WO2017047808A1

WO2017047808A1 - Copolymer, photoelectric conversion element, solar battery, and solar battery module

Info

Publication number: WO2017047808A1
Application number: PCT/JP2016/077599
Authority: WO
Inventors: 光教古屋; 和弘毛利; 理恵子藤田; 和矢白鳥; 茂中根; 潤也河井
Original assignee: 三菱化学株式会社
Priority date: 2015-09-18
Filing date: 2016-09-16
Publication date: 2017-03-23
Also published as: JPWO2017047808A1; JP6904252B2

Abstract

The purpose of the present invention is to provide a photoelectric conversion element having a high conversion efficiency. Provided is a copolymer comprising repeating units represented by formula (I) and repeating units represented by formula (II) which is different from formula (I).

Description

Copolymer, photoelectric conversion element, solar cell, and solar cell module

The present invention relates to a copolymer, a photoelectric conversion element, a solar cell, and a solar cell module.

Π-conjugated polymers are used as semiconductor materials for organic electronic devices such as organic solar cells, organic EL elements, organic thin film transistors, and organic light emitting sensors. In particular, in an organic solar cell, it is desired to improve sunlight absorption efficiency, and it is important to develop a polymer that can absorb light having a long wavelength. In order to achieve a longer absorption wavelength, an example in which a copolymer of a donor monomer and an acceptor monomer (hereinafter referred to as a copolymer) is used for a photoelectric conversion element has been reported.

Specifically, Patent Documents 1 to 3 describe photoelectric conversion elements using a copolymer having a naphthobisthiadiazole unit. Non-Patent Documents 1 and 2 describe examples of photoelectric conversion elements using a copolymer having a naphthobisthiadiazole unit and a benzodithiophene unit.

Chinese Patent Application No. 102060982 International Publication No. 2013/015298 Pamphlet International Publication No. 2012/133793 Pamphlet

High conversion efficiency is required for practical use of organic thin-film solar cells. However, according to the study by the present inventors, the organic thin-film solar cell using the copolymers described in Patent Documents 1 to 3 and Non-Patent Documents 1 and 2 may not obtain sufficient conversion efficiency. found. The present invention solves the above-described problems, and an object thereof is to provide a photoelectric conversion element having high conversion efficiency.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a copolymer having a specific repeating unit, and have achieved the present invention. That is, the first aspect of the present invention is summarized as follows.
[1] A copolymer having a repeating unit represented by the following formula (I) and a repeating unit represented by the following formula (II) different from the formula (I).

(In the formula (I), X ¹ and X ² each independently represent an atom selected from Group 16 elements of the periodic table, ^one of R ¹ and R ² is a monovalent organic group and the other is a hydrogen atom or halogen. An atom, one of R ³ and R ⁴ is a monovalent organic group and the other represents a hydrogen atom or a halogen atom, and D 1 represents a donor-like structural unit, wherein Ar ³ and Ar ⁴ are each Independently represents an optionally substituted aromatic group, c and d each independently represent an integer of 0 or more and 2 or less, A represents an acceptor constituent unit or a direct bond, and D2 represents (It represents a donor structural unit. In the formula (II), when A is a direct bond, c and d in the formula (II) are each independently 1 or 2.)
[2] In the above formula (I), R ¹ and R ⁴ are each independently a monovalent organic group, and R ² and R ³ are each independently a hydrogen atom or a halogen atom. Copolymer.
[3] The copolymer according to [1] or [2], wherein in the formula (I), D1 is a structural unit represented by the following formula (IV) or the following formula (V).

(In formula (IV), Ar ⁵ and Ar ⁶ each independently represent an aromatic ring optionally having a substituent, and X ³ and X ⁴ each independently represent Q ¹ (R ⁵ ) (R ⁶ ), Q ² (R ⁷ ), a sulfur atom (S), an oxygen atom (O) or a direct bond, provided that when one of X ³ and X ⁴ is a direct bond, X ³ and X The other group of ⁴ is Q ¹ (R ⁵ ) (R ⁶ ), Q ² (R ⁷ ), a sulfur atom (S) or an oxygen atom (O), where Q ¹ is a periodic table Represents an atom selected from group 14 elements, Q ² represents an atom selected from group 15 elements of the periodic table, and R ⁵ and R ⁶ each independently represents a hydrogen atom, a halogen atom or a monovalent organic group. represents, R ⁷ is a hydrogen atom,. formula represents a halogen atom or a monovalent organic group in (V), Ar ⁷ and Ar ⁸ are each independently have a substituent An aromatic ring, X ⁵ and X ⁶ each independently represent a group represented by Q ³ (R ^8). Incidentally, Q ³ represents an atom selected from the periodic table group 14 element, R ⁸ Represents a hydrogen atom, a halogen atom or a monovalent organic group.
[4] The copolymer according to any one of [1] to [3], wherein the repeating unit represented by the formula (II) is a repeating unit represented by the following formula (VII):

(In the formula (VII), X ⁷ and X ⁸ each independently represents an atom selected from Group 16 elements of the periodic table, and R ¹¹ to R ¹⁴ each independently represents a hydrogen atom, a halogen atom or a monovalent atom. Represents an organic group, A represents an acceptor structural unit or a direct bond, and D2 represents a donor structural unit.)
[5] The copolymer according to any one of [1] to [4], wherein A in Formula (II) is a structural unit represented by Formula (VIII) or Formula (IX).

(In Formula (VIII), Ar ⁹ may have an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, or a substituent. X ⁹ and X ¹⁰ each independently represents a nitrogen atom (N) or Q ⁴ (R ¹⁵ ), wherein Q ⁴ represents an atom selected from Group 14 elements of the periodic table. , R ¹⁵ represents a hydrogen atom, a halogen atom or a monovalent organic group, and in formula (IX), Ar ¹⁰ has an aromatic hydrocarbon ring which may have a substituent and a substituent. An aromatic heterocyclic ring which may be substituted, or an aliphatic heterocyclic ring which may have a substituent, and X ¹¹ represents an atom selected from Group 16 elements of the periodic table.
[6] The copolymer according to any one of [1] to [5], wherein D2 in the formula (II) is a repeating unit represented by the following formula (IV) or the following formula (V).

(In formula (IV), Ar ⁵ and Ar ⁶ each independently represent an aromatic ring optionally having a substituent, and X ³ and X ⁴ each independently represent Q ¹ (R ⁵ ) (R ⁶ ), Q ² (R ⁷ ), a sulfur atom (S), an oxygen atom (O) or a direct bond, provided that when one of X ³ and X ⁴ is a direct bond, X ³ and X The other group of ⁴ is Q ¹ (R ⁵ ) (R ⁶ ), Q ² (R ⁷ ), a sulfur atom (S) or an oxygen atom (O), where Q ¹ is a periodic table Represents an atom selected from group 14 elements, Q ² represents an atom selected from group 15 elements of the periodic table, and R ⁵ and R ⁶ each independently represents a hydrogen atom, a halogen atom or a monovalent organic group. represents, R ⁷ is a hydrogen atom,. formula represents a halogen atom or a monovalent organic group in (V), Ar ⁷ and Ar ⁸ are each independently have a substituent An aromatic ring, X ⁵ and X ⁶ each independently represent a group represented by Q ³ (R ^8). Incidentally, Q ³ represents an atom selected from the periodic table group 14 element, R ⁸ Represents a hydrogen atom, a halogen atom or a monovalent organic group.)
[7] In the formula (I), D1 is a repeating unit represented by the following formula (VI); in the formula (II), A is a repeating unit represented by the formula (X); The copolymer according to any one of [1] to [6], which is a repeating unit represented by VI).

(In Formula (X), R ¹⁶ and R ¹⁷ represent a hydrogen atom, a halogen atom or a monovalent organic group. In Formula (VI), R ⁹ and R ¹⁰ are each independently a hydrogen atom or a halogen atom. Or represents a monovalent organic group.)
[8] The copolymer according to any one of [1] to [7], wherein in formula (I), R ¹ and R ⁴ are each independently an aliphatic hydrocarbon group having 1 to 20 carbon atoms. .
[9] In any one of [1] to [8], in the copolymer, the ratio of the number of repeating units represented by the formula (I) to the number of repeating units represented by the formula (II) is 0.1 or more and 9 or less A copolymer according to any of the above.
[10] The copolymer according to any one of [1] to [9], which has a weight average molecular weight of 10,000 or more and 300,000 or less.
[11] A photoelectric conversion element having a pair of electrodes on a substrate and an active layer between the pair of electrodes, wherein the active layer is the copolymer according to any one of [1] to [10] The photoelectric conversion element characterized by containing. [12] A solar cell module having the photoelectric conversion element according to [11].

The present invention also provides the following second aspect.
[13] A copolymer having a repeating unit represented by the following formula (I).

(In Formula (I), X ¹ and X ² each independently represent an atom selected from Group 16 elements of the Periodic Table, and R ¹ and R ⁴ each independently represent a straight chain having 9 or more carbon atoms. An aliphatic hydrocarbon group, or a branched aliphatic hydrocarbon group having 9 or more carbon atoms in the main chain and 5 or less carbon atoms in the side chain; R ² and R ³ are each independently D1 represents a structural unit represented by formula (IV) or formula (V).

(In formula (IV), Ar ⁵ and Ar ⁶ each independently represent an aromatic ring optionally having a substituent. X ³ and X ⁴ each independently represent Q ¹ (R ⁵ ) (R ⁶ ), Q ² (R ⁷ ), a sulfur atom (S), an oxygen atom (O) or a direct bond, provided that when one of X ³ and X ⁴ is a direct bond, X ³ and X The other group of ⁴ is Q ¹ (R ⁵ ) (R ⁶ ), Q ² (R ⁷ ), a sulfur atom (S) or an oxygen atom (O) Q ¹ is group 14 of the periodic table R ⁵ and R ⁶ each independently represents a hydrogen atom, a halogen atom or a monovalent organic group, Q ² represents an atom selected from Group 15 elements of the periodic table, ⁷ represents a hydrogen atom, a halogen atom or a monovalent organic group.)

(In the formula (V), Ar ⁷ and Ar ⁸ each independently represents an aromatic ring optionally having a substituent. X ⁵ and X ⁶ are each represented by Q ³ (R ⁸ ). Q ³ represents an atom selected from Group 14 elements of the periodic table, and R ⁸ represents a hydrogen atom, a halogen atom, or a monovalent organic group.)
[14] The copolymer according to [13], wherein D1 in the formula (I) is a structural unit represented by the following formula (III).

(In formula (III), X ¹² and X ¹³ each independently represent an atom selected from Group 16 elements of the periodic table. R ⁹ and R ¹⁰ each independently represent a hydrogen atom, a halogen atom or a monovalent atom. Represents an organic group of
[15] The copolymer according to [14], wherein the structural unit represented by the formula (III) is a structural unit represented by the formula (XV).

(In the formula (XV), X ¹² to X ¹⁵ each independently represents an atom selected from Group 16 elements of the periodic table. R ²⁰ to R ²⁵ each independently represents a hydrogen atom or a halogen atom. Or a monovalent organic group, one of R ²⁰ to R ²² is a monovalent organic group, and the remaining two groups are each independently a hydrogen atom or a halogen atom, and R ²³ to R ²⁵ One of the groups is a monovalent organic group, and the remaining two groups are each independently a hydrogen atom or a halogen atom.)
[16] A photoelectric conversion element having a pair of electrodes on a substrate and an active layer between the pair of electrodes, wherein the active layer is the copolymer according to any one of [13] to [15] Containing a photoelectric conversion element.
[17] A solar cell module having the photoelectric conversion element according to [16].

According to the first aspect of the present invention, a photoelectric conversion element having high conversion efficiency can be provided. Furthermore, according to the first aspect of the present invention, a photoelectric conversion element having high light resistance can be provided. In addition, according to the second aspect of the present invention, a photoelectric conversion element having high conversion efficiency can be provided.

It is sectional drawing which shows typically the structure of the photoelectric conversion element as one Embodiment of this invention. It is sectional drawing which shows typically the structure of the solar cell as one Embodiment of this invention. It is sectional drawing which shows typically the structure of the solar cell module as one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail. The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not specified in these contents unless it exceeds the gist. That is, each embodiment described in the present specification can be variously modified within the scope not departing from the gist thereof, and within the feasible range, the features described by the other embodiments. Can be combined.

<1. Copolymer according to the first aspect of the present invention>
A copolymer according to an embodiment of the present invention (a copolymer according to the first aspect) includes a repeating unit represented by the following formula (I) and a repeating unit represented by the following formula (II) different from the following formula (I). Unit. In the present invention, the repeating unit represented by the formula (II) different from the formula (I) means that the repeating unit represented by the formula (II) is the same as the repeating unit represented by the formula (I). Means not. That is, in the present invention, even when the repeating unit represented by the formula (I) and the repeating unit represented by the formula (II) differ only in substituents, the repeating unit represented by the formula (I) and the formula (II) The repeating unit is different from the represented repeating unit.

In addition, the copolymer according to an embodiment of the present invention has a repeating unit represented by the formula (I) and a repeating unit represented by the formula (II), and the conversion efficiency of the photoelectric conversion element is improved as follows. The reason can be considered. That is, when the copolymer has only the repeating unit represented by the formula (I), the solubility is low, and furthermore, only light in a specific absorption wavelength region range can be absorbed, so that it tends to be difficult to obtain high conversion efficiency. is there. On the other hand, the copolymer has a repeating unit represented by the formula (II) in addition to the repeating unit represented by the formula (I), thereby improving the solubility and absorbing light in a wider wavelength region. In order to be possible, high conversion efficiency can be obtained.

In addition, since organic thin-film solar cells are expected to be used in environments exposed to sunlight, it is desirable to improve not only conversion efficiency but also light resistance for practical use of organic thin-film solar cells. It is. However, according to the study by the present inventors, even a photoelectric conversion element using a copolymer having a repeating unit represented by the formula (I) depends on the combination of R ¹ to R ⁴ and the repeating unit contained therein. It has been found that when light is irradiated, the element deteriorates and conversion efficiency may decrease. This is presumably because the copolymer constituting the photoelectric conversion element is deteriorated by light. In the copolymer of the first aspect of the present invention, the copolymer has a repeating unit represented by the formula (II) in addition to the repeating unit represented by the formula (I), and ^one of R ¹ and R ² is monovalent. The other is a hydrogen atom or a halogen atom, one of R ³ and R ⁴ is a monovalent organic group and the other is a hydrogen atom or a halogen atom, so that the conversion efficiency can be improved even after irradiation with light. Can be provided, and a photoelectric conversion element having high light resistance can be provided. Although this mechanism is not clear, the following reasons can be considered. By adding the repeating unit represented by the formula (II) in addition to the repeating unit represented by the formula (I), the crystallinity of the copolymer and / or the rigidity of the copolymer is relaxed, and a dense film is easily obtained. It is considered that resistance to photo-oxidation in the atmosphere is improved because oxygen and moisture hardly enter the film. Further, it is considered that the progress of aggregation of the copolymer in the film can be suppressed under light irradiation. Furthermore, ^one of R ¹ and R ² is a monovalent organic group and the other is a hydrogen atom or a halogen atom, one of R ³ and R ⁴ is a monovalent organic group and the other is a hydrogen atom or a halogen atom. Therefore, the steric hindrance in the copolymer can be suppressed, so that flatness can be easily obtained. For the above reasons, it is considered that a copolymer having high light resistance can be obtained and a photoelectric conversion element having high light resistance can be provided. Furthermore, since the light resistance of the copolymer is high, it can be produced with high productivity even in a light irradiation environment when producing a photoelectric conversion element.

In formula (I), X ¹ and X ² each independently represent an atom selected from Group 16 elements of the periodic table. Specifically, oxygen atom (O), sulfur atom (S), selenium atom (Se) ) Or tellurium atom (Te). Of these, X ¹ and X ² are preferably since it shows good semiconductor properties is a sulfur atom (S).

In the formula (I), ^one of R ¹ and R ² is a monovalent organic group and the other is a hydrogen atom or a halogen atom, one of R ³ and R ⁴ is a monovalent organic group and the other is a hydrogen atom or a halogen Represents an atom. In the present invention, the monovalent organic group means a monovalent group having one or more carbon atoms. The number of carbon atoms of the monovalent organic group is not particularly limited, but is usually 1 or more, preferably 4 or more, more preferably 6 or more, in order to improve solubility, 10 or more. On the other hand, it is preferably 30 or less, more preferably 20 or less, and particularly preferably 18 or less in order to prevent an increase in steric hindrance between adjacent structural units.

Specific examples of the monovalent organic group include, but are not limited to, a chain aliphatic hydrocarbon group, an alkoxy group, an alkylcarbonyl group, an alkoxy group in order to improve solubility and π-stackability between copolymers. Examples include a carbonyl group or an alkylthio group.

Examples of the chain aliphatic hydrocarbon group include a linear aliphatic hydrocarbon group and a branched aliphatic hydrocarbon group. The number of carbon atoms constituting the aliphatic hydrocarbon group is not particularly limited, but is usually 1 or more, preferably 4 or more, and 6 or more in order to improve solubility. More preferably, it is particularly preferably 10 or more, and on the other hand, in order to prevent an increase in steric hindrance between adjacent structural units, it is preferably 30 or less, more preferably 20 or less, and 18 or less. It is particularly preferred.

Examples of the linear aliphatic hydrocarbon group include a linear alkyl group, a linear alkenyl group, and a linear alkynyl group.

The straight-chain alkyl group is not particularly limited, but for example, n-butyl group, n-hexyl group, n-heptyl group, n-octyl group, n-decyl group, n-dodecyl group, tridecyl group, tetradecyl group , Pentadecyl group, hexadecyl group, heptadecyl group or octadecyl group.

The linear alkenyl group is not particularly limited, and examples thereof include a 5-hexenyl group, a 7-octenyl group, an 11-dodecenyl group, and a 12-tridecenyl group.

The linear alkynyl group is not particularly limited, and examples thereof include a 5-hexynyl group, a 7-octynyl group, a 9-decynyl group, and an 11-dodecynyl group.

Examples of the branched aliphatic hydrocarbon group include a branched alkyl group, a branched alkenyl group, and a branched alkynyl group.

Examples of the branched alkyl group include a branched primary alkyl group, a branched secondary alkyl group, and a branched tertiary alkyl group. The branched primary alkyl group means a branched alkyl group having two hydrogen atoms bonded to a carbon atom having a free valence. The branched secondary alkyl group means a branched alkyl group having one hydrogen atom bonded to a carbon atom having a free valence. The branched tertiary alkyl group means a branched alkyl group having no hydrogen atom bonded to a carbon atom having a free valence. Here, the free valence refers to a substance that can form a bond with another free valence as described in the organic chemistry / biochemical nomenclature (above) (Revised 2nd edition, Nankodo, 1992).

The branched primary alkyl group is not particularly limited, and examples thereof include 2-ethylhexyl group, 2-butyloctyl group, 3,7-dimethyloctyl group, 2-hexyldecyl group, and 2-decyltetradecyl group. .

The branched secondary alkyl group is not particularly limited, and examples thereof include isopropyl group, 3-ethyl-1,5-dimethylnonyl group, and 1-propylheptyl group.

The branched tertiary alkyl group is not particularly limited, and examples thereof include a t-butyl group, a 1-butyl-1-ethylpentyl group, a 1-butyl-1-methylpentyl group, and a 1-ethyl-1-methylhexyl group. 1-methyl-1-propylpentyl group, 1-ethyl-1-methylpropyl group or 1,1,2,2-tetramethylpropyl group.

The branched alkenyl group is not particularly limited, and examples thereof include a 2-methyl-2-propenyl group, a 3-methyl-3-butenyl group, and a 4-methyl-2-hexenyl group.

The branched alkynyl group is not particularly limited, and examples thereof include 1-methyl-2-propenyl group, 2-methyl-3-butenyl group, 4-methyl-2-hexenyl group and the like.

The alkoxy group is not particularly limited, but includes hexyloxy, decyloxy group, dodecyloxy group and the like.

The alkylcarbonyl group is not particularly limited, and examples thereof include a hexanoyl group, a decanoyl group, and a dodecanoyl group.

The alkoxycarbonyl group is not particularly limited, and examples thereof include a hexyloxycarbonyl group, a decyloxycarbonyl group, and a dodecyloxycarbonyl group.

The alkylthio group is not particularly limited, and examples thereof include a thiohexyl group, a thiodecyl group, and a thiododecyl group.

The above-mentioned chain aliphatic hydrocarbon group, alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, and alkylthio group may further have a substituent. The substituent is not particularly limited, and examples thereof include a chain aliphatic hydrocarbon group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylthio group, or a halogen atom. In addition, the total number of carbon atoms and hetero atoms constituting the substituent is preferably 6 or less, more preferably 4 or less, and particularly preferably 2 or less. Moreover, you may have 2 or more types of substituents.

Among these, R ¹ and R ⁴ are each a monovalent organic group in order to prevent an increase in steric hindrance with adjacent naphthobisthiadiazole units and to maintain a high π stacking property to improve conversion efficiency. And R ² and R ³ are preferably a hydrogen atom or a halogen atom. The monovalent organic group is preferably a chain aliphatic hydrocarbon group which may have a substituent in order to improve the solubility of the copolymer. That is, a combination in which R ¹ and R ⁴ are a chain-like aliphatic hydrocarbon group which may have a substituent, and R ² and R ³ are a hydrogen atom or a halogen atom is preferable. Among them, R ¹ and R ⁴ are a chain aliphatic hydrocarbon group having 4 to 30 carbon atoms which may have a substituent, and R ² and R ³ are a hydrogen atom or a halogen atom. A combination is more preferred, wherein R ¹ and R ⁴ are a linear alkyl group having 4 to 30 carbon atoms which may have a substituent, and R ² and R ³ are a hydrogen atom or a halogen atom. Particularly preferably, R ¹ and R ⁴ are most preferably a linear alkyl group having 8 to 20 carbon atoms.

In formula (I), D1 represents a donor structural unit. The donor structural unit is a structural unit having a small ionization potential and a strong tendency to donate electrons, and is an aromatic group which may have a substituent. Specifically, the donor structural unit D1 is a structural unit having a smaller ionization potential and electron affinity than the naphthobisthiadiazole unit in the formula (I). That is, in the present invention, the donor structural unit D1 is a structural unit having a higher HOMO energy level and a higher LUMO energy level than the naphthobisthiadiazole unit functioning as the acceptor structural unit in the formula (I). . The HOMO energy level and LUMO energy level of the acceptor structural unit and the donor structural unit are measured by photoelectron yield spectroscopy (PYS), ultraviolet photoelectron spectroscopy (UPS), inverse photoelectron spectroscopy (IPES), and cyclic voltammetry. In addition to being able to estimate experimentally, it can be calculated by quantum chemical calculation such as molecular orbital method (MO method) and density half function method (DFT method). Note that, when calculating the HOMO energy level and the LUMO energy level of the acceptor structural unit and the donor structural unit, the terminal part of each structural unit is replaced with a hydrogen atom.

Among them, in order to alleviate the rigidity of the copolymer and regularly arrange the copolymers, the donor structural unit D1 is preferably a structural unit represented by the following formula (IV) or the following formula (V).

In formula (IV), Ar ⁵ and Ar ⁶ each independently represents an aromatic ring which may have a substituent. The aromatic ring represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring.

The aromatic hydrocarbon ring is not particularly limited, but is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms constituting the ring. Specifically, monocyclic aromatic hydrocarbon rings such as benzene rings; condensed polycyclic rings such as naphthalene rings, indane rings, indene rings, phenanthrene rings, fluorene rings, anthracene rings, azulene rings, pyrene rings, and perylene rings An aromatic hydrocarbon ring of the formula Of these, a benzene ring or a naphthalene ring is preferable.

The aromatic heterocyclic ring is not particularly limited, but is preferably an aromatic heterocyclic ring having 3 to 30 atoms constituting the ring. Specifically, monocyclic aromatic heterocycles such as thiophene ring, furan ring, pyridine ring, pyrimidine ring, thiazole ring, oxazole ring, triazole ring; or thienothiophene ring, benzothiophene ring, benzofuran ring, benzothiazole Examples thereof include condensed polycyclic aromatic heterocycles such as a ring, a benzoxazole ring, a benzotriazole ring, and a thiadiazolopyridine ring. Among these, a thiophene ring, a pyridine ring, a pyrimidine ring, a thiazole ring, a thiadiazole ring, an oxazole ring, an oxadiazole ring, or a triazole ring is preferable.

The substituent that the aromatic hydrocarbon ring and aromatic heterocyclic ring may have is not particularly limited, and examples thereof include a halogen atom or a monovalent organic group. The carbon atom constituting the monovalent organic group is not particularly limited, but is preferably 1 or more and 30 or less. Specific examples of the monovalent organic group include an aliphatic hydrocarbon group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylthio group, an aromatic hydrocarbon group, an aliphatic heterocyclic group, or an aromatic heterocyclic group. It is done.

In the above formula (IV), X ³ and X ⁴ are each independently Q ¹ (R ⁵ ) (R ⁶ ), Q ² (R ⁷ ), sulfur atom (S), oxygen atom (O) or directly Represents a bond. However, when one of X ³ and X ⁴ is a direct bond, the other group of X ³ and X ⁴ is Q ¹ (R ⁵ ) (R ⁶ ), Q ² (R ⁷ ), a sulfur atom ( S) or an oxygen atom (O). Q1 represents an atom selected from Group 14 elements of the periodic table, preferably a carbon atom (C), a silicon atom (Si), or a germanium atom (Ge). Q ² represents an atom selected from Group 15 elements of the periodic table, preferably nitrogen atom (N) or phosphorus atom (P).

