Compounds, compositions, films, photoelectric conversion elements, and CMOS image sensors

Abstract

Provided are a compound capable of increasing the absorption wavelength while suppressing the dark current of a photoelectric conversion element, a composition using this compound, a film, a photoelectric conversion element, and a CMOS image sensor. 【Solution means】 A compound represented by the following general formula (1). TIFF2026047587000028.tif44170 In general formula (1), X 1 ~X 8 are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, or a cyano group, and at least one of X 1 ~X 8 is a cyano group, Y 1 ~Y 4 are each independently a hydrogen atom, an alkyl group, an alkoxy group, or an ester group, and at least one of Y 1 ~Y 4 is an alkyl group, an alkoxy group, or an ester group, Z 1 and Z 2 are each independently an oxygen atom or a dicyanomethylene group, and M is a nitrogen atom substituted with an alkyl group or an aryl group.

Description

[Technical Field]

[0001] The present invention relates to compounds, compositions, films, photoelectric conversion elements, and CMOS image sensors suitable as semiconductor materials used in photoelectric conversion elements. [Background technology]

[0002] CMOS image sensors, which are equipped with photoelectric conversion elements, are used, for example, as image sensors in digital cameras and smartphones. CMOS image sensors include inorganic CMOS image sensors and organic CMOS image sensors, with inorganic CMOS image sensors using silicon photodiodes being the most commonly used. On the other hand, organic CMOS image sensors, by utilizing the high light absorption capacity of organic thin films, can achieve both high resolution and a wide dynamic range, as well as the incorporation of a global shutter that minimizes image distortion. Thus, organic CMOS image sensors are considered to be able to solve the problem of achieving both a high dynamic range and a global shutter, which is difficult for inorganic CMOS image sensors, and therefore there is a demand for materials suitable for organic CMOS image sensors.

[0003] Furthermore, in photoelectric conversion elements (hereinafter also referred to as "inorganic photoelectric conversion elements") used in inorganic CMOS image sensors, inexpensive silicon semiconductors are generally used for photoresponses up to an absorption wavelength of 1000 nm, but very expensive indium gallium arsenide (InGaAs) semiconductors are used when the absorption wavelength exceeds 1000 nm. Therefore, there is a demand for semiconductor materials that are inexpensive and can be used in the long-wavelength region, and organic semiconductor materials (hereinafter also referred to as "organic semiconductor materials") are attracting attention as candidates for such materials.

[0004] In photoelectric conversion elements (hereinafter also referred to as "organic photoelectric conversion elements") incorporated into organic CMOS image sensors, the photoelectric conversion capability and absorption wavelength range can be controlled by the molecular design of the p-type and n-type semiconductor materials used in the organic thin film (photoelectric conversion layer) that constitutes the photoelectric conversion element. In recent years, high photoelectric conversion capability has been reported in elements using non-fullerene acceptors as n-type semiconductor materials. In photoelectric conversion elements using non-fullerene acceptors, the role of controlling the absorption wavelength range is mainly played by the n-type semiconductor material. As n-type semiconductor materials (light-absorbing and electron-transporting materials), compounds having an electron acceptor (A) part and an electron donor (D) part, so-called ADA-type compounds, are known. The absorption wavelength of ADA-type compounds can be designed by reducing the HOMO-LUMO gap by selecting the electron-withdrawing properties of part A and the electron-donating properties of part D.

[0005] ADA-type compounds include a cyclopentadithiophene central donor (D) moiety and a thiophene ring (D) substituted with a specific substituent. 1 ), (D 2 ) with section D sandwiched between, AD 1 -DD 2 -A type compounds are known. For example, Non-Patent Literature 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'-DD”-A type compound, and a compound represented by the following formula (c) which is an AD”-DD”-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 Literature 1, the compound represented by the following formula (a) is said to achieve the longest absorption wavelength. The compound represented by the following formula (a) is a compound in which the alkyl group bonded to the thiophene ring in the D” portion of the compound represented by the following formula (b) or the following formula (c) is replaced with an alkoxy group, which is a strong electron-donating group, to form the D' portion.

