Compound, composition, film, photoelectric conversion element, and CMOS image sensor

Abstract

To provide a compound that enables shifting of the absorption wavelength to a longer wavelength while maintaining light absorption properties in A-D-A type non-fullerene acceptor materials, and to provide a composition, a film, a photoelectric conversion element, and a CMOS image sensor, each made using the compound.SOLUTION: The present invention provides a compound represented by the following general formula (1): A-D-A. In general formula (1), each A independently represents a group represented by any one of the following general formulae (2a) to (2c), and D is an electron-donating group composed of 2 to 20 rings. In general formulae (2a) to (2c), Z is an oxygen atom or a dicyanomethylene group, Q is each independently an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom, and X is a sulfur atom, a carbon atom substituted with an alkyl group or an aryl group, a silicon atom substituted with an alkyl group or an aryl group, or a germanium atom substituted with an alkyl group or an aryl group.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a compound, a composition, a film, a photoelectric conversion element, and a CMOS image sensor that are suitable as a semiconductor material used in a photoelectric conversion element.

Background Art

[0002] A CMOS image sensor equipped with a photoelectric conversion element is used as an imaging element in, for example, a digital camera or a smartphone. CMOS image sensors include inorganic CMOS image sensors and organic CMOS image sensors, and inorganic CMOS image sensors using silicon photodiodes are generally used. On the other hand, an organic CMOS image sensor can achieve both high resolution and a wide dynamic range by taking advantage of the high light absorption ability of an organic thin film, and can also be equipped with a global shutter that is less likely to distort an image. Thus, it is said that an organic CMOS image sensor can solve the problem of achieving both a high dynamic range and a global shutter, which are difficult for an inorganic CMOS image sensor. Therefore, a material suitable for an organic CMOS image sensor is demanded.

[0003] In addition, in a photoelectric conversion element (hereinafter also referred to as an "inorganic photoelectric conversion element") provided in an inorganic CMOS image sensor, generally, a cheap silicon semiconductor is used for the light response with an absorption wavelength up to 1000 nm, but when the absorption wavelength exceeds 1000 nm, a very expensive indium gallium arsenide (InGaAs) semiconductor is used. Therefore, a semiconductor material that is inexpensive and can be used in the long wavelength region is demanded, and an organic semiconductor material (hereinafter also referred to as an "organic semiconductor material") has attracted attention as a candidate.

[0004] In an organic CMOS image sensor, in a photoelectric conversion element (hereinafter also referred to as an "organic photoelectric conversion element") provided therein, the photoelectric conversion ability and the absorption wavelength range can be controlled by the molecular design of a p-type semiconductor material and an n-type semiconductor material used in an organic thin film (photoelectric conversion layer) constituting the photoelectric conversion element. In recent years, high photoconversion ability has been reported in elements using a non-fullerene acceptor as an n-type semiconductor material. In a photoelectric conversion element using a non-fullerene acceptor, the role of absorption wavelength range control is mainly played by the n-type semiconductor material. As the n-type semiconductor material (light absorption material and electron transport material), a compound having an electron acceptor (A) part and an electron donor (D) part, a so-called A-D-A type compound (hereinafter also referred to as an "A-D-A type non-fullerene acceptor material") is known. The design of the absorption wavelength in an A-D-A type compound is possible by reducing the HOMO-LUMO gap by selecting the electron-withdrawing property of the A part and the electron-donating property of the D part.

[0005] As the A-D-A type compound, a compound having cyclopentadithiophene as a central donor (D) part and thiophene rings (D 1 ) and (D 2 ) sandwiching the D part, an A-D 1 -D-D 2 -A type compound is known. For example, Non-Patent Document 1 discloses a compound represented by the following formula (a) which is an A-D'-D-D'-A type compound, a compound represented by the following formula (b) which is an A-D'-D-D"-A type compound, and a compound represented by the following formula (c) which is an A-D"-D-D"-A type compound. Here, D' represents a thiophene ring substituted with an alkoxy group, and D" represents a thiophene ring substituted with an alkyl group. According to Non-Patent Document 1, the compound represented by the following formula (a) can achieve the longest absorption wavelength. The compound represented by the following formula (a) is a compound obtained by substituting the alkyl group bonded to the thiophene ring in the D" part of the compound represented by the following formula (b) or the following formula (c) with an alkoxy group which is a strong electron-donating group to form a D' part.

[0006]

Chemical formula

Prior Art Documents

Non-Patent Documents

[0007]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] By the way, in A-D-A type non-fullerene acceptor materials, in order to shift the absorption wavelength to a longer wavelength, a molecular design guideline for enhancing the electron-donating property of the D part or the electron-withdrawing property of the A part is known. However, if the electron-donating property of the D part or the electron-withdrawing property of the A part is enhanced too much, the excitation of intramolecular charge mobility becomes dominant, and the light absorption property may decrease. Since the decrease in the light absorption property leads to a decrease in the photoelectric conversion characteristics, in the A-D-A type compounds used in photoelectric conversion elements, a molecular design for shifting the absorption wavelength to a longer wavelength while maintaining the light absorption property and being able to enhance the electron-donating property of the D part or the electron-withdrawing property of the A part is required.

[0009] An object of the present invention is to provide a compound capable of shifting the absorption wavelength to a longer wavelength while maintaining the light absorption property in an A-D-A type non-fullerene acceptor material, and a composition, a film, a photoelectric conversion element, and a CMOS image sensor using this compound.

Means for Solving the Problems

[0010] In view of the above problems, the present inventors have studied compounds that can maintain light absorption properties while extending the absorption wavelength in A-D-A type non-fullerene acceptor materials. Specifically, the structure of the A moiety was studied. As a result, it was found that by using a specific heteroquinoid structure for the A moiety, the absorption wavelength can be extended while maintaining light absorption properties, leading to the completion of the present invention.

[0011] That is, the present invention has the following aspects. [1] A compound represented by the following general formula (1). A-D-A ···(1) In general formula (1), each A is independently a group represented by any one of the following general formulas (2a) to (2c), and D is an electron-donating group composed of 2 to 20 rings.

[0012] [Chemical formula]

[0013] In general formulas (2a) to (2c), Z is an oxygen atom or a dicyanomethylene group, each Q is independently an oxygen atom, a sulfur atom, a selenium atom or a tellurium atom, and X is a carbon atom substituted with a sulfur atom, an alkyl group or an aryl group, a silicon atom substituted with an alkyl group or an aryl group, or a germanium atom substituted with an alkyl group or an aryl group.

[0014] [2] The compound of [1] above, wherein Z in the general formulas (2a) to (2c) is a dicyanomethylene group. [3] The compound of [1] or [2] above, wherein Q in the general formulas (2a) to (2c) is a sulfur atom, and X is a carbon atom substituted with a sulfur atom, a dimethyl group or a diphenyl group, or a silicon atom substituted with a dimethyl group or a diphenyl group. [4] The compound of any one of [1] to [3] above, wherein D in the general formula (1) is a group represented by any one of the following general formulas (3) to (5).