R ⁵ and R ⁶ each represent a group bonded to Q ¹ , and each independently represents a hydrogen atom, a halogen atom or a monovalent organic group. R ⁵ and R ⁶ may be the same group or different groups. R ⁷ is a group bonded to Q ² and represents a hydrogen atom, a halogen atom or a monovalent organic group.

The monovalent organic group is not particularly limited, but is preferably an organic group having 1 to 30 carbon atoms. Among these, preferred groups include an aliphatic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, and an aliphatic complex which may have a substituent. A ring group, an aromatic heterocyclic group which may have a substituent, an alkoxy group which may have a substituent, an alkoxycarbonyl group which may have a substituent, and a substituent; And an alkylthio group which may have a substituent.

The aliphatic hydrocarbon group is not particularly limited, and examples thereof include a chain aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group. The chain aliphatic hydrocarbon group is not particularly limited, but preferred groups include the chain aliphatic hydrocarbon groups described in R ¹ to R ⁴ .

The cyclic aliphatic hydrocarbon group is not particularly limited, but preferably has 4 or more carbon atoms, preferably 6 or more, and preferably 30 or less, and 20 or less. Is particularly preferred. Specific examples include a cyclobutyl group, a cyclohexyl group, a cyclooctyl group, and a cyclononyl group.

The aromatic hydrocarbon group is not particularly limited, and examples thereof include a monocyclic aromatic hydrocarbon group, a polycyclic aromatic hydrocarbon group, and a condensed polycyclic aromatic hydrocarbon group. The aromatic hydrocarbon group has preferably 6 or more carbon atoms, on the other hand, preferably 30 or less, more preferably 20 or less, and particularly preferably 14 or less. Specific examples include a phenyl group, a naphthyl group, an indanyl group, an indenyl group, a fluorenyl group, an anthracenyl group, and an azulenyl group. Of these, a phenyl group is preferred.

The aliphatic heterocyclic group is not particularly limited, but the number of atoms constituting the ring is preferably 3 or more, on the other hand, preferably 30 or less, more preferably 14 or less. It is particularly preferred that Specific examples include an oxetanyl group, a pyrrolidinyl group, a tetrahydrofuryl group, a tetrahydrothienyl group, a piperidinyl group, a tetrahydropyranyl group, and a tetrahydrothiopyranyl group.

The aromatic heterocyclic group is not particularly limited, and examples thereof include a monocyclic aromatic heterocyclic group, a polycyclic aromatic heterocyclic group, and a condensed polycyclic aromatic heterocyclic group. The aromatic heterocyclic group is not particularly limited, but the number of atoms constituting the ring is preferably 3 or more, on the other hand, preferably 30 or less, more preferably 20 or less, It is especially preferable that it is 14 or less. Specifically, thienyl, furanyl, pyridyl, pyrrolyl, imidazolyl, pyrimidyl, thiazolyl, oxazolyl, isoxazolyl, isothiazolyl, pyrazolyl, triazolyl, benzothiophenyl, benzofuranyl, benzothiazolyl Group, benzoxazolyl group or benzotriazolyl group. Among these, a thienyl group, a pyridyl group, a pyrimidyl group, a thiazolyl group, or an oxazolyl group can be given.

Preferred examples of the alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, and alkylthio group include the groups listed for R ¹ to R ⁴ .

The halogen atom is not particularly limited, but includes a fluorine atom.

The substituent that the aliphatic hydrocarbon group, aromatic hydrocarbon group, aliphatic heterocyclic group, aromatic heterocyclic group, alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, and alkylthio group may have Although there is no particular limitation, an aromatic hydrocarbon group, an aliphatic heterocyclic group, an aromatic heterocyclic group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylthio group, a halogen atom and the like can be mentioned.

Specific examples of the structural unit represented by the formula (IV) are shown below. In addition, the structural unit represented by Formula (IV) is not necessarily limited to the following structural units.

In formula (V), Ar ⁷ and Ar ⁸ each independently represent an aromatic ring which may have a substituent. The aromatic ring includes an aromatic hydrocarbon ring or an aromatic heterocyclic ring. The substituent that the aromatic hydrocarbon ring, the aromatic heterocycle and the aromatic ring may have is not particularly limited. For example, the aromatic hydrocarbon ring and the aromatic mentioned in the above Ar ⁵ and Ar ⁶ A heterocyclic ring is mentioned, and a preferable ring is also the same.

In the above formula (V), X ⁵ and X ⁶ each independently represent a group represented by Q ³ (R ⁸ ). Q ³ represents an atom selected from Group 14 elements of the periodic table, and examples thereof include a carbon atom (C), a silicon atom (Si), and a germanium atom (Ge).

R ⁸ represents a group bonded to Q ³ and represents a hydrogen atom, a halogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, but is preferably a group having 1 to 30 carbon atoms. Specific examples of the monovalent organic group include an aliphatic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, and a substituent. An aliphatic heterocyclic group, an aromatic heterocyclic group which may have a substituent, an alkoxy group which may have a substituent, an alkoxycarbonyl group which may have a substituent, and a substituent An alkylcarbonyl group which may be substituted, or an alkylthio group which may have a substituent. Specific examples of these groups include the groups mentioned for the monovalent organic groups of R ⁵ to R ⁷ described above. Examples of the substituent that these groups may have include the substituents described for the monovalent organic groups of R ⁵ to R ⁷ .

Specific examples of the structural unit represented by the formula (V) are shown below. In addition, the structural unit represented by Formula (V) is not necessarily limited to the following structural units.

Among these, the donor structural unit (D1) in the above formula (I) is preferably a donor structural unit represented by the above formula (V) in order to improve the conversion efficiency. Especially, in order to obtain higher conversion efficiency, it is preferable that the donor structural unit represented by Formula (V) is the donor structural unit represented by Formula (III). In order to obtain higher conversion efficiency, the donor structural unit represented by the formula (III) is preferably a donor structural unit represented by the following formula (VI).

In formula (III), X ¹² and X ¹³ each independently represent an atom selected from Group 16 elements of the periodic table. Specific examples include an oxygen atom (O), a sulfur atom (S), a selenium atom (Se), or a tellurium atom (Te). Among these, X ¹² and X ¹³ are each preferably a sulfur atom (S) since the copolymer exhibits good semiconductor properties.

In formula (III), R ⁹ and R ¹⁰ are each independently a hydrogen atom, a halogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, but is preferably a group having 1 to 30 carbon atoms. Specific examples of the monovalent organic group include an aliphatic hydrocarbon group which may have a substituent, an alkoxy group which may have a substituent, and an alkoxycarbonyl group which may have a substituent. , An optionally substituted alkylcarbonyl group, an optionally substituted alkylthio group, an optionally substituted aromatic hydrocarbon group, and optionally having a substituent. Examples thereof include an aliphatic heterocyclic group or an aromatic heterocyclic group which may have a substituent. Specific examples of these groups include the groups mentioned for the monovalent organic groups of R ⁵ to R ⁷ described above. Examples of the substituent that these groups may have include the substituents described for the monovalent organic groups of R ⁵ to R ⁷ . R ⁹ and R ¹⁰ may be the same group or different groups.

Among them, in order to improve solubility, R ⁹ and R ¹⁰ are each independently an aliphatic hydrocarbon group which may have a substituent and an aromatic hydrocarbon group which may have a substituent. Or it is preferable that it is an aromatic heterocyclic group which may have a substituent. Among these, in order to extend the electron conjugation property, R ⁹ and R ¹⁰ are each independently preferably an aromatic heterocyclic group which may have a substituent.

The structural unit represented by the formula (III) is particularly preferably a structural unit represented by the following formula (VI).

Wherein (VI), R ⁹ and R ¹⁰ has the same meaning as R ⁹ and R ¹⁰ in formula (III).

Among them, in order to improve solubility, R ⁹ and R ¹⁰ are each independently an aliphatic hydrocarbon group which may have a substituent and an aromatic hydrocarbon group which may have a substituent. Or it is preferable that it is an aromatic heterocyclic group which may have a substituent. Especially, in order to expand the conjugation property of an electron, it is preferable that R < ⁹ > and R < ¹⁰ > are each independently the aromatic heterocyclic group which may have a substituent. The aromatic heterocyclic group is not particularly limited, but preferably, the aromatic heterocyclic group mentioned for R ⁵ to R ⁷ is used. Especially, in order to improve conversion efficiency, it is especially preferable that R ⁹ and R ¹⁰ are each a thienyl group which may have a substituent. The substituent is not particularly limited, and examples thereof include monovalent organic groups. Specific examples include the substituents described for the monovalent organic groups R ⁵ to R ⁷ . Especially, it is preferable that a substituent is a C8-C20 aliphatic hydrocarbon group, and it is especially preferable that it is a C8-C20 alkyl group.

As described above, the copolymer according to the first aspect of the present invention has a repeating unit represented by the following formula (II) in addition to the repeating unit represented by the above formula (I).

In the above formula (II), Ar ³ and Ar ⁴ each independently represent an aromatic group which may have a substituent. The aromatic group includes an aromatic hydrocarbon group or an aromatic heterocyclic group. Of these, Ar ³ and Ar ⁴ are preferably groups having a high degree of rotational freedom with respect to adjacent structural units. If Ar ³ and Ar ⁴ are groups having a high degree of rotational freedom, the rigidity of the copolymer can be relaxed, so that the copolymers can be regularly arranged and the conversion efficiency can be improved. For this reason, Ar ³ and Ar ⁴ are preferably groups that do not have a three-dimensional structure, and specifically, are preferably aromatic groups in which the number of atoms constituting the aromatic ring is 14 or less, It is more preferable that the number of atoms constituting the aromatic ring is 10 or less, and in order to improve the solubility, the number of atoms constituting the aromatic ring is 8 or less. Is particularly preferred. On the other hand, the number of atoms constituting the aromatic ring is usually 3 or more, and is particularly preferably 5 or more in order to improve carrier mobility. As an aromatic hydrocarbon group, a phenyl group or a naphthyl group is mentioned, for example. Examples of the aromatic heterocyclic group include thienyl group (thiophene), furanyl group (furan), thiazolyl group, thienothienyl group, thienofuranyl group, and thienophenyl. Further, the substituent that the aromatic group may have is not particularly limited, and examples thereof include a monovalent organic group. The monovalent organic group is not particularly limited, but in order to improve the solubility of the copolymer, it is preferably a group having 6 or more carbon atoms, more preferably 10 or more, while adjacent structural units. In order to prevent the steric hindrance from increasing, it is preferably 20 or less, particularly preferably 16 or less.

The monovalent organic group is not particularly limited, and examples thereof include a chain-like aliphatic hydrocarbon group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, and an alkylthio group. Among these, a chain-like aliphatic group is exemplified. A group hydrocarbon group is preferred. These groups may further have a substituent. The substituent is not particularly limited, and examples thereof include the groups mentioned for the monovalent organic group. In addition, the monovalent organic group may have a plurality of substituents within a replaceable range. Moreover, you may have 2 or more types of substituents.

In the above formula (II), c and d each represent an integer of 0 or more and 2 or less. When c is 2, two groups represented by Ar ³ are linked. In this case, the two groups represented by Ar ³ may be the same group or different groups. Good. Similarly, when d is 2, two groups represented by Ar ⁴ are linked. In this case, the two groups represented by Ar ⁴ may be the same group or different groups. Also good. Among these, it is preferable that both c and d are 1 in order to show the point that the solubility of the copolymer can be adjusted, the point that the crystallinity can be adjusted, and good semiconductor properties.

Among these, it is preferable that the repeating unit represented by the above formula (II) is a structural unit represented by the following formula (VII).

In the formula (VII), X ⁷ and X ⁸ each represent an atom selected from Group 16 elements of the periodic table, specifically, an oxygen atom (O), a sulfur atom (Si), a selenium atom (Se) or An example is a tellurium atom (Te). Especially, in order to improve a semiconductor characteristic, it is preferable that it is a sulfur atom (S).

In formula (VII), R ¹¹ to R ¹⁴ each independently represents a hydrogen atom, a halogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, but may have a chain-like aliphatic hydrocarbon group that may have a substituent, an alkoxy group that may have a substituent, or a substituent. Examples thereof include an alkoxycarbonyl group which may be substituted, an alkylcarbonyl group which may have a substituent, and an alkylthio group which may have a substituent. Specific examples of these groups include the groups listed for R ¹ to R ⁴ . Among these, in order to prevent deterioration of semiconductor characteristics, R ¹¹ to R ¹⁴ are preferably a hydrogen atom, a halogen atom, or a chain aliphatic hydrocarbon group. Furthermore, when A in Formula (VII) is a structural unit represented by Formula (VIII) described later or a structural unit represented by Formula (IX), each structural unit can be easily arranged on the same plane. ¹¹ to R ¹⁴ are preferably a hydrogen atom, a halogen atom, or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms. . Further, when A in formula (II) is not a direct bond, R ² and R ³ in formula (I) are each a hydrogen atom, and R ¹ and R ⁴ are monovalent organic groups, R ¹¹ to R ¹⁴ are preferably a hydrogen atom, a halogen atom, or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and a hydrogen atom or an aliphatic carbon atom having 1 to 3 carbon atoms in order to maintain high rigidity. More preferably, it is a hydrogen group. The aliphatic hydrocarbon group having 1 to 3 carbon atoms is preferably an alkyl group, more preferably a methyl group or an ethyl group, and still more preferably a methyl group.
In these cases, one of R ¹¹ and R ¹² is a hydrogen atom, the other is an aliphatic hydrocarbon group having 1 to 3 carbon atoms, one of R ¹³ and R ¹⁴ is a hydrogen atom, and the other is a carbon atom. A combination in which an aliphatic hydrocarbon group having a number of 1 or more and 3 or less is more preferable, a combination in which R ¹¹ and R ¹⁴ are an aliphatic hydrocarbon group having a carbon number of 1 to 3 and R ¹² and R ¹³ are hydrogen atoms Is particularly preferred. When A is a direct bond, R ¹¹ to R ¹⁴ are preferably a hydrogen atom or a halogen atom. The halogen atom is preferably a fluorine atom.

In the formula (II) and the formula (VII), D2 represents a donor structural unit in the same manner as D1 in the formula (I) and the formula (III). That is, D2 is a structural unit having a higher HOMO energy level and a higher LUMO energy level than the acceptor structural unit (A) in formula (II), and is an aromatic group that may have a substituent. is there. The HOMO energy level and the LUMO energy level can be measured by the method described in the item of the donor structural unit D1.

The donor structural unit D2 is not particularly limited, but is preferably a structural unit represented by the above formula (IV) or a structural unit represented by the above formula (V), like the donor structural unit D1, The structural unit represented by the above formula (V) is more preferred, and the structural unit represented by the above formula (VI) is particularly preferred. D1 and D2 may be the same structural unit or different structural units, but in order to match the energy band gap of each unit included in the copolymer and maintain good charge separation D1 and D2 are preferably the same structural unit.

In the above formulas (II) and (VII), A represents an acceptor structural unit or a direct bond. In the formula (II), when A is a direct bond, c and d in the formula (II) are 1 or 2, respectively. When A is a direct bond, when c and d are 1 or 2,-(Ar ³ ) _c- (Ar ⁴ ) _d- functions as an acceptor constituent unit. In the present invention, the acceptor structural unit is a structural unit having a large electron affinity and a strong tendency to accept electrons, and examples thereof include an aromatic group which may have a substituent. Specifically, the acceptor structural unit A is a structural unit having a larger ionization potential and electron affinity than the donor structural unit D2. That is, in the present invention, the acceptor structural unit is a structural unit having a lower HOMO energy level and a lower LUMO energy level than the donor structural unit D2. The HOMO energy level and the LUMO energy level can be measured by the method described in the item of the donor structural unit D1.

Among them, the acceptor structural unit is preferably a structural unit different from the naphthobisthiadiazole unit in the formula (I) from the viewpoint of photoelectric conversion efficiency. This is because the accepting structural unit (A) is a structural unit different from the naphthobisthiadiazole unit in the formula (I), so that the energy band gap and the absorption wavelength can be adjusted, so that the light can be efficiently reflected. This is because absorption is possible, and as a result, the conversion efficiency of the photoelectric conversion element is improved.

Among these, the acceptor structural unit (A) is preferably a structural unit represented by the following formula (VIII) or the following formula (IX).

In the formula (VIII), Ar ⁹ is an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, or an aliphatic which may have a substituent. Represents a family heterocycle.

The aromatic hydrocarbon ring and the aromatic heterocyclic ring are not particularly limited, and examples thereof include the aromatic hydrocarbon ring and the aromatic heterocyclic ring mentioned above for Ar ⁵ and Ar ⁶ . Among these, a thiophene ring, a pyridine ring, a pyrimidine ring, a thiazole ring, a thiadiazole ring, an oxazole ring, an oxadiazole ring, or a triazole ring is preferable.

The aliphatic heterocyclic ring is not particularly limited, but is preferably an aliphatic heterocyclic ring having 4 to 8 atoms constituting the ring. Specific examples include a pyrrolidine ring or a piperidine ring.

The substituent that the aromatic hydrocarbon ring, aromatic heterocyclic ring and aliphatic heterocyclic ring may have is not particularly limited, and examples thereof include monovalent organic groups. The monovalent organic group is not particularly limited, and is an aliphatic hydrocarbon group, aromatic hydrocarbon group, aliphatic heterocyclic group, aromatic heterocyclic group, alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, alkylthio group. Or a halogen atom is mentioned.

In the above formula (VIII), X ⁹ and X ¹⁰ each independently represent a nitrogen atom (N) or Q ⁴ (R ¹⁵ ). Q ⁴ represents an atom selected from Group 14 elements of the periodic table, and among these, a carbon atom (C) is preferable. R ¹⁵ represents a group bonded to Q ⁴ and represents a hydrogen atom, a halogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, and may have an aliphatic hydrocarbon group that may have a substituent, an aromatic hydrocarbon group that may have a substituent, or a substituent. May be an aliphatic heterocyclic group, an aromatic heterocyclic group which may have a substituent, an alkoxy group which may have a substituent, an alkoxycarbonyl group which may have a substituent, a substituent And an alkylthio group which may have a substituent, or an alkylthio group which may have a substituent. Specific examples include the groups described above for R ⁵ to R ⁷ .

Examples of structural units represented by the formula (VIII) are shown below. Note that the structural unit represented by the formula (VIII) is not limited to the following.

In the above formula (IX), Ar ¹⁰ may have an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, or a substituent. Represents an aliphatic heterocycle. The aromatic hydrocarbon ring, aromatic heterocyclic ring, and aliphatic heterocyclic ring are not particularly limited. Specifically, the aromatic hydrocarbon ring, aromatic heterocyclic ring, and aliphatic heterocyclic ring mentioned in Ar ⁹ are Can be mentioned. The substituent that the aromatic hydrocarbon ring, the aromatic heterocyclic ring and the aliphatic heterocyclic ring may have is not particularly limited, and specifically, the aromatic hydrocarbon ring exemplified in Ar ⁹ , Examples thereof include the same substituents as the substituents that the aromatic heterocyclic ring and the aliphatic heterocyclic ring may have.

In the above formula (IX), X ¹¹ represents an atom selected from Group 16 elements of the periodic table. Specifically, an oxygen atom (O), a sulfur atom (S), a selenium atom (Se) or a tellurium atom ( Te). Among these, X ¹¹ is preferably a sulfur atom for improving semiconductor characteristics.

Examples of structural units represented by the formula (IX) are shown below. Note that the structural unit represented by the formula (IX) is not limited to the following.

Among these, the acceptor structural unit (A) is preferably a structural unit represented by the formula (VIII), and is a structural unit represented by the following formula (X) in order to improve the conversion efficiency. It is particularly preferred.

In the above formula (X), R ¹⁶ and R ¹⁷ represent a hydrogen atom, a halogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, but may have an aliphatic hydrocarbon group that may have a substituent, an aromatic hydrocarbon group that may have a substituent, or a substituent. May be an aliphatic heterocyclic group, an aromatic heterocyclic group which may have a substituent, an alkoxy group which may have a substituent, an alkoxycarbonyl group which may have a substituent, a substituent And an alkylthio group which may have a substituent, or an alkylthio group which may have a substituent. Specific examples thereof include the groups listed for R ⁵ to R ⁷ . Among these, R ¹⁶ and R ¹⁷ are preferably each independently a chain aliphatic hydrocarbon group having 1 to 20 carbon atoms or a halogen atom. In particular, it is particularly preferable that both R ¹⁶ and R ¹⁷ are fluorine atoms in order to reinforce the packing between polymer main chains by the interaction between dipoles and to adjust the energy gap by the effect of electron withdrawing. .

Among the above, D1 in the formula (I) is a repeating unit represented by the formula (VI), A in the formula (II) is a repeating unit represented by the formula (X), and D2 is represented by the formula ( A combination which is a repeating unit represented by VI) is preferred.

The copolymer containing the repeating units represented by the formula (I) and the formula (II) according to the first aspect of the present invention is a repeating unit represented by the formula (I) and a repeating unit represented by the formula (II). May be included one by one, and either one or both may be included.
Further, the copolymer according to the first aspect of the present invention is a repeating unit other than the repeating unit represented by the above formula (I) and the repeating unit represented by the above formula (II), as long as the effects of the present invention are not impaired. You may have a unit. Other repeating units are not particularly limited, and include the above-described acceptor constituent units and donor constituent units.

In the copolymer according to the first aspect of the present invention, the arrangement state of the repeating unit represented by the above formula (I), the repeating unit represented by the above formula (II) and other repeating units is alternately, block Or any of random may be sufficient. That is, the copolymer according to the first aspect of the present invention may be an alternating copolymer, a block copolymer, or a random copolymer. In addition, a copolymer having an intermediate structure among these copolymers, for example, a random copolymer having a block property may be used. Also included are copolymers and dendrimers that are branched in the main chain and have three or more terminal portions. Among these, a block copolymer or a random copolymer is preferable because it is easy to synthesize and regularity can be lowered, and the solubility of the copolymer is improved and the storage stability of the ink in which the copolymer is dissolved is improved. In view of this, a random copolymer is more preferable.

The terminal portion of the copolymer according to the first aspect of the present invention is not particularly limited, but is preferably end-gapped with an aromatic hydrocarbon ring, an aromatic heterocyclic ring, or a hydrogen atom.

In the copolymer according to the first aspect of the present invention, the ratio (I / II) of the number of repeating units represented by the above formula (I) to the number of repeating units represented by the above formula (II) is not particularly limited. In order to maintain the energy band gap of the structural unit represented by formula (I), absorb in the long wavelength region, and adjust the solubility of the copolymer, it is preferably 0.1 or more, 0.2 or more More preferably, it is particularly preferably 0.3 or more. On the other hand, the ratio of the number of repeating units represented by the above formula (I) to the number of repeating units represented by the above formula (II) adjusts the energy band gap of the polymer, widens the absorption region, and the main chain. Is preferably 9 or less, more preferably 4 or less, still more preferably 3 or less, in order to change the rotation barrier or planarity of the film and adjust the interaction between main chains. It is particularly preferred that

Among the copolymers according to the first aspect of the present invention, the repeating unit represented by the above formula (I) and the repeating represented by the above formula (II) with respect to the total number of repeating units constituting the copolymer according to the first aspect of the present invention. The ratio of the total number of units (the ratio of the total number of repeating units represented by formula (I) and the number of repeating units represented by formula (II) to the total number of structural units constituting the copolymer) is not limited. However, in order to obtain good semiconductor characteristics, it is preferably 0.1 or more, more preferably 0.3 or more, and particularly preferably 0.5 or more. On the other hand, the upper limit is 1.

Particularly preferably, the copolymer according to the first aspect of the present invention comprises a repeating unit represented by the formula (I) and a repeating unit represented by the formula (II) and is constituted only by these repeating units. Or a polymer chain containing these repeating units and composed only of these repeating units.

<1-2. Copolymer according to Second Aspect of the Present Invention>
A copolymer according to another embodiment of the present invention (a copolymer according to the second aspect) has a structural unit represented by the following formula (I).

In formula (I), X ¹ and X ² each independently represents an atom selected from Group 16 elements of the periodic table. Specific examples include an oxygen atom (O), a sulfur atom (S), a selenium atom (Se), or a tellurium atom (Te). Among these, X ¹ and X ² are each preferably a sulfur atom (S) in order to improve the semiconductor properties of the copolymer.

In the formula (I), R ¹ and R ⁴ are each independently a linear aliphatic hydrocarbon group having 9 or more carbon atoms, or the main chain having 9 or more carbon atoms, and the side chain carbon number. Represents a branched aliphatic hydrocarbon group having 5 or less. In the present invention, the main chain in the branched aliphatic hydrocarbon group means a carbon chain having the maximum carbon number in the branched aliphatic hydrocarbon group. The side chain means a carbon chain portion branched from the main chain. In the present invention, the side chain carbon number of 5 or less means that when the branched aliphatic hydrocarbon group has a plurality of side chains, the carbon number of each side chain is 5 or less. .
When R ¹ and R ⁴ are linear aliphatic hydrocarbon groups having 9 or more carbon atoms or branched aliphatic hydrocarbon groups having 9 or more carbon atoms in the main chain, a highly soluble copolymer can be obtained. Further, in the active layer of the photoelectric conversion element, it is considered that the conversion efficiency of the photoelectric conversion element can be improved by the conjugated structure of the copolymer and the interaction between the main chains. In order to further improve the solubility and interaction of the polymer, the linear aliphatic hydrocarbon group preferably has 10 or more carbon atoms, more preferably 12 or more, and more preferably 13 or more. It is particularly preferred. Similarly, the carbon number of the main chain of the branched aliphatic hydrocarbon group is more preferably 10 or more, further preferably 12 or more, and particularly preferably 13 or more.

