organic thin film solar cell module by integrating a plurality of organic thin film solar cells.
In addition, by applying light from a transparent or translucent electrode in a state where a voltage is applied between the electrodes, a photocurrent flows and it can be operated as an organic photosensor. It can also be used as an organic image sensor by integrating a plurality of organic photosensors.

Examples will be shown below for illustrating the present invention in more detail, but the present invention is not limited to these examples.
The polystyrene equivalent weight average molecular weight of the polymer compound was determined by size exclusion chromatography (SEC).
Column: TOSOH TSKgel SuperHM-H (2) + TSKgel SuperH2000 (4.6 mm Id × 15 cm); Detector: RI (SHIMADZU RID-10A); Mobile phase: tetrahydrofuran reference example 1 (synthesis of compound 1)

A 1000 mL four-necked flask in which the gas in the flask was replaced with argon was charged with 13.0 g (80.0 mmol) of 3-bromothiophene and 80 mL of diethyl ether to obtain a uniform solution. While maintaining the solution at −78 ° C., 31 mL (80.6 mmol) of 2.6M butyllithium (n-BuLi) in hexane was added dropwise. After reacting at −78 ° C. for 2 hours, a solution prepared by dissolving 8.96 g of 3-thiophenaldehyde (80.0 mmol) in 20 mL of diethyl ether was added dropwise to the reaction solution. After dropping, the reaction solution was stirred at -78 ° C for 30 minutes, and further stirred at room temperature (25 ° C) for 30 minutes. The reaction solution was cooled again to −78 ° C., and 62 mL (161 mmol) of 2.6 M n-BuLi in hexane was added dropwise over 15 minutes. After dropping, the reaction solution was stirred at −25 ° C. for 2 hours, and further stirred at room temperature (25 ° C.) for 1 hour. Thereafter, the reaction solution was cooled to −25 ° C., and a solution in which 60 g of iodine (236 mmol) was dissolved in 1000 mL of diethyl ether was added dropwise over 30 minutes. After the dropwise addition, the reaction solution was stirred at room temperature (25 ° C.) for 2 hours, and 50 mL of 1N aqueous sodium thiosulfate solution was added to stop the reaction. Diethyl ether was added to the reaction solution to extract the reaction product, and then the organic layer containing the reaction product was dried over magnesium sulfate and concentrated to obtain 35 g of a crude product. The crude product was purified by recrystallization using chloroform to obtain 28 g of Compound 1.
Reference Example 2 (Synthesis of Compound 2)

To a 300 mL four-necked flask, 10 g (22.3 mmol) of bisiodothienylmethanol (Compound 1) and 150 mL of methylene chloride were added to obtain a uniform solution. To the solution, 7.50 g (34.8 mmol) of pyridinium chlorochromate was added and stirred at room temperature (25 ° C.) for 10 hours. The reaction solution was filtered to remove insoluble matters, and then the filtrate was concentrated to obtain 10.0 g (22.4 mmol) of Compound 2.
Reference Example 3 (Synthesis of Compound 3)

To a 300 mL flask in which the gas in the flask was replaced with argon, 10.0 g (22.3 mmol) of Compound 2, 6.0 g (94.5 mmol) of copper powder, and 120 mL of dehydrated N, N-dimethylformamide were added. Stir at 4 ° C. for 4 hours. After the reaction, the flask was cooled to room temperature (25 ° C.), and the reaction solution was passed through a silica gel column to remove insoluble components. Thereafter, 500 mL of water was added to the reaction solution, and chloroform was further added to extract an organic layer containing the reaction product. The organic layer was dried over magnesium sulfate and concentrated to give a crude product. The crude product was purified with a silica gel column whose developing solution was chloroform, and 3.26 g of compound 3 was obtained.
Reference Example 4 (Synthesis of Compound 4)

A uniform solution was prepared by adding 3.85 g (20.0 mmol) of Compound 3, 50 mL of chloroform, and 50 mL of trifluoroacetic acid to a 300 mL four-necked flask equipped with a mechanical stirrer and replacing the gas in the flask with argon. To the solution was added 5.99 g (60 mmol) of sodium perborate monohydrate, and the mixture was stirred at room temperature (25 ° C.) for 45 minutes. Thereafter, 200 mL of water was added to the reaction solution, and chloroform was further added to extract the reaction product. The organic layer containing the reaction product was passed through a silica gel column, and the solvent was distilled off with an evaporator. The residue was recrystallized using methanol to obtain 534 mg of compound 4.
¹ H NMR in CDCl ₃ (ppm): 7.64 (d, 1H), 7.43 (d, 1H), 7.27 (d, 1H), 7.10 (d, 1H)
Reference Example 5 (Synthesis of Compound 5)