[0015] [Chemical formula]

[0016] In general formulas (3) to (5), W is C-(R 1 )2, Si-(R 1 )2, Ge-(R 1 )2, N-R 1 or CR 1 -O, and each R 1 is independently an alkyl group, an aryl group which may be substituted, or a heteroaryl group which may be substituted. E, J, K, and L are each independently composed of 1 to 4 rings and are an aryl group or a heteroaryl group containing an oxygen atom, a sulfur atom, a nitrogen atom, a silicon atom, a germanium atom, or a selenium atom. G is a heteroaryl ring containing a nitrogen atom, s is a number from 0 to 1, and t is a number from 0 to 3.

[0017] [5] In the above general formulas (3) to (5), -(E) t - is a heteroaryl group composed of 3 to 4 condensed rings selected from optionally substituted thiophene, furan, selenophene, thienothiophene, bithiophene, terthiophene, fluorene, or benzene, thiophene, furan, selenophene, cyclopentadiene, silole, and pyrrole. J and K are each independently an optionally substituted phenyl group, furan, thiophene, selenophene, or thienothiophene. L is an optionally substituted phenyl group, naphthyl group, thiophene, thienothiophene, or a heteroaryl group composed of 3 condensed rings selected from benzene, thiophene, furan, selenophene, cyclopentadiene, silole, and pyrrole. G is thiadiazole, selenadiazole, triazole, benzoquinoxaline, or diphenylpyrazine, and it is the compound of the above [4] where s is 0. [6] A compound of any one of the above [1] to [5] represented by the following general formula (3a).

[0018]

Chemical formula

[0019] In the general formula (3a), each A is independently a group represented by any one of the general formulas (2a) to (2c), and Y 1 ~Y 4 are each independently a hydrogen atom, an alkyl group, an alkoxy group, or an ester group, and M is a carbon atom substituted with an alkyl group or an aryl group, a silicon atom substituted with an alkyl group or an aryl group, or a germanium atom substituted with an alkyl group or an aryl group.

[0020] [7] The compound according to [6], wherein M in the general formula (3a) is a carbon atom substituted with an alkyl group or an aryl group or a silicon atom substituted with an alkyl group or an aryl group. [8] Y in the general formula (3a) 1 and Y 2 are each independently an alkyl group, an alkoxy group, or an ester group, and Y 3 and Y 4 are hydrogen atoms, and the compound according to [6] or [7]. [9] Each A in the general formula (3a) is independently a group represented by the general formula (2b) or (2c), Y 1 and Y 2 are the same and are an alkoxy group, Y 3 and Y 4 are hydrogen atoms, M is a carbon atom substituted with an alkyl group or an aryl group, and Z in the general formulas (2b) and (2c) is a dicyanomethylene group, Q is a sulfur atom, and X is a sulfur atom, a carbon atom substituted with a dimethyl group or a diphenyl group, or a silicon atom substituted with a dimethyl group or a diphenyl group, and the compound according to any one of [6] to [8].

[10] A composition containing the compound according to any one of [1] to [9].

[11] A film containing the compound according to any one of [1] to [9].

[12] A photoelectric conversion element including the film according to

[11] .

[13] A CMOS image sensor including the photoelectric conversion element according to

[12] . [Effect of the Invention]

[0021] According to the present invention, in an A-D-A type non-fullerene acceptor material, a compound capable of extending the absorption wavelength while maintaining light absorption properties, a composition, a film, a photoelectric conversion element, and a CMOS image sensor using this compound can be provided.

Brief Description of the Drawings

[0022]

Figure 1

Embodiments for Carrying Out the Invention

[0023] Preferred embodiments of the invention will be given below to explain the present invention in more detail. However, the following description is an example of an embodiment of the present invention, and the present invention is not limited to the following description as long as it does not exceed the gist of the invention. In this specification, "~" indicating a numerical range means including the numerical values described before and after as the lower limit value and the upper limit value. In the present invention, the wavy line in the general formula represents the bonding position with the adjacent group. In addition, the cross double bond in the general formula and the structural formula means that the group or compound represented by the formula may exist as an E isomer, a Z isomer, or a mixture thereof.

[0024] [Compound] The compound of the present invention is a compound represented by the following general formula (1) (hereinafter, also referred to as "compound (1)". The same applies hereinafter). A-D-A ···(1) In general formula (1), each A is independently a group represented by any of the following general formulas (2a) to (2c), and D is an electron-donating group composed of 2 to 20 rings.

[0025]

Chemical formula

[0026] In general formulas (2a) to (2c), Z is an oxygen atom or a dicyanomethylene group, Q is each independently an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom, and X is a carbon atom substituted with a sulfur atom, an alkyl group, or an aryl group, a silicon atom substituted with an alkyl group or an aryl group, or a germanium atom substituted with an alkyl group or an aryl group.

[0027] Since the A part of the A-D-A type non-fullerene acceptor material of the compound of the present invention is a group represented by any of the general formulas (2a) to (2c), the absorption wavelength can be lengthened while maintaining the light absorption property.

[0028] The reason why the compound of the present invention can lengthen the absorption wavelength while maintaining the light absorption property is not clear, but it is speculated as follows. The compound of the present invention has a group represented by any of the general formulas (2a) to (2c) in which the A part of the A-D-A type non-fullerene acceptor material has a heteroquinoid structure. In addition to the fact that the group represented by any of the general formulas (2a) to (2c) has enhanced electron-withdrawing properties compared to the A part in the conventional A-D-A type non-fullerene acceptor material, it has a cyanine structure in which the conjugated system is likely to expand throughout the molecule. Therefore, it is speculated that it enables both the lengthening of the absorption wavelength and the maintenance of the light absorption property. Therefore, the compound of the present invention is considered to be able to achieve both the lengthening of the absorption wavelength and the maintenance of the light absorption property.

[0029] In the general formula (1), A is each independently a group represented by any of the general formulas (2a) to (2c). The group represented by any of the general formulas (2a) to (2c) is an electron-withdrawing group. A may be the same or different, but it is preferably the same.

[0030] In the general formulas (2a) to (2c), Z is an oxygen atom or a dicyanomethylene group. It is considered that when Z is an oxygen atom or a dicyanomethylene group, it can become an electron-withdrawing group of the acceptor part. In the general formulas (2a) to (2c), Z is preferably a dicyanomethylene group.

[0031] In the general formulas (2a) to (2c), Q is each independently an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom. In the general formulas (2a) to (2c), Q is preferably a sulfur atom.

[0032] In the general formulas (2a) to (2c), X is a sulfur atom, a carbon atom substituted with an alkyl group or an aryl group, a silicon atom substituted with an alkyl group or an aryl group, or a germanium atom substituted with an alkyl group or an aryl group. The carbon atom substituted with an alkyl group or an aryl group is represented by the following general formula (ii). The silicon atom substituted with an alkyl group or an aryl group is represented by the following general formula (iii). The germanium atom substituted with an alkyl group or an aryl group is represented by the following general formula (iv).

[0033]

Chemical formula

[0034] In the general formulas (ii) to (iv), R 3 ~R 8 are each independently an alkyl group or an aryl group. R 3 ~R 8 The number of carbon atoms of the alkyl group of R 3 ~R 8 is preferably small in terms of the conductivity of the material. Therefore, the number of carbon atoms of the alkyl group of R 3 ~R 8 is preferably 30 or less, more preferably 20 or less, still more preferably 15 or less, and particularly preferably 10 or less. Also, the number of carbon atoms of the alkyl group of R 3 ~R 8 R 3 ~R 8The alkyl group may be linear or cyclic. When the alkyl group is linear, it may be straight-chain or branched-chain.