On the other hand, the upper limit of the carbon number of the linear aliphatic hydrocarbon group and the main chain carbon number of the branched aliphatic hydrocarbon group is not particularly limited, but R ¹ is maintained while maintaining high solubility. In order to prevent steric hindrance between the 5-membered ring having R ⁴ and the adjacent donor unit represented by D1 in the formula (I), and to maintain the planarity of the copolymer, the carbon number is It is preferably 25 or less, more preferably 20 or less, and particularly preferably 16 or less. In addition, when the planarity of the copolymer is maintained, the copolymers tend to be regularly arranged in the active layer of the photoelectric conversion element, and high conversion efficiency tends to be easily obtained.

In addition, when R ¹ and / or R ⁴ is a branched aliphatic hydrocarbon group, a 5-membered group having R ¹ and R ⁴ in the formula (I) by reducing the number of carbons in the side chain to 5 or less. Steric hindrance with the donor structural unit represented by D1 in the formula (I) adjacent to the ring is less likely to occur, and the planarity of the copolymer is easily obtained. Therefore, the copolymers can be easily arranged regularly in the active layer, and the conversion efficiency of the photoelectric conversion element can be improved. In order to further reduce the steric hindrance with the donor structural unit, the number of carbon atoms in the side chain is more preferably 4 or less, and even more preferably 2 or less.

Specific examples of the linear alkyl group include a decyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, and an icosyl group.

Specific examples of the linear alkenyl group include a decenyl group, a dodecenyl group, a tridecenyl group, a tetradecenyl group, a pentadecenyl group, and a hexadecenyl group.

Specific examples of the linear alkynyl group include a decynyl group, a dodecynyl group, a tridecynyl group, a tetradecynyl group, a pentadecynyl group, and a hexadecynyl group.

Examples of the branched alkyl group include, for example, ethyldecyl group, ethyldodecyl group, ethylpentadecyl group, 2,6-dimethyldecyl group, 2,6-dimethyldodecyl group and the like.

Examples of the branched alkenyl group include, for example, ethyldecenyl group, ethyldodecenyl group, ethylpentadecenyl group, 2,6-dimethyldecenyl group, 2,6-dimethyldodecenyl group and the like.

Examples of the branched alkynyl group include an ethyldecynyl group, an ethyldodecynyl group, an ethylpentadecynyl group, a 2,6-dimethyldecynyl group, a 2,6-dimethyldodecynyl group, and the like.

Of these, the aliphatic hydrocarbon group is preferably a linear aliphatic hydrocarbon group in order to maintain the planarity of the polymer.

Note that some or all of the hydrogen atoms of the aliphatic hydrocarbon group may be substituted with fluorine atoms. In the present invention, an aliphatic hydrocarbon group in which some or all of the hydrogen atoms are substituted with fluorine atoms is also regarded as an aliphatic hydrocarbon group.

In formula (I), R ² and R ³ each independently represent a hydrogen atom or a halogen atom. If R ² and R ³ are hydrogen atoms or halogen atoms, it is possible to suppress the occurrence of steric hindrance between the 5-membered ring having R ² and the 5-membered ring having R ³ and the adjacent naphthobisthiadiazole unit. The copolymers can be regularly arranged in the active layer of the photoelectric conversion element. Especially, it is preferable that both R < ² > and R < ³ > are a hydrogen atom or a fluorine atom, and it is more preferable that both are hydrogen atoms.

In formula (I), D1 represents a donor structural unit. The donor structural unit is a structural unit having a small ionization potential and a strong tendency to donate electrons, and is an aromatic group which may have a substituent. Specifically, the donor structural unit D1 is a structural unit having a smaller ionization potential and electron affinity than the naphthobisthiadiazole unit in the formula (I). That is, in the present invention, the donor structural unit D1 is a structural unit having a higher HOMO energy level and a higher LUMO energy level than the naphthobisthiadiazole unit in the formula (I). In addition, the HOMO energy level and LUMO energy level of the naphthobisthiadiazole unit and donor structural unit are measured by photoelectron yield spectroscopy (PYS) measurement, ultraviolet photoelectron spectroscopy (UPS) measurement, inverse photoelectron spectroscopy (IPES) measurement, and cyclic voltammetry measurement. Etc., and can be estimated experimentally. Further, the HOMO energy level and LUMO energy level of the naphthobisthiadiazole unit and the donor constituent unit can be calculated by quantum chemical calculations such as a molecular orbital method (MO method) and a density half function method (DFT method). . When calculating the HOMO energy level and the LUMO energy level of the naphthobisthiadiazole unit and the donor structural unit, the terminal part of each structural unit is replaced with a hydrogen atom.

The number of carbon atoms constituting the aromatic hydrocarbon ring is preferably 6 or more and 30 or less. Specifically, monocyclic aromatic hydrocarbon such as benzene ring; condensed polycyclic such as naphthalene ring, indane ring, indene ring, phenanthrene ring, fluorene ring, anthracene ring, azulene ring, pyrene ring, perylene ring And aromatic hydrocarbons. Of these, a benzene ring or a naphthalene ring is preferable.

It is preferable that the sum of the numbers of carbon atoms and heteroatoms constituting the aromatic heterocyclic ring is 3 or more and 30 or less. Examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom. Specific examples of the aromatic heterocycle include monocyclic aromatic heterocycles such as a thiophene ring, a furan ring, a pyridine ring, a pyrimidine ring, a thiazole ring, an oxazole ring, and a triazole ring; or a thienothiophene ring and a benzothiophene Examples thereof include condensed polycyclic aromatic heterocycles such as a ring, a benzofuran ring, a benzothiazole ring, a benzoxazole ring, a benzotriazole ring, and a thiadiazolopyridine ring. Among these, a thiophene ring, a pyridine ring, a pyrimidine ring, a thiazole ring, a thiadiazole ring, an oxazole ring, an oxadiazole ring, or a triazole ring is preferable.

The substituent that the aromatic hydrocarbon ring and aromatic heterocyclic ring may have is not particularly limited, and examples thereof include a halogen atom or a monovalent organic group. The number of carbon atoms in the monovalent organic group is not particularly limited, but is preferably 1 or more and 30 or less. Specific examples of the monovalent organic group include an aliphatic hydrocarbon group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylthio group, an aromatic hydrocarbon group, an aliphatic heterocyclic group, or an aromatic heterocyclic group. It is done.

In the above formula (IV), X ³ and X ⁴ are each independently Q ¹ (R ⁵ ) (R ⁶ ), Q ² (R ⁷ ), sulfur atom (S), oxygen atom (O) or directly Represents a bond. However, when one of X ³ and X ⁴ is a direct bond, the other group of X ³ and X ⁴ is Q ¹ (R ⁵ ) (R ⁶ ), Q ² (R ⁷ ), a sulfur atom ( S) or an oxygen atom (O). Q ¹ represents an atom selected from Group 14 elements of the periodic table, preferably a carbon atom (C), a silicon atom (Si), or a germanium atom (Ge). Q ² represents an atom selected from Group 15 elements of the periodic table, preferably a nitrogen atom (N).

R ⁵ and R ⁶ each represent a group bonded to Q ¹ , and each independently represents a hydrogen atom, a halogen atom or a monovalent organic group. R ⁵ and R ⁶ may be the same group or different from each other. R ⁷ is a group bonded to Q ² and represents a hydrogen atom, a halogen atom or a monovalent organic group.

The monovalent organic group is not particularly limited, but is preferably a group having 1 to 30 carbon atoms. Specific examples of the monovalent organic group include an aliphatic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, and a substituent. An aliphatic heterocyclic group, an aromatic heterocyclic group which may have a substituent, an alkoxy group which may have a substituent, an alkoxycarbonyl group which may have a substituent, and a substituent An alkylcarbonyl group which may be substituted, an alkylthio group which may have a substituent, or a halogen atom.

The aliphatic hydrocarbon group is not particularly limited, and examples thereof include a chain aliphatic hydrocarbon group or a cyclic aliphatic hydrocarbon group.

The number of carbon atoms of the chain aliphatic hydrocarbon group is preferably 4 or more in order to improve the solubility of the copolymer, more preferably 6 or more, while it is 30 or less in order to avoid steric hindrance. Preferably, it is preferably 20 or less.

Examples of the chain aliphatic hydrocarbon group include a linear aliphatic hydrocarbon group and a branched aliphatic hydrocarbon group.

The linear alkyl group is not particularly limited, and examples thereof include n-butyl group, n-hexyl group, n-heptyl group, n-octyl group, n-decyl group and n-dodecyl group.

The linear alkenyl group is not particularly limited, and examples thereof include a 5-hexenyl group, a 7-octynyl group, and an 11-dodecenyl group.

The branched alkynyl group is not particularly limited, and examples thereof include a 1-methyl-2-propynyl group, a 2-methyl-3-butynyl group, and a 4-methyl-2-hexynyl group.

The number of carbon atoms of the cyclic aliphatic hydrocarbon group is not particularly limited, but is preferably 4 or more, preferably 6 or more, on the other hand, preferably 30 or less, and 20 or less. Is particularly preferred. Specific examples include a cyclobutyl group, a cyclohexyl group, a cyclooctyl group, and a cyclononyl group.

The carbon number of the alkoxy group is not particularly limited, but is preferably 4 or more, preferably 6 or more, on the other hand, preferably 30 or less, particularly preferably 20 or less. Specific examples include hexyloxy, decyloxy group, dodecyloxy group and the like.

The number of carbon atoms of the alkylcarbonyl group is not particularly limited, but is preferably 4 or more, preferably 6 or more, on the other hand, preferably 30 or less, particularly preferably 20 or less. Specific examples include a hexanoyl group, a decanoyl group, and a dodecanoyl group.

The number of carbon atoms of the alkoxycarbonyl group is not particularly limited, but is preferably 4 or more, preferably 6 or more, on the other hand, preferably 30 or less, particularly preferably 20 or less. Specific examples include a hexyloxycarbonyl group, a decyloxycarbonyl group, a dodecyloxycarbonyl group, and the like.

The number of carbon atoms of the alkylthio group is not particularly limited, but is preferably 4 or more, preferably 6 or more, on the other hand, preferably 30 or less, particularly preferably 20 or less. Specific examples include a thiohexyl group, a thiodecyl group, a thiododecyl group, and the like.

The aromatic hydrocarbon group is not particularly limited, and examples thereof include a monocyclic aromatic hydrocarbon group, a polycyclic aromatic hydrocarbon group, and a condensed polycyclic aromatic hydrocarbon group. The number of carbon atoms of the aromatic hydrocarbon group is not particularly limited, but is preferably 6 or more, preferably 30 or less, more preferably 20 or less, and 14 or less. Particularly preferred. Specific examples include a phenyl group, a naphthyl group, an indanyl group, an indenyl group, a fluorenyl group, an anthracenyl group, and an azulenyl group.

The aliphatic heterocyclic group is not particularly limited, but the number of atoms constituting the ring is preferably 3 or more, on the other hand, preferably 30 or less, more preferably 14 or less. It is particularly preferred that The atoms constituting the ring are not particularly limited, and examples thereof include a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom. Specific examples include an oxetanyl group, a pyrrolidinyl group, a tetrahydrofuryl group, a tetrahydrothienyl group, a piperidinyl group, a tetrahydropyranyl group, and a tetrahydrothiopyranyl group.

The aromatic heterocyclic group is not particularly limited, and examples thereof include a monocyclic aromatic heterocyclic group, a polycyclic aromatic heterocyclic group, and a condensed polycyclic aromatic heterocyclic group. The aromatic heterocyclic group is not particularly limited, but the number of atoms constituting the ring is preferably 3 or more, on the other hand, preferably 30 or less, more preferably 20 or less, It is especially preferable that it is 14 or less. The atoms constituting the ring are not particularly limited, and examples thereof include a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom. Specifically, thienyl, furanyl, pyridyl, pyrrolyl, imidazolyl, pyrimidyl, thiazolyl, oxazolyl, isoxazolyl, isothiazolyl, pyrazolyl, triazolyl, benzothiophenyl, benzofuranyl, benzothiazolyl Group, benzoxazolyl group or benzotriazolyl group. Among these, a thienyl group, a pyridyl group, a pyrimidyl group, a thiazolyl group, or an oxazolyl group can be given.

The halogen atom is not particularly limited, but includes a fluorine atom.

In addition, an aliphatic hydrocarbon group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, and an alkylthio group, an aromatic hydrocarbon group, an aliphatic heterocyclic group, and an aromatic heterocyclic group may have Are not particularly limited, for example, aliphatic hydrocarbon groups, alkoxy groups, alkoxycarbonyl groups, alkylcarbonyl groups, and alkylthio groups, aromatic hydrocarbon groups, aliphatic heterocyclic groups, aromatic heterocyclic groups and halogens. An atom etc. are mentioned.

In formula (V), Ar ⁷ and Ar ⁸ each independently represent an aromatic ring which may have a substituent. The aromatic ring includes an aromatic hydrocarbon ring or an aromatic heterocyclic ring. The aromatic hydrocarbon ring and the aromatic heterocyclic ring are not particularly limited, and examples thereof include the aromatic hydrocarbon ring and the aromatic heterocyclic ring mentioned above for Ar ⁵ and Ar ⁶ , and the preferred rings are also the same. .

R ⁸ represents a group bonded to Q ³ and represents a hydrogen atom, a halogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, but is preferably an organic group having 1 to 30 carbon atoms. Specific examples of the monovalent organic group include an aliphatic hydrocarbon group which may have a substituent, an alkoxy group which may have a substituent, and an alkoxycarbonyl group which may have a substituent. , An optionally substituted alkylcarbonyl group, an optionally substituted alkylthio group, an optionally substituted aromatic hydrocarbon group, and optionally having a substituent. Examples thereof include an aliphatic heterocyclic group or an aromatic heterocyclic group which may have a substituent. Specific examples of these groups include the groups mentioned for the monovalent organic groups of R ⁵ to R ⁷ described above. Examples of the substituent that these groups may have include the substituents described for the monovalent organic groups of R ⁵ to R ⁷ .

Among these, the donor structural unit (D1) in the above formula (I) is preferably a donor structural unit represented by the above formula (V) in order to improve the conversion efficiency. Especially, in order to obtain higher conversion efficiency, it is preferable that the donor structural unit represented by the formula (V) is a donor structural unit represented by the following formula (III).

In formula (III), R ⁹ and R ¹⁰ are each independently a hydrogen atom, a halogen atom or a monovalent organic group. The monovalent organic group is not particularly limited, but is preferably an organic group having 1 to 30 carbon atoms. Specific examples of the monovalent organic group include an aliphatic hydrocarbon group which may have a substituent, an alkoxy group which may have a substituent, and an alkoxycarbonyl group which may have a substituent. , An optionally substituted alkylcarbonyl group, an optionally substituted alkylthio group, an optionally substituted aromatic hydrocarbon group, and optionally having a substituent. Examples thereof include an aliphatic heterocyclic group or an aromatic heterocyclic group which may have a substituent. Specific examples of these groups include the groups mentioned for the monovalent organic groups of R ⁵ to R ⁷ described above. Examples of the substituent that these groups may have include the substituents described for the monovalent organic groups of R ⁵ to R ⁷ . R ⁹ and R ¹⁰ may be the same group or different groups.

Among them, in order to improve solubility, R ⁹ and R ¹⁰ are each independently an aliphatic hydrocarbon group which may have a substituent and an aromatic hydrocarbon group which may have a substituent. Or it is preferable that it is an aromatic heterocyclic group which may have a substituent.

Among these, in order to extend the electron conjugation property, R ⁹ and R ¹⁰ are each independently preferably an aromatic heterocyclic group which may have a substituent. Among these, the structural unit represented by the formula (III) is particularly preferably a structural unit represented by the following formula (XV).

Wherein (XV), X ¹² and X ¹³ has the same meaning as X ¹² and X ¹³ in formula (III). X ¹⁴ and X ¹⁵ each independently represent an atom selected from Group 16 elements of the Periodic Table. That is, X ¹² to X ¹⁵ each independently represent an atom selected from Group 16 elements of the periodic table. Specific examples of the atom selected from Group 16 elements of the periodic table include an oxygen atom (O), a sulfur atom (S), a selenium atom (Se), and a tellurium atom (Te). Among these, X ¹² to X ¹⁵ are each preferably a sulfur atom (S) since the copolymer exhibits good semiconductor properties.

R ²⁰ to R ²⁵ each represents a hydrogen atom, a halogen atom or a monovalent organic group.

The monovalent organic group is not particularly limited, but is preferably an organic group having 1 to 30 carbon atoms. Specific examples of the monovalent organic group include a chain aliphatic hydrocarbon group having 1 to 30 carbon atoms which may have a substituent, and 1 to 30 carbon atoms which may have a substituent. It has the following alkoxy group, an alkoxycarbonyl group having 1 to 30 carbon atoms which may have a substituent, an alkylcarbonyl group having 1 to 30 carbon atoms which may have a substituent, or a substituent. Examples thereof include an alkylthio group having 1 to 30 carbon atoms which may be used. Specific examples of these groups include the chain aliphatic hydrocarbon groups, alkoxy groups, alkoxycarbonyl groups, alkylcarbonyl groups, and alkylthio groups mentioned above for R ⁵ to R ⁷ .

Among these, in order to reduce steric hindrance, one of R ²⁰ to R ²² is preferably a monovalent organic group, and the remaining two groups are preferably hydrogen atoms. Similarly, one of R ²³ to R ²⁵ is preferably a monovalent organic group, and the remaining two groups are preferably hydrogen atoms.

Among these, for the following reasons, R ²⁰ is preferably a monovalent organic group, and R ²¹ and R ²² are preferably hydrogen atoms. According to the study by the present inventors, it is considered preferable to reduce the steric hindrance in the copolymer and maintain the planarity and the conjugated structure in order to obtain high conversion efficiency. For this reason, it is preferable that there are no adjacent structural units or substituents of adjacent structural units in the extending direction of R ¹ and R ⁴ in formula (I). Here, the extending direction of the R ^22, 5-membered ring adjacent to the naphthoquinone jumping steel thiadiazole units, or to the 5-membered ring has groups (R ¹ or R ⁴⁾ are present, R ²² is these and steric hindrance It is preferably a hydrogen atom that is difficult to cause. In the 5-membered ring having R ²⁰ to R ²² , R ²⁰ is bonded to the 5-position of the ring, and R ²¹ is bonded to the 4-position of the ring. Here, since the ring has an atom selected from Group 16 elements of the periodic table as represented by X ¹⁴ , the distance between the 2-position and 5-position of the ring is It is longer than between 2nd and 4th. Therefore, when R ²⁰ is a monovalent organic group and R ²¹ is a hydrogen atom, steric hindrance with the 5-membered ring adjacent to the naphthobisthiadiazole unit can be further reduced.

For the same reason, it is preferable that R ²³ is a monovalent organic group, and R ²⁴ and R ²⁵ are hydrogen atoms.

In this case, R ²⁰ and R ²³ are preferably branched aliphatic hydrocarbon groups for the following reasons. The groups represented by R ¹ and R ⁴ in formula (I) are limited in improving the solubility of the copolymer due to the limitation in the number of carbon atoms and the shape thereof. On the other hand, even if R ²⁰ and R ²³ are branched aliphatic hydrocarbon groups, the planarity of the copolymer is maintained because steric hindrance is unlikely to occur with other rings and substituents for the above reasons. In addition, it is considered that the solubility can be improved.

In particular, when R ²⁰ and R ²³ are branched aliphatic hydrocarbon groups, the solubility of the aliphatic hydrocarbon group is improved in order to improve the solubility and the interaction between the conjugated structure and the main chain. The number of carbon atoms is preferably 7 or more, more preferably 12 or more, more preferably 14 or more, on the other hand, preferably 24 or less, more preferably 20 or less, 18 The following is more preferable, and 16 is most preferable.

The copolymer according to the second aspect of the present invention may have a repeating unit other than the repeating unit represented by the formula (I) as long as the effects of the present invention are not impaired. Other repeating units are not particularly limited, and include the above-described acceptor constituent units and donor constituent units. The ratio of the number of repeating units represented by the formula (I) to the total number of repeating units constituting the copolymer according to the present invention is not particularly limited, but is usually 0.02 or more, preferably 0.1 or more, more preferably Is 0.25 or more, more preferably 0.5 or more, still more preferably 0.7 or more, and the upper limit is 1.

The terminal portion of the copolymer according to the second aspect of the present invention is not particularly limited, but is preferably end-gapped with an aromatic hydrocarbon ring, an aromatic heterocyclic ring, or a hydrogen atom.

The polystyrene-converted weight average molecular weight (Mw) of the copolymer according to the first aspect of the present invention is not particularly limited, but is 10,000 or more in order to obtain a longer wavelength and high carrier mobility. Preferably, it is more preferably 30,000 or more, particularly preferably 40,000 or more. On the other hand, in order to ensure adequate solubility, it is preferably 300,000 or less, and 250,000 or less. More preferably, it is particularly preferably 245,000 or less. The weight average molecular weight is preferably in this range from the viewpoint of increasing the light absorption wavelength, from the viewpoint of realizing high absorbance, from the viewpoint of realizing high carrier movement, and from the viewpoint of solubility in an organic solvent.

The polystyrene-converted weight average molecular weight (Mw) of the copolymer according to the second aspect of the present invention is not particularly limited, but may be 10,000 or more in order to obtain a longer wavelength and higher carrier mobility. Preferably, it is more preferably 100,000 or more, and particularly preferably 150,000 or more. On the other hand, in order to ensure adequate solubility, it is preferably 450,000 or less, and is 400,000 or less. More preferably, it is more preferably 380,000 or less. The weight average molecular weight is preferably in this range from the viewpoint of increasing the light absorption wavelength, from the viewpoint of realizing high absorbance, from the viewpoint of realizing high carrier movement, and from the viewpoint of solubility in an organic solvent.

The polystyrene-equivalent number average molecular weight (Mn) of the copolymer according to one embodiment of the present invention is not particularly limited, but is preferably 5,000 or more in order to obtain a longer wavelength and high carrier mobility. It is more preferably 10,000 or more, particularly preferably 15,000 or more. On the other hand, in order to ensure adequate solubility, it is preferably 100,000 or less, and 80,000 or less. Is more preferable, and 60,000 or less is particularly preferable.

The molecular weight distribution (PDI, (weight average molecular weight / number average molecular weight (Mw / Mn))) of the copolymer according to one embodiment of the present invention is usually 1.0 or more, preferably 1.1 or more. Is more preferably 2 or more, and particularly preferably 1.3 or more. On the other hand, the molecular weight distribution of the copolymer according to the present invention is usually 50.0 or less, preferably 20.0 or less, more preferably 15.0 or less, and particularly preferably 10.0 or less. .

The polystyrene equivalent weight average molecular weight, number average molecular weight, and molecular weight distribution of the copolymer according to one embodiment of the present invention can be determined by gel permeation chromatography (GPC). Specifically, two Polymer Laboratories GPC columns (PLgel MIXED-B 10 μm, inner diameter 7.5 mm, length 30 cm) are connected in series as a column, and LC-10AT (manufactured by Shimadzu Corporation) as a pump, as an oven It can be measured by using CTO-10A (manufactured by Shimadzu Corporation), a differential refractive index detector (manufactured by Shimadzu Corporation: RID-10A), and a UV-vis detector (manufactured by Shimadzu Corporation: SPD-10A). As a measuring method, a copolymer (1 mg) to be measured is dissolved in chloroform (200 mg), and 1 μL of the obtained solution is injected into a column. Measurement is carried out at a flow rate of 1.0 mL / min at 80 ° C. using o-dichlorobenzene as a mobile phase. LC-Solution (manufactured by Shimadzu Corporation) is used for the analysis.

The solubility of the copolymer according to one embodiment of the present invention is not particularly limited, but the solubility in chlorobenzene at 25 ° C. is usually 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass. On the other hand, it is usually 30% by mass or less, preferably 20% by mass. High solubility is preferable because a thicker film can be formed by coating.

The copolymer according to one embodiment of the present invention preferably has an appropriate interaction between molecules. In the present specification, the interaction between molecules means that the distance between polymer chains is shortened by an interaction such as π-π stacking between molecules. The stronger the interaction, the higher the mobility and / or crystallinity, and the more suitable the semiconductor material is. That is, in a copolymer that interacts between molecules, electron transfer between molecules is likely to occur. For example, when the copolymer according to the present invention is used in an active layer in a photoelectric conversion element, a p-type semiconductor compound in the active layer is used. It is considered that holes generated at the interface between the n-type semiconductor compound and the n-type semiconductor compound can be efficiently transported to the electrode (anode).

An example of the crystallinity measuring method is X-ray diffraction (XRD). In this specification, having crystallinity means that an X-ray diffraction spectrum obtained by XRD measurement has a diffraction peak. Having crystallinity is considered to mean that it has a laminated structure in which molecules are arranged, and is preferable in that the active layer described later tends to be thickened. XRD measurement can be performed based on a method described in a known document (X-ray crystal analysis guide (applied physics selection book 4)).

The hole mobility (sometimes referred to as hole mobility) of the copolymer according to one embodiment of the present invention is usually 1.0 × 10 ⁻⁷ cm ² / Vs or more, preferably 1.0 × 10 ⁻⁶ cm ^2. / Vs or more, more preferably 1.0 × 10 ⁻⁵ cm ² / Vs or more, and particularly preferably 1.0 × 10 ⁻⁴ cm ² / Vs or more. On the other hand, the hole mobility of the copolymer according to the present invention is usually 1.0 × 10 ⁴ cm ² / Vs or less, preferably 1.0 × 10 ³ cm ² / Vs or less, and more preferably 1.0 × 10 6. ² cm ² / Vs or less, particularly preferably 1.0 × 10 cm ² / Vs or less. When the hole mobility is in this range, the copolymer according to the present invention is suitably used as a semiconductor material. Further, in order to obtain high conversion efficiency in the photoelectric conversion element, it is important to balance the mobility of the n-type semiconductor compound and the mobility of the p-type semiconductor compound. When the copolymer according to the present invention is used as a p-type semiconductor compound in a photoelectric conversion element, from the viewpoint of bringing the hole mobility of the copolymer according to the present invention close to the electron mobility of the n-type semiconductor compound, the copolymer according to the present invention is positive. The hole mobility is preferably within this range. As a method for measuring the hole mobility, there is an FET method. The FET method can be performed by a method described in a known document (Japanese Patent Application Laid-Open No. 2010-045186).