[0006] [ka] [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] Jaewon Lee, et al., “ACS Energy Lett.”, 2019, Vol. 4, pp. 1401-1409. [Overview of the project] [Problems that the invention aims to solve]

[0008] Incidentally, in organic semiconductor materials, increasing the absorption wavelength results in a trade-off where dark current increases and sensor sensitivity decreases. This is because the HOMO-LUMO gap of the organic semiconductor material becomes smaller, increasing the probability of carrier generation by thermal excitation. Therefore, in ADA-type compounds used in photoelectric conversion elements, there is a need for compounds that can suppress the dark current of the photoelectric conversion element while achieving longer absorption wavelengths for the organic semiconductor material.

[0009] The present invention aims to provide a compound that can suppress the dark current of a photoelectric conversion element while extending the absorption wavelength, as well as a composition, film, photoelectric conversion element, and CMOS image sensor using this compound. [Means for solving the problem]

[0010] In view of the above-mentioned problems, the inventors investigated compounds that can suppress the dark current of a photoelectric conversion element while extending the absorption wavelength. Specifically, AD as shown in Non-Patent Document 1 1 -DD 2 - We investigated substituents in the A and D portions of the type A compound. As a result, we found that by having a dithienopyrrole structure in the D portion and substituting at least one of the terminals of the A portion with a cyano group, it is possible to suppress the dark current of the photoelectric conversion element while extending the absorption wavelength, thus completing the present invention.

[0011] That is, the present invention has the following aspects. [1] A compound represented by the following general formula (1).

[0012] [Chemical formula]

[0013] In the general formula (1), X 1 ~X 8 are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom or a cyano group, and among X 1 ~X 8 , at least one is a cyano group, Y 1 ~Y 4 are each independently a hydrogen atom, an alkyl group, an alkoxy group or an ester group, and among Y 1 ~Y 4 , at least one is an alkyl group, an alkoxy group or an ester group, Z 1 and Z 2 are each independently an oxygen atom or a dicyanomethylene group, and M is a nitrogen atom substituted with an alkyl group or an aryl group.

[0014] [2] The compound according to [1], wherein in the general formula (1), all of Z 1 are dicyanomethylene groups and all of Z 2 [[ID=4�]]are oxygen atoms. [3] The compound according to [1] or [2], wherein in the general formula (1), X 1 , X 4 , X 5 and X 8 are hydrogen atoms, and X 2 , X 3 , X 6 and X 7 are cyano groups. [4] The compound according to any one of [1] to [3], wherein in the general formula (1), M is a nitrogen atom substituted with an alkyl group. [5] One of Y 1 and Y 3 in the general formula (1) is a hydrogen atom and the other is an alkyl group, an alkoxy group or an ester group, and Y2 and Y 4 A compound of any of the above [1] to [4], wherein one of the atoms is a hydrogen atom and the other is an alkyl group, an alkoxy group, or an ester group. [6] Y in the general formula (1) 3 and Y 4 Y is a hydrogen atom, 1 and Y 2 A compound of any of the above [1] to [5], wherein each of the groups is independently an alkyl group, an alkoxy group, or an ester group. [7] X in the general formula (1) 1 , X 4 , X 5 and X 8 X is a hydrogen atom, 2 , X 3 , X 6 and X 7 The cyano group is Y 3 and Y 4 Y is a hydrogen atom, 1 and Y 2 The alkoxy group is Z 1 Both are dicyanomethylene groups, Z 2 A compound of any of the above [1] to [6], wherein all of are oxygen atoms and M is a nitrogen atom substituted with an alkyl group. [8] Y in the general formula (1) 2 and Y 3 Y is a hydrogen atom, 1 and Y 4 A compound of any of the above [1] to [5], wherein each of the groups is independently an alkyl group, an alkoxy group, or an ester group. [9] X in the general formula (1) 1 , X 4 , X 5 and X 8 X is a hydrogen atom, 2 , X 3 , X 6 and X 7 The cyano group is Y 2 and Y 3 Y is a hydrogen atom, 1 and Y 4 Each of these is independently an alkyl group or an alkoxy group, Z 1Both are dicyanomethylene groups, Z 2 A compound of any of the above [1] to [5], [8], wherein all of are oxygen atoms and M is a nitrogen atom substituted with an alkyl group.