[0035] R 3 ~R 8 In terms of the conductivity of the material, it is preferable that the number of carbon atoms of the aryl group of R 3 ~R 8 is small. Therefore, the number of carbon atoms of the aryl group of R 3 ~R 8 is preferably 18 or less, more preferably 12 or less, even more preferably 10 or less, and particularly preferably 6. Note that the lower limit of the number of carbon atoms of the aryl group of R R 3 ~R 8 may or may not have a substituent. That is, the aryl group of R 3 ~R 8 is an unsubstituted or substituted aryl group. Examples of the substituent include an alkyl group, an alkoxy group, a hydroxy group, an amino group, and the like.

[0036] From the viewpoint of ease of synthesis of the compound (1), the two alkyl groups or aryl groups possessed by the carbon atom, silicon atom, and germanium atom in X are preferably the same. From the viewpoint of shifting the absorption wavelength to a longer wavelength, X in the general formula (2c) is preferably a sulfur atom, a carbon atom substituted with an alkyl group or an aryl group, or a silicon atom substituted with an alkyl group or an aryl group, and more preferably a sulfur atom, a carbon atom substituted with a dimethyl group or a diphenyl group, or a silicon atom substituted with a dimethyl group or a diphenyl group. From the viewpoint of enhancing solubility, X in the general formula (2c) is preferably a carbon atom substituted with an alkyl group or an aryl group, a silicon atom substituted with an alkyl group or an aryl group, or a germanium atom substituted with an alkyl group or an aryl group. In the present invention, the carbon atom substituted with a dimethyl group refers to a carbon atom in which two hydrogen atoms bonded to the carbon atom are each substituted with a methyl group, that is, R in the general formula (ii) 3 and R 4 are methyl groups. The carbon atom substituted with a diphenyl group refers to a carbon atom in which two hydrogen atoms bonded to the carbon atom are each substituted with a phenyl group, that is, R in the general formula (ii) 3 and R 4 are phenyl groups. The silicon atom substituted with a dimethyl group refers to a silicon atom in which two hydrogen atoms bonded to the silicon atom are each substituted with a methyl group, that is, R in the general formula (iii) 5 and R 6 are methyl groups. The silicon atom substituted with a diphenyl group refers to a silicon atom in which two hydrogen atoms bonded to the silicon atom are each substituted with a phenyl group, that is, R in the general formula (iii) 5 and R 6 are phenyl groups.

[0037] A is more preferably a group represented by the general formula (2b) or (2c). In particular, Z in the general formulas (2b) and (2c) is a dicyanomethylene group, Q is a sulfur atom, and X is a sulfur atom, a carbon atom substituted with a dimethyl group or a diphenyl group, or a silicon atom substituted with a dimethyl group or a diphenyl group, which is preferable.

[0038] In the general formula (1), D is an electron-donating group composed of 2 to 20 rings. D is preferably a group represented by any one of the following general formulas (3) to (5).

[0039]

Chemical formula

[0040] In the general formulas (3) to (5), W is C-(R 1 )2, Si-(R 1)2. Ge-(R 1 )2. N-R 1 or CR 1 -O, and R 1 are each independently an alkyl group, an optionally substituted aryl group, or an optionally substituted heteroaryl group, E, J, K, and L are each independently composed of 1 to 4 rings and are an aryl group or a heteroaryl group containing an oxygen atom, a sulfur atom, a nitrogen atom, a silicon atom, a germanium atom, or a selenium atom, G is a heteroaryl ring containing a nitrogen atom, s is a number from 0 to 1, and t is a number from 0 to 3.

[0041] In the general formulas (3) to (5), W is C-(R 1 )2, Si-(R 1 )2, Ge-(R 1 )2, N-R 1 or CR 1 -O, and R 1 are each independently an alkyl group, an optionally substituted aryl group, or an optionally substituted heteroaryl group. R 1 As the alkyl group of R 3 ~R 8 the alkyl groups exemplified above in the description of R R 1 As the aryl group of R 3 ~R 8 the aryl groups exemplified above in the description of R R 1 As the heteroaryl group of R 1 groups generated by removing one hydrogen atom from any ring atom of heteroarenes such as thiophene are exemplified, and heteroaryl groups containing an oxygen atom, a sulfur atom, or a selenium atom are preferred. The number of carbon atoms of the heteroaryl group of R 1 is preferably 17 or less, more preferably 11 or less, even more preferably 9 or less, and particularly preferably 4. Note that the lower limit of the number of carbon atoms of the heteroaryl group of R R 1The aryl group and heteroaryl group may each have a substituent or may not have a substituent. That is, R 1 's aryl group is an unsubstituted or substituted aryl group, and R 1 's heteroaryl group is an unsubstituted or substituted heteroaryl group. Examples of the substituent include an alkyl group, an alkoxy group, a hydroxy group, an amino group, and the like.

[0042] In the general formulas (3) to (5), E is composed of 1 to 4 rings and is an aryl group or a heteroaryl group containing an oxygen atom, a sulfur atom, a nitrogen atom, a silicon atom, a germanium atom, or a selenium atom. -(E) t - is preferably a substituted or unsubstituted heteroaryl group composed of 3 to 4 condensed rings selected from thiophene, furan, selenophene, thienothiophene, bithiophene, terthiophene, fluorene, or benzene, thiophene, furan, selenophene, cyclopentadiene, silole, and pyrrole. Specific examples of the heteroaryl group composed of 3 condensed rings selected from benzene, thiophene, furan, selenophene, cyclopentadiene, silole, and pyrrole include dibenzothiophene, dibenzofuran, dibenzosilole, carbazole, dithienocyclopentadiene, dithienosilole, dithienogermole, dithienothiophene, and dithienopyrrole. Among these, dithienocyclopentadiene, dithienosilole, dithienogermole, and dithienopyrrole are preferred, dithienocyclopentadiene and dithienosilole are more preferred, and dithienocyclopentadiene is even more preferred. As the heteroaryl group composed of 4 condensed rings selected from benzene, thiophene, furan, selenophene, cyclopentadiene, silole, and pyrrole, a heteroaryl group composed of 4 condensed rings selected from thiophene, cyclopentadiene, silole, and pyrrole is preferred, and a heteroaryl group in which both ends of the 4 condensed rings are thiophene and which contains a total of 2 to 3 rings of thiophene is more preferred.

[0043] In the general formulas (3) to (5), J and K are each independently a 1- to 4-ring aryl group or a heteroaryl group containing an oxygen atom, a sulfur atom, a nitrogen atom, a silicon atom, a germanium atom, or a selenium atom. J and K are each independently preferably a phenyl group, furan, thiophene, selenophene, or thienothiophene which may be substituted.

[0044] In the general formulas (3) to (5), L is a 1- to 4-ring aryl group or a heteroaryl group containing an oxygen atom, a sulfur atom, a nitrogen atom, a silicon atom, a germanium atom, or a selenium atom. L is preferably a phenyl group, naphthyl group, thiophene, thienothiophene, or a heteroaryl group consisting of a 3-fused ring selected from benzene, thiophene, furan, selenophene, cyclopentadiene, silole, and pyrrole which may be substituted. Specific examples of the heteroaryl group consisting of a 3-fused ring selected from benzene, thiophene, furan, selenophene, cyclopentadiene, silole, and pyrrole include dibenzothiophene, dibenzofuran, dibenzosilole, carbazole, dithienocyclopentadiene, dithienosilole, dithienogermole, dithienothiophene, and dithienopyrrole. Among these, dithienocyclopentadiene, dithienosilole, dithienothiophene, and dithienopyrrole are preferred, dithienocyclopentadiene, dithienosilole, and dithienopyrrole are more preferred, and dithienocyclopentadiene is even more preferred.