A 100 mL four-necked flask in which the gas in the flask was replaced with argon was charged with 1.00 g (4.80 mmol) of Compound 4 and 30 ml of dry tetrahydrofuran to obtain a uniform solution. While maintaining the flask at −20 ° C., 12.7 mL of 1M 3,7-dimethyloctylmagnesium bromide ether solution was added. The temperature of the mixture was raised to −5 ° C. over 30 minutes and stirred at −5 ° C. for 30 minutes. Subsequently, the temperature was raised to 0 ° C. over 10 minutes, and the reaction solution was stirred at 0 ° C. for 1.5 hours. Thereafter, water was added to the reaction solution to stop the reaction, and ethyl acetate was further added to extract the reaction product. The organic layer containing the reaction product was dried over sodium sulfate and passed through a silica gel column, and then the solvent was distilled off to obtain 1.50 g of compound 5.
¹ H NMR in CDCl ₃ (ppm): 8.42 (b, 1H), 7.25 (d, 1H), 7.20 (d, 1H), 6.99 (d, 1H), 6.76 ( d, 1H), 2.73 (b, 1H), 1.90 (m, 4H), 1.58-1.02 (b, 20H), 0.92 (s, 6H), 0.88 (s) , 12H)
Reference Example 6 (Synthesis of Compound 6)

In a 200 mL flask in which the gas in the flask was replaced with argon, 1.50 g of Compound 5 and 30 mL of toluene were added to obtain a uniform solution. 100 mg of sodium p-toluenesulfonate monohydrate was added to the solution, and the mixture was stirred at 100 ° C. for 1.5 hours. After cooling the reaction solution to room temperature (25 ° C.), 50 mL of water was added, and toluene was further added to extract the reaction product. The organic layer containing the reaction product was dried over sodium sulfate, and the solvent was distilled off. The obtained crude product was produced on a silica gel column whose developing solvent was hexane, and 1.33 g of compound 6 was obtained. The operation so far was performed several times.
¹ H NMR in CDCl ₃ (ppm): 6.98 (d, 1H), 6.93 (d, 1H), 6.68 (d, 1H), 6.59 (d, 1H), 1.89 ( m, 4H), 1.58-1.00 (b, 20H), 0.87 (s, 6H), 0.86 (s, 12H)
Reference Example 7 (Synthesis of Compound 7)

Into a 200 mL flask in which the gas in the flask was replaced with argon, 2.16 g (4.55 mmol) of Compound 6 and 100 mL of dry tetrahydrofuran were added to obtain a uniform solution. The solution was kept at −78 ° C., and 4.37 mL (11.4 mmol) of 2.6M n-BuLi in hexane was added dropwise to the solution over 10 minutes. After the addition, the reaction solution was stirred at -78 ° C for 30 minutes, and then stirred at room temperature (25 ° C) for 2 hours. Thereafter, the flask was cooled to −78 ° C., and 4.07 g (12.5 mmol) of tributyltin chloride was added to the reaction solution. After the addition, the reaction solution was stirred at −78 ° C. for 30 minutes, and then stirred at room temperature (25 ° C.) for 3 hours. Thereafter, 200 ml of water was added to the reaction solution to stop the reaction, and ethyl acetate was added to extract the reaction product. The organic layer containing the reaction product was dried over sodium sulfate, and the solvent was distilled off with an evaporator. The obtained oily substance was purified by a silica gel column whose developing solvent was hexane. As the silica gel of the silica gel column, silica gel previously immersed in hexane containing 5% by weight of triethylamine for 5 minutes and then rinsed with hexane was used. After purification, 3.52 g (3.34 mmol) of compound 7 was obtained.
Example 1 (Synthesis of polymer compound 1)