The copolymer according to one embodiment of the present invention preferably has high storage stability in a solution state. High storage stability means that it is difficult to aggregate when made into a solution. More specifically, 2 mg of the copolymer according to the present invention was placed in a 2 mL screw vial, dissolved in o-xylene to a concentration of 1.5% by mass, and then cooled to room temperature. Then, it is preferable not to gel for 5 minutes or more, and it is more preferable not to gel for 1 hour or more.

The impurities in the copolymer according to one embodiment of the present invention are preferably as few as possible. In particular, when a copolymer having a repeating unit represented by the formula (1) is synthesized, when a transition metal catalyst such as palladium or copper is used, these may remain in the copolymer. If these metal catalysts remain in the copolymer, exciton traps due to the heavy atom effect of the transition metal occur and charge transfer is inhibited. As a result, when the copolymer according to the present invention is used in a photoelectric conversion element, There is a risk of reducing the conversion efficiency. Therefore, the concentration of the transition metal catalyst is usually 1000 ppm or less, preferably 500 pm or less, more preferably 100 ppm or less per 1 g of copolymer. On the other hand, it is usually larger than 0 ppm and may be 1 ppm or more, or 3 ppm or more.

The impurities contained in the copolymer can be measured by, for example, ICP mass spectrometry. ICP mass spectrometry can be carried out by a method described in a known document (“Plasma ion source mass spectrometry” (Academic Publishing Center)). Specifically, for palladium atoms and copper atoms, after the sample is wet-decomposed, Pd and Sn in the decomposition solution are obtained by a calibration curve method using an ICP mass spectrometer (ICP mass spectrometer 7500ce type manufactured by Agilent Technologies). It can be quantified.

<2-1. Method for producing copolymer according to first aspect of the present invention>
The method for producing the copolymer according to the first aspect of the present invention is not particularly limited. For example, the compound represented by the following formula (XI), the compound represented by the following formula (XII), and the following formula ( XIII) and a compound represented by the following formula (XIV) can be produced by a polymerization reaction.

X ¹ , X ² , R ¹ , R ² , R ³ and R ⁴ in the above formula (XI) are respectively X ¹ , X ² , in the above formula (I) described in the copolymer according to the first embodiment, Synonymous with R ¹ , R ² , R ³ and R ⁴ . A in the above formula ^{(XII), Ar 3, Ar} 4, c and d are as defined ^{^{A, Ar 3, Ar 4,}} c and d of the above formula (II). D1 in the above formula (XIII) has the same meaning as D1 in the above formula (I). D2 in the above formula (XIV) has the same meaning as D2 in the above formula (II). In the case where D1 and D2 are the same structural unit, a copolymer is obtained by a polymerization reaction of the compound represented by the above formula (XI), the compound represented by the above formula (XII), and the compound represented by the above formula (XIII). Can be manufactured.

Y ¹ to Y ⁸ in the formulas (XI) to (XIV) are active groups. The active group is not particularly limited and may be arbitrarily selected depending on the type of synthesis reaction. Specific active groups include, for example, halogen atoms, alkylstannyl groups, alkylsulfo groups, arylsulfo groups, arylalkylsulfo groups, boric acid ester residues, sulfonium methyl groups, phosphonium methyl groups, phosphonate methyl groups, mono Examples thereof include a halogenated methyl group, a boric acid residue (—B (OH) ₂ ), a formyl group, an alkenyl group, and an alkynyl group.

The copolymerization reaction is not particularly limited as long as the copolymer of the present invention is obtained. For example, a Suzuki-Miyaura cross-coupling reaction method, a Stille coupling reaction method, a Yamamoto coupling reaction method, a Grignard reaction method, a Heckard reaction method, and the like. Examples include a reaction method, a Sonogashira reaction method, a reaction method using an oxidizing agent such as FeCl ₃ , a method using an electrochemical oxidation reaction, a reaction method by decomposition of an intermediate compound having an appropriate leaving group, and the like. Among these, the Suzuki-Miyaura coupling reaction method, Stille coupling reaction method, Yamamoto coupling reaction method, and Grignard reaction method are preferable in terms of easy structure control. In particular, the Suzuki-Miyaura cross-coupling reaction method, the Stille coupling reaction method, and the Grignard reaction method are preferable from the viewpoint of easy availability of materials and easy reaction operation. These reactions include "cross coupling-basics and industrial applications-(CMC Publishing)", "transition metal catalyzed reactions for organic synthesis (written by Jiro Jiro: edited by the Society of Synthetic Organic Chemistry)", "for organic synthesis" The reaction can be carried out according to a method described in known literature such as “catalytic reaction 103 (Teijiro Hatakeyama: Tokyo Kagaku Dojin)”.

More specifically, compounds represented by the above formulas (XI) to (XIV) are produced by a known Stille coupling reaction using Y ¹ to Y ⁴ as an alkylstannyl group and Y ⁵ to Y ⁸ as a halogen atom. Y ¹ to Y ⁴ as boric acid ester residues or boric acid residues, Y ⁵ to Y ⁸ as halogen atoms, and a known Suzuki-Miyaura coupling reaction, and Y ¹ to Y ⁴ as silyl Examples of the group include a method of producing Y ⁵ to Y ⁸ as a halogen atom by a Hiyama coupling reaction.

In the polymerization reaction, a catalyst may be used as necessary.

It is preferable to end-treat the copolymer obtained by the polymerization reaction. By performing the terminal treatment of the copolymer, the residual amount of the terminal residues (Y ¹ to Y ⁸ described above) can be reduced. By performing such terminal treatment, the amount of active groups such as halogen atoms and alkylstannyl groups in the resulting copolymer can be reduced, so that the conversion efficiency and durability of the photoelectric conversion element are improved. Can do.

The method for producing the compounds represented by the above formulas (XI) to (XIV) is not particularly limited and can be produced by a known method. For example, as a method for producing the compound represented by the above formula (XI), it can be produced by a known method of JP-A-2014-009163. Examples of the method for producing the compounds represented by the above formulas (XI) to (XIV) include Polymer, 1990, 31, 1379-1383, Adv. Mater. , 2007, 19, 4160-4165, Macromolecules, 2010, 43, 6936-6938, Adv. Mater. , 2011, 23, 3315-3319, Angew. Chem. Int. Ed. 2012, 51, 2068-2071, J. MoI. Mater. Chem. 2011, 21, 3895-3902, J. MoI. Am. Chem. Soc. , 2011, 133, 10062-10065 or Chem. Commun. , 2011, 47, 4920, WO2013 / 180243, and the like.

<2-2. Method for Producing Copolymer According to Second Aspect of the Present Invention>
The method for producing the copolymer according to the second aspect of the present invention is not particularly limited, and for example, by a polymerization reaction between a compound represented by the following formula (XI) and a compound represented by the following formula (XIII). Can be manufactured.

X ¹ , X ² , R ¹ , R ² , R ³ and R ⁴ in the above formula (XI) are respectively X ¹ , X ² , R in the formula (I) described in the copolymer according to the second embodiment. ^1, the same meaning as R ^2, R ³ and R ^4. D1 in the above formula (XIII) has the same meaning as D1 in the above formula (I).

Y ¹ and Y ^{2 in} formula (XI) and Y ⁵ and Y ^{6 in} formula (XIII) each represent an active group. The active group is not particularly limited and may be arbitrarily selected depending on the type of synthesis reaction. Specific active groups include, for example, halogen atoms, alkylstannyl groups, alkylsulfo groups, arylsulfo groups, arylalkylsulfo groups, boric acid ester residues, sulfonium methyl groups, phosphonium methyl groups, phosphonate methyl groups, mono Examples thereof include a halogenated methyl group, a boric acid residue (—B (OH) ₂ ), a formyl group, an alkenyl group, and an alkynyl group.

The polymerization reaction of the copolymer is not particularly limited as long as the copolymer of the present invention is obtained, and the method described in the method for producing a copolymer of the first aspect can be used.

More specifically, Y ¹ and Y ² are alkylstannyl groups, Y ⁵ and Y ⁶ are halogen atoms, and the compounds represented by the above formulas (XI) and (XIII) are produced by a known Stille coupling reaction. Y ¹ and Y ² as boric acid ester residues or boric acid residues, Y ⁵ and Y ⁶ as halogen atoms, and production by a known Suzuki-Miyaura coupling reaction, Y ¹ and Y ² as silyl Examples of the group include a method in which Y ⁵ and Y ⁶ are used as halogen atoms and are produced by a Hiyama coupling reaction.

In the polymerization reaction, a catalyst may be used as necessary.

It is preferable to end-treat the copolymer obtained by the polymerization reaction. By performing the terminal treatment of the copolymer, the residual amount of the terminal residues of the copolymer (the above-mentioned Y ¹ to Y ² and Y ⁵ to Y ⁶ ) can be reduced. By performing such terminal treatment, the amount of active groups such as halogen atoms and alkylstannyl groups in the resulting copolymer can be reduced, so that the conversion efficiency and durability of the photoelectric conversion element are improved. Can do.

The method for producing the compounds represented by the above formulas (XI) and (XIII) is not particularly limited, and can be produced by a known method described in the method for producing a copolymer of the first aspect.

<3. Photoelectric conversion element>
The copolymer according to the present invention can be used as a material for a photoelectric conversion element. Specifically, the active layer of the photoelectric conversion element contains the copolymer according to the present invention, so that it has high conversion efficiency and high exposure stability. It can be a photoelectric conversion element. Hereinafter, an embodiment of a photoelectric conversion element using the copolymer according to the present invention will be described.

The photoelectric conversion element according to the present invention has at least a base material, a pair of electrodes formed on the base material, and an active layer formed between the pair of electrodes. Hereinafter, an embodiment of a photoelectric conversion element according to the present invention will be described with reference to FIG.

As shown in FIG. 1, one embodiment of the photoelectric conversion element according to the present invention includes a lower electrode 101, a lower buffer layer 102, an active layer 103, an upper buffer layer 104, and an upper electrode on a substrate 106. 105 have a layer structure in which are sequentially formed. In the present invention, the lower electrode means an electrode laminated on the substrate 106 side, and the upper electrode means an electrode laminated above the lower electrode when the substrate 106 is used as the bottom. . In the present invention, the lower electrode 101 and the upper electrode 105 may be collectively referred to as a pair of electrodes. In addition, the lower buffer layer 102 and the upper buffer layer 104 are not essential components, and may be provided arbitrarily, and may include only one of the lower buffer layer 102 and the upper buffer layer 104. Moreover, the photoelectric conversion element may optionally have another layer other than the above. Hereinafter, each component of the photoelectric conversion element will be described.

<3-1. Substrate 106>
The photoelectric conversion element 107 is usually formed on a base material 106 that serves as a support. There is no particular limitation on the material of the substrate 106. Preferable examples of the material of the substrate 106 include inorganic materials such as quartz, glass, sapphire, and titania, and flexible substrates. Specific examples of the flexible substrate include, but are not limited to, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, fluororesin film, vinyl chloride. Or polyolefin such as polyethylene; organic material (resin substrate) such as cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate, polynorbornene, or epoxy resin; paper material such as paper or synthetic paper; stainless steel, Examples thereof include composite materials such as a metal foil such as titanium or aluminum whose surface is coated or laminated in order to impart insulation. Examples of the glass include soda glass, blue plate glass, and non-alkali glass. Among these, alkali-free glass is preferable in that there are few eluted ions from the glass.

There are no particular restrictions on the shape, configuration, etc. of the substrate 106, and well-known techniques can be referred to. For example, those described in International Publication No. 2011/016430 or Japanese Patent Application Laid-Open No. 2012-191194 can be employed.

<3-2. Pair of electrodes (lower electrode 101 and upper electrode 105)>
The pair of electrodes (101, 106) has a function of collecting holes and electrons generated by light absorption. Accordingly, the pair of electrodes includes an electrode suitable for collecting holes (hereinafter sometimes referred to as an anode) and an electrode suitable for collecting electrons (hereinafter sometimes referred to as a cathode). It is preferable to use it. One of the pair of electrodes preferably has translucency, and both electrodes may have translucency. Note that having translucency means that sunlight passes through 40% or more. Further, the solar light transmittance of the transparent electrode is preferably 70% or more in order to allow light to reach the active layer through the transparent electrode. The light transmittance can be measured with a normal spectrophotometer.

The anode is an electrode having a function of collecting holes generated by the active layer 3 absorbing light, and the cathode has a function of collecting electrons generated in the active layer 3. Electrode. When the lower electrode 101 is an anode, the upper electrode 105 is preferably a cathode. When the lower electrode 101 is a cathode, the upper electrode 105 may be an anode.

The material for forming the lower electrode 101 and the upper electrode 105 is not particularly limited, and nickel oxide, tin oxide, indium oxide, indium tin oxide (ITO), indium-zirconium oxide (IZO), titanium oxide, indium oxide, or zinc oxide. Conductive metal oxides such as gold, platinum, silver, copper, iron, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, cesium, calcium, magnesium or cobalt, or alloys thereof .

Among the above materials, when the lower electrode 101 is an anode and the upper electrode 105 is a cathode, it is preferable to use a material having a work function larger than that of the upper electrode 105 for the lower electrode 101. On the other hand, when the lower electrode 101 is a cathode and the upper electrode 105 is an anode, the lower electrode 101 is preferably formed of a material having a work function smaller than that of the upper electrode 105. Note that when the photoelectric conversion element includes the lower buffer layer 102 and / or the upper buffer layer 104 as described later, the lower electrode 101 and the upper buffer layer 104 are adjusted by adjusting the work function of the lower buffer layer 102 and / or the upper buffer layer 104. The electrode 105 can also be formed of a material having the same work function.

Each of the lower electrode 101 and the upper electrode 105 may be a single layer or a stacked layer.

In addition, when making the base-material 106 side into a light-receiving surface, it is preferable that the lower electrode 101 has translucency. On the other hand, when the upper electrode 105 side is the light receiving surface, the lower electrode 2 may be translucent or translucent as long as the upper electrode 105 has translucency. You don't have to.

The film thickness of the lower electrode 101 and the upper electrode 105 is not particularly limited, but is preferably 10 nm or more, more preferably 20 nm or more, particularly 50 nm or more in order to suppress sheet resistance. On the other hand, in order to ensure high translucency, it is preferably 10 μm or less, more preferably 1 μm or less, and particularly preferably 500 nm or less.

The formation method of the lower electrode 101 and the upper electrode 105 is not particularly limited, and may be formed by a known method according to the material to be used. For example, a vacuum film forming method such as a vapor deposition method or a sputtering method, or a wet coating method in which an ink containing nanoparticles or a precursor is applied to form a film. Note that electrical characteristics, wetting characteristics, and the like may be improved by performing surface treatment on the lower electrode 101 and the upper electrode 105.

<3-3. Active layer 103>
The active layer 103 is a layer that contains a p-type semiconductor compound and an n-type semiconductor compound and undergoes photoelectric conversion. Specifically, when the photoelectric conversion element 107 receives light, the light is absorbed by the active layer 103, electricity is generated at the interface between the p-type semiconductor material and the n-type semiconductor material, and the generated electricity is extracted from the anode and the cathode. It is.

As the layer structure of the active layer 103, a thin film stack type in which a layer containing a p-type semiconductor compound and a layer containing an n-type semiconductor compound are stacked, or a layer in which a p-type semiconductor compound and an n-type semiconductor compound are mixed is used. A bulk heterojunction type. Note that the bulk heterojunction active layer may have a structure in which a layer containing a p-type semiconductor compound and / or a layer containing an n-type semiconductor compound is further stacked in addition to the mixed layer. From the viewpoint that high photoelectric conversion efficiency can be expected, a bulk heterojunction type is preferable.

The active layer 103 preferably contains a copolymer according to the present invention as a p-type semiconductor compound. When the active layer 103 contains the copolymer according to the present invention, a photoelectric conversion element having high conversion efficiency can be provided.

The active layer 103 may contain other p-type semiconductor compounds besides the copolymer according to the present invention. The other p-type semiconductor compound may be a low molecular organic compound or a high molecular compound. These p-type semiconductor compounds are not particularly limited, but for example, those described in known literatures such as International Publication No. 2011-016430 or Japanese Unexamined Patent Publication No. 2012-191194 can be used.

The n-type semiconductor compound is not particularly limited. For example, fullerene; fullerene derivative; quinolinol derivative metal complex represented by 8-hydroxyquinoline aluminum; condensed ring such as naphthalenetetracarboxylic acid diimide or perylenetetracarboxylic acid diimide Tetracarboxylic acid diimides; perylene diimide derivatives, terpyridine metal complexes, tropolone metal complexes, flavonol metal complexes, perinone derivatives, benzimidazole derivatives, benzoxazole derivatives, thiazole derivatives, benzthiazole derivatives, benzothiadiazole derivatives, oxadiazole derivatives, thiadiazoles Derivatives, triazole derivatives, aldazine derivatives, bisstyryl derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, benzox Phosphorus derivatives, bipyridine derivatives, borane derivatives; total fluorides of condensed polycyclic aromatic hydrocarbons such as anthracene, pyrene, naphthacene or pentacene; single-walled carbon nanotubes, n-type polymers (n-type polymer semiconductor materials), etc. .

Among these, fullerene compounds, borane derivatives, thiazole derivatives, benzothiazole derivatives, benzothiadiazole derivatives, N-alkyl substituted naphthalene tetracarboxylic acid diimides, N-alkyl substituted perylene diimide derivatives or n-type polymer semiconductor materials More preferred are fullerene compounds, N-alkyl-substituted perylene diimide derivatives, N-alkyl-substituted naphthalene tetracarboxylic acid diimides or n-type polymer semiconductor compounds, and fullerene compounds are particularly preferred. These compounds are not particularly limited, but for example, those described in known literatures such as International Publication No. 2011-016430 or Japanese Unexamined Patent Publication No. 2012-191194 can be used. In addition, a kind of compound may be used among the above, and a mixture of a plurality of kinds of compounds may be used. Among these, it is particularly preferable to use 60 PCBM, 70 PCBM or a mixture thereof.

The thickness of the active layer 103 is not particularly limited, but is preferably 10 nm or more, more preferably 50 nm or more, and more preferably 100 nm or more in order to improve film uniformity and suppress short circuit. On the other hand, it is preferably 1 μm or less, more preferably 500 nm or less, and particularly preferably 200 nm or less in order to reduce internal resistance and improve charge diffusion.

The method for forming the active layer 103 is not particularly limited, but is preferably formed by a coating method because productivity is improved. Specifically, the active layer 103 is preferably formed by applying a composition for forming an active layer containing a copolymer according to the present invention.

As the coating method, any method can be used. For example, spin coating method, reverse roll coating method, gravure coating method, kiss coating method, roll brush method, spray coating method, air knife coating method, wire barber coating method, pipe Examples include a doctor method, an impregnation / coating method, and a curtain coating method.

When forming a laminated type active layer, an active layer forming ink containing at least a copolymer according to the present invention as a p-type semiconductor compound and an active layer ink containing an n-type semiconductor compound are used, respectively, by a coating method. An active layer may be formed by stacking a p-type semiconductor-containing layer and an n-type semiconductor-containing layer. On the other hand, when forming a bulk hetero type active layer, a bulk hetero type is formed by a coating method using an active layer forming composition containing at least a copolymer according to the present invention as a p type semiconductor compound and an n type semiconductor compound. The active layer may be formed.

The above-mentioned composition for forming an active layer usually contains a solvent in addition to the above-mentioned compound. The solvent is not particularly limited, but for example, aliphatic hydrocarbons such as hexane, heptane, octane, isooctane, nonane, tetralin or decane; toluene, xylene, mesitylene, cyclohexylbenzene, chlorobenzene or orthodichlorobenzene, etc. Aromatic hydrocarbons; cycloaliphatic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, tetralin or decalin; lower alcohols such as methanol, ethanol or propanol; acetone, methyl ethyl ketone, cyclopentanone Or aliphatic ketones such as cyclohexanone; aromatic ketones such as acetophenone or propiophenone; esters such as ethyl acetate, butyl acetate or methyl lactate; Chloroform, methylene chloride, dichloroethane, halogenated hydrocarbons such as trichloroethane or trichlorethylene; ethers such as ethyl ether and tetrahydrofuran or dioxane; or an amide such as dimethylformamide or dimethylacetamide, and the like.

As the solvent, one type of solvent may be used alone, or any two or more types of solvents may be used in combination at an arbitrary ratio. When two or more kinds of solvents are used in combination, it is preferable to combine a low boiling point solvent having a boiling point of 60 ° C. or higher and 150 ° C. or lower and a high boiling point solvent having a boiling point of 180 ° C. or higher and 250 ° C. or lower. Examples of combinations of low and high boiling solvents include non-halogen aromatic hydrocarbons and alicyclic hydrocarbons, non-halogen aromatic hydrocarbons and aromatic ketones, ethers and alicyclic carbonization. Examples thereof include hydrogens, ethers and aromatic ketones, aliphatic ketones and alicyclic hydrocarbons, or aliphatic ketones and aromatic ketones. Specific examples of preferred combinations include toluene and tetralin, xylene and tetralin, toluene and acetophenone, xylene and acetophenone, tetrahydrofuran and tetralin, tetrahydrofuran and acetophenone, methyl ethyl ketone and tetralin, methyl ethyl ketone and acetophenone, and the like.

In addition, the composition for active layer formation may contain other additives other than the compounds described above as long as the effects according to the present invention are not impaired.

<3-4. Lower Buffer Layer 102 and Upper Buffer Layer 104>
The photoelectric conversion element according to an embodiment of the present invention includes a lower buffer layer 102 between the lower electrode 101 and the active layer 103, and an upper buffer layer 104 between the upper electrode 105 and the active layer 103. The lower buffer layer 102 and the upper buffer layer 104 each have a function of improving the electron extraction efficiency from the active layer 103 to the cathode or the hole extraction efficiency from the active layer 103 to the anode. Note that a buffer layer having a function of improving the electron extraction efficiency from the active layer 103 to the cathode is referred to as an electron extraction layer, and a buffer layer having a function of improving the electron extraction efficiency from the active layer 103 to the cathode is referred to as a hole extraction layer. As described above, the lower buffer layer 102 and the upper buffer layer 104 are not essential constituent members of the photoelectric conversion element according to the present invention, and may not include the lower buffer layer 102 and the upper buffer layer 104. Moreover, you may have only any one layer.

Either the lower buffer layer 102 or the upper buffer layer 104 may be an electron extraction layer or a hole extraction layer, but when the lower electrode 101 is a cathode and the upper electrode 105 is an anode, the lower buffer layer 102 is an electron extraction layer. The upper buffer layer 104 is preferably a hole extraction layer. On the other hand, when the lower electrode 101 is an anode and the upper electrode 105 is a cathode, the lower buffer layer 102 is preferably a hole extraction layer and the upper buffer layer 104 is preferably an electron extraction layer.

<3-4-1. Electron extraction layer>
The material of the electron extraction layer is not particularly limited as long as it is a material that improves the efficiency of extracting electrons from the active layer 103 to the cathode, and examples thereof include inorganic compounds and organic compounds.

Examples of inorganic compounds include salts of alkali metals such as Li, Na, K or Cs; n-type semiconductor oxides such as titanium oxide (TiO _x ) and zinc oxide (ZnO). Among them, the alkali metal salt is preferably a fluoride salt such as LiF, NaF, KF or CsF, and the n-type semiconductor oxide is preferably zinc oxide (ZnO). Although the operation mechanism of such a material is unknown, it is conceivable to reduce the work function of the cathode when combined with a cathode made of Al or the like and increase the voltage applied to the solar cell element.

Examples of organic compounds include phosphine compounds having a double bond between a phosphorus atom and a group 16 element such as triarylphosphine oxide compounds; substituents such as bathocuproin (BCP) or bathophenanthrene (Bphen) A phenanthrene compound in which the 1-position and the 10-position may be replaced by a heteroatom; a boron compound such as triarylboron; an organic such as (8-hydroxyquinolinato) aluminum (Alq ₃ ) Metal oxide; Compound having 1 or 2 ring structure which may have a substituent such as oxadiazole compound or benzimidazole compound; naphthalenetetracarboxylic anhydride (NTCDA) or perylenetetracarboxylic anhydride Product (PTCDA), such as dicarboxylic acid anhydride Aromatic compounds having a condensed dicarboxylic acid structure.

The film thickness of the electron extraction layer is usually 0.1 nm or more, preferably 1 nm or more, more preferably 10 nm or more. On the other hand, it is usually 400 nm or less, preferably 200 nm or less. When the film thickness of the electron extraction layer is 0.1 nm or more, it functions as a buffer material. When the film thickness of the electron extraction layer is 400 nm or less, electrons are easily extracted and the photoelectric conversion efficiency is improved. Can improve.

The LUMO energy level of the material of the electron extraction layer is not particularly limited, but is usually −4.0 eV or more, preferably −3.9 eV or more. On the other hand, it is usually −1.9 eV or less, preferably −2.0 eV or less. It is preferable that the LUMO energy level of the material for the electron extraction layer is −1.9 eV or less because charge transfer can be promoted. It is preferable that the LUMO energy level of the material for the electron extraction layer is −4.0 eV or more because reverse electron transfer to the n-type semiconductor material can be prevented.