[0045] In the general formulas (3) to (5), G is a heteroaryl ring containing a nitrogen atom. G is preferably thiadiazole, selenadiazole, triazole, benzoquinoxaline, or diphenylpyrazine.

[0046] s is a number from 0 to 1, and 0 is preferred. t is a number from 0 to 3.

[0047] As the compound (1), it is preferable that D in the general formula (1) is a group represented by the general formula (3). Examples of such a compound include a compound represented by the following general formula (3a) (hereinafter, also referred to as "compound (3a)").

[0048]

Chemical formula

[0049] In the general formula (3a), each A is independently a group represented by any one of the general formulas (2a) to (2c), and Y 1 ~Y 4 are each independently a hydrogen atom, an alkyl group, an alkoxy group or an ester group, and M is a carbon atom substituted with an alkyl group or an aryl group, a silicon atom substituted with an alkyl group or an aryl group, or a germanium atom substituted with an alkyl group or an aryl group.

[0050] A in the general formula (3a) is the same as A in the general formula (1). Among them, in particular, each A is preferably independently a group represented by the general formula (2b) or (2c), Z in the general formula (2b) or (2c) is a dicyanomethylene group, Q is a sulfur atom, and X is more preferably a sulfur atom, a carbon atom substituted with an alkyl group or an aryl group, or a silicon atom substituted with an alkyl group or an aryl group, and X is further preferably a sulfur atom, a carbon atom substituted with a dimethyl group or a diphenyl group, or a silicon atom substituted with a dimethyl group or a diphenyl group.

[0051] Y 1 ~Y 4 are each independently a hydrogen atom, an alkyl group, an alkoxy group or an ester group. Y 1 ~Y 4 Examples of the alkyl group of 3 ~R 8 include the alkyl groups exemplified above in the description of Y 1 ~Y4 The alkyl group may be linear or cyclic. When the alkyl group is linear, it may be straight-chain or branched-chain. From the viewpoint of ease of synthesis, it is preferably a straight-chain or branched-chain alkyl group in which the carbon atom bonded to the thiophene ring is a primary carbon atom. From the viewpoint of the solubility of the material, it is preferably a branched-chain alkyl group in which the carbon atom bonded to the thiophene ring is a primary carbon atom, or a straight-chain, branched-chain or cyclic alkyl group in which the carbon atom bonded to the thiophene ring is a secondary carbon atom. From the viewpoints of ease of synthesis and solubility, it is more preferably a branched-chain alkyl group in which the carbon atom bonded to the thiophene ring is a primary carbon atom. Y 1 ~Y 4 When the alkyl group of ~Y is branched-chain, it may be branched at the 1-position or branched at a position other than the 1-position.

[0052] Y 1 ~Y 4 In terms of the conductivity of the material, the number of carbon atoms in the alkoxy group of Y~Y is preferably small. Therefore, 1 ~Y 4 the number of carbon atoms in the alkoxy group of Y~Y is preferably 30 or less, more preferably 20 or less, even more preferably 15 or less, and particularly preferably 10 or less. Also, 1 ~Y 4 the number of carbon atoms in the alkoxy group of Y~Y is preferably 2 or more, more preferably 4 or more, even more preferably 6 or more, and particularly preferably 8 or more. The alkoxy group has a structure in which an alkyl group is bonded to an oxygen atom. The alkyl group bonded to the oxygen atom may be linear or cyclic. When the alkyl group bonded to the oxygen atom is linear, it may be straight-chain or branched-chain. That is, the alkoxy group may be linear or branched. From the viewpoint of ease of synthesis, it is preferably a straight-chain or branched-chain alkyl group in which the carbon atom bonded to the oxygen atom is a primary carbon atom. In terms of the solubility of the material, the alkoxy group is preferably branched. The alkoxy group may be branched at the 1-position or at a position other than the 1-position. That is, it is preferably a branched-chain alkyl group in which the carbon atom bonded to the oxygen atom is a primary carbon atom, or a linear, branched-chain or cyclic alkyl group in which the carbon atom bonded to the oxygen atom is a secondary carbon atom. More preferably, it is a linear, branched-chain or cyclic alkyl group in which the carbon atom bonded to the oxygen atom is a secondary carbon atom, and even more preferably, it is a linear or branched-chain alkyl group in which the carbon atom bonded to the oxygen atom is a secondary carbon atom.

[0053] Y 1 ~Y 4 Examples of the ester group of ~Y include monovalent groups having an ester bond. Specifically, groups represented by the following general formula (i) can be mentioned. -COO-R 2 ···(i) In general formula (i), R 2 is an alkyl group or an aryl group. R 2 Examples of the alkyl group of include the alkyl groups exemplified above in the description of R 3 ~R 8 . R 2 The alkyl group of may be linear or cyclic. When the alkyl group is linear, it may be straight-chain or branched-chain. From the viewpoint of ease of synthesis, it is preferably a straight-chain or branched-chain alkyl group in which the carbon atom bonded to the oxygen atom is a primary carbon atom. In terms of the solubility of the material, it is preferably a branched-chain alkyl group in which the carbon atom bonded to the oxygen atom is a primary carbon atom, or a linear, branched-chain or cyclic alkyl group in which the carbon atom bonded to the oxygen atom is a secondary carbon atom. More preferably, it is a linear, branched-chain or cyclic alkyl group in which the carbon atom bonded to the oxygen atom is a secondary carbon atom, and even more preferably, it is a linear or branched-chain alkyl group in which the carbon atom bonded to the oxygen atom is a secondary carbon atom.

[0054] R 2 Examples of the aryl group of include the R3 ~R 8 In the description of ~R, the aryl groups exemplified above can be mentioned. R 2 The aryl group of R may or may not have a substituent. That is, the aryl group of R 2 is an unsubstituted or substituted aryl group. Examples of the substituent include an alkyl group, an alkoxy group, a hydroxy group, an amino group, and the like.

[0055] Y 1 ~Y 4 may be the same or different. In particular, from the viewpoint of shifting the absorption wavelength to a longer wavelength, Y 1 and Y 2 are each independently an alkyl group, an alkoxy group or an ester group, and it is preferable that Y 3 and Y 4 are hydrogen atoms, and it is more preferable that Y 1 and Y 2 are each independently an alkoxy group. Among them, in particular, from the viewpoint of ease of synthesis, it is even more preferable that Y 1 and Y 2 are the same, and it is particularly preferable that they are the same alkoxy group.

[0056] M in the general formula (3a) is a carbon atom substituted with an alkyl group or an aryl group, a silicon atom substituted with an alkyl group or an aryl group, or a germanium atom substituted with an alkyl group or an aryl group. It is considered that the compound (3a) can enhance the solubility by M being a carbon atom substituted with an alkyl group or an aryl group, a silicon atom substituted with an alkyl group or an aryl group, or a germanium atom substituted with an alkyl group or an aryl group. The carbon atom substituted with an alkyl group or an aryl group is represented by the general formula (ii). The silicon atom substituted with an alkyl group or an aryl group is represented by the general formula (iii). The germanium atom substituted with an alkyl group or an aryl group is represented by the general formula (iv).