In a 100 mL flask in which the gas in the flask was replaced with argon, 198.9 mg (0.189 mmol) of compound 7, 90 mg (0.182 mmol) of compound 8 (manufactured by Luminescence Technology Corporation), and 14 ml of toluene were placed in a uniform solution. did. The resulting toluene solution was bubbled with argon for 30 minutes. Thereafter, 2.59 mg (0.00283 mmol) of tris (dibenzylideneacetone) dipalladium and 5.2 mg (0.017 mmol) of tris (2-toluyl) phosphine were added to the toluene solution, and the mixture was stirred at 100 ° C. for 6 hours. Thereafter, 271 mg of phenyl bromide was added to the reaction solution, and the mixture was further stirred for 5 hours. Thereafter, the flask was cooled to 25 ° C., and the reaction solution was poured into 300 mL of methanol. The precipitated polymer was filtered, and the obtained polymer was put in a cylindrical filter paper and extracted with methanol, acetone and hexane for 5 hours using a Soxhlet extractor. The polymer remaining in the cylindrical filter paper was dissolved in 100 mL of o-dichlorobenzene, 2 g of sodium diethyldithiocarbamate and 40 mL of water were added, and the mixture was stirred under reflux for 8 hours. After removing the aqueous layer, the organic layer is washed twice with 50 ml of water, then twice with 50 mL of a 3 wt% aqueous acetic acid solution, then twice with 50 mL of water, and then 50 mL of 5% aqueous potassium fluoride solution. And then washed twice with 50 mL of water, and the resulting solution was poured into methanol to precipitate a polymer. The polymer was filtered and dried, and the obtained polymer was dissolved again in 50 mL of o-dichlorobenzene and passed through an alumina / silica gel column. The obtained solution was poured into methanol to precipitate a polymer, and the polymer was filtered and dried to obtain 72 mg of a purified polymer compound. Hereinafter, this polymer is referred to as polymer compound 1.
Reference Example 8 (Synthesis of polymer compound 2)

Into a 2 L four-necked flask in which the gas in the flask was replaced with argon, 7.928 g (16.72 mmol) of compound (E), 13.00 g (17.60 mmol) of compound (F), trioctylmethylammonium chloride ( 4.979 g of trade name Aliquat 336 (registered trademark), manufactured by Sigma-Aldrich, CH ₃ N [(CH ₂ ) ₇ CH ₃ ] ₃ Cl, density 0.884 g / ml, 25 ° C.), and 405 ml of toluene were added and stirred. Then, argon was bubbled through the reaction system for 30 minutes. 0.02 g of dichlorobis (triphenylphosphine) palladium (II) was added to the flask, the temperature was raised to 105 ° C., and 42.2 ml of a 2 mol / L sodium carbonate aqueous solution was added dropwise with stirring. After completion of the dropwise addition, the reaction was allowed to proceed for 5 hours, and then 2.6 g of phenylboronic acid and 1.8 ml of toluene were added, followed by stirring at 105 ° C. for 16 hours. Thereafter, 700 ml of toluene and 200 ml of a 7.5 wt% sodium diethyldithiocarbamate trihydrate aqueous solution were added to the reaction solution, followed by stirring at 85 ° C. for 3 hours. After removing the aqueous layer of the reaction solution, the organic layer was washed twice with 300 ml of ion exchange water at 60 ° C., once with 300 ml of 3 wt% acetic acid at 60 ° C., and further three times with 300 ml of ion exchange water at 60 ° C. The organic layer was passed through a column packed with celite, alumina and silica to obtain an eluate. Thereafter, the column was washed with 800 ml of hot toluene, and the washed toluene solution and the eluate were combined. After the obtained solution was concentrated to 700 ml, the concentrated solution was added to 2 L of methanol to reprecipitate the polymer. The polymer was filtered and then washed sequentially with 500 ml of methanol, 500 ml of acetone, and 500 ml of methanol. The polymer was vacuum-dried overnight at 50 ° C. to obtain 12.21 g of a pentathienyl-fluorene copolymer (polymer compound 2). The polymer compound 2 had a weight average molecular weight in terms of polystyrene of 1.1 × 10 ⁵ .
Measurement Example 1 (Measurement of absorbance of organic thin film)
The polymer compound 1 was dissolved in o- dichlorobenzene at a concentration of 0.5 wt%, to prepare a coating solution. The obtained coating solution was applied onto a glass substrate by spin coating. The coating operation was performed at 23 ° C. Then, it baked for 5 minutes on the conditions of 120 degreeC in air | atmosphere, and obtained the organic thin film about 100 nm in thickness. The absorption spectrum of the organic thin film was measured with a spectrophotometer (trade name: V-670, manufactured by JASCO Corporation). The measured spectrum is shown in FIG. Table 1 shows the absorbance at 600 nm and 650 nm.
Comparative Example 1 (Measurement of absorbance of organic thin film)
An organic thin film was prepared in the same manner as in Measurement Example 1 except that the polymer compound 2 was used instead of the polymer compound 1, and the absorption spectrum of the organic thin film was measured. The measured spectrum is shown in FIG. Table 1 shows the absorbance at 600 nm and 650 nm.

