JP5050625B2 - Copolymer and organic photoelectric conversion device using the same - Google Patents

Description

  The present invention relates to a copolymer and an organic photoelectric conversion device using the copolymer.

  In recent years, studies using an organic semiconductor material for an active layer of an organic photoelectric conversion element (such as an organic solar cell or an optical sensor) have been actively conducted. In particular, if a polymer compound is used as the organic semiconductor material, an active layer can be produced by an inexpensive coating method, and therefore various studies have been made on fluorene copolymers having excellent solubility in organic solvents. For example, 2,7-dibromo-9,9-dioctylfluorene, 2,7-bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -9,9-dioctyl The following repeating unit (M) and the following repeating unit (N) obtained by polymerizing fluorene and 4,7-bis (5-bromo-2-thienyl) -2,1,3-benzothiadiazole by the Suzuki coupling reaction (Patent Document 1) describes the use of a random copolymer comprising:

繰り返し単位（Ｍ） 繰り返し単位（Ｎ）

Repeating unit (M) Repeating unit (N)

Applied Physics Letters Vol.84, No.10 1653-1655 (2004)

  However, even if the fluorene copolymer is used in an organic photoelectric conversion element, there is a problem that the photoelectric conversion efficiency is not always sufficient.

  Then, an object of this invention is to provide the polymer which can provide the photoelectric conversion efficiency excellent when it uses for manufacture of an organic photoelectric conversion element.

（式中、Ｒ、Ｒ¹およびＲ²は、水素原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、又は置換基を有していてもよい炭素数６〜６０のアリール基を表す。これらの基に含まれる水素原子はフッ素原子で置換されていてもよい。複数個のＲは同一であっても相異なってもよい。） In the present invention, a block comprising a repeating unit consisting of a structure represented by the following formula (1a) and / or a structure represented by the following formula (1b) and a structure represented by the following formula (2) (A And a block (B) containing a repeating unit consisting of a structure represented by the following formula (1a) and / or a structure represented by the following formula (1b) and a structure represented by the following formula (3) A copolymer is provided.

(In the formula, R, R ¹ and R ² are each a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an optionally substituted group having 6 to 60 carbon atoms. Represents an aryl group, and the hydrogen atom contained in these groups may be substituted with a fluorine atom, and a plurality of R may be the same or different.

  The present invention secondly provides an organic photoelectric conversion device having an organic layer containing the copolymer of the present invention.

  The present invention thirdly, a pair of electrodes, at least one of which is transparent or translucent, a first organic layer containing the copolymer of the present invention between the electrodes, and adjacent to the first organic layer. And an organic photoelectric conversion element having a second organic layer containing an electron donating compound.

  Fourthly, the present invention provides a pair of electrodes, at least one of which is transparent or translucent, a first organic layer containing an electron-accepting compound between the electrodes, and adjacent to the first organic layer. An organic photoelectric conversion device having a second organic layer containing the obtained copolymer of the present invention is provided.

  Fifth, the present invention provides an organic photoelectric conversion device having a pair of electrodes, at least one of which is transparent or translucent, and an organic layer containing the copolymer of the present invention and an electron donating compound between the electrodes. .

  Sixth, the present invention provides an organic photoelectric conversion device having a pair of electrodes, at least one of which is transparent or translucent, and an organic layer containing an electron accepting compound and the copolymer of the present invention between the electrodes. .

  The copolymer of the present invention can impart excellent photoelectric conversion efficiency when used in the production of an organic photoelectric conversion element. Moreover, it is excellent in the solubility to an organic solvent, and the active layer of an organic photoelectric conversion element can be produced by a coating method.

  Hereinafter, the present invention will be described in detail.

<Copolymer>
The copolymer of the present invention is a block comprising a repeating unit comprising the structure represented by the formula (1a) and / or the structure represented by the formula (1b) and the structure represented by the formula (2) ( A) and a block (B) containing a repeating unit comprising the structure represented by the formula (1a) and / or the structure represented by the formula (1b) and the structure represented by the formula (3) It is characterized by being a copolymer.

In the formula (1a), R, R ¹ and R ² may each independently have a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a substituent. A good aryl group having 6 to 60 carbon atoms is represented. The hydrogen atom contained in these groups may be substituted with a fluorine atom. A plurality of R may be the same or different. R ¹ and R ² are preferably an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryl group having 6 to 60 carbon atoms which may have a substituent.

In the formula (1a), R, the alkyl group having 1 to 20 carbon atoms represented by R ¹ and R ^2, a methyl group, an ethyl group, n- propyl group, i- propyl, n- butyl group, Examples include i-butyl, t-butyl, s-butyl, 3-methylbutyl, pentyl, hexyl, 2-ethylhexyl, heptyl, octyl, nonyl, decyl, lauryl and the like. From the viewpoint of the balance between solubility in an organic solvent and photoelectric conversion efficiency, an alkyl group having 1 to 10 carbon atoms is preferable, and a pentyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, and a decyl group are more preferable. A hydrogen atom in the alkyl group may be substituted with a fluorine atom. Examples of the substituent include a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group, a perfluorohexyl group, and a perfluorooctyl group.

In the formula (1a), the alkoxy group having 1 to 20 carbon atoms represented by R, R ¹ and R ² includes a methoxy group, an ethoxy group, an n-propyloxy group, an i-propyloxy group, and n-butoxy. Group, i-butoxy group, s-butoxy group, t-butoxy group, pentyloxy group, hexyloxy group, cyclohexyloxy group, heptyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, 3 , 7-dimethyloctyloxy group, lauryloxy group and the like. A hydrogen atom in the alkoxy group may be substituted with a fluorine atom. Examples of the substituent include a trifluoromethoxy group, a pentafluoroethoxy group, a perfluorobutoxy group, a perfluorohexyl group, and a perfluorooctyl group.

In the formula (1a), examples of the aryl group having 6 to 60 carbon atoms which may have a substituent represented by R, R ¹ and R ² include a phenyl group and a C _{1 to} C ₁₂ alkoxyphenyl. group (C ₁ -C ₁₂ indicates that it is 1 to 12 carbon atoms. the same applies is less.), C ₁ -C ₁₂ alkylphenyl group, 1-naphthyl, 2-naphthyl and the like , An aryl group having 6 to 20 carbon atoms is preferable, and a C _{1 to} C ₁₂ alkoxyphenyl group and a C _{1 to} C ₁₂ alkylphenyl group are more preferable. The aryl group may have a substituent. Examples of the substituent include a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and an alkoxy group having a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms in its structure. And a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms is preferable. A hydrogen atom in the aryl group may be substituted with a fluorine atom.

Examples of the structure represented by the formula (1a) include the following structures.