[0057] In terms of the ease of synthesis of compound (3a), it is preferable that the two alkyl groups or aryl groups possessed by M, which is a carbon atom, a silicon atom, or a germanium atom, are the same. From the viewpoint of shifting the absorption wavelength to a longer wavelength, M is preferably a carbon atom substituted with an alkyl group or an aryl group or a silicon atom substituted with an alkyl group or an aryl group, more preferably a carbon atom substituted with an alkyl group or an aryl group, and even more preferably a carbon atom substituted with an alkyl group.

[0058] As compound (3a), A in the general formula (3a) is each independently a group represented by the general formula (2b) or (2c), Y 1 and Y 2 are the same and are an alkoxy group, Y 3 and Y 4 are hydrogen atoms, M is a carbon atom substituted with an alkyl group or an aryl group, and Z in the general formula (2b) and (2c) is a dicyanomethylene group, Q is a sulfur atom, and X is a sulfur atom, a carbon atom substituted with a dimethyl group or a diphenyl group, or a silicon atom substituted with a dimethyl group or a diphenyl group. Among them, in particular, it is more preferable that A in the general formula (3a) is the same and is a group represented by the general formula (2b) or (2c).

[0059] Specific examples of compound (1) include compounds represented by the following formulae, etc., but compound (1) is not limited thereto.

[0060]

Chemical formula

[0061]

Chemical formula

[0062]

Chemical formula

[0063]

Chem.

[0064]

Chem.

[0065]

Chem.

[0066]

Chem.

[0067]

Chem.

[0068]

Chem.

[0069]

Chem.

[0070]

Chem.

[0071] Among the above-mentioned compounds, Y 1 ~Y 4At least one of them is an alkoxy group, and in the alkoxy group, the alkyl group bonded to the oxygen atom is linear, branched or cyclic, and the carbon atom bonded to the oxygen atom is a secondary carbon atom (that is, a compound in which the alkoxy group bonded to the thiophene ring is branched at the 1-position) has particularly excellent solubility. Examples of such compounds include compound (3-2a-4), (3-2b-4) to (3-2b-12), (3-2b-15), (3-2b-16), (3-2c-7) to (3-2c-14), (3-2c-17), (3-2c-18), etc.

[0072] The production method of compound (1) is not particularly limited, but as an example of the production method of compound (1), the production method of the following compound (A) will be specifically described. Y in compound (A) corresponds to any of Y 1 ~Y 4 in the general formula (3a), and M in compound (A) corresponds to M in the general formula (3a).

[0073]

Chemical formula

[0074] First, a compound (B) of the following formula which is a 3-substituted thiophene is reacted with lithium diisopropylamide (LDA) in a reaction solvent, and then N,N-dimethylformamide is further reacted to obtain a compound (C) of the following formula.

[0075]

Chemical formula

[0076] Here, compound (B) may be synthesized by a known method or a commercially available product may be used. The charging ratio of the raw materials is preferably such that LDA is 0.9 to 1.5 equivalents with respect to compound (B), and N,N-dimethylformamide is preferably 0.9 equivalent or more. Note that N-formylpiperidine may be used instead of N,N-dimethylformamide. The reaction solvent is not particularly limited as long as it does not react with the starting compounds. Examples include saturated aliphatic hydrocarbon solvents such as hexane; ether solvents such as tetrahydrofuran (THF), diethyl ether, cyclopentyl methyl ether, and methyl t-butyl ether; aromatic hydrocarbon solvents such as toluene and xylene, etc. The reaction temperature is preferably -78 to 50 °C. The reaction time is preferably 10 minutes to 12 hours after adding LDA and 10 minutes to 12 hours after adding N,N-dimethylformamide.

[0077] Next, compound (C) and N-bromosuccinimide (NBS) are reacted in a reaction solvent to obtain compound (D) of the following formula.

[0078]

Chemical formula

[0079] The charging ratio of the starting materials is preferably 0.9 to 1.2 equivalents of NBS with respect to compound (C), more preferably 0.9 to 1.05 equivalents. Note that bromine may be used instead of NBS. The reaction solvent is not particularly limited as long as it does not react with the starting compounds. Examples include saturated aliphatic hydrocarbon solvents such as hexane; ether solvents such as tetrahydrofuran (THF); aromatic hydrocarbon solvents such as toluene and xylene; halogen solvents such as chloroform; N,N-dimethylformamide, etc. The reaction temperature is preferably -78 to 50 °C. The reaction time is preferably 10 minutes to 24 hours after adding NBS.

[0080] In the production of compound (A), compound (F) of the following formula may be used instead of compound (D). Compound (F) can be obtained, for example, as follows.

[0081] That is, first, a compound (B) of the following formula, which is 3-substituted thiophene, is reacted with lithium diisopropylamide (LDA) in a reaction solvent, and then 1,2-dibromo-1,1,2,2-tetrachloroethane is further reacted to obtain a compound (E) of the following formula.

[0082]

Chemical formula

[0083] Here, the compound (B) may be synthesized by a known method or a commercially available product may be used. The charging ratio of the raw materials is preferably such that LDA is 0.9 to 1.5 equivalents with respect to the compound (B), and preferably 1,2-dibromo-1,1,2,2-tetrachloroethane is 0.9 equivalent or more. The reaction solvent is not particularly limited as long as it does not react with the raw material compounds, and examples thereof include saturated aliphatic hydrocarbon solvents such as hexane; ether solvents such as tetrahydrofuran (THF), diethyl ether, cyclopentyl methyl ether, and methyl t-butyl ether; and aromatic hydrocarbon solvents such as toluene and xylene. The reaction temperature is preferably -78 to 50°C. The reaction time is preferably 10 minutes to 12 hours after adding LDA and 10 minutes to 12 hours after adding 1,2-dibromo-1,1,2,2-tetrachloroethane.

[0084] Next, the compound (E) and lithium diisopropylamide (LDA) are reacted in a reaction solvent, and then N,N-dimethylformamide is further reacted to obtain a compound (F) of the following formula.

[0085]

Chemical formula

[0086] The charging ratio of raw materials is preferably such that LDA is 0.9 to 1.5 equivalents and N,N-dimethylformamide is 0.9 equivalent or more with respect to compound (E). Note that N-formylpiperidine may be used instead of N,N-dimethylformamide. The reaction solvent is not particularly limited as long as it does not react with the raw material compounds. Examples include saturated aliphatic hydrocarbon solvents such as hexane; ether solvents such as tetrahydrofuran (THF), diethyl ether, cyclopentyl methyl ether, and methyl t-butyl ether; and aromatic hydrocarbon solvents such as toluene and xylene. The reaction temperature is preferably -78 to 50°C. The reaction time is preferably 10 minutes to 12 hours after adding LDA and 10 minutes to 12 hours after adding N,N-dimethylformamide.