Example 2 (Production and Evaluation of Organic Thin Film Solar Cell)
Fullerene derivative C60PCBM (phenyl C61-butyric acid methyl ester, product name: E100), which is an electron-accepting compound, and polymer compound 1, which is an electron-donating compound, at a weight ratio of 3: 1. The mixture was dissolved in o-dichlorobenzene so that the concentration of the mixture was 2% by weight. The obtained solution was filtered through a Teflon (registered trademark) filter having a pore size of 1.0 μm to prepare a coating solution 1.
A glass substrate provided with an ITO film with a thickness of 150 nm by a sputtering method was subjected to surface treatment by ozone UV treatment. Next, a PEDOT: PSS solution (CleviosP VP AI4083 manufactured by HC Starck Co., Ltd.) is applied onto the ITO film by spin coating, and heated at 120 ° C. for 10 minutes in the atmosphere to thereby form a hole injection layer having a thickness of 50 nm. It was created. Next, the coating solution 1 was applied onto the ITO film by spin coating to obtain a functional layer of an organic thin film solar cell. The film thickness of the functional layer was 100 nm. Then, the organic thin film solar cell was produced by vapor-depositing calcium with a film thickness of 4 nm with a vacuum evaporation machine, and vapor-depositing aluminum with a film thickness of 100 nm. The degree of vacuum at the time of vapor deposition was all 1 to 9 × 10 ⁻³ Pa. The shape of the organic thin film solar cell thus obtained was a square of 2 mm × 2 mm. The obtained organic thin film solar cell is irradiated with constant light using a solar simulator (trade name OTENTO-SUNII: AM1.5G filter, irradiance 100 mW / cm ² , manufactured by Spectrometer Co., Ltd.), and the generated current and voltage are measured. did. The photoelectric conversion efficiency is 2.3%, Jsc (short circuit current density) is 6.7 mA / cm ² , Voc (open circuit voltage) is 0.80 V, and FF (fill factor) is 0.44. there were.

The polymer compound of the present invention is useful for an organic photoelectric conversion element because of its large absorbance of light having a long wavelength.

Claims

Formula (1)

[In the formula, R represents a hydrogen atom, a fluorine atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aryl group, or an optionally substituted heteroaryl. Group or formula (3)

(In the formula, m1 represents an integer of 0 to 6, and m2 represents an integer of 0 to 6. R ′ represents an alkyl group which may be substituted with fluorine, an aryl group which may be substituted, or a substituted group. A hydrogen atom in the formula represented by (CH 2 ) m1 or (CH 2 ) m2 may be fluorine-substituted). The four Rs may be the same or different from each other. ]
And a repeating unit represented by formula (2)

[Wherein R represents the same meaning as described above. ]
A polymer compound comprising a repeating unit represented by:
R is a hydrogen atom, a fluorine atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, an optionally substituted fluorine group having 1 to 20 carbon atoms, or an optionally substituted phenyl group. The polymer compound according to claim 1, wherein the substituent of the phenyl group is a halogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms.
An organic photoelectric conversion element having a pair of electrodes and a functional layer provided between the electrodes, wherein the functional layer includes an electron-accepting compound and the polymer compound according to claim 1.
The organic photoelectric conversion device according to claim 2, wherein the amount of the electron-accepting compound contained in the functional layer is 10 to 1000 parts by weight with respect to 100 parts by weight of the polymer compound.
The organic photoelectric conversion element according to claim 3, wherein the electron-accepting compound is a fullerene derivative.