In the formula (1b), R, R ¹ and R ² may each independently have a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a substituent. A good aryl group having 6 to 60 carbon atoms is represented. The hydrogen atom contained in these groups may be substituted with a fluorine atom. A plurality of R may be the same or different. R ¹ and R ² are preferably an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryl group having 6 to 60 carbon atoms which may have a substituent.

In the formula (1b), examples of the alkyl group having 1 to 20 carbon atoms represented by R, R ¹ and R ² include the same groups as in the case of the above (1a).

In the formula (1b), examples of the alkoxy group having 1 to 20 carbon atoms represented by R, R ¹ and R ² include the same groups as those in the above-mentioned (1a).

In the formula (1b), the aryl group having 6 to 60 carbon atoms which may have a substituent represented by R, R ¹ and R ² is the same group as in the case of the above (1a). can give.

Examples of the structure represented by the formula (1b) include the following structures.

  In the formula (2), R represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryl group having 6 to 60 carbon atoms which may have a substituent. To express. The hydrogen atom contained in these groups may be substituted with a fluorine atom. A plurality of R may be the same or different.

  In the formula (2), examples of the alkyl group having 1 to 20 carbon atoms represented by R include the same groups as those described in the above (1a).

  In the formula (2), examples of the alkoxy group having 1 to 20 carbon atoms represented by R include the same groups as those described in the above (1a).

  In the formula (2), examples of the aryl group having 6 to 60 carbon atoms which may have a substituent represented by R include the same groups as those described in the above (1a).

Examples of the structure represented by the formula (2) include the following structures.

  As the repeating unit comprising the structure represented by the formula (1a) and / or the structure represented by the formula (1b) and the structure represented by the formula (2), one or more types of the formula (1a) are used. A repeating unit comprising a structure represented by formula (1) and one or more types of structures represented by formula (2), one or more types of structures represented by formula (1b) and one or more types of formulas (2) A repeating unit composed of a structure represented by one or more types, a structure represented by one or more types of the formula (1a), a structure represented by one or more types of the formula (1b) and The repeating unit which consists of a structure is mentioned.

  Specific examples of the repeating unit include the following repeating units.

  The block (A) contained in the copolymer of the present invention may contain a repeating unit structure other than the repeating unit. Examples of the repeating unit include repeating units represented by the following formulas (6-A) to (6-H).

（式中、Ｒは、前記で定義したとおりである。複数個存在するＲは、同一であっても異なっていてもよい。）

(In the formula, R is as defined above. A plurality of R may be the same or different.)

（式中、Ｒ¹およびＲ²は前述と同じ意味を表す。Ｒ³は、直鎖状の炭素数１〜２０のアルキル基を表す。２個のＲ³は同一であっても相異なってもよい。） The block (A) is preferably composed of a repeating unit represented by the following formula (4) from the viewpoint of increasing the solubility in an organic solvent and increasing the absorption wavelength.

(In the formula, R ¹ and R ² represent the same meaning as described above. R ³ represents a linear alkyl group having 1 to 20 carbon atoms. Two R ^{3 s} may be the same or different. May be good.)

  In the formula (3), R represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryl group having 6 to 60 carbon atoms which may have a substituent. To express. The hydrogen atom contained in these groups may be substituted with a fluorine atom. A plurality of R may be the same or different.

  In the formula (3), examples of the alkyl group having 1 to 20 carbon atoms represented by R include the same groups as those in the above (1a).

  In the above formula (3), examples of the alkoxy group having 1 to 20 carbon atoms represented by R include the same groups as in the case of the above (1a).

  In the formula (3), examples of the aryl group having 6 to 60 carbon atoms which may have a substituent represented by R include the same groups as those described in the above (1a).

  The block (B) contained in the copolymer of the present invention has a structure represented by the formula (1a) and / or a structure represented by the formula (1b) and a structure represented by the formula (3). A repeating unit other than the repeating unit may be included. Examples of the repeating unit include repeating units represented by the formulas (6-A) to (6-H).

Examples of the structure represented by the formula (3) include the following structures.

  Examples of the repeating unit include one or more types of repeating units composed of a structure represented by the formula (1a) and one or more types of structures represented by the formula (3), and one or more types of the formula (1b). A repeating unit comprising a structure represented by one or more types of the formula (3), one or more structures represented by the formula (1a) and one or more types represented by the formula (1b) And repeating units composed of one or more types of structures represented by the formula (3).

  Specific examples of the repeating unit include the following repeating units.

  The block (B) contained in the copolymer of the present invention may contain a repeating unit other than the above repeating unit. Examples of the repeating unit include repeating units represented by the formulas (6-A) to (6-H).

（式中、Ｒ¹、Ｒ²は、前述と同じ意味を表す。Ｒ⁴は、直鎖状の炭素数１〜２０のアルキル基を表す。２個のＲ⁴は同一であっても相異なってもよい。） The block (B) is preferably composed of a repeating unit represented by the following formula (5) from the viewpoint of increasing the charge mobility and the absorption wavelength.

(Wherein R ¹ and R ² represent the same meaning as described above. R ⁴ represents a linear alkyl group having 1 to 20 carbon atoms. Two R ^{4 s} may be the same or different. May be.)

  When the total of all repeating units in the copolymer of the present invention is 100 mol, the structure represented by the formula (1a) or the structure represented by the formula (1b) contained as a repeating unit is usually The repeating unit represented by the formula (2) is usually in the range of 1 mol to 60 mol, and the repeating unit represented by the formula (3) is usually 1 mol. The range is from mol to 60 mol. The copolymer of the present invention is a repeating unit represented by the formula (1a), a repeating unit represented by the formula (1b), a repeating unit represented by the formula (2), and the formula (3). When the repeating unit other than the repeating unit represented by the formula (1) is included, the total of the repeating units is usually in the range of 0.1 mol to 30 mol with respect to all the repeating units in the copolymer.

The copolymer of the present invention preferably has a photoelectric conversion efficiency characteristics of the element, from the viewpoint of solubility in an organic solvent, a number average molecular weight in terms of polystyrene is ^{1 × 10 3 ~1 × 10 8} , 1 × 10 4 More preferably, it is ˜1 × 10 ⁷ . The weight average molecular weight in terms of polystyrene is preferably 1 × 10 ³ to 1 × 10 ⁸ , and more preferably 1 × 10 ⁴ to 1 × 10 ⁷ .

In the copolymer of the present invention, the block (A) preferably has a polystyrene-equivalent number average molecular weight of 1 × 10 ³ to 1 × 10 ⁵ from the viewpoint of photoelectric conversion efficiency characteristics of the device and solubility. It is more preferable that it is 1 × 10 ⁴ to 1 × 10 ⁵ . The weight average molecular weight in terms of polystyrene is ^{1 × 10 3 ~1 × 10 5} , more preferably ^{1 × 10 4 ~1 × 10 5} .

  In the present invention, the polystyrene-equivalent number average molecular weight and weight average molecular weight can be determined by gel permeation chromatography (GPC).