The HOMO energy level of the material for the electron extraction layer is not particularly limited, but is usually −9.0 eV or more, preferably −8.0 eV or more. On the other hand, it is usually −5.0 eV or less, preferably −5.5 eV or less. It is preferable that the HOMO energy level of the material for the electron extraction layer is −5.0 eV or less in terms of preventing movement of holes.

As a method for calculating the LUMO energy level and the HOMO energy level of the material of the electron extraction layer, there is a cyclic voltammogram measurement method. For example, it can implement with reference to the method as described in well-known literature (International Publication 2011/016430).

When the material of the electron extraction layer is an organic compound, the glass transition temperature of the compound as measured by the DSC method (hereinafter sometimes referred to as Tg) is not particularly limited, but is not observed, or It is preferable that it is 55 degreeC or more. That the glass transition temperature is not observed by the DSC method means that there is no glass transition temperature. Specifically, the determination is made based on the presence or absence of a glass transition temperature of 400 ° C. or lower. A material in which the glass transition temperature by the DSC method is not observed is preferable in that it has high thermal stability.

Among the compounds having a glass transition temperature of 55 ° C. or higher as measured by the DSC method, the glass transition temperature is preferably 65 ° C. or higher, more preferably 80 ° C. or higher, more preferably 110 ° C. or higher, particularly preferably. A compound having a temperature of 120 ° C. or higher is desirable. On the other hand, the upper limit of the glass transition temperature is not particularly limited, but is usually 400 ° C. or lower, preferably 350 ° C. or lower, more preferably 300 ° C. or lower. Moreover, it is preferable that the material of an electron taking-out layer is a thing by which the glass transition temperature by DSC method is not observed below 30 degreeC or more and less than 55 degree | times.

In the present specification, the glass transition temperature is defined as a point at which the specific heat changes in an amorphous solid, which is a temperature at which local molecular motion is started by thermal energy. When the temperature rises further than Tg, the solid structure changes and crystallization occurs (the temperature at this time is defined as the crystallization temperature (Tc)). When the temperature rises further, it generally melts at the melting point (Tm) and changes to a liquid state. However, these phase transitions may not be observed due to molecular decomposition or sublimation at high temperatures.

DSC method is a measurement method of thermophysical properties (differential scanning calorimetry) defined in JIS K-0129 “General Rules for Thermal Analysis”. In order to determine the glass transition temperature more clearly, it is desirable to measure after rapidly cooling a sample once heated to a temperature higher than the glass transition temperature. For example, the measurement can be carried out by a method described in a known document (International Publication No. 2011/016430).

When the glass transition temperature of the compound used for the electron extraction layer is 55 ° C. or higher, the structure of this compound is difficult to change against external stress such as applied electric field, flowing current, stress due to bending or temperature change. It is preferable in terms of durability. Furthermore, since there is a tendency that the crystallization of the thin film of the compound does not proceed easily, the stability of the electron extraction layer is improved by making it difficult for the compound to change between the amorphous state and the crystalline state in the operating temperature range. Therefore, it is preferable in terms of durability. This effect becomes more prominent as the glass transition temperature of the material is higher.

There is no limitation on the method of forming the electron extraction layer. For example, when a material having sublimation property is used, it can be formed by a vacuum deposition method or the like. For example, when a material soluble in a solvent is used, it can be formed by a wet coating method such as spin coating or inkjet.

When the electron extraction layer is formed by a coating method, a surfactant may be further contained in the coating solution. By using the surfactant, the occurrence of dents due to adhesion of fine bubbles or foreign matters and / or uneven coating in the drying process is suppressed. Known surfactants (cationic surfactants, anionic surfactants, nonionic surfactants) can be used as the surfactant. Of these, silicon-based surfactants, acetylenic diol-based surfactants, and fluorine-based surfactants are preferable. In addition, as surfactant, only 1 type may be used and 2 or more types may be used together by arbitrary combinations and a ratio.
Specifically, for example, when an alkali metal salt is used as a material for the electron extraction layer, the electron extraction layer can be formed by using a vacuum film formation method such as vacuum deposition or sputtering. Especially, it is desirable to form an electron taking-out layer by vacuum vapor deposition by resistance heating. By using vacuum deposition, damage to other layers such as an active layer can be reduced.

On the other hand, for metal oxides of n-type semiconductors, for example, when zinc oxide ZnO is used as the material for the electron extraction layer, a vacuum film formation method such as sputtering can be used. It is desirable to form the extraction layer. For example, Sol-Gel Science, C.I. J. et al. Brinker, G.M. W. According to the sol-gel method described by Scherer, Academic Press (1990), an electron extraction layer composed of zinc oxide can be formed. In this case, the film thickness is usually 0.1 nm or more, preferably 2 nm or more, more preferably 5 nm or more, and usually 1 μm or less, preferably 100 nm or less, more preferably 50 nm or less. If the electron extraction layer is too thin, the effect of improving the electron extraction efficiency is not sufficient, and if it is too thick, the electron extraction layer tends to deteriorate the characteristics of the device by acting as a series resistance component.

<3-4-2. Hole extraction layer>
The material for the hole extraction layer is not particularly limited as long as it is a material capable of improving the efficiency of extracting holes from the active layer 103 to the anode. Specifically, polythiophene, polypyrrole, polyacetylene, triphenylenediamine, polyaniline, or the like, a conductive polymer doped with sulfonic acid and / or iodine, a polythiophene derivative having a sulfonyl group as a substituent, or a conductive organic such as arylamine Examples thereof include compounds, copper oxide, nickel oxide, manganese oxide, molybdenum oxide, vanadium oxide, metal oxide such as tungsten oxide, Nafion, and a p-type semiconductor described later. Among them, a conductive polymer doped with sulfonic acid is preferable, and (3,4-ethylenedioxythiophene) poly (styrenesulfonic acid) (PEDOT: PSS) in which a polythiophene derivative is doped with polystyrene sulfonic acid is more preferable. It is. A thin film of metal such as gold, indium, silver or palladium can also be used. A thin film of metal or the like may be formed alone or in combination with the above organic material.

The film thickness of the hole extraction layer is usually 0.1 nm or more. On the other hand, it is usually 400 nm or less, preferably 200 nm or less. When the film thickness of the hole extraction layer is 0.1 nm or more, it functions as a buffer material. When the film thickness of the hole extraction layer is 400 nm or less, holes are easily extracted, Conversion efficiency can be improved.

There is no restriction | limiting in the formation method of a positive hole taking-out layer. For example, when a material having sublimation property is used, it can be formed by a vacuum deposition method or the like. For example, when a material soluble in a solvent is used, it can be formed by a wet coating method such as a spin coating method or an ink jet method. When a semiconductor material is used for the hole extraction layer, the precursor may be converted into a semiconductor compound after forming the layer using the precursor, similarly to the low-molecular organic semiconductor compound of the active layer.
Especially, when using PEDOT: PSS as a material of a hole taking-out layer, it is preferable to form a hole taking-out layer by the method of apply | coating a dispersion liquid. Examples of the dispersion of PEDOT: PSS include CLEVIOSTM series manufactured by Heraeus, ORGACONTM series manufactured by Agfa, and the like.

When the hole extraction layer is formed by a coating method, a surfactant may be further contained in the coating solution. By using the surfactant, the occurrence of dents due to adhesion of fine bubbles or foreign matters and / or uneven coating in the drying process is suppressed. Known surfactants (cationic surfactants, anionic surfactants, nonionic surfactants) can be used as the surfactant. Of these, silicon-based surfactants, acetylenic diol-based surfactants, and fluorine-based surfactants are preferable. In addition, as surfactant, only 1 type may be used and 2 or more types may be used together by arbitrary combinations and a ratio.

As mentioned above, although the example of the photoelectric conversion element which concerns on one Embodiment of this invention was demonstrated, the structure of the photoelectric conversion element which concerns on this invention is not limited to said structure. For example, the photoelectric conversion element may have a tandem structure having two or more active layers 103.

<3-5. Manufacturing method of photoelectric conversion element>
A photoelectric conversion element 107 having the configuration shown in FIG. 1 is formed on a base 106 by a lower electrode 101, a lower buffer layer 102, an active layer 103, an upper buffer layer 104, and an upper electrode in accordance with the method described above for each layer. It can be manufactured by sequentially stacking 105.

After laminating the lower electrode 101 and / or the upper electrode 105, annealing may be performed by heating. By performing the annealing treatment, the adhesion of each layer can be improved. When performing the annealing treatment, the heating temperature is not particularly limited, but in order to improve the adhesion of each layer, it is preferably 50 ° C. or higher, more preferably 80 ° C. or higher, while the photoelectric conversion element Is preferably 300 ° C. or less, and particularly preferably 250 ° C. or less, in order to suppress thermal decomposition of the material constituting the material.

The heating time is not particularly limited, but is preferably 1 minute or longer, more preferably 3 minutes or longer, on the other hand, preferably 3 hours or shorter, more preferably 1 hour or shorter. . The annealing treatment is preferably performed under normal pressure and in an inert gas atmosphere.

The heating may be performed by placing the photoelectric conversion element on a heat source such as a hot plate, or by placing the photoelectric conversion element in a heating atmosphere such as an oven. The heating may be performed batchwise or continuously.

Each layer constituting the photoelectric conversion element according to the present invention is not particularly limited, and may be formed by a sheet-to-sheet (sheet-fed) method or a roll-to-roll method.

The roll-to-roll method is a method in which a flexible base material wound in a roll shape is fed out and processed intermittently or continuously until it is taken up by a take-up roll. is there. According to the roll-to-roll method, it is possible to batch-process long substrates on the order of km, so that the production method is more suitable for mass production than the sheet-to-sheet method.

<3-6. Photoelectric conversion characteristics>
The photoelectric conversion characteristics of the photoelectric conversion element 107 can be obtained as follows. The photoelectric conversion element 107 is irradiated with light of AM1.5G by a solar simulator with an irradiation intensity of 100 mW / cm @ 2.
Irradiate with and measure the current-voltage characteristics. From the obtained current-voltage curve, photoelectric conversion characteristics such as photoelectric conversion efficiency (PCE), short circuit current density (Jsc), open circuit voltage (Voc), fill factor (FF), series resistance, and shunt resistance can be obtained.

The photoelectric conversion efficiency of the photoelectric conversion element according to the present invention is not particularly limited, but is usually 1% or more, preferably 1.5% or more, more preferably 2% or more. On the other hand, there is no particular limitation on the upper limit, and the higher the better.

Moreover, as a method for measuring the durability of the photoelectric conversion element, a method for obtaining a maintenance ratio of the photoelectric conversion efficiency before and after exposing the photoelectric conversion element to the atmosphere can be mentioned.
(Maintenance rate) = (Photoelectric conversion efficiency after N hours of atmospheric exposure) / (Photoelectric conversion efficiency immediately before atmospheric exposure)

In order to put a photoelectric conversion element into practical use, it is important to have high photoelectric conversion efficiency and high durability in addition to simple and inexpensive manufacture. From this viewpoint, the maintenance rate of photoelectric conversion efficiency before and after exposure to the atmosphere for one week is preferably 60% or more, more preferably 80% or more, and the higher the better.

<4. Solar cell>
The photoelectric conversion element according to the above-described embodiment is preferably used as a solar cell, particularly a solar cell element of a thin film solar cell. FIG. 2 is a cross-sectional view schematically showing the configuration of a thin-film solar cell as one embodiment of the present invention. As shown in FIG. 2, the thin film solar cell 14 of this embodiment includes a weather-resistant protective film 1, an ultraviolet cut film 2, a gas barrier film 3, a getter material film 4, a sealing material 5, and a photoelectric conversion element. 6, a sealing material 7, a getter material film 8, a gas barrier film 9, and a back sheet 10 are provided in this order. And a thin film solar cell is normally irradiated with light from the side (downward in the figure) in which the weather-resistant protective film 1 was formed, and the photoelectric conversion element 6 generates electric power. Note that the thin-film solar cell does not need to have all of these constituent members, and each constituent member may be arbitrarily selected and provided.

There are no particular restrictions on these constituent members constituting the thin-film solar cell and the manufacturing method thereof, and well-known techniques can be used. For example, those described in known documents such as International Publication No. 2011/016430 or Japanese Patent Application Laid-Open No. 2012-191194 can be used.

There is no particular limitation on the use of the solar cell according to the present invention, particularly the thin film solar cell 14 described above, and it can be used for any application. Examples include solar cells for building materials, solar cells for automobiles, solar cells for spacecrafts, solar cells for home appliances, solar cells for mobile phones, solar cells for toys, and the like.

The solar cell according to the present invention, particularly a thin-film solar cell, may be used as it is, or for example, a solar cell may be installed on a substrate and used as a solar cell module. For example, as shown in FIG. 3, the solar cell module 13 having the thin film solar cell 14 on the base 12 can be installed and used at a place of use. For the substrate 12, well-known techniques can be used, for example, those described in International Publication No. 2011-016430 or Japanese Unexamined Patent Publication No. 2012-191194. For example, when a building material plate is used as the substrate 12, a solar cell panel can be produced as the solar cell module 13 by providing the thin film solar cell 14 on the surface of the plate.

Hereinafter, embodiments of the present invention will be described by way of examples. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.
The items described in the examples were measured by the following methods.

[Method for measuring weight average molecular weight and number average molecular weight]
The polystyrene equivalent weight average molecular weight (Mw) and number average molecular weight (Mn) were determined by gel permeation chromatography (GPC). The molecular weight distribution (PDI) represents Mw / Mn.

Gel permeation chromatography (GPC) measurement was performed under the following conditions.
Column: PolymerLaboratories GPC column (PLgel MIXED-B 10 μm, inner diameter 7.5 mm, length 30 cm), connected in series Pump: LC-10AT (manufactured by Shimadzu Corporation)
Oven: CTO-10A (manufactured by Shimadzu Corporation)
Detector: Differential refractive index detector (manufactured by Shimadzu Corporation, RID-10A) and UV-vis detector (manufactured by Shimadzu Corporation, RID-10A) and UV-vis detector (manufactured by Shimadzu Corporation, SPD-10A)
Sample: 1 μL of 1 mg sample dissolved in orthodichlorobenzene (200 mg)
Mobile phase: orthodichlorobenzene
Flow rate: 1.0 mL / min
Temperature: 80 ° C
Analysis: LC-Solution (manufactured by Shimadzu Corporation)

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A1) (29.8 mg, 0.033 mmol), with reference to JP-T-2014-501032 4,7-bis- (5-bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A2) (16.3 mg, 0.033 mmol) And 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bi, which was obtained by referring to the method described in JP-T-2014-501032 (Trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex ( 2.7 mg, 4.0 mol%), tris (2-methylphenyl) phosphine (6.4 mg, 32 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. did. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 1A was obtained in a yield of 74%. The resulting copolymer 1A had a weight average molecular weight Mw of 187,000 and a PDI of 4.5.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A1) (59.6 mg, 0.066 mmol) and described in JP-T-2014-501032 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b] obtained by referring to the method of : 4,5-b ′] dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and tetrakis (triphenylphosphine) palladium (0) (2.3 mg, 3.00). ol%), triphenylphosphine-containing heterogeneous palladium complex catalyst Pd-EnCatTPP30 (Aldrich, 3.0 mg, 1.53 mol%), toluene (4.0 mL), and N, N-dimethylformamide (1.0 mL) ) And stirred at 100 ° C. for 1 hour and then at 110 ° C. for 2 hours. The reaction solution was diluted twice with toluene and heated and stirred at 110 ° C. for another 0.5 hours, and then trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment and stirred at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 2A was obtained in a yield of 87%. The obtained copolymer 2A had a weight average molecular weight Mw of 52,000 and a PDI of 2.2.

4,7-bis- (5-bromo-thiophen-2-yl) -5,6-- obtained as a monomer in a 50 mL two-necked eggplant flask under a nitrogen atmosphere with reference to JP-T-2014-501032 Difluoro-benzo [1,2,5] thiadiazole (compound A2) (32.6 mg, 0.066 mmol) and 4,8-bis- obtained by referring to the method described in JP-T-2014-501032 [5- (2-Hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound D1) (74 0.5 mg, 0.066 mmol), tris (dibenzylideneacetone) dipalladium chloroform complex (2.73 mg, 4.00 mol%), tris (2-methyl Eniru) phosphine (3.21mg, 16.00mol%), was placed chlorobenzene (5.0 mL), 1 hour at 100 ° C., followed by stirring for 2 hours at 110 ° C.. After diluting the reaction solution with chlorobenzene twice and heating and stirring at 110 ° C. for another 0.5 hours, as a terminal treatment, trimethyl (phenyl) tin (0.03 mL) was added and heating and stirring at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 3A was obtained in a yield of 56%. The obtained copolymer 3A had a weight average molecular weight Mw of 199,000 and a PDI of 4.1.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound A1) (29.8 mg, 0.033 mmol), known literature (Chem. Mater., 2008, 20, 4045-4050), 4,7-bis- (5-bromo-thiophen-2-yl) -benzo [1,2,5] thiadiazole (Compound A3) (15.1 mg, 0 0.033 mmol) and 4,8-bis- [5- (2-hexyldecyl) -thiophene-2-] obtained by referring to the method described in JP-T-2014-501032 L] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (compound D1) (74.5 mg, 0.066 mmol) was added, and tetrakis (tri Phenylphosphine) palladium (0) (2.3 mg, 3.00 mol%), triphenylphosphine-containing heterogeneous palladium complex catalyst Pd-EnCatTPP30 (manufactured by Aldrich, 3.0 mg, 1.53 mol%), toluene (4. 0 mL) and N, N-dimethylformamide (1.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 2 hours. The reaction solution was diluted twice with toluene and heated and stirred at 110 ° C. for another 0.5 hours, and then trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment and stirred at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 4A was obtained in a yield of 84%. The resulting copolymer 4A had a weight average molecular weight Mw of 54,000 and a PDI of 2.4.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A1) (17.9 mg, 0.020 mmol), referring to JP-T-2014-501032 4,7-bis- (5-bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A2) (22.8 mg, 0.046 mmol) And 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bi, which was obtained by referring to the method described in JP-T-2014-501032 (Trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and tetrakis (triphenylphosphine) palladium (0) ( 2.3 mg, 3.00 mol%), triphenylphosphine-containing heterogeneous palladium complex catalyst Pd-EnCatTPP30 (Aldrich, 3.0 mg, 1.53 mol%), toluene (4.0 mL), and N, N- Dimethylformamide (1.0 mL) was added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 2 hours. The reaction solution was diluted twice with toluene and heated and stirred at 110 ° C. for another 0.5 hours, and then trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment and stirred at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 5A was obtained in a yield of 56%. The weight average molecular weight Mw of the obtained copolymer 5A was 67,000, and PDI was 3.0.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A1) (29.8 mg, 0.033 mmol), with reference to JP-T-2014-501032 4,7-bis- (5-bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A2) (16.3 mg, 0.033 mmol) 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis () obtained by referring to the method described in JP-T-2014-501032 Limethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound D1) (37.3 mg, 0.033 mmol) was added, and known literature (ACS Macro Lett., 2013, 2,605-) 608) 4,8-bis- [5- (2-butyloctyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1 , 2-b: 4,5-b ′] dithiophene (compound D2) (33.6 mg, 0.033 mmol) was added, and tetrakis (triphenylphosphine) palladium (0) (2.3 mg, 3.00 mol%) Triphenylphosphine-containing heterogeneous palladium complex catalyst Pd-EnCatTPP30 (manufactured by Aldrich, 3.0 mg, 1.53 mol%), Ene (4.0 mL), and N, placed N- dimethylformamide (1.0 mL), 1 hour at 100 ° C., followed by stirring for 2 hours at 110 ° C.. The reaction solution was diluted twice with toluene and heated and stirred at 110 ° C. for another 0.5 hours, and then trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment and stirred at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 6A was obtained in a yield of 86%. The obtained copolymer 6A had a weight average molecular weight Mw of 47,000 and a PDI of 2.5.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A1) (29.8 mg, 0.033 mmol), with reference to JP-T-2014-501032 4,7-bis- (5-bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A2) (16.3 mg, 0.033 mmol) And 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bi, which was obtained by referring to the method described in JP-T-2014-501032 (Trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and tetrakis (triphenylphosphine) palladium (2.3 mg) was added. , 3.0 mol%), triphenylphosphine-containing heterogeneous palladium complex catalyst Pd-EnCatTPP30 (purchased from Aldrich, 3.0 mg, 3 mol%), toluene (4.0 mL), and N, N-dimethylformamide (1 0.0 mL) and stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 7A was obtained with a yield of 79%. The resulting copolymer 7A had a weight average molecular weight Mw of 72,000 and a PDI of 2.7.

<Synthesis Example 8A: Synthesis of Copolymer 8A>
[Synthesis Example: Synthesis of 4-tetradecyl-2-trimethylstannylthiophene (Compound T2)]

2,2,6,6-tetramethylpiperidine (2.18 g, 15 mmol) was added to a 50 mL two-necked flask, and nitrogen substitution was performed three times. 10 mL of dry THF was added, and the mixture was cooled to −78 ° C. with a dry ice acetone bath. n-Butyllithium (1.6M, 8.9 mL, 14.3 mmol) was added dropwise at −78 ° C., stirred for 30 minutes, and then heated to 0 ° C. in an ice bath. On the other hand, 3-tetradecylthiophene (Compound T1) (4.3 g, 15 mmol) was added to a 500 mL four-necked flask, and nitrogen substitution was performed three times. 190 mL of dry THF was added, and the mixture was cooled to −40 ° C. with a dry ice acetone bath. The previously prepared LiTMP was slowly added dropwise at −40 ° C., and after stirring, the mixture was further stirred for 1 hour, and then trimethyltin chloride (1M in THF, 15 mL, 15 mmol) was added dropwise and stirred for 30 minutes. 100 mL of distilled water was added to quench the reaction, and the aqueous layer was extracted once with hexane. The organic layer was washed 3 times with water and dried over anhydrous sodium sulfate. The solvent was distilled off with an evaporator and dried under reduced pressure (oil pump) at 40 ° C. to obtain 4-tetradecyl-2-trimethylstannylthiophene (Compound T2). As a result of proton NMR, the purity of the tin body was 70%.

[Synthesis Example: Synthesis of 3,7-di (3-tetradecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T4) ]

In a 50 mL two-necked flask, 4-tetradecyl-2-trimethylstannylthiophene (Compound T2) (2.37 g (P.70%) 3.75 mmol), 3,7-dibromo-naphtho [1,2-c: 5, 6-c] bis [1,2,5] thiadiazole (Compound T3) (603 mg, 1.5 mmol) was added, and nitrogen substitution was performed three times. Tetrakistriphenylphosphine palladium (34.9 mg, 0.02 mmol) was added, and nitrogen substitution was performed twice. 70 mL of dehydrated toluene and 7 mL of dehydrated DMF were added and stirred at 115 ° C. for 3 hours. After cooling to room temperature, toluene was distilled off. 20 mL of ethyl acetate was added and stirred, followed by filtration. The filtered solid was washed with ethyl acetate 3 times and dried. The resulting orange solid was dissolved by heating in 300 mL of chloroform and purified by a short pass silica gel column. The solvent was distilled off and dried under reduced pressure to obtain 3,7-di (3-tetradecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5 ] 1.13 g of thiadiazole (compound T4) was obtained with a yield of 94%.

[Synthesis Example: 3,7-di (2-bromo-3-tetradecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound Synthesis of A4)

In a 2 L eggplant flask, 3,7-di (3-tetradecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T4) (1 .13 g, 1.42 mmol) was added, 1000 mL of chloroform was added, and the mixture was heated and stirred using a dryer. After cooling to room temperature and shielding the flask from light with aluminum foil, a chloroform solution of bromine (493 mg, 3.09 mmol) was quickly added dropwise at room temperature. After stirring at room temperature for 1 hour, 90% of the solvent was distilled off. The obtained red slurry was filtered under reduced pressure and washed by sprinkling with chloroform three times. By drying at 50 ° C. under reduced pressure, 3,7-di (2-bromo-3-tetradecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2, 5] 1.34 g of thiadiazole (Compound A4) was obtained with a yield of 98%.

[Synthesis Example: Synthesis of Copolymer 8A]

In a 50 mL two-necked eggplant flask under a nitrogen atmosphere, 3,7-di (2-bromo-3-tetradecylthiophen-5-yl) -naphtho [1,2-c: obtained by the above method as a monomer was used. 5,6-c] bis [1,2,5] thiadiazole (compound A4) (31.6 mg, 0.033 mmol), 4,7-bis- ( 5-Bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A2) (16.3 mg, 0.033 mmol) and described in JP-T-2014-501032 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b] obtained by referring to the method of : 4, -B ′] dithiophene (compound D1) (74.5 mg, 0.066 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.0 mol%), tris (2-methylphenyl) Phosphine (3.2 mg, 16 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 8A was obtained in a yield of 77%. The resulting copolymer 8A had a weight average molecular weight Mw of 162,000 and a PDI of 4.2.