[0087] Next, in the reaction solvent, compound (I) is obtained by a cross-coupling reaction of at least one of compound (D) and compound (F) with compound (G) of the following formula. The production method of compound (I) is not particularly limited. For example, compound (I) can be produced by a method similar to the methods described in literature such as Adv. Energy Mater., 2018, Vol. 8, p. 1801212.; J. Mater. Chem. C, 2020, Vol. 8, p. 15175.; ACS Energy Lett., 2019, Vol. 4, p. 1401. An example of specific production conditions is as follows.

[0088]

Chemical formula

[0089] Here, compound (G) may be synthesized by a known method (for example, Polym. Chem., 2013, Vol. 4, p. 5351 - 5360; J. Phys. Chem. C, 2011, Vol. 15, p. 2398 - 2405; Chem. Commun., 2012, Vol. 48, p. 11130 - 11132), or a commercially available product may be used. Also, compound (G) corresponding to the cross - coupling reaction (where "L" in compound (G) is an alkyltin group, boric acid, boric acid ester group, zinc halide, magnesium halide, or silyl group, etc.) may be used. The type of cross - coupling reaction, which is a reaction between at least one of compound (D) and compound (F) and compound (G), is not particularly limited, and the reaction can be carried out by Stille coupling, Suzuki coupling, Negishi coupling, Kumada coupling, Hiyama coupling, etc. The cross - coupling reaction may be carried out in the presence of a catalyst such as a palladium catalyst, a nickel catalyst, or a copper catalyst. For example, when reacting compound (D) or compound (F) with compound (G) by the Stille coupling reaction, the charging ratio of the raw materials is preferably such that compound (D) or compound (F) is 1.9 - 3.0 equivalents relative to compound (G). Also, it is preferable to use a palladium catalyst during the Stille coupling reaction, and the palladium content in the catalyst is preferably 0.1 - 50 mol%. The reaction solvent is not particularly limited as long as it does not react with the raw material compounds, and examples include saturated aliphatic hydrocarbon solvents such as hexane; ether solvents such as diethyl ether, cyclopentyl methyl ether, tetrahydrofuran (THF), 1,4 - dioxane; aromatic hydrocarbon solvents such as toluene, xylene; N,N - dimethylformamide (DMF), dimethyl sulfoxide, N - methyl - 2 - pyrrolidone, etc. The reaction temperature is preferably from 20°C to the reflux temperature of the reaction solvent. The reaction time is preferably 1 - 24 hours.

[0090] Next, in a reaction solvent, compound (I) and compound (J) are reacted to obtain compound (A). The method for producing compound (A) is not particularly limited. For example, compound (A) can be produced by a method similar to the methods described in Org. Biomol. Chem., 2013, Vol. 11, p. 6338, etc. An example of specific production conditions is as follows.

[0091] [Chemical formula]

[0092] Here, compound (J) can be synthesized by a known method (for example, Heterocycles, 1996, Vol. 43, p. 1927, etc.). The charging ratio of the raw materials is preferably 1.5 to 10 equivalents of compound (J) with respect to compound (I), and more preferably 1.9 to 2.5 equivalents. The reaction solvent is not particularly limited as long as it does not react with the raw material compounds, and examples thereof include acetic anhydride. The reaction temperature is preferably from room temperature to the reflux temperature. The reaction time is preferably 10 minutes to 24 hours.

[0093] In this way, compound (A) can be produced. Here, Y in compound (A) is any one of Y 1 ~Y 4 and M in compound (A) is M in the general formula (3a).

[0094] Since the compound of the present invention can extend the absorption wavelength while maintaining light absorption properties, it is suitable as an n-type semiconductor material (light absorption material and electron transport material) used in a photoelectric conversion element. The use of the compound of the present invention is not limited to those described above. For example, since the compound of the present invention also has excellent luminescence properties, it can also be used in bioimaging, organic EL, near-infrared luminescent dyes for wavelength conversion films / compositions, etc.

[0095] [Composition] The composition of the present invention contains the above-described compound (1). Compound (1) may be used alone or in combination of two or more kinds at any ratio. The content of compound (1) in the composition of the present invention is not particularly limited. However, when the composition of the present invention is used for forming the photoelectric conversion layer (active layer) of a photoelectric conversion element, the content of compound (1) is preferably large in terms of light absorption amount, and on the other hand, preferably small in terms of carrier balance. Therefore, with respect to the total amount (total mass) of all components other than the solvent in the composition of the present invention, the content of compound (1) is preferably 10% by mass or more, more preferably 25% by mass or more, and even more preferably 40% by mass or more. Also, with respect to the total amount (total mass) of all components other than the solvent in the composition of the present invention, the content of compound (1) is preferably 100% by mass or less, more preferably 90% by mass or less, even more preferably 75% by mass or less, and particularly preferably 60% by mass or less.

[0096] The composition of the present invention may further contain a solvent. The composition containing compound (1) and a solvent is suitable as an ink (composition for forming an active layer) for forming the photoelectric conversion layer (active layer) of a photoelectric conversion element. As the solvent, a liquid that does not react with compound (1) and dissolves compound (1) is preferred, and examples include aromatic hydrocarbon solvents such as toluene and xylene; halogen solvents such as dichloromethane and chloroform. When the composition of the present invention contains a solvent, the solvent may be used alone or in combination of two or more kinds at any ratio. When the composition of the present invention contains a solvent, the content of compound (1) in the composition of the present invention is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and still more preferably 1.0% by mass or more with respect to the total mass of the composition of the present invention. Further, the content of compound (1) is preferably 5.0% by mass or less, more preferably 3.5% by mass or less, and still more preferably 2.0% by mass or less with respect to the total mass of the composition of the present invention.

[0097] When the composition of the present invention is used as a composition for forming an active layer, the composition preferably further contains a p-type semiconductor material in addition to compound (1). The p-type semiconductor material is not particularly limited as long as it can be used in the photoelectric conversion layer of an organic optoelectronic conversion element. Examples thereof include polymers described in documents (ACS Energy Lett., 2019, Vol. 4, p. 1401; Adv. Optical Mater., 2022, Vol. 10, p. 2200747). When the composition of the present invention contains a p-type semiconductor material, the p-type semiconductor material may be used alone or in combination of two or more in any ratio. The mass ratio of compound (1) to the p-type semiconductor material (compound (1) / p-type semiconductor material) is preferably 0.1 or more, more preferably 0.5 or more, and still more preferably 0.75 or more. Further, the mass ratio of compound (1) to the p-type semiconductor material is preferably 3.0 or less, more preferably 2.0 or less, and still more preferably 1.5 or less.

[0098] The composition of the present invention may further contain components other than compound (1), the p-type semiconductor material, and the solvent (optional components) as necessary, as long as the effects of the present invention are not impaired. Examples of the optional components include 1,8-diiodooctane, 1-chloronaphthalene, and the like. When the composition of the present invention contains an optional component, the optional component may be used alone or in combination of two or more in any ratio. When containing an optional component, it is preferable that the amount of the optional component is large in terms of the easy manifestation of the effect by containing the optional component. On the other hand, in terms of the easy maintenance of the physical properties suitable for the photoelectric conversion element of the composition of the present invention, it is preferable that the content of the compound (1) is large. Therefore, when the composition of the present invention contains an optional component, the content of the optional component is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, based on the total amount (total mass) of all components other than the solvent in the composition of the present invention. Further, the content of the optional component is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, based on the total amount (total mass) of all components other than the solvent in the composition of the present invention.