    When the total number of blocks (A) and blocks (B) contained in the copolymer of the present invention is defined as 100, the number of blocks (A) is preferably 5 to 95, and preferably 10 to 90. More preferred is 15 to 85.

  In addition, if a polymerization active group remains at the terminal of the copolymer of the present invention as it is, there is a possibility that the photoelectric conversion efficiency when it is made into an element may decrease, so the terminal of the copolymer is a stable protective group. It may be protected. As the protecting group, those having a conjugated bond continuous with the conjugated structure of the main chain are preferable, and examples thereof include those having a structure bonded to an aryl group or a heterocyclic group via a carbon-carbon bond. It is done. Specific examples include substituents described in Chemical formula 10 of JP-A-9-45478.

  Examples of the good solvent for the copolymer of the present invention include chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene, mesitylene, tetralin, decalin, and n-butylbenzene. Although depending on the structure and molecular weight of the copolymer, it is usually possible to dissolve the copolymer in an amount of 0.1% by weight or more in these solvents.

<Method for producing copolymer>
Next, the manufacturing method of the copolymer of this invention is demonstrated.
As a method for synthesizing the copolymer, for example, a method of synthesizing a high molecular weight block (A), adding a monomer constituting the block (B) to the polymer and polymerizing the copolymer, a high molecular weight block (A) and a high molecular weight in advance. And a method of synthesizing these blocks (B) and polymerizing them together.

For example, a compound represented by Y ₁ -Ar ₁ -Y ₂ , a compound represented by Y ₃ -Ar ₂ -Y ₄ , a compound represented by Y ₅ -Ar ₃ -Y ₆ , and Y ₇ -Ar ₄ -Y ₈ The copolymer of the present invention can be produced by using the compound shown as a raw material and subjecting it to condensation polymerization (wherein Ar ₁ is the formula (1a), Ar ₂ is the formula (1b), Ar ₃ represents the structure of the above formula (2), Ar ₄ represents the structure of the above formula (3), and Y _{1 to} Y ₈ each independently represent a substituent involved in the condensation polymerization.

In the method for producing a copolymer of the present invention, examples of the substituent (Y _{1 to} Y ₈ ) involved in condensation polymerization include a halogen atom, an alkylsulfo group, an arylsulfo group, an arylalkylsulfo group, a borate group, and a sulfonium. Examples thereof include a methyl group, a phosphonium methyl group, a phosphonate methyl group, a monohalogenated methyl group, -B (OH) ₂ , a formyl group, a cyano group, and a vinyl group.

  Examples of the alkylsulfo group include a methanesulfo group, an ethanesulfo group, and a trifluoromethanesulfo group. Examples of the arylsulfo group include a benzenesulfo group and a p-toluenesulfo group. Examples of the arylalkylsulfo group include a benzylsulfo group.

  Examples of the borate group include groups represented by the following formula.

（式中、Ｍｅはメチル基を示し、Ｅｔはエチル基を示す。）

(In the formula, Me represents a methyl group, and Et represents an ethyl group.)

Examples of the sulfonium methyl group include groups represented by the following formula.
_{^{-CH 2 S + Me 2 X -}} , -CH 2 S + Ph 2 X -
(In the formula, X represents a halogen atom, Me represents a methyl group, and Ph represents a phenyl group.)

Examples of the phosphonium methyl group include groups represented by the following formula.
-CH ₂ P ⁺ Ph ₃ X ^-
(In the formula, X represents a halogen atom, and Ph represents a phenyl group.)

Examples of the phosphonate methyl group include groups represented by the following formula.
-CH ₂ PO (OR ') ₂
(In the formula, R ′ represents an alkyl group, an aryl group, or an arylalkyl group.)

  Examples of the monohalogenated methyl group include a methyl fluoride group, a methyl chloride group, a methyl bromide group, and a methyl iodide group.

A preferable substituent as a substituent involved in the condensation polymerization varies depending on the kind of the polymerization reaction. For example, when a zero-valent nickel complex (Ni (0) complex) such as a Yamamoto coupling reaction is used, a halogen atom, an alkylsulfo group, An arylsulfo group or an arylalkylsulfo group is mentioned. In the case of using a nickel catalyst or a palladium catalyst such as a Suzuki coupling reaction, an alkylsulfo group, a halogen atom, a borate group, -B (OH) _{2 and the} like can be mentioned.

  Specifically, the method for producing a copolymer of the present invention comprises dissolving a compound, which is a monomer and having two substituents involved in condensation polymerization, in an organic solvent as necessary, for example, an alkali or an appropriate catalyst. Can be used at a temperature not lower than the melting point of the organic solvent and not higher than the boiling point. For example, “Organic Reactions”, Vol. 14, pp. 270-490, John Wiley & Sons, Inc., 1965, “Organic Synthesis”, Collective Volume 6. (Collective Volume VI), 407-411, John Wiley & Sons, Inc., 1988, Chemical Review (Chem. Rev.), 95, 2457 (1995), Journal of Organometallic. Chemistry (J. Organomet. Chem.), 576, 147 (1999), Macromolecular Chemistry Macro Rekyura Symposium (Macromol.Chem., Macromol.Symp.), Vol. 12, page 229 (1987) may be a known method described, for example.

In the method for producing a copolymer of the present invention, a known condensation reaction can be used depending on the substituent involved in the condensation polymerization. For example, a method of polymerizing a corresponding monomer by a Suzuki coupling reaction, a method of polymerizing by a Grignard reaction, a method of polymerizing by a zerovalent nickel complex, a method of polymerizing by an oxidizing agent such as FeCl _3, a method of electrochemical oxidative polymerization Or a method by decomposition of an intermediate polymer having an appropriate leaving group. Among these, the method of polymerizing by Suzuki coupling reaction, the method of polymerizing by Grignard reaction, and the method of polymerizing by zero-valent nickel complex are preferable because the structure can be easily controlled.

In the method for producing a copolymer of the present invention, substituents (Y _{1 to} Y ₈ ) involved in condensation polymerization are independently selected from a halogen atom, an alkylsulfo group, an arylsulfo group or an arylalkylsulfo group, A production method in which condensation polymerization is performed in the presence of a zerovalent nickel complex is preferred. Examples of the raw material compound include dihalogenated compounds, bis (alkyl sulfonate) compounds, bis (aryl sulfonate) compounds, bis (aryl alkyl sulfonate) compounds, halogen-alkyl sulfonate compounds, halogen-aryl sulfonate compounds, and halogen-aryl alkyl sulfonates. Compounds, alkyl sulfonate-aryl sulfonate compounds, alkyl sulfonate-aryl alkyl sulfonate compounds, and aryl sulfonate-aryl alkyl sulfonate compounds. Among these, as raw material compounds, for example, halogen-alkyl sulfonate compounds, halogen-aryl sulfonate compounds, halogen-aryl alkyl sulfonate compounds, alkyl sulfonate-aryl sulfonate compounds, alkyl sulfonate-aryl alkyl sulfonate compounds, or aryl sulfonate-aryl alkyls. The method of manufacturing the copolymer which controlled the sequence by using a sulfonate compound is mentioned.