<Synthesis Example 9A: Synthesis of Copolymer 9A>
[Synthesis Example: Synthesis of 4-decyl-2-trimethylstannylthiophene (Compound T6)]

2,2,6,6-tetramethylpiperidine (3.15 g, 22.3 mmol) was added to a 100 mL two-necked flask, and nitrogen substitution was performed three times. 15 mL of dry THF was added, and the mixture was cooled to −78 ° C. with a dry ice acetone bath. n-Butyllithium (1.54M, 13.7 mL, 21.1 mmol) was added dropwise at −78 ° C., stirred for 30 minutes, and then heated to 0 ° C. in an ice bath. On the other hand, 3-decylthiophene (Compound T5) (5 g, 22.3 mmol) was added to a 500 mL four-necked flask, and nitrogen substitution was performed three times. 250 mL of dry THF was added, and the mixture was cooled to −30 ° C. with a dry ice acetone bath. The previously prepared LiTMP was slowly added dropwise at −30 ° C., and the mixture was further stirred for 45 minutes, and then a THF solution of trimethyltin chloride (4.45 g, 22.3 mmol) was added dropwise and stirred for 45 minutes. 100 mL of distilled water was added to quench the reaction, and the aqueous layer was extracted once with hexane. The organic layer was washed 3 times with water and dried over anhydrous sodium sulfate. The solvent was distilled off with an evaporator and dried under reduced pressure (oil pump) at 40 ° C. to obtain 4-decyl-2-trimethylstannylthiophene (Compound T6). As a result of proton NMR, the purity of the tin body was 86.9%.

[Synthesis Example: Synthesis of 3,7-di (3-decylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T7)]

In a 100 mL two-necked flask, 4-decyl-2-trimethylstannylthiophene (Compound T6) (1.14 g (P.86.9%) 2.5 mmol), 3,7-dibromo-naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T3) (403 mg, 1 mmol) was added, and nitrogen substitution was performed three times. Tetrakistriphenylphosphine palladium (23.1 mg, 0.02 mmol) was added, and nitrogen substitution was performed twice. 45 mL of dehydrated toluene and 4.5 mL of dehydrated DMF were added and stirred at 115 ° C. for 3 hours. After cooling to room temperature, 20 mL of ethyl acetate was added and stirred, followed by filtration. The filtered solid was washed with ethyl acetate 3 times and dried. The resulting orange solid was dissolved by heating in 200 mL of chloroform and purified by a short-pass silica gel column. The solvent was distilled off and dried under reduced pressure to obtain 3,7-di (3-decylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] Thiadiazole (Compound T7) was obtained. Used as is in the next step.

[Synthesis Example: 3,7-di (2-bromo-3-decylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A5 )

Into a 1 L eggplant flask was placed 3,7-di (3-decylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T7). Chloroform 500mL was added and it heat-stirred using the dryer. After cooling to room temperature and shielding the flask from light with aluminum foil, a chloroform solution of bromine (450 mg, 2.8 mmol) was quickly added dropwise at room temperature. After stirring at room temperature for 1 hour, 90% of the solvent was distilled off. The obtained red slurry was filtered under reduced pressure and washed by sprinkling with chloroform three times. By drying at 50 ° C. under reduced pressure, 3,7-di (2-bromo-3-decylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5 717 mg of thiadiazole (Compound A5) was obtained in a yield of 84% (two steps).

[Synthesis Example: Synthesis of Copolymer 9A]

In a 50 mL two-necked eggplant flask under a nitrogen atmosphere, 3,7-di (2-bromo-3-decylthiophen-5-yl) -naphtho [1,2-c: 5 obtained by the above method as a monomer was used. , 6-c] bis [1,2,5] thiadiazole (Compound A5) (27.4 mg, 0.032 mmol), 4,7-bis- (5 obtained with reference to JP-T-2014-501032 -Bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A2) (16.0 mg, 0.032 mmol), and JP-A-2014-501032 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: obtained by referring to the method: 4,5-b Dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.0 mol%), tris (2-methylphenyl) phosphine (3 0.2 mg, 16 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 9A was obtained in a yield of 77%. The weight average molecular weight Mw of the obtained copolymer 9A was 162,000, and PDI was 5.9.

<Synthesis Example 10A: Synthesis of Copolymer 10A>
[Synthesis Example: Synthesis of 3-pentadecylthiophene (Compound T9)]

[1,3-bis (diphenylphosphino) propane] dichloronickel (542 mg, 1 mmol) was added to a 500 mL four-necked flask, and nitrogen substitution was performed three times. 100 mL of dry diethyl ether was added, and a THF solution (0.4 M, 5 mL, 2 mmol) of pentadecylmagnesium bromide was slowly added dropwise at room temperature. Thereafter, 3-bromothiophene (Compound T8) (16.3 g, 100 mmol) was added. A solution of pentadecylmagnesium bromide in THF (0.4M, 245 mL, 98 mmol) was added dropwise, and the mixture was further stirred for 2 hours. The reaction was quenched by adding 20 mL of 1N hydrochloric acid, and the aqueous layer was extracted once with hexane. The organic layer was washed once with water and once with a saturated aqueous sodium chloride solution, and dried over anhydrous sodium sulfate. The solvent was distilled off with an evaporator, and the origin component was removed with a short-pass silica gel column. The alkyl residue was removed under reduced pressure (oil pump) at 100 ° C. to obtain 26.7 g of 3-pentadecylthiophene (Compound T9) in a yield of 90%.

[Synthesis Example: Synthesis of 4-pentadecyl-2-trimethylstannylthiophene (Compound T10)]

TMPMgCl·LiCl (1.0 M THF solution, 12 mL, 12 mmol) was added to a nitrogen-substituted 50 mL two-necked flask, and 3-pentadecylthiophene (compound T9) (2.95 g, 10 mmol) and 5 mL of dry THF were added. After stirring for 2 hours, the mixture was cooled in an ice bath, and a dry THF solution of trimethyltin chloride (2.4 g, 12 mmol) was slowly added dropwise. The mixture was warmed to room temperature, stirred for 1 hour, and then quenched with water. The aqueous layer was extracted once with hexane, and the organic layer was washed 3 times with water and dried over anhydrous sodium sulfate. The solvent was distilled off with an evaporator and dried at 50 ° C. under reduced pressure (oil pump). Purification by recycle preparative GPC gave 4-pentadecyl-2-trimethylstannylthiophene (Compound T10). As a result of proton NMR, the purity of the tin body was 90%.

[Synthesis Example: Synthesis of 3,7-di (3-pentadecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T11) ]

In a 100 mL two-necked flask, 4-pentadecyl-2-trimethylstannylthiophene (Compound T10) (656 mg (P. 90%), 1.29 mmol), 3,7-dibromo-naphtho [1,2-c: 5,6 -C] Bis [1,2,5] thiadiazole (Compound T3) (200 mg, 0.497 mmol) was added, and nitrogen substitution was performed three times. Tetrakistriphenylphosphine palladium (11.5 mg, 0.01 mmol) was added, and nitrogen substitution was performed twice. 20 mL of dehydrated toluene and 2 mL of dehydrated DMF were added and stirred at 115 ° C. for 3 hours. After cooling to room temperature, 10 mL of ethyl acetate was added and stirred, followed by filtration. The filtered solid was washed with ethyl acetate 3 times and dried. The resulting orange solid was dissolved by heating in 200 mL of chloroform and purified by a short-pass silica gel column. The solvent was distilled off and dried under reduced pressure to obtain 3,7-di (3-pentadecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5 ] 410 mg of thiadiazole (compound T11) was obtained with a yield of 99%.

[Synthesis Example: 3,7-di (2-bromo-3-pentadecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound Synthesis of A6)

In a 1 L eggplant flask, 3,7-di (3-pentadecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T11) (410 mg) , 0.497 mmol), 400 mL of chloroform was added, and the mixture was heated and stirred using a dryer. After cooling to room temperature and shielding the flask from light with aluminum foil, a chloroform solution of bromine (238 mg, 1.49 mmol) was quickly added dropwise at room temperature. After stirring at room temperature for 1 hour, 90% of the solvent was distilled off. The obtained red slurry was filtered under reduced pressure and washed by sprinkling with chloroform three times. By drying at 50 ° C. under reduced pressure, 3,7-di (2-bromo-3-pentadecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2, 5] 485 mg of thiadiazole (compound A6) was obtained in a yield of 99%.

[Synthesis Example: Synthesis of Copolymer 10A]

In a 50 mL two-necked eggplant flask under a nitrogen atmosphere, 3,7-di (2-bromo-3-pentadecylthiophen-5-yl) -naphtho [1,2-c: obtained by the above method as a monomer was used. 5,6-c] bis [1,2,5] thiadiazole (Compound A6) (32.6 mg, 0.033 mmol), 4,7-bis- ( 5-Bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A2) (16.3 mg, 0.033 mmol) and described in JP-T-2014-501032 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b] obtained by referring to the method of : 4, -B ′] dithiophene (compound D1) (74.5 mg, 0.066 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.0 mol%), tris (2-methylphenyl) Phosphine (3.2 mg, 16 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 10A was obtained in a yield of 75%. The resulting copolymer 10A had a weight average molecular weight Mw of 244,000 and a PDI of 4.8.

<Synthesis Example 11A: Synthesis of Copolymer 11A>
[Synthesis Example: Synthesis of 4-octadecyl-2-trimethylstannylthiophene (Compound T13)]

TMPMgCl·LiCl (1.0 M THF solution, 12 mL, 12 mmol) was added to a nitrogen-substituted 50 mL two-necked flask, and 3-octadecylthiophene (compound T12) (3.35 g, 10 mmol) in dry THF (5 mL) was added at room temperature. added. After stirring for 2 hours, the mixture was cooled in an ice bath, and a dry THF solution of trimethyltin chloride (2.4 g, 12 mmol) was slowly added dropwise. The mixture was warmed to room temperature, stirred for 1 hour, and then quenched with water. The aqueous layer was extracted once with hexane, and the organic layer was washed 3 times with water and dried over anhydrous sodium sulfate. The solvent was distilled off with an evaporator and dried at 50 ° C. under reduced pressure (oil pump). Purification by recycle preparative GPC gave 4-octadecyl-2-trimethylstannylthiophene (compound T13). As a result of proton NMR, the purity of the tin body was 68%.

[Synthesis Example: Synthesis of 3,7-di (3-octadecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T14)]

In a 100 mL two-necked flask, 4-octadecyl-2-trimethylstannylthiophene (Compound T13) (988 mg (P.68%), 1.32 mmol), 3,7-dibromo-naphtho [1,2-c: 5,6 -C] Bis [1,2,5] thiadiazole (Compound T3) (200 mg, 0.497 mmol) was added, and nitrogen substitution was performed three times. Tetrakistriphenylphosphine palladium (11.5 mg, 0.01 mmol) was added, and nitrogen substitution was performed twice. 20 mL of dehydrated toluene and 2 mL of dehydrated DMF were added and stirred at 115 ° C. for 3 hours. After cooling to room temperature, 10 mL of ethyl acetate was added and stirred, followed by filtration. The filtered solid was washed with ethyl acetate 3 times and dried. The resulting orange solid was dissolved by heating in 200 mL of chloroform and purified by a short-pass silica gel column. The solvent was distilled off and dried under reduced pressure to obtain 3,7-di (3-octadecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] 440 mg of thiadiazole (compound T14) was obtained in a yield of 97%.

[Synthesis Example: 3,7-di (2-bromo-3-octadecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A7 )

In a 1 L eggplant flask, 3,7-di (3-octadecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T14) (444 mg, 0.486 mmol) was added, 500 mL of chloroform was added, and the mixture was heated and stirred using a dryer. After cooling to room temperature and shielding the flask from light with aluminum foil, a chloroform solution of bromine (408 mg, 2.55 mmol) was quickly added dropwise at room temperature. After stirring at room temperature for 1 hour, 90% of the solvent was distilled off. The obtained red slurry was filtered under reduced pressure and washed by sprinkling with chloroform three times. By drying at 50 ° C. under reduced pressure, 3,7-di (2-bromo-3-octadecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5 494 mg, 95% yield of thiadiazole (Compound A7) was obtained.

[Synthesis Example: Synthesis of Copolymer 11A]

In a 50 mL two-necked eggplant flask under a nitrogen atmosphere, 3,7-di (2-bromo-3-octadecylthiophen-5-yl) -naphtho [1,2-c: 5 obtained by the above method as a monomer was used. , 6-c] bis [1,2,5] thiadiazole (Compound A7) (35.4 mg, 0.033 mmol), 4,7-bis- (5 obtained with reference to JP-T-2014-501032 -Bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A2) (16.3 mg, 0.033 mmol) and described in JP-T-2014-501032 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: obtained by referring to the method: 4, -B ′] dithiophene (compound D1) (74.5 mg, 0.066 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.0 mol%), tris (2-methylphenyl) Phosphine (3.2 mg, 16 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 11A was obtained in a yield of 75%. The resulting copolymer 11A had a weight average molecular weight Mw of 149,000 and a PDI of 4.4.

<Synthesis Example 12A: Synthesis of Copolymer 12A>
[Synthesis Example: Synthesis of 3,4-didodecylthiophene (Compound T16)]

In a 500 mL two-necked eggplant flask, 3,4-dibromothiophene (Compound T15) (5.09 g, 20.7 mmol), [1,3-bis (diphenylphosphino) propane] dichloronickel (224 mg, 0.41 mmol) were added. In addition, nitrogen substitution was performed three times. 200 mL of dry diethyl ether was added and cooled to 0 ° C. A THF solution (1.0 M, 45.5 mL, 45.5 mmol) of dodecylmagnesium bromide was slowly added. After completion of the dropwise addition, the mixture was heated to reflux and stirred for 10 hours. The mixture was cooled again to 0 ° C. and quenched by adding aqueous hydrochloric acid. The aqueous layer was extracted once with hexane, and the organic layer was washed twice with water. After drying over anhydrous sodium sulfate, the solvent was distilled off. The origin component was removed by short-pass silica gel column chromatography using hexane as a developing solution. After distilling off the solvent, low-boiling components were removed under reduced pressure to obtain 8.5 g of 3,4-didodecylthiophene (Compound T16) in a yield of 97%.

[Synthesis Example: Synthesis of 3,4-didodecyl-2-trimethylstannylthiophene (Compound T17)]

3,4-Didodecylthiophene (Compound T16) (4.2 g, 9.98 mmol) was added to a 100 mL two-necked eggplant flask, and nitrogen substitution was performed three times. 20 mL of dry THF was added and cooled in an ice bath. n-Butyllithium (1.6M, 6.3 mL, 10 mmol) was added dropwise at 0 ° C. and stirred for 1 hour 30 minutes, and then a dry THF solution of trimethyltin chloride (2 g, 10 mmol) was slowly added dropwise. Water was added to quench, the aqueous layer was extracted once with hexane, and the organic layer was washed three times with water. After drying over anhydrous sodium sulfate, the solvent was distilled off. By drying at 40 ° C. under reduced pressure (oil pump), 5.5 g of 3,4-didodecyl-2-trimethylstannylthiophene (Compound T17) was obtained with a yield of 94%.

[Synthesis Example: 3,7-di (3,4-didodecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T18) Synthesis]

In a 100 mL two-necked eggplant flask, 3,4-didodecyl-2-trimethylstannylthiophene (compound T17) (1.46 g, 2.5 mmol), 3,7-dibromo-naphtho [1,2-c: 5,6 -C] bis [1,2,5] thiadiazole (compound T3) (403 mg, 1.0 mmol), dichlorobis [di-t-butyl (p-dimethylaminophenyl) phosphino] palladium (14.4 mg, 0.02 mmol) And nitrogen substitution was performed 3 times. 16 mL of dry toluene and 4 mL of dry DMF were added and stirred at 100 ° C. for 8 hours. It cooled to room temperature and put methanol and cooled. The precipitated solid was filtered and dried under reduced pressure. The origin component was removed by short-pass silica gel column chromatography using chloroform as a developing solution. Purified by recycle preparative GPC using chloroform as a developing solvent, and 3,7-di (3,4-didodecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [ 568 mg, 52% yield of 1,2,5] thiadiazole (compound T18).

[Synthesis Example: 3,7-di (2-bromo-3,4-didodecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Synthesis of Compound A8)

3,7-di (3,4-didodecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c ′] bis [1,2,5] thiadiazole (Compound T18) (568 mg, 0.525 mmol) was added with 14 mL of orthodichlorobenzene and heated to 90 ° C. N-bromosuccinimide (186 mg, 1.04 mmol) and 1.0 mL of acetic acid were added and stirred for 1 hour. After cooling to room temperature, methanol was added and ultrasonic cleaning was performed. The precipitated solid was filtered off and dried at 50 ° C. under reduced pressure to give 3,7-di (2-bromo-3,4-didodecylthiophen-5-yl) -naphtho [1,2-c: 5, 613 mg of 6-c] bis [1,2,5] thiadiazole (Compound A8) was obtained with a yield of 94%.

[Synthesis Example: Synthesis of Copolymer 12A]

In a 50 mL two-necked eggplant flask under a nitrogen atmosphere, 3,7-di (2-bromo-3,4-didodecylthiophen-5-yl) -naphtho [1,2- c: 5,6-c] bis [1,2,5] thiadiazole (Compound A8) (39.3 mg, 0.032 mmol), 4,7-bis obtained with reference to JP-T-2014-501032 -(5-Bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A2) (15.7 mg, 0.032 mmol), and JP-T-2014-501032 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2] obtained by referring to the method described in 1. -B: 4 5-b ′] dithiophene (compound D1) (74.5 mg, 0.066 mmol) was added, and further tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.0 mol%), tris (2-methylphenyl) ) Phosphine (3.2 mg, 16 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 12A was obtained in a yield of 73%. The resulting copolymer 12A had a weight average molecular weight Mw of 66,000 and a PDI of 2.2.

<Synthesis Example 13A: Synthesis of Copolymer 13A>
[Synthesis Example: Synthesis of 3-dodecyl-2-bromothiophene (Compound T20)]

3-Dodecylthiophene (Compound T19) (10.5 g, 39.8 mmol), chloroform (50 mL) and acetic acid (50 mL) were added to a 200 mL two-necked eggplant flask. After cooling in an ice bath and shielding the flask from light with aluminum foil, NBS (6.38 g, 35.8 mmol) was added in small portions. After confirming disappearance of the raw material by TLC, ice was added to quench. The aqueous layer was extracted once with hexane. The organic layer was washed 3 times with water and 3 times with saturated brine, and dried over anhydrous sodium sulfate. The solvent was removed by an evaporator, and the crude product was purified by silica gel column chromatography to obtain 12.7 g of 3-dodecyl-2-bromothiophene (Compound T20) in a yield of 96%.

[Synthesis Example: Synthesis of 3-dodecyl-2-trimethylstannylthiophene (Compound T21)]

3-Bromo-2-dodecylthiophene (Compound T20) (12.6 g, 38 mmol) was added to a 300 mL two-necked eggplant flask, and nitrogen substitution was performed three times. 115 mL of dry THF was added and cooled to 0 ° C. Isopropylmagnesium chloride lithium chloride complex (1.18M, 35 mL, 41.3 mmol) was added. The mixture was warmed to room temperature and stirred for 1 hour. The mixture was cooled again to 0 ° C., trimethyltin chloride (1.0 M in THF, 42 mL, 42 mmol) was added, and the mixture was stirred for 1 hour. Quench with water and extract the aqueous layer three times with hexane. The organic layer was washed 3 times with water and once with saturated brine. After drying over anhydrous sodium sulfate, the solvent was distilled off to obtain 16.2 g of 3-dodecyl-2-trimethylstannylthiophene (Compound T21). As a result of proton NMR, the purity of the tin body was 80%.

[Synthesis Example: Synthesis of 3,7-di (3-dodecylthiophen-2-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T22)

In a 100 mL two-necked eggplant flask, 3-dodecyl-2-trimethylstannylthiophene (Compound T21) (969 mg, 1.87 mmol), 3,7-dibromo-naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T3) (300 mg, 0.746 mmol) and dichlorobis [di-t-butyl (p-dimethylaminophenyl) phosphino] palladium (10.6 mg, 0.015 mmol) were added to replace nitrogen. Was performed three times. 24 mL of dry toluene and 6 mL of dry DMF were added and stirred at 100 ° C. for 6 hours. After cooling to room temperature, methanol was added and sonicated. Filter and dry under reduced pressure. The origin component was removed by short-pass silica gel column chromatography using chloroform as a developing solvent, and reprecipitation with ethyl acetate was performed, whereby 3,7-di (3-dodecylthiophen-2-yl) -naphtho [1,2 -C: 5,6-c] bis [1,2,5] thiadiazole (Compound T22) was obtained in 532 mg in a yield of 82%.

[Synthesis Example: 3,7-di (2-bromo-4-dodecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A9 )

3,7-di (3-dodecylthiophen-2-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T22) (74.5 mg, 0. 1 mmol) was added with 5 mL of orthodichlorobenzene and heated to 90 ° C. N-bromosuccinimide (41.6 mg, 0.23 mmol) and acetic acid 0.5 mL were added and stirred for 4 hours. Cool to room temperature, add methanol and filter. The obtained solid was dried at 50 ° C. under reduced pressure to give 3,7-di (2-bromo-4-dodecylthiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [ 1,2,5] thiadiazole (Compound A9) was obtained in 73.6 mg in a yield of 81%.

[Synthesis Example: Synthesis of Copolymer 13A]

In a 50 mL two-necked eggplant flask under a nitrogen atmosphere, 3,7-di (2-bromo-4-dodecylthiophen-5-yl) -naphtho [1,2-c: 5 obtained by the above method as a monomer was used. , 6-c] bis [1,2,5] thiadiazole (Compound A9) (28.6 mg, 0.032 mmol), 4,7-bis- (5 obtained with reference to JP-T-2014-501032 -Bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A2) (15.7 mg, 0.032 mmol), and JP-A-2014-501032 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: obtained by referring to the method: 4,5- '] Dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.0 mol%), tris (2-methylphenyl) phosphine ( 3.2 mg, 16 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 13A was obtained in a yield of 51%. The resulting copolymer 13A had a weight average molecular weight Mw of 124,000 and a PDI of 4.5.

<Synthesis Example 14A: Synthesis of Copolymer 14A>
[Synthesis Example: Synthesis of 5-trimethylsilyl-2-trimethylstannylthiophene (Compound T24)]

2-Trimethylsilylthiophene (Compound T23) (1.57 g, 10 mmol) was added to a 100 mL two-necked flask, and nitrogen substitution was performed three times. 30 mL of dry THF was added, and the mixture was cooled to −78 ° C. with a dry ice acetone bath. LDA (1.13M, 7.9 mL, 9 mmol) was added dropwise at −78 ° C. and stirred for 1 hour, and then trimethyltin chloride (1.79 g, 9 mmol) was added and stirred for 1 hour. Distilled water was added to quench the reaction, and the aqueous layer was extracted once with hexane. The organic layer was washed 3 times with water and dried over anhydrous sodium sulfate. The solvent was distilled off with an evaporator and dried under reduced pressure (oil pump) to obtain 2.3 g of 5-trimethylsilyl-2-trimethylstannylthiophene (Compound T24). As a result of proton NMR, the purity of the tin body was 90%.

[Synthesis Example: Synthesis of 3,7-di (5-trimethylsilylthiophen-2-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T25)]

In a 100 mL two-necked flask, 5-trimethylsilyl-2-trimethylstannylthiophene (Compound T24) (886 mg (P. 90%) 2.5 mmol), 3,7-dibromo-naphtho [1,2-c: 5,6- c] Bis [1,2,5] thiadiazole (Compound T3) (402 mg, 1.0 mmol) was added, and nitrogen substitution was performed three times. Tetrakistriphenylphosphine palladium (23.1 mg, 0.02 mmol) was added, and nitrogen substitution was performed twice. 50 mL of dehydrated toluene and 5 mL of dehydrated DMF were added and stirred at 115 ° C. for 7 hours. After cooling to room temperature, toluene was distilled off. Methanol was added and stirred and filtered off. The obtained orange solid was dissolved by heating in 250 mL of chloroform, and purified by silica gel column chromatography with a short path. The solvent was distilled off and dried under reduced pressure to obtain 3,7-di (5-trimethylsilylthiophen-2-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] Thiadiazole (Compound T25) was obtained in a yield of 528 mg and a yield of 95%.

[Synthesis Example: Synthesis of 3,7-di (2-bromothiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A10)]

In a 2 L eggplant flask, 3,7-di (5-trimethylsilylthiophen-2-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound T25) (528 mg, 0.95 mmol) was added, 1000 mL of chloroform was added, and the mixture was heated and stirred using a dryer. After cooling to room temperature and shielding the flask from light with aluminum foil, a chloroform solution of bromine (323 mg, 2.02 mmol) was quickly added dropwise at room temperature. After stirring at room temperature for 1 hour, 90% of the solvent was distilled off. The obtained red slurry was filtered under reduced pressure and washed by sprinkling with chloroform three times. 3,7-di (2-bromothiophen-5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound) by drying at 50 ° C. under reduced pressure 540 mg of A10) was obtained with a yield of 100%.