[0099] The composition of the present invention can be obtained, for example, by dissolving the compound (1) and, if necessary, one or more of the p-type semiconductor material and the optional component in a solvent. Further, by removing the solvent from the obtained composition, a composition of the present invention that does not contain a solvent can be obtained.

[0100] The composition of the present invention is suitable as an ink (composition for forming an active layer) for forming a photoelectric conversion layer (active layer) of a photoelectric conversion element.

[0101] [Film] The film of the present invention is a film containing the above-described compound (1), and is also referred to as an organic thin film. The film of the present invention can be obtained, for example, by removing the solvent from the above-described composition of the present invention containing a solvent. Specifically, it can be obtained by drying after applying the composition of the present invention on a substrate. The content of compound (1) in the film is the same as the content of compound (1) with respect to the total amount (total mass) of all components other than the solvent in the composition of the present invention described above. That is, with respect to the total mass of the film, the content of compound (1) is preferably 10% by mass or more, more preferably 25% by mass or more, and even more preferably 40% by mass or more. Also, with respect to the total mass of the film, the content of compound (1) is preferably 100% by mass or less, more preferably 90% by mass or less, even more preferably 75% by mass or less, and particularly preferably 60% by mass or less.

[0102] The film thickness is preferably thick in terms of the light absorption amount. On the other hand, in terms of the external quantum efficiency (EQE) when the film of the present invention is used as the photoelectric conversion layer (active layer) of a photoelectric conversion element, the film thickness is preferably thin. Therefore, the film thickness is preferably 10 nm or more, and more preferably 100 nm or more. Also, the film thickness is preferably 1000 nm or less, and more preferably 500 nm or less. The film thickness can be adjusted by the coating amount of the composition applied to the substrate.

[0103] The coating method of the composition is not particularly limited, and examples include brush coating, bar coating, spray coating, dip coating, spin coating, curtain coating, and the like. The drying temperature after coating is preferably 20 to 250 °C. The drying time is preferably 10 minutes to 5 hours.

[0104] The film of the present invention is suitable as the photoelectric conversion layer (active layer) of a photoelectric conversion element.

[0105] [Photoelectric conversion element] The photoelectric conversion element of the present invention is an element including the film of the present invention described above, and is also referred to as an organic photoelectric conversion element. Specifically, the photoelectric conversion element of the present invention includes the film of the present invention as the photoelectric conversion layer (active layer). The structure of the photoelectric conversion element can adopt the structure of a known organic photoelectric conversion element. For example, reference can be made to the description in Japanese Patent Application Laid-Open No. 2007-324587. Although the specific structure is not particularly limited, for example, an element having a laminated structure in which a photoelectric conversion layer (active layer) is sandwiched between a pair of electrodes can be mentioned.

[0106] Hereinafter, an example of the photoelectric conversion element of the present invention will be described with reference to FIG. 1. In addition, in each drawing used in the following description, for the sake of easy understanding of its features, there are cases where the characteristic parts are enlarged for convenience, and the dimensional ratios of each component may be different from the actual ones. Further, the materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto, and it can be appropriately changed and implemented without changing the gist thereof.

[0107] The photoelectric conversion element 10 shown in FIG. 1 has a structure in which a transparent electrode 12, a hole transport layer 13, a photoelectric conversion layer 14, an electron transport layer 15, and a metal electrode 16 are laminated in this order on a transparent substrate 11. Note that the positions of the hole transport layer 13 and the electron transport layer 15 may be exchanged. That is, the photoelectric conversion element may have a structure in which a transparent electrode, an electron transport layer, a photoelectric conversion layer (active layer), a hole transport layer, and a metal electrode are laminated in this order on a transparent substrate.

[0108] Examples of the transparent substrate 11 include a base material having an average transmittance of 80% or more in visible light of 450 nm or more. Examples of the material for forming the transparent substrate 11 include glass; plastics such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, and polyethylene sulfide.

[0109] Examples of the transparent electrode 12 include an electrode having an average transmittance of 80% or more in visible light of 450 nm or more. The material for forming the transparent electrode 12 is not particularly limited as long as the transparent electrode 12 can be formed. For example, indium tin oxide (ITO) doped with tin, indium zinc oxide (IZO) doped with zinc, indium tungsten oxide (IWO) doped with tungsten, zinc-aluminum oxide (AZO), indium oxide (In2O3), zinc oxide (ZnO), titanium dioxide (TiO2), etc. can be mentioned.

[0110] The metal electrode 16 is an electrode paired with the transparent electrode 12. The material constituting the metal electrode 16 is not particularly limited. For example, metals such as gold, platinum, silver, aluminum, nickel, titanium, magnesium, calcium, barium, sodium, chromium, copper, and cobalt, or their alloys, etc. can be mentioned. The metal electrode 16 is preferably a transparent electrode or a reflective electrode. That is, the photoelectric conversion element preferably has a laminated structure in which a photoelectric conversion layer (active layer) is sandwiched between a pair of electrodes (transparent or metal), and more preferably has a laminated structure in which an electron transport layer, a photoelectric conversion layer (active layer), and a hole transport layer are sandwiched between a pair of electrodes (transparent or metal). In the case of a pair of transparent electrodes, the materials for forming the electrodes may be of the same type or different types. The film thickness of the metal electrode 16 is not particularly limited. From the viewpoint of enhancing transparency, about 10 nm is preferable. When transparency is not required, considering durability, etc., 40 nm or more is preferable, and 100 nm or more is more preferable.

[0111] The methods for forming the transparent electrode 12 and the metal electrode 16 are not particularly limited. For example, they can be formed by dry processes such as vacuum evaporation and sputtering; wet processes using conductive inks, etc.

[0112] When providing the constituent members and manufacturing method in the case of providing the hole transport layer 13 and the electron transport layer 15, there are no particular restrictions, and known techniques can be used. For example, the members and their manufacturing methods described in known documents such as International Publication No. 2013 / 171517, International Publication No. 2013 / 180230, or Japanese Patent Application Laid-Open No. 2012-191194 can be used.

[0113] The photoelectric conversion layer 14 is a layer that absorbs light and separates charges. The photoelectric conversion layer 14 of the photoelectric conversion element of the present invention is a layer containing the compound (1) of the present invention described above. More specifically, it is the film of the present invention described above. The photoelectric conversion layer 14 can be formed, for example, by applying the composition of the present invention described above onto a layer below the photoelectric conversion layer 14 such as the hole transport layer 13 and drying it.

[0114] The photoelectric conversion element 10 can be obtained, for example, by forming a transparent electrode 12, a hole transport layer 13, a photoelectric conversion layer 14, an electron transport layer 15, and a metal electrode 16 in this order on a transparent substrate 11.

[0115] Since the photoelectric conversion layer 14 of the photoelectric conversion element of the present invention contains the compound (1), it can suppress the dark current, increase the absorption wavelength to a longer wavelength, and has high sensor sensitivity on the long-wavelength side.

[0116] [CMOS Image Sensor] The CMOS image sensor of the present invention includes the photoelectric conversion element of the present invention described above. The structure of the CMOS image sensor can adopt the structure of a known CMOS image sensor. Specifically, for example, reference can be made to the description in Japanese Patent Application Laid-Open No. 2021-57422, and it is not particularly limited. More specifically, a CMOS image sensor having a structure in which a metal wiring, the photoelectric conversion element of the present invention, a color filter, and a microlens are laminated in this order on a substrate such as a silicon substrate can be mentioned.