In the production method of the present invention, the substituents (Y _{1 to} Y ₈ ) involved in the condensation polymerization are independently halogen atoms, alkylsulfo groups, arylsulfo groups, arylalkylsulfo groups, boric acid groups (— B (OH) ₂ ) or a boric acid ester group, and the total number (M) of moles of halogen atoms, alkylsulfo groups, arylsulfo groups and arylalkylsulfo groups possessed by all raw material compounds, and boric acid groups And the ratio K / J to the total number of moles of boric acid ester groups (K) is substantially 1 (usually in the range of 0.7 to 1.2), and is a condensation polymerization using a nickel catalyst or a palladium catalyst. The manufacturing method is preferred. Specific examples of the combination of raw material compounds include a combination of a dihalogenated compound, a bis (alkyl sulfonate) compound, a bis (aryl sulfonate) compound or a bis (aryl alkyl sulfonate) compound and a diboric acid compound or a diboric acid ester compound. . Also, halogen-boric acid compounds, halogen-boric acid ester compounds, alkyl sulfonate-boric acid compounds, alkyl sulfonate-boric acid ester compounds, aryl sulfonate-boric acid compounds, aryl sulfonate-boric acid ester compounds, arylalkyl sulfonate-borates An acid compound and an arylalkyl sulfonate-borate ester compound are mentioned. Among these, as raw material compounds, for example, halogen-boric acid compounds, halogen-boric acid ester compounds, alkyl sulfonate-boric acid compounds, alkyl sulfonate-boric acid ester compounds, aryl sulfonate-boric acid compounds, aryl sulfonate-boric acid. The method of manufacturing the copolymer which controlled the sequence by using an ester compound, an arylalkyl sulfonate-borate compound, and an arylalkyl sulfonate-borate ester compound is mentioned.

Although the solvent used for the reaction varies depending on the compound used and the reaction, it is generally preferable to perform sufficient deoxygenation treatment in order to suppress side reactions. The reaction is preferably allowed to proceed under an inert atmosphere. Similarly, the solvent used in the reaction is preferably subjected to dehydration treatment.
However, this is not the case in the case of a two-phase reaction with water, such as the Suzuki coupling reaction.

  Solvents include saturated hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane, decalin, aromatic hydrocarbons such as benzene, toluene, ethylbenzene, n-butylbenzene, xylene, tetralin, carbon tetrachloride, chloroform, dichloromethane, Halogenated saturated hydrocarbons such as chlorobutane, bromobutane, chloropentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane, bromocyclohexane, halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene, methanol, ethanol, propanol , Alcohols such as isopropanol, butanol and t-butyl alcohol, carboxylic acids such as formic acid, acetic acid and propionic acid, dimethyl ether, diethyl ether Ethers such as ter, methyl-t-butyl ether, tetrahydrofuran, tetrahydropyran and dioxane, amines such as trimethylamine, triethylamine, N, N, N ′, N′-tetramethylethylenediamine and pyridine, N, N-dimethylformamide, Examples include amides such as N, N-dimethylacetamide, N, N-diethylacetamide, and N-methylmorpholine oxide. These solvents may be used alone or in combination. Of these, ethers are preferable, and tetrahydrofuran and diethyl ether are more preferable.

  In order to make it react, an alkali and a suitable catalyst are added suitably. These may be selected according to the reaction used. The alkali or catalyst is preferably one that is sufficiently dissolved in the solvent used in the reaction. Examples of the alkali include inorganic bases such as potassium carbonate and sodium carbonate; organic bases such as triethylamine; inorganic salts such as cesium fluoride. Examples of the catalyst include palladium [tetrakis (triphenylphosphine)] and palladium acetates. As a method of mixing the alkali or catalyst, slowly add the alkali or catalyst solution while stirring the reaction solution under an inert atmosphere such as argon or nitrogen, or conversely, slowly add the reaction solution to the alkali or catalyst solution. And the method of adding.

  When the copolymer of the present invention is used for an organic solar cell or the like, the purity affects the device performance such as photoelectric conversion efficiency. Therefore, the monomer before polymerization is purified by a method such as distillation, sublimation purification, and recrystallization. It is preferable to polymerize later. Further, after the polymerization, it is preferable to carry out a purification treatment such as reprecipitation purification and fractionation by chromatography.

<Organic photoelectric conversion element>
The organic photoelectric conversion element of the present invention is not particularly limited as long as a pair of electrodes, and an electron accepting compound and an electron donating compound contained between the electrodes are adjacent to form a heterojunction interface. Is
1. A pair of electrodes, a first organic layer containing the copolymer of the present invention between the electrodes, and a second organic layer containing an electron donating compound provided adjacent to the first organic layer An organic photoelectric conversion element having:
2. A pair of electrodes, a first organic layer containing an electron-accepting compound between the electrodes, and a second organic layer containing the copolymer of the present invention provided adjacent to the first organic layer An organic photoelectric conversion element having:
3. An organic photoelectric conversion element having at least one organic layer containing a pair of electrodes and the copolymer of the present invention and an electron donating compound between the electrodes;
4). An organic photoelectric conversion element having a pair of electrodes and an organic layer containing an electron-accepting compound and the copolymer of the present invention between the electrodes;
5. An organic photoelectric conversion element having at least one organic layer containing a pair of electrodes and an electron-accepting compound and a copolymer of the present invention provided between the electrodes, wherein the electron-accepting compound is a fullerene derivative Photoelectric conversion element;

  In addition, said 5. In the organic photoelectric conversion device, the ratio of the fullerene derivative in the organic layer containing the fullerene derivative and the copolymer of the present invention is 10 to 1000 parts by weight with respect to 100 parts by weight of the copolymer of the present invention. Preferably, it is 50-500 weight part.

  Next, the operation mechanism of the organic photoelectric conversion element will be described. Light energy incident from a transparent or translucent electrode is absorbed by the electron-accepting compound and / or the electron-donating compound to generate excitons in which electrons and holes are combined. When the generated excitons move and reach the heterojunction interface where the electron-accepting compound and the electron-donating compound are adjacent to each other, electrons and holes are separated due to the difference in HOMO energy and LUMO energy at the interface. Electric charges (electrons and holes) that can move are generated. The generated charges can be taken out as electric energy (current) by moving to the electrodes.

  In order for the organic photoelectric conversion element to have high conversion efficiency, the electron-accepting compound and the electron-donating compound have an absorption region that can efficiently absorb a desired incident light spectrum, It is important that the junction interface includes many heterojunction interfaces in order to efficiently separate excitons, and that the junction interface has a charge transport property for quickly transporting the charges generated by the heterojunction interface to the electrode.