[Synthesis Example: Synthesis of Copolymer 14A]

In a 50 mL two-necked eggplant flask under a nitrogen atmosphere, 3,7-di (2-bromo-thiophen-5-yl) -naphtho [1,2-c: 5,6- c] Bis [1,2,5] thiadiazole (Compound A10) (17.6 mg, 0.031 mmol), 4,7-bis- (5-bromo-) obtained with reference to JP-T-2014-501032 Reference is made to thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (compound A2) (15.3 mg, 0.031 mmol) and the method described in JP-T-2014-501032. 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,5 -B '] Fen (compound D1) (74.5 mg, 0.066 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.0 mol%), tris (2-methylphenyl) phosphine (3. 2 mg, 16 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was insoluble in solvents such as chloroform, toluene, orthodichlorobenzene and the like.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound A1) (29.8 mg, 0.033 mmol), known literature (Materials Chemistry, 2011, 21, 13,247-13255) obtained with reference to 4,7-bis- (5-bromo-thiophen-2-yl)-[1,2,5] thiadiazolo [3,4-c] pyridine (compound A11) ( 15.8 mg, 0.033 mmol), and 4,8-bis- [5- (5- -Hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (compound D1) (74.5 mg, 0. 066 mmol), tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.0 mol%), tris (2-methylphenyl) phosphine (3.2 mg, 16 mol%), chlorobenzene (5.0 mL) And stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 15A was obtained in a yield of 80%. The resulting copolymer 15A had a weight average molecular weight Mw of 120,000 and a PDI of 4.4.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-tetradecylthiophene-5 obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask -Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound A4) (44.5 mg, 0.046 mmol), non-patent literature (Chem. Mater. 5,5′-dibromo-3,3′-difluoro-2,2′-bithiophene (Compound A12) (7.2 mg, 0.020 mmol) obtained by the method described in Japanese Patent No. 2014, 26, 4214-4220), and a special table 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6 obtained by referring to the method described in JP2014-501032A Bis (trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (compound D1) (76.3 mg, 0.068 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex was added. (2.8 mg, 4.0 mol%), tris (2-methylphenyl) phosphine (6.6 mg, 32 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was 100 ° C. for 1 hour, followed by 110 ° C. for 1 hour. Stir. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (2.5 mL) were added to the reaction solution as a terminal treatment, heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 16A was obtained in a yield of 75%. The weight average molecular weight Mw of the obtained copolymer 16A was 161,000, and PDI was 3.9.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound A1) (29.2 mg, 0.032 mmol), known literature (Materials Chemistry C, 2015, 3 , 8916-8925), 2,2′-bis- (5-bromo-thiophen-2-yl) -2,5-difluoro-1,4-phenylene (Compound A13) (14.1 mg) , 0.032 mmol) and 4,8-bis- [5- (2-hexyl) obtained by referring to the method described in JP-T-2014-501032 Decyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (compound D1) (74.5 mg, 0.066 mmol) And tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.0 mol%), tris (2-methylphenyl) phosphine (3.2 mg, 16 mol%), and chlorobenzene (5.0 mL). The mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 17A was obtained with a yield of 79%. The weight average molecular weight Mw of the obtained copolymer 17A was 98,000, and PDI was 3.7.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound A1) (29.2 mg, 0.032 mmol), with reference to JP-T-2014-501032. 4,7-bis- (5-bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A2) (8.0 mg, 0.016 mmol) 2,2′-bis- (5-bromo-thiophene) obtained by referring to known literature (Materials Chemistry C, 2015, 3, 8916-8925). -2-yl) -2,5-difluoro-1,4-phenylene (Compound A13) (7.1 mg, 0.016 mmol) and the method described in JP-T-2014-501032 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and further tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.0 mol%), tris (2-methylphenyl) phosphine (3.2 mg) , 16 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 18A was obtained in a yield of 78%. The resulting copolymer 18A had a weight average molecular weight Mw of 116,000 and a PDI of 4.5.

<Synthesis Example 19A: Synthesis of Copolymer 19A>
[Synthesis Example: Synthesis of 4,7-bis (3-dodecyl [2,2′-bithiophene] -5-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound T28)]

2-Tributylstannylthiophene (Compound T27) (0.73 g, 1.96 mmol), 4,7-bis (5-bromo-4 -Dodecylthiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound T28) (0.65 g, 0.78 mmol) was added, and nitrogen substitution was performed three times. Tetrakistriphenylphosphine palladium (37.5 mg, 0.03 mmol) was added, and nitrogen substitution was performed twice. 8 mL of dehydrated toluene and 2 mL of dehydrated DMF were added and stirred at 115 ° C. for 3 hours. After cooling to room temperature, toluene was distilled off. 20 mL of methanol was added and stirred, followed by filtration. The solid filtered off was washed by spraying with methanol three times and dried. The resulting orange solid was dissolved by heating in 50 mL of chloroform and purified with a short-pass silica gel column. The solvent was distilled off and dried under reduced pressure to give 4,7-bis (3-dodecyl [2,2′-bithiophen] -5-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound T29) was obtained in an amount of 0.55 g and a yield of 84%.

[Synthesis Example: 4,7-bis (5′-bromo-3-dodecyl [2,2′-bithiophen] -5-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A14 )

In a 2 L eggplant flask, 4,7-bis (3-dodecyl [2,2′-bithiophene] -5-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound T29) (0.55 g) , 0.66 mmol) was added, and 10.5 mL of chloroform and 3.5 mL of acetic acid were added and stirred. N-bromosuccinimide (234 mg, 1.31 mmol) was added, and the mixture was stirred with heating at 75 ° C. for 3 hr. After cooling to room temperature, 20 mL of methanol was added and stirred, followed by filtration. The solid filtered off was washed by spraying with methanol three times and dried. By drying at 50 ° C. under reduced pressure, 4,7-bis (5′-bromo-3-dodecyl [2,2′-bithiophen] -5-yl) -5,6-difluoro-benzo [1,2,5 ] 0.61 g of thiadiazole (compound A14) was obtained with a yield of 93%.

[Synthesis Example: Synthesis of Copolymer 19A]

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound A1) (29.8 mg, 0.033 mmol), 4,7 obtained by the method described above -Bis (5′-bromo-3-dodecyl [2,2′-bithiophene] -5-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A14) (32.8 mg, 0 0.033 mmol), and 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-- obtained by referring to the method described in JP-T-2014-501032 Screw Trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (2 0.7 mg, 4.0 mol%), tris (2-methylphenyl) phosphine (3.2 mg, 16 mol%), and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. . Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 19A was obtained in a yield of 81%. The resulting copolymer 19A had a weight average molecular weight Mw of 222,000 and a PDI of 4.0.

<Synthesis Example 20A: Synthesis of Copolymer 20A>
[Synthesis Example: Synthesis of 4,7-bis (4′-dodecyl [2,2′-bithiophene] -5-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound T31)]

2-Trimethylstannyl-4-dodecylthiophene (compound T30) (1.50 g, 3.61 mmol) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 in a 50 mL two-necked flask, special table 4,7-bis- (5-bromo-thiophen-2-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (compound A2) obtained by referring to JP 2014-501032 A 0.71 g, 1.44 mmol) was added, and nitrogen substitution was performed three times. Tetrakistriphenylphosphine palladium (50.0 mg, 0.04 mmol) was added, and nitrogen substitution was performed twice. 12 mL of dehydrated toluene and 3 mL of dehydrated DMF were added and stirred at 115 ° C. for 3 hours. After cooling to room temperature, toluene was distilled off. 30 mL of methanol was added and stirred, followed by filtration. The solid filtered off was washed by spraying with methanol three times and dried. The resulting orange solid was dissolved by heating in 50 mL of chloroform and purified with a short-pass silica gel column. The solvent was distilled off and the residue was dried under reduced pressure to give 4,7-bis (4′-dodecyl [2,2′-bithiophen] -5-yl) -5,6-difluoro-benzo [1,2,5] 0.98 g of thiadiazole (compound T31) was obtained in a yield of 82%.

[Synthesis Example: 4,7-bis (5′-bromo-4′-dodecyl [2,2′-bithiophene] -5-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (compound Synthesis of A15)]

In a 2 L eggplant flask, 4,7-bis (4′-dodecyl [2,2′-bithiophen] -5-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound T31) (0. 63 g, 0.76 mmol) was added, and 12.0 mL of chloroform and 4.0 mL of acetic acid were added and stirred. N-bromosuccinimide (283 mg, 1.52 mmol) was added, and the mixture was stirred with heating at 75 ° C. for 3 hr. After cooling to room temperature, 20 mL of methanol was added and stirred, followed by filtration. The solid filtered off was washed by spraying with methanol three times and dried. By drying at 50 ° C. under reduced pressure, 4,7-bis (5′-bromo-4′-dodecyl [2,2′-bithiophen] -5-yl) -5,6-difluoro-benzo [1,2, 5] 0.72 g of thiadiazole (Compound A15) was obtained with a yield of 95%. *

[Synthesis Example: Synthesis of Copolymer 20A]

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound A1) (29.8 mg, 0.033 mmol), 4,7 obtained by the method described above -Bis (5'-bromo-4'-dodecyl [2,2'-bithiophene] -5-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A15) (32.8 mg, 0.08 mmol) and 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6 obtained by referring to the method described in JP-T-2014-501032 -Bi (Trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex ( 2.7 mg, 4.0 mol%), tris (2-methylphenyl) phosphine (3.2 mg, 16 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. did. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 20A was obtained in a yield of 83%. The resulting copolymer 20A had a weight average molecular weight Mw of 200,000 and a PDI of 4.4.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound A1) (40.0 mg, 0.044 mmol), 4,7 obtained by the method described above -Bis (5′-bromo-3-dodecyl [2,2′-bithiophene] -5-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A14) (18.9 mg, 0 0,19 mmol) and 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-- obtained by referring to the method described in JP-T-2014-501032 Screw Trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (2 0.7 mg, 4.0 mol%), tris (2-methylphenyl) phosphine (3.2 mg, 16 mol%), and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. . Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 21A was obtained with a yield of 79%. The weight average molecular weight Mw of the obtained copolymer 21A was 86,000, and PDI was 2.6.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound A1) (40.0 mg, 0.044 mmol), 4,7 obtained by the method described above -Bis (5′-bromo-4′-dodecyl [2,2′-bithiophene] -5-yl) -5,6-difluoro-benzo [1,2,5] thiadiazole (Compound A15) (18.9 mg, 0.018 mmol) and 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6 obtained with reference to the method described in JP-T-2014-501032 -Bi (Trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex ( 2.7 mg, 4.0 mol%), tris (2-methylphenyl) phosphine (3.2 mg, 16 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 1 hour. did. Trimethyl (phenyl) tin (0.03 mL) and chlorobenzene (5.0 mL) were added to the reaction solution as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour, and further bromobenzene (1.0 mL) was added. The mixture was heated and stirred at 110 ° C. for 1.0 hour, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 22A was obtained in a yield of 80%. The resulting copolymer 22A had a weight average molecular weight Mw of 145,000 and a PDI of 4.1.

<Example 1A: Production and evaluation of photoelectric conversion element 1A>
[Preparation of composition for forming active layer]
Copolymer 1A obtained in Synthesis Example 1A as a p-type semiconductor compound, and a mixture of PC61BM (phenyl C61 butyric acid methyl ester) and PC71BM (phenyl C71 butyric acid methyl ester) which are fullerene compounds as an n-type semiconductor compound (Frontier Carbon Co., Ltd., nanom spectra E123) was dissolved in a mixed solvent of o-xylene and tetralin (volume ratio 9: 1) in a nitrogen atmosphere to a concentration of 3.6% by mass. Note that the mass ratio of the p-type semiconductor compound to the n-type semiconductor compound was p-type semiconductor compound: n-type semiconductor compound = 1: 2. This solution was stirred and mixed on a hot stirrer at a temperature of 80 ° C. for 1 hour. The solution after stirring and mixing was filtered through a 1 μm polytetrafluoroethylene (PTFE) filter to prepare an active layer forming composition.

A glass substrate (manufactured by Geomatic Co., Ltd.) patterned with an indium tin oxide (ITO) transparent conductive film is subjected to ultrasonic cleaning with acetone, followed by ultrasonic cleaning with isopropanol, followed by drying with nitrogen blow and UV-ozone treatment. went.

Next, a mixed solvent of 2-methoxyethanol (Aldrich) and ethanolamine (Aldrich) at a concentration of 105 mg / mL of zinc (II) acetate dihydrate (Wako Pure Chemical Industries) (volume ratio 100: The solution (about 0.1 mL) dissolved in 3) was spin-coated at a speed of 3000 rpm, subjected to UV-ozone treatment, and then heated in an oven at 200 ° C. for 15 minutes to form an electron extraction layer.
By bringing the substrate on which the electron extraction layer is formed into a glove box, heat-treating at 150 ° C. for 3 minutes in a nitrogen atmosphere, and spin-coating the active layer coating composition (0.12 mL) prepared as described above after cooling. An active layer having a thickness of about 200 nm was formed. Then, it heated at 140 degreeC for 10 minute (s) on the hotplate. Next, the substrate on which the active layer was formed was taken out of the glove box, allowed to stand in the air (25 ° C., humidity 1% or less) for 3 hours under light shielding, and then brought back into the glove box.

Next, a molybdenum trioxide (MoO3) film with a thickness of 1.5 nm is formed on the active layer as a hole extraction layer, and then a silver film with a thickness of 100 nm is formed as an upper electrode by resistance heating vacuum deposition. A 5 mm square photoelectric conversion element was produced by sequentially forming a film. The photoelectric conversion element 1A-1 thus manufactured was evaluated by measuring the current-voltage characteristics as described above, and the photoelectric conversion efficiency (PCE) was obtained.

In addition, after taking out the substrate on which the active layer has been formed from the glove box, instead of leaving it in the atmosphere (25 ° C., humidity 1% or less) for 3 hours under light shielding, in the atmosphere (25 A photoelectric conversion element 1A-2 was produced in the same manner as the photoelectric conversion element 1A-1, except that the film was allowed to stand at 3 ° C. and a humidity of 1% or less for 3 hours. The 1A-2 conversion efficiency of the photoelectric conversion element thus obtained is obtained, and the maintenance ratio with respect to the conversion efficiency of the photoelectric conversion element 1A-1 in which the active layer is not exposed (light-shielded) (the conversion efficiency of the photoelectric conversion element 1A-2) / Conversion efficiency of photoelectric conversion element 1A-1) was calculated as light resistance. The obtained results are shown in Table 1.

<Reference Example 1A: Production and Evaluation of Photoelectric Conversion Element 2A>
A photoelectric conversion element 2A was prepared and evaluated in the same manner as in Example 1A, except that the copolymer 2A obtained in Synthesis Example 2A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Reference Example 2A: Production and Evaluation of Photoelectric Conversion Element 3A>
A photoelectric conversion element 3A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 3A obtained in Synthesis Example 3A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 2A: Production and Evaluation of Photoelectric Conversion Element 4A>
A photoelectric conversion element 4A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 4A obtained in Synthesis Example 4A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 3A: Production and evaluation of photoelectric conversion element 5A>
A photoelectric conversion element 5 was produced and evaluated in the same manner as in Example 1A, except that the copolymer 5A obtained in Synthesis Example 5A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 4A: Production and evaluation of photoelectric conversion element 6A>
A photoelectric conversion element 6A was produced and evaluated in the same manner as in Example 1A except that the copolymer 6A obtained in Synthesis Example 6A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 5A: Production and evaluation of photoelectric conversion element 7A>
A photoelectric conversion element 7A was produced and evaluated in the same manner as in Example 1A except that the copolymer 6A obtained in Synthesis Example 7A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 6A: Production and evaluation of photoelectric conversion element 8A>
A photoelectric conversion element 8A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 8A obtained in Synthesis Example 8A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 7A: Production and evaluation of photoelectric conversion element 9A>
A photoelectric conversion element 9A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 9A obtained in Synthesis Example 9A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 8A: Production and evaluation of photoelectric conversion element 10A>
10 A of photoelectric conversion elements were produced and evaluated by the same method as Example 1A except having used the copolymer 10A obtained by the synthesis example 10A instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 9A: Production and evaluation of photoelectric conversion element 11A>
11 A of photoelectric conversion elements were produced and evaluated by the same method as Example 1A except having used the copolymer 11A obtained by the synthesis example 11A instead of the copolymer 1A. The obtained results are shown in Table 1.

<Reference Example 3A: Production and Evaluation of Photoelectric Conversion Element 12A>
A photoelectric conversion element 12A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 12A obtained in Synthesis Example 12A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 10A: Production and evaluation of photoelectric conversion element 13A>
A photoelectric conversion element 13A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 13A obtained in Synthesis Example 13A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Reference Example 4A: Production and Evaluation of Photoelectric Conversion Element 14A>
An attempt was made to produce a photoelectric conversion element 14A in the same manner as in Example 1A, except that the copolymer 14A obtained in Synthesis Example 14A was used instead of the copolymer 1A. However, the copolymer 14A was not dissolved in a solvent such as chloroform, toluene, or orthodichlorobenzene, and a photoelectric conversion element could not be produced. Therefore, evaluation of photoelectric conversion efficiency and light resistance could not be performed.

<Example 11A: Production and evaluation of photoelectric conversion element 15A>
A photoelectric conversion element 15A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 15A obtained in Synthesis Example 15A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 12A: Production and evaluation of photoelectric conversion element 16A>
A photoelectric conversion element 16A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 16A obtained in Synthesis Example 16A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 13A: Production and evaluation of photoelectric conversion element 17A>
A photoelectric conversion element 17A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 17A obtained in Synthesis Example 17A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 14A: Production and evaluation of photoelectric conversion element 18A>
A photoelectric conversion element 18A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 18A obtained in Synthesis Example 18A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 15A: Production and evaluation of photoelectric conversion element 19A>
A photoelectric conversion element 19A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 19A obtained in Synthesis Example 19A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 16A: Production and evaluation of photoelectric conversion element 20A>
A photoelectric conversion element 20A was produced and evaluated in the same manner as in Example 1A except that the copolymer 20A obtained in Synthesis Example 20A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 17A: Production and evaluation of photoelectric conversion element 21A>
A photoelectric conversion element 21A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 21A obtained in Synthesis Example 21A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

<Example 18A: Production and evaluation of photoelectric conversion element 22A>
A photoelectric conversion element 22A was produced and evaluated in the same manner as in Example 1A, except that the copolymer 22A obtained in Synthesis Example 22A was used instead of the copolymer 1A. The obtained results are shown in Table 1.

From the results in Table 1, the conversion efficiencies of the photoelectric conversion elements obtained in Reference Example 1A and Reference Example 2A were 5.75% and 0.76%, respectively, whereas that of copolymer 2 of Reference Example 1A was The conversion efficiency of the photoelectric conversion element according to Example 1A using the copolymer 1 having both the structural unit and the structural unit of the copolymer 3 of Reference Example 2A is 8.76%, which is two repetitions. It can be confirmed that the conversion efficiency is greatly improved by using the unit. Furthermore, while the maintenance rates of the photoelectric conversion elements obtained in Reference Example 1A and Reference Example 2A were 79% and 54%, respectively, the maintenance rates of the photoelectric conversion elements obtained in Example 1A were It can be confirmed that not only the conversion efficiency but also the light resistance is improved.

Moreover, since the copolymer 14A in which R ¹ to R ⁴ represented by the formula (I) are all hydrogen atoms was not dissolved in a solvent such as chloroform, toluene, or orthodichlorobenzene, a photoelectric conversion element could not be produced. Furthermore, the conversion efficiency of the photoelectric conversion device according to Reference Example 3A using the copolymer 12A in which R ¹ to R ⁴ are all monovalent organic groups is 5.39%, and the exposure resistance is 57%. In contrast, the conversion efficiencies of the photoelectric conversion elements according to Example 1A and Example 10A using the copolymer 1A and the copolymer 13A in which the groups R ¹ to R ⁴ are selected according to the present invention are both high. It was. From this result, as in the copolymer according to the first embodiment, it has structural units represented by the formula (I) and the formula (II), and further includes substituents on the 5-membered ring in the formula (I). By adjusting the position, it can be confirmed that high conversion efficiency and high light resistance can be obtained. It can also be seen that the photoelectric conversion elements according to Examples 2A to 18A have high conversion efficiency and high light resistance as in Example 1A.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-) obtained in a 50 mL two-necked eggplant flask as a monomer with reference to the method described in US Patent Application Publication No. 2012/0227812 5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound A1) (60.0 mg, 0.066 mmol), known literature (J. Am. Chem) Soc., 2011, 133, 9638-9641) 4,8-bis-[(4,5-dihexyl) -thiophen-2-yl] -2,6-bis obtained by referring to the method described in Soc. (Trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound B1) (69.0 mg, 0.068 mmol) was added, and tetrakis (triphenylphosphine) was added. N) palladium (0) (2.8 mg, 3.00 mol%), triphenylphosphine-containing heterogeneous palladium complex catalyst Pd-EnCatTPP30 (manufactured by Aldrich, 3.6 mg, 1.53 mol%), toluene (4.8 mL) ) And N, N-dimethylformamide (1.2 mL), and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 2 hours. The reaction solution was diluted twice with toluene and heated and stirred at 110 ° C. for another 0.5 hours, and then trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment and stirred at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 1B was obtained in a yield of 61%. The weight average molecular weight Mw of the obtained copolymer 1B was 34,000, and PDI was 1.7.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-) obtained in a 50 mL two-necked eggplant flask as a monomer with reference to the method described in US Patent Application Publication No. 2012/0227812 5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (compound A1) (60.0 mg, 0.066 mmol), known literature (ACS Macro Lett., 2013, 2, 605-608) 4,8-bis- [5- (2-butyloctyl) -thiophen-2-yl] -2,6-bis (trimethyl ester) obtained by referring to the method described in Nyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound D2) (68.0 mg, 0.067 mmol) was added, and tetrakis (triphenylphosphite) was added. ) Palladium (0) (2.3 mg, 3.00 mol%), triphenylphosphine-containing heterogeneous palladium complex catalyst Pd-EnCatTPP30 (Aldrich, 3.0 mg, 1.53 mol%), toluene (4.0 mL) And N, N-dimethylformamide (1.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 2 hours. The reaction solution was diluted twice with toluene and heated and stirred at 110 ° C. for another 0.5 hours, and then trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment and stirred at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 2 was obtained in a yield of 76%. The weight average molecular weight Mw of the obtained copolymer 2 was 42,000, and PDI was 2.4.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-) obtained in a 50 mL two-necked eggplant flask as a monomer with reference to the method described in US Patent Application Publication No. 2012/0227812 5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A1) (60.0 mg, 0.066 mmol), see the method described in Patent 5698371 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,5 -B ′] dithiophene (compound D1) (74.7 mg, 0.067 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.00 mo) was added. %), Tris (2-methylphenyl) phosphine (6.4 mg, 32.00 mol%), and chlorobenzene (5.0 mL), the temperature was raised from 45 ° C. to 105 ° C. every 5 minutes, and 115 ° C. after 1 hour. The temperature was raised to. After further 3 hours, the temperature was raised to 130 ° C. and stirred for 2.5 hours. The reaction solution was diluted twice with chlorobenzene, and as a terminal treatment, trimethyl (phenyl) tin (0.03 mL) was added, and the mixture was heated and stirred at 130 ° C. for 1.5 hours, and further bromobenzene (1.00 mL) was added. The mixture was heated and stirred at 130 ° C. for 2.0 hours. The reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred at room temperature for 30 minutes and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 3B was obtained in a yield of 72%. The resulting copolymer 3B had a weight average molecular weight Mw of 150,000 and a PDI of 4.5.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-) obtained in a 50 mL two-necked eggplant flask as a monomer with reference to the method described in US Patent Application Publication No. 2012/0227812 5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A1) (59.6 mg, 0.066 mmol), see the method described in Japanese Patent No. 5698371 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,5 -B ′] dithiophene (compound D1) (37.3 mg, 0.033 mmol) was added, and referring to the method described in (Macromolecules, 2011, 44, 7207-7219) 4,8-bis-[(2-hexyldecyl) oxy] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound B4) ) (32.9 mg, 0.033 mmol), tris (dibenzylideneacetone) dipalladium chloroform complex (2.73 mg, 4.00 mol%), tris (2-methylphenyl) phosphine (3.21 mg, 16.3 mmol). 00 mol%) and chlorobenzene (5.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 2 hours. The reaction solution was diluted twice with toluene and heated and stirred at 110 ° C. for another 0.5 hours, and then trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment and stirred at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 4B was obtained in a yield of 82%. The resulting copolymer 4B had a weight average molecular weight Mw of 116,000 and a PDI of 4.5.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-) obtained in a 50 mL two-necked eggplant flask as a monomer with reference to the method described in US Patent Application Publication No. 2012/0227812 5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A1) (58.6 mg, 0.065 mmol), known literature (ACS Macro Lett., 2013, 2, 605-608) 4,8-bis- [5- (2-octyldodecyl) -thiophen-2-yl] -2,6-bis (trimethyl ester) obtained by referring to the method described in Nyl) -benzo [1,2-b: 4,5-b ′] dithiophene (compound B5) (80.5 mg, 0.065 mmol) is added, and tris (dibenzylideneacetone is added. Add dipalladium chloroform complex (2.7 mg, 4.00 mol%), tris (2-methylphenyl) phosphine (6.3 mg, 32.00 mol%), chlorobenzene (5.0 mL), and continue at 100 ° C. for 1 hour. And stirred at 110 ° C. for 2 hours. The reaction solution was diluted 2-fold with chlorobenzene and further heated and stirred at 110 ° C. for 1 hour. Then, trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour. Bromobenzene (1.0 mL) was further added, and the mixture was stirred with heating at 110 ° C. for 1.0 hour. The reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 5 was obtained in a yield of 83%. The weight average molecular weight Mw of the obtained copolymer 5 was 119,000, and PDI was 4.2.

<Synthesis Example 6B: Synthesis of Copolymer 6B>
[Synthesis Example: Synthesis of 4-tetradecyl-2-trimethylstannylthiophene (Compound T2)]

2,2,6,6-tetramethylpiperidine (2.18 g, 15 mmol) was added to a 50 mL two-necked flask, and nitrogen substitution was performed three times. 10 mL of dry THF was added, and the mixture was cooled to −78 ° C. with a dry ice acetone bath. n-Butyllithium (1.6M, 8.9 mL, 14.3 mmol) was added dropwise at −78 ° C., stirred for 30 minutes, and then heated to 0 ° C. in an ice bath. Meanwhile, 3-tetradecylthiophene (compound T1) (4.3 g, 15 mmol) was added to a 500 mL four-necked flask, and nitrogen substitution was performed three times. 190 mL of dry THF was added, and the mixture was cooled to −40 ° C. with a dry ice acetone bath. The previously prepared LiTMP was slowly added dropwise at −40 ° C., and after the addition was further stirred for 1 hour, trimethyltin chloride (1M in THF, 15 mL, 15 mmol) was added dropwise and stirred for 30 minutes. 100 mL of distilled water was added to quench the reaction, and the aqueous layer was extracted once with hexane. The organic layer was washed 3 times with water and dried over anhydrous sodium sulfate. The solvent was distilled off with an evaporator and dried under reduced pressure (oil pump) at 40 ° C. to obtain 4-tetradecyl-2-trimethylstannylthiophene (Compound T2). As a result of proton NMR, the purity of the tin body was 70%.