Examples

[0117] Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples do not limit the scope of the present invention.

[0118] [Compound] As model compounds of compound (1), the following model compounds (3-2a-2-1), (3-2b-2-1), (3-2c-2-1), (3-2c-5-1) were used, and as model comparative compounds of compound (1), the following model comparative compounds (N-1), (N-2) were used. Note that the model comparative compound (N-1) was set with reference to a known document ("ACS Energy Lett.", 2019, Vol. 4, p. 1401.). The model comparative compound (N-2) was set with reference to a known document ("Sci. Adv.", 2023, Vol. 9, eadf6152.).

[0119] [Chemical Formula]

[0120] [Measurement and Evaluation Method] <Evaluation Based on Theoretical Calculation> The bathochromic shift and absorbance of each model compound and model comparative compound were evaluated based on the following theoretical calculations. As software for molecular orbital calculations, Spartan’20 manufactured by Wavefunction was used, and the HOMO-LUMO gap and oscillator strength of each compound were obtained by theoretical calculations. B3LYP / 6-31G(d) was adopted as the calculation method for the HOMO-LUMO gap, and TD-B3LYP / 6-31G(d) / / B3LYP / 6-31G(d) was adopted as the calculation method for the oscillator strength. The HOMO-LUMO gap of each compound was evaluated as an index for the bathochromic shift of the absorption wavelength, and the oscillator strength of each compound was evaluated as an index for absorbance. Note that the HOMO-LUMO gap and oscillator strength of the model comparative compound (N-1) were used as reference values. The absorbance was evaluated based on the following evaluation criteria. These results are shown in Table 1. (Evaluation Criteria for Absorbance) 〇: Decrease or improvement of less than 5% from the reference value △: Decrease of 5 - 25% from the reference value ×: Decrease of more than 25% from the reference value

[0121]

Table 1

[0122] As is clear from the results in Table 1, for the model comparison compound (N - 1) (reference value), the model comparison compound (N - 2) substituted with a strong electron - withdrawing group was able to reduce the HOMO - LUMO gap, but showed a significant decrease in the oscillator strength. Therefore, it was difficult to achieve both a longer absorption wavelength and absorbance. On the other hand, the model compounds (3 - 2a - 2 - 1), (3 - 2b - 2 - 1), (3 - 2c - 2 - 1), (3 - 2c - 5 - 1) substituted with a heteroquinoid group, which are model compounds of the compound (1) of the present invention, were able to reduce the HOMO - LUMO gap while maintaining the reference in the oscillator strength. Therefore, it was shown that the compound (1) of the present invention can achieve a longer absorption wavelength while maintaining absorbance, compared with conventional A - D - A type non - fullerene acceptor materials.

Industrial Applicability

[0123] The compound of the present invention can extend the absorption wavelength while maintaining absorbance, and is useful as a semiconductor material used in a photoelectric conversion element.

Explanation of Symbols

[0124] 10 Photoelectric conversion element 11 Transparent substrate 12 Transparent electrode 13 Hole transport layer 14 Photoelectric conversion layer 15 Electron transport layer 16 Metal electrode

Claims

1. A compound represented by the following general formula (1). A-D-A... (1) In general formula (1), each A is independently a group represented by any one of the following general formulas (2a) to (2c), and D is an electron-donating group composed of 2 to 20 rings. 【Chemical 1】 In general formulas (2a) to (2c), Z is an oxygen atom or a dicyanomethylene group, each Q is independently an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom, and X is a carbon atom substituted with a sulfur atom, an alkyl group, or an aryl group, a silicon atom substituted with an alkyl group or an aryl group, or a germanium atom substituted with an alkyl group or an aryl group.

2. The compound according to claim 1, wherein Z in the general formulas (2a) to (2c) is a dicyanomethylene group.

3. The compound according to claim 1, wherein Q in the general formulas (2a) to (2c) is a sulfur atom, and X is a carbon atom substituted with a sulfur atom, a dimethyl group, or a diphenyl group, or a silicon atom substituted with a dimethyl group or a diphenyl group.

4. The compound according to claim 1, wherein D in the general formula (1) is a group represented by any one of the following general formulas (3) to (5). 【Chemical 2】 In general formulas (3) to (5), W is C-(R １ ), ２ Si-(R １ ), ２ Ge-(R １ ), ２ N-R １ or CR １ -O, R １ is each independently an alkyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group, E, J, K, L are each independently composed of 1 to 4 rings and are an aryl group or a heteroaryl group containing an oxygen atom, a sulfur atom, a nitrogen atom, a silicon atom, a germanium atom or a selenium atom, G is a heteroaryl ring containing a nitrogen atom, s is a number from 0 to 1, and t is a number from 0 to 3.

5. -(E) in the general formulas (3) to (5) ｔ - is a heteroaryl group consisting of 3 to 4 condensed rings selected from optionally substituted thiophene, furan, selenophene, thienothiophene, bithiophene, terthiophene, fluorene or benzene, thiophene, furan, selenophene, cyclopentadiene, silole and pyrrole; J and K are each independently an optionally substituted phenyl group, furan, thiophene, selenophene or thienothiophene; L is an optionally substituted phenyl group, naphthyl group, thiophene, thienothiophene or a heteroaryl group consisting of 3 condensed rings selected from benzene, thiophene, furan, selenophene, cyclopentadiene, silole and pyrrole; G is thiadiazole, selenadiazole, triazole, benzoquinoxaline or diphenylpyrazine; s is 0. The compound according to claim 4.

6. The compound according to claim 1, represented by the following general formula (3a). 【Chemical Formula 3】 In the general formula (3a), each A is independently a group represented by any one of the general formulas (2a) to (2c), and Y １ ~Y ４ are each independently a hydrogen atom, an alkyl group, an alkoxy group, or an ester group, and M is a carbon atom substituted with an alkyl group or an aryl group, a silicon atom substituted with an alkyl group or an aryl group, or a germanium atom substituted with an alkyl group or an aryl group.

7. The compound according to claim 6, wherein M in the general formula (3a) is a carbon atom substituted with an alkyl group or an aryl group, or a silicon atom substituted with an alkyl group or an aryl group.

8. Y in the general formula (3a) １ and Y ２ are each independently an alkyl group, an alkoxy group or an ester group, and Y ３ and Y ４ is a hydrogen atom, the compound according to claim 6

9. In the general formula (3a), each A is independently a group represented by the general formula (2b) or (2c), and Y １ and Y ２ are the same and are an alkoxy group, Y ３ and Y ４ are hydrogen atoms, M is a carbon atom substituted with an alkyl group or an aryl group, and Z in the general formulas (2b) and (2c) is a dicyanomethylene group, Q is a sulfur atom, and X is a sulfur atom, a carbon atom substituted with a dimethyl group or a diphenyl group, or a silicon atom substituted with a dimethyl group or a diphenyl group. The compound according to claim 6.

10. A composition containing the compound according to any one of claims 1 to 9.

11. A film containing the compound according to any one of claims 1 to 9.

12. A photoelectric conversion element provided with the film according to claim 11.

13. A CMOS image sensor provided with the photoelectric conversion element according to claim 12.

Images