  From such a viewpoint, the organic photoelectric conversion device of the present invention includes the above-mentioned 3, and 4. Or 5. From the viewpoint of including many heterojunction interfaces, 5. Is more preferable. In the organic photoelectric conversion element of the present invention, an additional layer may be provided between at least one electrode and the organic layer in the element. Examples of the additional layer include a charge transport layer that transports holes or electrons.

  When the copolymer of the present invention is used as an electron donor, the electron acceptor suitably used for the organic photoelectric conversion element is such that the HOMO energy of the electron acceptor is higher than the HOMO energy of the copolymer, and the electron acceptor. The LUMO energy of the copolymer becomes higher than the LUMO energy of the copolymer. In addition, when the copolymer of the present invention is used as an electron acceptor, the electron donor that is preferably used for the organic photoelectric conversion element has an electron donor whose HOMO energy is lower than that of the copolymer, The LUMO energy of the donor is lower than the LUMO energy of the copolymer.

  The organic photoelectric conversion element of the present invention is usually formed on a substrate. This substrate may be any substrate that does not 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.

  Examples of the transparent or translucent electrode material include a conductive metal oxide film and a translucent metal thin film. Specifically, indium oxide, zinc oxide, tin oxide, and a composite film made of conductive glass made of indium / tin / oxide (ITO), indium / zinc / oxide, etc. (NESA) Etc.), gold, platinum, silver, copper and the like 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. Furthermore, as the electrode material, a metal, a conductive polymer, or the like can be used. Preferably, one of the pair of electrodes is preferably a material having a small 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 two of them One or more alloys, or one or more of them and an alloy of one or more of gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, tin, graphite, or a graphite intercalation compound are used. It is done. 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, calcium-aluminum alloy and the like.

  As materials used for the charge transport layer as the additional layer, that is, the hole transport layer and the electron transport layer, an electron donating compound and an electron accepting compound described later can be used, respectively. As a material used as a buffer layer as an additional layer, an alkali metal such as lithium fluoride, an alkaline earth metal halide, an oxide, or the like can be used. In addition, fine particles of an inorganic semiconductor such as titanium oxide can be used.

  As said organic layer (organic layer containing the copolymer of this invention) in the organic photoelectric conversion element of this invention, the organic thin film containing the copolymer of this invention can be used, for example.

  The organic thin film has a thickness of usually 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 said organic thin film may contain the copolymer of this invention individually by 1 type, or may contain it in combination of 2 or more types. In order to improve the hole transport property of the organic thin film, a low molecular compound and / or a polymer other than the copolymer of the present invention is mixed as an electron donating compound and / or an electron accepting compound in the organic thin film. Can also be used.

  Examples of the electron donating compound include, in addition to the copolymer of the present invention, pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine derivatives, oligothiophene and derivatives thereof, polyvinylcarbazole and derivatives thereof, polysilane and derivatives thereof. And polysiloxane derivatives having an aromatic amine in the side chain or main chain, polyaniline and derivatives thereof, polythiophene and derivatives thereof, polypyrrole and derivatives thereof, polyphenylene vinylene and derivatives thereof, polythienylene vinylene and derivatives thereof, and the like.

Examples of the electron-accepting compound include, in addition to the copolymer of the present invention, oxadiazole derivatives, anthraquinodimethane and derivatives thereof, benzoquinone and derivatives thereof, naphthoquinone and derivatives thereof, anthraquinones and derivatives thereof, tetracyanoanthra Quinodimethane and derivatives thereof, 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 fullerenes and derivatives thereof, phenanthrene derivatives such as bathocuproine, and the like. Fullerenes and derivatives thereof are particularly preferable.

Examples of fullerenes include C ₆₀ , C ₇₀ , carbon nanotubes, and derivatives thereof. Specific examples of the derivative include the following.

<Method for producing organic thin film>
The method for producing the organic thin film is not particularly limited, and examples thereof include a method by film formation from a solution containing the copolymer of the present invention, but the thin film may be formed by vacuum deposition.

  The solvent used for film formation from a solution is not particularly limited as long as it dissolves the copolymer of the present invention. Examples of the solvent include unsaturated hydrocarbon solvents such as toluene, xylene, mesitylene, tetralin, decalin, bicyclohexyl, n-butylbenzene, sec-butylbezen, and tert-butylbenzene, carbon tetrachloride, chloroform, and dichloromethane. Halogenated saturated hydrocarbon solvents such as dichloroethane, chlorobutane, bromobutane, chloropentane, bromopentane, chlorohexane, bromohexane, chlorocyclohexane and bromocyclohexane, and halogenated unsaturated hydrocarbons such as chlorobenzene, dichlorobenzene and trichlorobenzene Examples of the solvent include ether solvents such as tetrahydrofuran and tetrahydropyran. The copolymer 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 Coating methods such as a printing method, an offset printing method, an ink jet 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 ink jet 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.

<Application of device>
An organic thin film solar cell module and an organic image sensor can be configured by integrating a plurality of the organic photoelectric conversion elements of the present invention.

  Examples will be shown below for illustrating the present invention in more detail, but the present invention is not limited to these examples.

  In the following examples, the molecular weight of the polymer was determined as the number average molecular weight in terms of polystyrene by GPC (trade name: LC-10Avp) manufactured by Shimadzu Corporation or GPC (PL-GPC2000) manufactured by GPC Laboratory. When measured by LC-10Avp, the polymer was dissolved in tetrahydrofuran to a concentration of about 0.5% by weight, and 50 μL was injected into GPC. Tetrahydrofuran was used as the GPC mobile phase, and flowed at a flow rate of 0.6 mL / min. As for the column, two TSKgel SuperHM-H (manufactured by Tosoh) and one TSKgel SuperH2000 (manufactured by Tosoh) were connected in series. A differential refractive index detector (manufactured by Shimadzu Corporation, trade name: RID-10A) was used as the detector. When measured with PL-GPC2000, the polymer was dissolved in o-dichlorobenzene so as to have a concentration of about 1% by weight. As the mobile phase of GPC, o-dichlorobenzene was used and allowed to flow at a measurement temperature of 140 ° C. at a flow rate of 1 mL / min. As the column, three PLGEL 10 μm MIXED-B (manufactured by PL Laboratory) were connected in series.