[Synthesis Example 6B: Synthesis of Copolymer 6B]

In a 50 mL two-necked eggplant flask under a nitrogen atmosphere, 3,7-di (2-bromo-3-tetradecylthiophen-5-yl) -naphtho [1,2-c: obtained by the above method as a monomer was used. 5,6-c] bis [1,2,5] thiadiazole (compound A4) (38.4 mg, 0.040 mmol), a method described in known literature (ACS Macro Lett., 2013, 2, 605-608). 4,8-bis- [5- (2-butyloctyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,4 obtained by reference 5-b ′] dithiophene (compound D2) (40.7 mg, 0.040 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (1.65 mg, 4.00 mo) was added. %), Tris (2-methylphenyl) phosphine (1.95 mg, 16.00Mol%), was placed chlorobenzene (3.0 mL), 1 hour at 100 ° C., followed by stirring for 2 hours at 110 ° C.. After diluting the reaction solution with chlorobenzene twice and heating and stirring at 110 ° C. for another 0.5 hours, as a terminal treatment, trimethyl (phenyl) tin (0.03 mL) was added and heating and stirring at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 6B was obtained in a yield of 76%. The obtained copolymer 6B had a weight average molecular weight Mw of 270,000 and a PDI of 8.7.

In a 50 mL two-necked eggplant flask under a nitrogen atmosphere, 3,7-di (2-bromo-3-tetradecylthiophen-5-yl) -naphtho [1,2-c: obtained by the above method as a monomer was used. 5,6-c] bis [1,2,5] thiadiazole (Compound A4) (62.0 mg, 0.065 mmol), a method described in known literature (ACS Macro Lett., 2013, 2, 605-608). 4,8-bis- [5- (2-butyloctyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,4 obtained by reference 5-b ′] dithiophene (compound D2) (32.9 mg, 0.032 mmol), 4,8-bis- [5- (5- (2)) obtained by referring to the method described in Japanese Patent Publication No. 2014-501032. 2-heki Rudecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (compound D1) (36.5 mg, 0.032 mmol) And tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.00 mol%), tris (2-methylphenyl) phosphine (6.3 mg, 32.00 mol%), chlorobenzene (5.0 mL) And stirred at 100 ° C. for 1 hour and then at 110 ° C. for 2 hours. The reaction solution was diluted 2-fold with chlorobenzene and further heated and stirred at 110 ° C. for 1 hour. Then, as a terminal treatment, trimethyl (phenyl) tin (0.03 mL) was added and heated and stirred at 110 ° C. for 1.0 hour. Bromobenzene (1.0 mL) was further added, and the mixture was stirred with heating at 110 ° C. for 1.0 hour. The reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 7B was obtained in a yield of 86%. The resulting copolymer 7B had a weight average molecular weight Mw of 367,000 K and a PDI of 8.2.

In a 50 mL two-necked eggplant flask under a nitrogen atmosphere, 3,7-di (2-bromo-3-tetradecylthiophen-5-yl) -naphtho [1,2-c: obtained by the above method as a monomer was used. 5,6-c] bis [1,2,5] thiadiazole (Compound A4) (62.0 mg, 0.065 mmol), 4 obtained by referring to the method described in Japanese Patent Special Publication No. 2014-501032 , 8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene ( Compound D1) (73.0 mg, 0.065 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (2.7 mg, 4.00 mol%), tris (2-methylphenyl) Sufin (6.3mg, 32.00mol%), was placed chlorobenzene (5.0 mL), 1 hour at 100 ° C., followed by stirring for 2 hours at 110 ° C.. The reaction solution was diluted 2-fold with chlorobenzene and further heated and stirred at 110 ° C. for 1 hour. Then, trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour. Bromobenzene (1.0 mL) was further added, and the mixture was stirred with heating at 110 ° C. for 1.0 hour. The reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 8B was obtained in a yield of 90%. The resulting copolymer 8B had a weight average molecular weight Mw of 291,000 and a PDI of 6.4.

In a 50 mL two-necked eggplant flask under a nitrogen atmosphere, 3,7-di (2-bromo-3-tetradecylthiophen-5-yl) -naphtho [1,2-c: obtained by the above method as a monomer was used. 5,6-c] bis [1,2,5] thiadiazole (Compound A4) (60.7 mg, 0.063 mmol), a method described in known literature (ACS Macro Lett., 2013, 2, 605-608). 4,8-bis- [5- (2-octyldodecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b: 4,4 obtained by reference 5-b ′] dithiophene (compound B5) (78.5 mg, 0.063 mmol) was added, and tris (dibenzylideneacetone) dipalladium chloroform complex (2.6 mg, 4.00 mo) was added. %), Tri-1-naphthyl phosphine (8.3mg, 32.00mol%), was placed chlorobenzene (5.0 mL), 1 hour at 100 ° C., followed by stirring for 2 hours at 110 ° C.. The reaction solution was diluted 2-fold with chlorobenzene and further heated and stirred at 110 ° C. for 1 hour. Then, trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment, and the mixture was heated and stirred at 110 ° C. for 1.0 hour. Bromobenzene (1.0 mL) was further added, and the mixture was stirred with heating at 110 ° C. for 1.0 hour. The reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 9B was obtained in a yield of 85%. The resulting copolymer 9B had a weight average molecular weight Mw of 261,000 and a PDI of 5.6.

3,7-di (2-bromo-3-hexylthiophene-) obtained as a monomer in a 50 mL two-necked eggplant flask under a nitrogen atmosphere with reference to the method described in US Patent Application Publication No. 2012/0227812 5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A17) (40.0 mg, 0.054 mmol), known literature (J. Am. Chem) Soc., 2011, 133, 9638-9641) 4,8-bis-[(4,5-dihexyl) -thiophen-2-yl] -2,6-bis obtained by referring to the method described in Soc. (Trimethylstannyl) -benzo [1,2-b: 4,5-b ′] dithiophene (Compound B1) (57.0 mg, 0.056 mmol) was added, and tetrakis (triphenylphosphine) was added. ) Palladium (0) (2.3 mg, 3.00 mol%), triphenylphosphine-containing heterogeneous palladium complex catalyst Pd-EnCatTPP30 (manufactured by Aldrich, 3.0 mg, 1.53 mol%), toluene (4. 0 mL) and N, N-dimethylformamide (1.0 mL) were added, and the mixture was stirred at 100 ° C. for 1 hour and then at 110 ° C. for 2 hours. The reaction solution was diluted twice with toluene and heated and stirred at 110 ° C. for another 0.5 hours, and then trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment and stirred at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. By concentrating the solution, the target copolymer 10B was obtained in a yield of 51%. The resulting copolymer 10B had a weight average molecular weight Mw of 24,000 and a PDI of 1.9.

3,7-di (2-bromo-3-hexylthiophene-) obtained as a monomer in a 50 mL two-necked eggplant flask under a nitrogen atmosphere with reference to the method described in US Patent Application Publication No. 2012/0227812 5-yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A17) (40.0 mg, 0.054 mmol), Japanese National Table 2014-1401032 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1, obtained by referring to the method described in the publication 2-b: 4,5-b ′] dithiophene (compound D1) (63.0 mg, 0.056 mmol) was added, and tetrakis (triphenylphosphine) palladium (0) (2.3 mg 3.00 mol%), a triphenylphosphine-containing heterogeneous palladium complex catalyst Pd-EnCatTPP30 (Aldrich, 3.0 mg, 1.53 mol%), toluene (4.0 mL), and N, N-dimethylformamide (1 0.0 mL) and stirred at 100 ° C. for 1 hour and then at 110 ° C. for 2 hours. The reaction solution was diluted twice with toluene and heated and stirred at 110 ° C. for another 0.5 hours, and then trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment and stirred at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. The target copolymer 11B was obtained with a yield of 51% by concentrating the solution. The obtained copolymer 11B had a weight average molecular weight Mw of 38,000 and a PDI of 2.3.

Under a nitrogen atmosphere, 3,7-di (2-bromo-3-dodecylthiophene-5-5) obtained by referring to a method described in US Patent Application Publication No. 2012/0227812 as a monomer in a 50 mL two-necked eggplant flask. Yl) -naphtho [1,2-c: 5,6-c] bis [1,2,5] thiadiazole (Compound A1) (59.6 mg, 0.066 mmol) and described in JP-T-2014-501032 4,8-bis- [5- (2-hexyldecyl) -thiophen-2-yl] -2,6-bis (trimethylstannyl) -benzo [1,2-b] obtained by referring to the method of : 4,5-b ′] dithiophene (Compound D1) (74.5 mg, 0.066 mmol) was added, and tetrakis (triphenylphosphine) palladium (0) (2.3 mg, 3.00). ol%), triphenylphosphine-containing heterogeneous palladium complex catalyst Pd-EnCatTPP30 (Aldrich, 3.0 mg, 1.53 mol%), toluene (4.0 mL), and N, N-dimethylformamide (1.0 mL) ) And stirred at 100 ° C. for 1 hour and then at 110 ° C. for 2 hours. The reaction solution was diluted twice with toluene and heated and stirred at 110 ° C. for another 0.5 hours, and then trimethyl (phenyl) tin (0.03 mL) was added as a terminal treatment and stirred at 110 ° C. for 1.0 hour. Further, bromobenzene (1.00 mL) was added and stirred with heating at 110 ° C. for 1.0 hour, and the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 1 hour at room temperature and passed through a short column of acidic silica gel. The target copolymer 12B was obtained with a yield of 87% by concentrating the solution. The resulting copolymer 12B had a weight average molecular weight Mw of 52,000 and a PDI of 2.2.

<Example 1B: Production and evaluation of photoelectric conversion element>
[Preparation of composition for forming active layer]
Copolymer 1B obtained in Synthesis Example 1B as a p-type semiconductor compound, and a mixture of PC61BM (phenyl C61 butyric acid methyl ester) and PC71BM (phenyl C71 butyric acid methyl ester) which are fullerene compounds as an n-type semiconductor compound (Frontier Carbon Corporation, nanom spectra E123) was dissolved in a mixed solvent of o-xylene and tetralin (volume ratio 9: 1) in a nitrogen atmosphere to a concentration of 3.6% by mass. Note that the mass ratio of the p-type semiconductor compound to the n-type semiconductor compound was p-type semiconductor compound: n-type semiconductor compound = 1: 2. This solution was stirred and mixed on a hot stirrer at a temperature of 80 ° C. for 1 hour. The solution after stirring and mixing was filtered through a 1 μm polytetrafluoroethylene (PTFE) filter to prepare an active layer forming composition.

Next, a mixed solvent of 2-methoxyethanol (Aldrich) and ethanolamine (Aldrich) at a concentration of 105 mg / mL of zinc (II) acetate dihydrate (Wako Pure Chemical Industries) (volume ratio 100: The solution (about 0.1 mL) dissolved in 3) was spin-coated at a speed of 3000 rpm, subjected to UV-ozone treatment, and then heated in an oven at 200 ° C. for 15 minutes to form an electron extraction layer.
By bringing the substrate on which the electron extraction layer is formed into a glove box, heat-treating at 150 ° C. for 3 minutes in a nitrogen atmosphere, and spin-coating the active layer coating composition (0.12 mL) prepared as described above after cooling. An active layer having a thickness of about 300 nm was formed. Then, it heated at 140 degreeC for 10 minute (s) on the hotplate.

Next, a molybdenum trioxide (MoO ₃ ) film having a thickness of 1.5 nm is formed as a hole extraction layer on the active layer, and then a silver film having a thickness of 100 nm is formed as an upper electrode by resistance heating vacuum deposition. Then, a 5 mm square photoelectric conversion element was produced. The photoelectric conversion element thus prepared was evaluated by measuring the current-voltage characteristics as described above, and the photoelectric conversion efficiency (PCE) when the active layer was not exposed was obtained. The obtained results are shown in Table 2.

<Example 2B: Production and Evaluation of Photoelectric Conversion Element>
A photoelectric conversion element was prepared and evaluated in the same manner as in Example 1B, except that the copolymer 2 obtained in Synthesis Example 2B was used instead of the copolymer 1B. The obtained results are shown in Table 2.

<Example 3B: Production and evaluation of photoelectric conversion element>
A photoelectric conversion element was produced and evaluated in the same manner as in Example 1B except that the copolymer 3B obtained in Synthesis Example 3B was used instead of the copolymer 1B. The obtained results are shown in Table 2.

<Example 4B: Production and Evaluation of Photoelectric Conversion Element>
A photoelectric conversion device was prepared and evaluated in the same manner as in Example 1B, except that the copolymer 4B obtained in Synthesis Example 4B was used instead of the copolymer 1B. The obtained results are shown in Table 2.

<Example 5B: Production and evaluation of photoelectric conversion element>
A photoelectric conversion element was produced and evaluated in the same manner as in Example 1B except that the copolymer 5B obtained in Synthesis Example 5B was used instead of the copolymer 1B. The obtained results are shown in Table 2.

<Example 6B: Production and evaluation of photoelectric conversion element>
A photoelectric conversion element was produced and evaluated in the same manner as in Example 1B except that the copolymer 6B obtained in Synthesis Example 6B was used instead of the copolymer 1. The obtained results are shown in Table 2.

<Example 7: Production and evaluation of photoelectric conversion element>
A photoelectric conversion element was produced and evaluated in the same manner as in Example 1B except that the copolymer 7B obtained in Synthesis Example 7B was used instead of the copolymer 1B. The obtained results are shown in Table 2.

<Example 8B: Production and evaluation of photoelectric conversion element>
A photoelectric conversion element was produced and evaluated in the same manner as in Example 1B except that the copolymer 8B obtained in Synthesis Example 8B was used instead of the copolymer 1B. The obtained results are shown in Table 2.

<Example 9B: Production and evaluation of photoelectric conversion element>
A photoelectric conversion element was produced and evaluated in the same manner as in Example 1B except that the copolymer 9B obtained in Synthesis Example 9B was used instead of the copolymer 1B. The obtained results are shown in Table 2.

<Example 10B: Production and evaluation of photoelectric conversion element>
A photoelectric conversion element was produced and evaluated in the same manner as in Example 1B, except that the copolymer 12B obtained in Synthesis Example 9B was used instead of the copolymer 1B. The obtained results are shown in Table 2.

<Reference Example 1B: Production and Evaluation of Photoelectric Conversion Element>
A photoelectric conversion element was produced and evaluated in the same manner as in Example 1B except that the copolymer 10B obtained in Synthesis Example 10B was used instead of the copolymer 1B. The obtained results are shown in Table 2.

<Reference Example 2B: Production and Evaluation of Photoelectric Conversion Element>
A photoelectric conversion element was produced and evaluated in the same manner as in Example 1B, except that the copolymer 11B obtained in Synthesis Example 11B was used instead of the copolymer 1B. The obtained results are shown in Table 2.

In Table 2, C6 represents an n-hexyl group, C12 represents an n-dodecyl group, C14 represents an n-tetradecyl group, and H represents a hydrogen atom.

From the results in Table 2, the photoelectric conversion element according to Example 1B has higher conversion efficiency than the photoelectric conversion elements according to Reference Example 1B and Reference Example 2B. From the results, the R ¹ and R ⁴ in formula (I), it can be seen that the improved conversion efficiency of the photoelectric conversion element by a specific aliphatic hydrocarbon group. Further, it can be seen that the conversion efficiency of the photoelectric conversion elements according to Examples 2B to 9B is greatly improved compared to the photoelectric conversion element according to Example 1B. From this result, R ¹ and R ⁴ in formula (I) are specific aliphatic hydrocarbon groups, R ²¹ , R ²² , R ²⁴ and R ²⁵ are hydrogen atoms in formula (XV), and R ²⁰ And R ²³ is a branched aliphatic hydrocarbon group having a specific number of carbon atoms, steric hindrance in the copolymer can be suppressed, and the conversion efficiency is greatly improved. Moreover, when Example 3B and Example 10B which have the same repeating unit are compared, it turns out that conversion efficiency is improved more in Example 3B with a large molecular weight.

DESCRIPTION OF SYMBOLS 101 Lower electrode 102 Lower buffer layer 103 Active layer 104 Upper buffer layer 105 Upper electrode 106 Base material 107 Photoelectric conversion element 1 Weatherproofing protective film 2 UV cut film 3,9 Gas barrier film 4,8 Getter material film 5,7 Sealing material 6 Solar cell element 10 Back sheet 12 Base material 13 Solar cell unit 14 Thin film solar cell

Claims

A copolymer having a repeating unit represented by the following formula (I) and a repeating unit represented by the following formula (II) different from the formula (I).

(In the formula (I), X 1 and X 2 each independently represent an atom selected from Group 16 elements of the periodic table, one of R 1 and R 2 is a monovalent organic group and the other is a hydrogen atom or halogen. An atom, one of R 3 and R 4 is a monovalent organic group and the other represents a hydrogen atom or a halogen atom, and D 1 represents a donor-like structural unit, wherein Ar 3 and Ar 4 are each Independently represents an optionally substituted aromatic group, c and d each independently represent an integer of 0 or more and 2 or less, A represents an acceptor constituent unit or a direct bond, and D2 represents (It represents a donor structural unit. In the formula (II), when A is a direct bond, c and d in the formula (II) are each independently 1 or 2.)
The copolymer according to claim 1, wherein, in the formula (I), R 1 and R 4 are each independently a monovalent organic group, and R 2 and R 3 are each independently a hydrogen atom or a halogen atom.
The copolymer according to claim 1 or 2, wherein D1 in the formula (I) is a structural unit represented by the following formula (IV) or the following formula (V).

(In formula (IV), Ar 5 and Ar 6 each independently represent an aromatic ring optionally having a substituent, and X 3 and X 4 each independently represent Q 1 (R 5 ) (R 6 ), Q 2 (R 7 ), a sulfur atom (S), an oxygen atom (O) or a direct bond, provided that when one of X 3 and X 4 is a direct bond, X 3 and X The other group of 4 is Q 1 (R 5 ) (R 6 ), Q 2 (R 7 ), a sulfur atom (S) or an oxygen atom (O), where Q 1 is a periodic table Represents an atom selected from group 14 elements, Q 2 represents an atom selected from group 15 elements of the periodic table, and R 5 and R 6 each independently represents a hydrogen atom, a halogen atom or a monovalent organic group. represents, R 7 is a hydrogen atom,. formula represents a halogen atom or a monovalent organic group in (V), Ar 7 and Ar 8 are each independently have a substituent An aromatic ring, X 5 and X 6 each independently represent a group represented by Q 3 (R 8). Incidentally, Q 3 represents an atom selected from the periodic table group 14 element, R 8 Represents a hydrogen atom, a halogen atom or a monovalent organic group.
The copolymer according to any one of claims 1 to 3, wherein the repeating unit represented by the formula (II) is a repeating unit represented by the following formula (VII).

(In the formula (VII), X 7 and X 8 each independently represents an atom selected from Group 16 elements of the periodic table, and R 11 to R 14 each independently represents a hydrogen atom, a halogen atom or a monovalent atom. Represents an organic group, A represents an acceptor structural unit or a direct bond, and D2 represents a donor structural unit.)
The copolymer according to any one of claims 1 to 4, wherein A in the formula (II) is a structural unit represented by the following formula (VIII) or the following formula (IX).

(In Formula (VIII), Ar 9 may have an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocyclic ring which may have a substituent, or a substituent. X 9 and X 10 each independently represents a nitrogen atom (N) or Q 4 (R 15 ), wherein Q 4 represents an atom selected from Group 14 elements of the periodic table. , R 15 represents a hydrogen atom, a halogen atom or a monovalent organic group, and in formula (IX), Ar 10 has an aromatic hydrocarbon ring which may have a substituent and a substituent. An aromatic heterocyclic ring which may be substituted, or an aliphatic heterocyclic ring which may have a substituent, and X 11 represents an atom selected from Group 16 elements of the periodic table.
The copolymer according to any one of claims 1 to 5, wherein in the formula (II), D2 is a repeating unit represented by the following formula (IV) or the following formula (V).

(In formula (IV), Ar 5 and Ar 6 each independently represent an aromatic ring optionally having a substituent, and X 3 and X 4 each independently represent Q 1 (R 5 ) (R 6 ), Q 2 (R 7 ), a sulfur atom (S), an oxygen atom (O) or a direct bond, provided that when one of X 3 and X 4 is a direct bond, X 3 and X The other group of 4 is Q 1 (R 5 ) (R 6 ), Q 2 (R 7 ), a sulfur atom (S) or an oxygen atom (O), where Q 1 is a periodic table Represents an atom selected from group 14 elements, Q 2 represents an atom selected from group 15 elements of the periodic table, and R 5 and R 6 each independently represents a hydrogen atom, a halogen atom or a monovalent organic group. represents, R 7 is a hydrogen atom,. formula represents a halogen atom or a monovalent organic group in (V), Ar 7 and Ar 8 are each independently have a substituent An aromatic ring, X 5 and X 6 each independently represent a group represented by Q 3 (R 8). Incidentally, Q 3 represents an atom selected from the periodic table group 14 element, R 8 Represents a hydrogen atom, a halogen atom or a monovalent organic group.)
In the formula (I), D1 is a repeating unit represented by the following formula (VI), in the formula (II), A is a repeating unit represented by the formula (X), and D2 is represented by the formula (VI). The copolymer according to any one of claims 1 to 6, which is a repeating unit represented.

(In Formula (X), R 16 and R 17 represent a hydrogen atom, a halogen atom or a monovalent organic group. In Formula (VI), R 9 and R 10 are each independently a hydrogen atom or a halogen atom. Or represents a monovalent organic group.)
The copolymer according to any one of claims 1 to 7, wherein in the formula (I), R 1 and R 4 are each independently an aliphatic hydrocarbon group having 1 to 20 carbon atoms.
The ratio of the number of repeating units represented by the formula (I) to the number of repeating units represented by the formula (II) in the copolymer is 0.1 or more and 9 or less, according to any one of claims 1 to 8. Copolymer.
The copolymer according to any one of claims 1 to 9, having a weight average molecular weight of 10,000 or more and 300,000 or less.
A photoelectric conversion element having a pair of electrodes and an active layer between the pair of electrodes on a substrate,
A photoelectric conversion element, wherein the active layer contains the copolymer according to any one of claims 1 to 10.
A solar cell module having the photoelectric conversion element according to claim 11.
A copolymer having a repeating unit represented by the following formula (I).

(In Formula (I), X 1 and X 2 each independently represent an atom selected from Group 16 elements of the Periodic Table, and R 1 and R 4 each independently represent a straight chain having 9 or more carbon atoms. An aliphatic hydrocarbon group, or a branched aliphatic hydrocarbon group having 9 or more carbon atoms in the main chain and 5 or less carbon atoms in the side chain; R 2 and R 3 are each independently D1 represents a structural unit represented by formula (IV) or formula (V).

(In formula (IV), Ar 5 and Ar 6 each independently represent an aromatic ring optionally having a substituent. X 3 and X 4 each independently represent Q 1 (R 5 ) (R 6 ), Q 2 (R 7 ), a sulfur atom (S), an oxygen atom (O) or a direct bond, provided that when one of X 3 and X 4 is a direct bond, X 3 and X The other group of 4 is Q 1 (R 5 ) (R 6 ), Q 2 (R 7 ), a sulfur atom (S) or an oxygen atom (O) Q 1 is group 14 of the periodic table R 5 and R 6 each independently represents a hydrogen atom, a halogen atom or a monovalent organic group, Q 2 represents an atom selected from Group 15 elements of the periodic table, 7 represents a hydrogen atom, a halogen atom or a monovalent organic group.)

(In the formula (V), Ar 7 and Ar 8 each independently represents an aromatic ring optionally having a substituent. X 5 and X 6 are each represented by Q 3 (R 8 ). Q 3 represents an atom selected from Group 14 elements of the periodic table, and R 8 represents a hydrogen atom, a halogen atom, or a monovalent organic group.)
The copolymer according to claim 13, wherein D1 in the formula (I) is a structural unit represented by the following formula (III).

(In formula (III), X 12 and X 13 each independently represent an atom selected from Group 16 elements of the periodic table. R 9 and R 10 each independently represent a hydrogen atom, a halogen atom or a monovalent atom. Represents an organic group of
The copolymer according to claim 14, wherein the structural unit represented by the formula (III) is a structural unit represented by the formula (XV).

(In the formula (XV), X 12 to X 15 each independently represents an atom selected from Group 16 elements of the periodic table. R 20 to R 25 each independently represents a hydrogen atom or a halogen atom. Or a monovalent organic group, one of R 20 to R 22 is a monovalent organic group, and the remaining two groups are each independently a hydrogen atom or a halogen atom, and R 23 to R 25 One of the groups is a monovalent organic group, and the remaining two groups are each independently a hydrogen atom or a halogen atom.)
A photoelectric conversion element having a pair of electrodes and an active layer between the pair of electrodes on a base material, wherein the active layer contains the copolymer according to any one of claims 13 to 15. , Photoelectric conversion element.
A solar cell module having the photoelectric conversion element according to claim 16.