窒素雰囲気化、三つ口フラスコに化合物Ｃ、0.11g（0.23mmol）と化合物Ｄ、0.18g（0.24mmol）、ジクロロビス（トリフェニルホスフィン）パラジウム（II）0.1mg、メチルトリオクチルアンモニウムクロライド（商品名：aliquat336、Aldrich製、CH₃N[(CH₂)₇CH₃]₃Cl、density 0.884g/ml,25℃、trademark of Henkel Corporation） 0.03gを入れ、あらかじめ30分間窒素バブリングしたトルエン5mlを加えた。105℃まで加熱し、2mol/lの炭酸ナトリウム水溶液0.5mlを滴下した。滴下終了後、２時間加熱還流し、室温まで冷却し、ブロックＢを得た。続いて化合物Ｃ、0.47g（1.0mmol）と化合物Ｅ、0.61g（0.97mmol）、ジクロロビス（トリフェニルホスフィン）パラジウム（II） 0.4mg、メチルトリオクチルアンモニウムクロライド（商品名：aliquat336、Aldrich製、CH₃N[(CH₂)₇CH₃]₃Cl、density 0.884g/ml,25℃、trademark of Henkel Corporation） 0.2gと窒素バブリングしたトルエン13mlを加えた。105℃まで加熱し、2mol/lの炭酸ナトリウム水溶液2mlを滴下した後、4時間加熱環流した。フェニルボロン酸0.02gを加えて更に5時間加熱還流し、N,N-ジエチルジチオカルバミド酸ナトリウム三水和物0.5gとイオン交換水6.18mlを加えて90℃で3時間撹拌した。室温まで冷却後、水層を除去し、有機層を60℃のイオン交換水30mlで3回、2％酢酸水溶液で3回、更に60℃のイオン交換水で3回洗浄した。シリカゲル−アルミナカラムで精製し、メタノールに沈殿させることにより、ブロックＡとブロックＢからなる共重合体の重合体１を0.7g得た。ブロックＡは下式繰り返し単位（Ａ−１）からなり、ブロックＢは下記繰り返し単位（Ｂ−１）からなる。得られた重合体１の分子量はポリスチレン換算で数平均分子量Mn=8.2×10⁴、重量平均分子量Mw＝2.9×10⁵であった。

繰り返し単位（Ｂ−１）

繰り返し単位（Ａ−１） Example 1
(Synthesis of polymer 1)
Copolymer having block (A) and block (B)

In a nitrogen atmosphere, compound C, 0.11 g (0.23 mmol) and compound D, 0.18 g (0.24 mmol), dichlorobis (triphenylphosphine) palladium (II) 0.1 mg, methyl trioctyl ammonium chloride (trade name) : Aliquat336, manufactured by Aldrich, CH ₃ N [(CH ₂ ) ₇ CH ₃ ] ₃ Cl, density 0.884g / ml, 25 ° C, trademark of Henkel Corporation) Add 0.03g, and add 5ml of toluene bubbling nitrogen for 30 minutes in advance It was. The mixture was heated to 105 ° C., and 0.5 ml of a 2 mol / l aqueous sodium carbonate solution was added dropwise. After completion of dropping, the mixture was heated to reflux for 2 hours and cooled to room temperature to obtain Block B. Subsequently, Compound C, 0.47 g (1.0 mmol) and Compound E, 0.61 g (0.97 mmol), dichlorobis (triphenylphosphine) palladium (II) 0.4 mg, methyltrioctylammonium chloride (trade name: aliquat336, manufactured by Aldrich, CH ₃ N [(CH ₂ ) ₇ CH ₃ ] ₃ Cl, density 0.884 g / ml, 25 ° C., trademark of Henkel Corporation) 0.2 g and 13 ml of toluene bubbled with nitrogen were added. The mixture was heated to 105 ° C., 2 ml of a 2 mol / l aqueous sodium carbonate solution was added dropwise, and the mixture was refluxed with heating for 4 hours. 0.02 g of phenylboronic acid was added and the mixture was further heated under reflux for 5 hours, 0.5 g of sodium N, N-diethyldithiocarbamate trihydrate and 6.18 ml of ion-exchanged water were added, and the mixture was stirred at 90 ° C. for 3 hours. After cooling to room temperature, the aqueous layer was removed, and the organic layer was washed 3 times with 30 ml of 60 ° C. ion exchange water, 3 times with 2% aqueous acetic acid, and 3 times with ion exchange water at 60 ° C. Purification by a silica gel-alumina column and precipitation in methanol gave 0.7 g of copolymer 1 consisting of block A and block B. Block A consists of the following repeating unit (A-1), and block B consists of the following repeating unit (B-1). The molecular weight of the obtained polymer 1 was a number average molecular weight Mn = 8.2 × 10 ⁴ and a weight average molecular weight Mw = 2.9 × 10 ⁵ in terms of polystyrene.

Repeating unit (B-1)

Repeating unit (A-1)

化合物Ｃ、０．９４９ｇと化合物Ｅ、１．２５３ｇとメチルトリオクチルアンモニウムクロライド（商品名：aliquat336、Aldrich製、CH₃N[(CH₂)₇CH₃]₃Cl、density 0.884g/ml,25℃、trademark of Henkel Corporation）０．３０ｇと、ジクロロビス（トリフェニルホスフィン）パラジウム（II） ３．４ｍｇとを反応容器に仕込み、反応容器内をアルゴンガスで置換した。この反応容器に、予めアルゴンガスをバブリングして、脱気したトルエン ４５ｍｌを加えた。次に、この溶液に、攪拌下、予めアルゴンガスでバブリングして、脱気した１６．７重量％炭酸ナトリウム水溶液 １０ｍｌを滴下し、１２時間還流した。次に、反応溶液を冷却し、フェニルホウ酸０．１ｇ／テトラヒドロフラン０．５ｍｌ混合溶液を加え、２時間還流した。なお、反応はアルゴンガス雰囲気下で行った。反応終了後、反応溶液を冷却した後、この反応溶液にトルエン６０ｇを加えた。この反応溶液を静置し、分液して、トルエン溶液を回収した。次に、このトルエン溶液を濾過し、不溶物を除去した。次に、このトルエン溶液を、アルミナカラムを通し、精製した。次に、このトルエン溶液をメタノール中に注ぎ込み、再沈精製し、生成した沈殿を回収した。次に、この沈殿を、減圧乾燥した後、再びトルエンに溶解した。次に、このトルエン溶液をろ過した後、このトルエン溶液を、アルミナカラムを通し、精製した。次に、このトルエン溶液をメタノール中に注ぎ込み、再沈精製し、生成した沈殿を回収した。この沈殿をメタノールで洗浄した後、減圧乾燥して重合体２、０．５ｇを得た。重合体２のポリスチレン換算の重量平均分子量は９．９×１０⁴であり、ポリスチレン換算の数平均分子量は６．１×１０⁴であった。仕込みから推定される重合体２に含まれる繰り返し単位は、下記のとおりである。

Reference synthesis example 1
(Synthesis of polymer 2)

Compound C, 0.949 g and Compound E, 1.253 g and methyltrioctylammonium chloride (trade name: aliquat336, manufactured by Aldrich, CH ₃ N [(CH ₂ ) ₇ CH ₃ ] ₃ Cl, density 0.884 g / ml, 25 C., trademark of Henkel Corporation) 0.30 g and dichlorobis (triphenylphosphine) palladium (II) 3.4 mg were charged into a reaction vessel, and the inside of the reaction vessel was replaced with argon gas. To this reaction vessel, 45 ml of toluene deaerated by bubbling argon gas in advance was added. Next, 10 ml of a 16.7 wt% sodium carbonate aqueous solution deaerated by bubbling with argon gas in advance under stirring was added dropwise to the solution and refluxed for 12 hours. Next, the reaction solution was cooled, a mixed solution of 0.1 g of phenylboric acid / 0.5 ml of tetrahydrofuran was added, and the mixture was refluxed for 2 hours. The reaction was performed in an argon gas atmosphere. After completion of the reaction, the reaction solution was cooled, and 60 g of toluene was added to the reaction solution. The reaction solution was allowed to stand and separated to collect a toluene solution. Next, this toluene solution was filtered to remove insoluble matters. Next, this toluene solution was purified through an alumina column. Next, this toluene solution was poured into methanol and purified by reprecipitation, and the generated precipitate was recovered. Next, this precipitate was dried under reduced pressure and then dissolved again in toluene. Next, after filtering this toluene solution, this toluene solution was purified by passing through an alumina column. Next, this toluene solution was poured into methanol and purified by reprecipitation, and the generated precipitate was recovered. This precipitate was washed with methanol and then dried under reduced pressure to obtain 0.5 g of polymer 2. The polystyrene equivalent weight average molecular weight of the polymer 2 was 9.9 × 10 ⁴ , and the polystyrene equivalent number average molecular weight was 6.1 × 10 ⁴ . The repeating unit contained in the polymer 2 estimated from the preparation is as follows.

化合物Ｃ、０．９５７ｇと化合物Ｅ、１．００３ｇと化合物Ｄ、０．３００ｇとメチルトリオクチルアンモニウムクロライド（商品名：aliquat336、Aldrich製、CH₃N[(CH₂)₇CH₃]₃Cl、density 0.884g/ml,25℃、trademark of Henkel Corporation）０．３５ｇと、ジクロロビス（トリフェニルホスフィン）パラジウム（II） ４．０ｍｇとを反応容器に仕込み、反応容器内をアルゴンガスで置換した。この反応容器に、予めアルゴンガスをバブリングして、脱気したトルエン ４５ｍｌを加えた。次に、この溶液に、攪拌下、予めアルゴンガスでバブリングして、脱気した１６．７重量％炭酸ナトリウム水溶液 １０ｍｌを滴下し、３時間還流した。次に、反応溶液を冷却し、フェニルホウ酸０．１ｇ／テトラヒドロフラン１．０ｍｌ混合溶液を加え、１．５時間還流した。なお、反応はアルゴンガス雰囲気下で行った。
反応終了後、反応溶液を冷却した後、この反応溶液にトルエン８０ｇを加えた。この反応溶液を静置し、分液して、トルエン溶液を回収した。次に、このトルエン溶液を濾過し、不溶物を除去した。次に、このトルエン溶液を、アルミナカラムを通し、精製した。次に、このトルエン溶液をメタノール中に注ぎ込み、再沈精製し、生成した沈殿を回収した。次に、この沈殿を、減圧乾燥した後、再びトルエンに溶解した。次に、このトルエン溶液をろ過した後、このトルエン溶液を、アルミナカラムを通し、精製した。次に、このトルエン溶液をメタノール中に注ぎ込み、再沈精製し、生成した沈殿を回収した。この沈殿をメタノールで洗浄した後、減圧乾燥して重合体３、０．６７ｇを得た。重合体３のポリスチレン換算の重量平均分子量は１．０×１０⁴であり、ポリスチレン換算の数平均分子量は４．８×１０³であった。
仕込みから推定される重合体３は、下記繰り返し単位（Ｃ−１）と下記繰り返し単位（Ｄ−１）が、８０／２０のモル比で共重合したランダム共重合体である。

繰り返し単位（Ｃ−１） 繰り返し単位（Ｄ−１） Reference synthesis example 2
(Synthesis of Polymer 3)

Compound C, 0.957 g and Compound E, 1.003 g and Compound D, 0.300 g and methyltrioctylammonium chloride (trade name: aliquat336, manufactured by Aldrich, CH ₃ N [(CH ₂ ) ₇ CH ₃ ] ₃ Cl, density 0.884 g / ml, 25 ° C., trademark of Henkel Corporation) 0.35 g and dichlorobis (triphenylphosphine) palladium (II) 4.0 mg were charged into the reaction vessel, and the inside of the reaction vessel was replaced with argon gas. To this reaction vessel, 45 ml of toluene deaerated by bubbling argon gas in advance was added. Next, 10 ml of a 16.7 wt% aqueous sodium carbonate solution deaerated by bubbling with argon gas in advance under stirring was added dropwise to the solution and refluxed for 3 hours. Next, the reaction solution was cooled, a mixed solution of 0.1 g of phenylboric acid / 1.0 ml of tetrahydrofuran was added, and the mixture was refluxed for 1.5 hours. The reaction was performed in an argon gas atmosphere.
After completion of the reaction, the reaction solution was cooled, and 80 g of toluene was added to the reaction solution. The reaction solution was allowed to stand and separated to collect a toluene solution. Next, this toluene solution was filtered to remove insoluble matters. Next, this toluene solution was purified through an alumina column. Next, this toluene solution was poured into methanol and purified by reprecipitation, and the generated precipitate was recovered. Next, this precipitate was dried under reduced pressure and then dissolved again in toluene. Next, after filtering this toluene solution, this toluene solution was purified by passing through an alumina column. Next, this toluene solution was poured into methanol and purified by reprecipitation, and the generated precipitate was recovered. The precipitate was washed with methanol and then dried under reduced pressure to obtain 0.67 g of polymer 3. The polystyrene equivalent weight average molecular weight of the polymer 3 was 1.0 × 10 ⁴ , and the polystyrene equivalent number average molecular weight was 4.8 × 10 ³ .
The polymer 3 estimated from preparation is a random copolymer obtained by copolymerizing the following repeating unit (C-1) and the following repeating unit (D-1) at a molar ratio of 80/20.

Repeating unit (C-1) Repeating unit (D-1)

アルゴン置換した2L四つ口フラスコに化合物Ｃ（7.928g、16.72mmol）、化合物Ｄ（13.00g、17.60mmol）、メチルトリオクチルアンモニウムクロライド（商品名：aliquat336、Aldrich製、CH₃N[(CH₂)₇CH₃]₃Cl、density 0.884g/ml,25℃、trademark of Henkel Corporation）（4.979g）、およびトルエン405mlを入れ、撹拌しながら系内を30分間アルゴンバブリングする。ジクロロビス（トリフェニルホスフィン）パラジウム（II）（0.02g）を加え、105℃に昇温、撹拌しながら2mol／Lの炭酸ナトリウム水溶液42.2mlを滴下した。滴下終了後5時間反応させ、フェニルボロン酸（2.6g）とトルエン1.8mlを加えて105℃で16時間撹拌した。トルエン700mlおよび7.5％ジエチルジチオカルバミン酸ナトリウム三水和物水溶液200mlを加えて85℃で3時間撹拌した。水層を除去後、60℃のイオン交換水300mlで2回、60℃の3％酢酸300mlで1回、さらに60℃のイオン交換水300mlで3回洗浄した。有機層をセライト、アルミナ、シリカを充填したカラムに通し、熱トルエン800mlでカラムを洗浄した。溶液を700mlまで濃縮した後、2Lのメタノールに注加、再沈殿させた。重合体をろ過して回収し、500mlのメタノール、アセトン、メタノールで洗浄した。50℃で一晩真空乾燥することにより、下記式：

で表されるペンタチエニル−フルオレンコポリマー（以下、「重合体４」という） １２．２１ｇを得た。重合体４のポリスチレン換算の数平均分子量は５．４×１０⁴、重量平均分子量は１．１×１０⁵であった。 Reference synthesis example 3
(Synthesis of polymer 4)

Compound C (7.928 g, 16.72 mmol), Compound D (13.00 g, 17.60 mmol), methyltrioctylammonium chloride (trade name: aliquat336, manufactured by Aldrich, CH ₃ N [(CH ₂ ) ₇ CH ₃ ] ₃ Cl, density 0.884 g / ml, 25 ° C., trademark of Henkel Corporation) (4.979 g), and 405 ml of toluene, and argon bubbling in the system for 30 minutes while stirring. Dichlorobis (triphenylphosphine) palladium (II) (0.02 g) was added, and the temperature was raised to 105 ° C. and 42.2 ml of a 2 mol / L aqueous sodium carbonate solution was added dropwise with stirring. After completion of the dropwise addition, the mixture was reacted for 5 hours, phenylboronic acid (2.6 g) and 1.8 ml of toluene were added, and the mixture was stirred at 105 ° C. for 16 hours. Toluene 700 ml and 7.5% sodium diethyldithiocarbamate trihydrate 200 ml were added and stirred at 85 ° C. for 3 hours. After removing the aqueous layer, washing was performed twice with 300 ml of ion exchange water at 60 ° C., once with 300 ml of 3% 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 filled with celite, alumina, and silica, and the column was washed with 800 ml of hot toluene. The solution was concentrated to 700 ml, poured into 2 L of methanol, and reprecipitated. The polymer was recovered by filtration and washed with 500 ml of methanol, acetone, and methanol. By vacuum drying overnight at 50 ° C., the following formula:

12.21 g of a pentathienyl-fluorene copolymer represented by the following (hereinafter referred to as “polymer 4”) was obtained. The polystyrene equivalent number average molecular weight of the polymer 4 was 5.4 × 10 ⁴ , and the weight average molecular weight was 1.1 × 10 ⁵ .

Example 2
(Production and evaluation of organic thin-film solar cells)
The polymer shown in Table 1 as an electron donor was dissolved in xylene at a concentration of 0.75% (wt%). Thereafter, PCBM (Phenyl C61-butyric acid methyl ester, trade name E100, manufactured by Frontier Carbon Co., Ltd.) 3 times the weight of the polymer was mixed into the solution as an electron acceptor. Subsequently, it filtered with the 1.0 micrometer Teflon (trademark) filter, and produced the application | coating solution.

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, the coating solution was applied by spin coating to obtain an active layer (film thickness of about 80 nm) of the organic thin film solar cell. Then, 4 nm of lithium fluoride and then 100 nm of Al were vapor-deposited by a vacuum vapor deposition machine. The degree of vacuum at the time of vapor deposition was 1 to 9 × 10 ⁻³ Pa in all cases. Moreover, the shape of the obtained organic thin-film solar cell was a regular square of 2 mm × 2 mm. The photoelectric conversion efficiency of the obtained organic thin film solar cell was measured with a solar simulator (manufactured by Spectrometer, trade name OTENTO-SUNII: AM1.5G filter, irradiance 100 mW / cm ² ). The measurement results are shown in Table 1.

-Evaluation-
As can be seen from Table 1, the organic thin film solar cell (Example 2) formed using the copolymer 1 containing the block (A) and the block (B) is a polymer other than the copolymer of the present invention. High photoelectric conversion efficiency was shown compared with the organic thin film solar cell (Comparative Examples 1-3) formed using.

Claims (10)

A block (A) containing a repeating unit composed of a structure represented by the following formula (1a) and / or a structure represented by the following formula (1b) and a structure represented by the following formula (2); And / or a block (B) containing a repeating unit consisting of a structure represented by the following formula (1b) and a structure represented by the following formula (3).

(Wherein R, R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or an optionally substituted carbon group having 6 carbon atoms. Represents an aryl group of ˜60.The hydrogen atom contained in these groups may be substituted with a fluorine atom, and a plurality of R may be the same or different.   The copolymer according to claim 1, wherein the number of blocks (A) is 5 to 95 when the total number of blocks (A) and blocks (B) contained in the copolymer is 100. The copolymer according to claim 1 or 2, wherein the block (A) comprises a repeating unit represented by the following formula (4).

(Wherein R ¹ and R ² represent the same meaning as described above. R ³ represents a linear alkyl group having 1 to 20 carbon atoms. Two R ^{3 s} may be the same or different. May be.) The copolymer according to any one of claims 1 to 3, wherein the block (B) comprises a repeating unit represented by the following formula (5).

(Wherein R ¹ and R ² represent the same meaning as described above. R ⁴ represents a linear alkyl group having 1 to 20 carbon atoms. Two R ^{4 s} may be the same or different. May be.)   The organic photoelectric conversion element which has an organic layer containing the copolymer in any one of Claims 1-4.   A pair of electrodes, at least one of which is transparent or translucent, a first organic layer containing the copolymer according to any one of claims 1 to 4 between the electrodes, and adjacent to the first organic layer And an organic photoelectric conversion element having a second organic layer containing an electron donating compound.   A pair of electrodes, at least one of which is transparent or translucent, a first organic layer containing an electron-accepting compound between the electrodes, and the first organic layer adjacent to the first organic layer. An organic photoelectric conversion device having a second organic layer containing the copolymer according to any one of the above.   An organic photoelectric conversion device comprising a pair of electrodes, at least one of which is transparent or translucent, and an organic layer containing the copolymer and the electron donating compound according to any one of claims 1 to 4 between the electrodes.   An organic photoelectric conversion device comprising a pair of electrodes, at least one of which is transparent or translucent, and an organic layer containing an electron-accepting compound and the copolymer according to claim 1 between the electrodes.   The organic photoelectric conversion device according to claim 9, wherein the electron-accepting compound is a fullerene derivative.