[10] A composition containing any of the compounds described in [1] to [9] above.

[11] A membrane containing any of the compounds described in [1] to [9] above.

[12] A photoelectric element comprising the film described in

[11] .

[13] A CMOS image sensor equipped with the photoelectric conversion element described in

[12] above. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a compound that can suppress the dark current of a photoelectric conversion element while extending the absorption wavelength, as well as a composition, film, photoelectric conversion element, and CMOS image sensor using this compound. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic cross-sectional view showing an example of an embodiment of the photoelectric conversion element of the present invention. [Modes for carrying out the invention]

[0017] The present invention will be described in more detail below with reference to preferred embodiments, but the following description is merely one example of an embodiment of the present invention, and the present invention is not limited to the following description unless it exceeds the gist of the invention. In this specification, the "~" symbol indicating a numerical range means that the values ​​before and after it are included as the lower and upper limits, respectively.

[0018] [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).

[0019] [ka]

[0020] In general formula (1), X 1 ~X 8 Each of these is independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, or a cyano group, and X 1 ~X 8 Of these, at least one is a cyano group, Y 1 ~Y 4 Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, or an ester group, Y 1 ~Y 4 Of these, at least one is an alkyl group, an alkoxy group, or an ester group, Z 1 and Z 2 Each of these is independently an oxygen atom or a dicyanomethylene group, and M is a nitrogen atom substituted with an alkyl or aryl group.

[0021] The compound of the present invention is AD 1 -DD 2 -The A-type compound has a dithienopyrrole structure in the D portion, and at least one of the A-terminus is substituted with a cyano group, which allows for the absorption wavelength to be lengthened while suppressing the dark current of the photoelectric conversion element.

[0022] The reason why the compound of the present invention can suppress the dark current of the photoelectric conversion element while extending the absorption wavelength is not clear, but it is presumed to be as follows. The compound of the present invention has substituents on the nitrogen atom at the center of the dithienopyrrole structure of the D portion that extend outwards from the π-conjugated plane, while D 1 Department and D 2 In this compound, substituents extend in the same direction on the π-conjugated plane. Therefore, in the compound of the present invention, substituents extending from the π-conjugated plane between molecules tend to slip without overlapping, forming a π-stack structure. On the other hand, substituents on the π-conjugated plane between molecules form a lamellar structure, so the compound of the present invention is considered to be a compound capable of having a densely packed structure. Furthermore, the central nitrogen atom has a lone pair of electrons in the p-orbital, making it excellent at electron-donating and suitable for incorporation into the D-part. Moreover, in the compound of the present invention, at least one of the terminals of the A part of the A-D 1 -D-D 2 -type compound having a dense packing structure is substituted with a cyano group that is more likely to exhibit intermolecular interaction than the conventional A-D 1 -D-D 2 -type compound. Therefore, in the direction orthogonal to the lamellar structure (i.e., the long axis direction of the π-conjugated skeleton of the molecule), the dense packing structure between the A-D 1 -D-D 2 -type compounds is promoted, and it is considered that the charge separation between the n-type semiconductor material and the p-type semiconductor material under dark conditions can be suppressed. Thus, the compound of the present invention can achieve both the elongation of the absorption wavelength due to strong electron-withdrawing properties and the suppression of the increase in dark current due to the dense packing structure, in addition to the packing structure due to the characteristic direction of the substituent in the D 1 -D-D 2 part in the A-D 1 -D-D 2 -type compound by substituting at least one of the terminals of the A part with a cyano group.

[0023] In the general formula (1), X<关于标签 1 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 1 ~X<关于标签 8 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 8 are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom or a cyano group, and at least one of X<关于标签 1 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 1 ~X<关于标签 8 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 8 is a cyano group. The compound (1) is considered to be able to maintain and improve the electron-withdrawing property of the A part by X<关于标签 1 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 1 ~X<关于标签 8 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 8 being a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom or a cyano group. Furthermore, at least one of X<关于标签<0OO0097>的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 1 ~X<关于标签 8 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 8 being a cyano group can suppress the increase in dark current due to the dense packing structure in addition to the elongation of the absorption wavelength due to strong electron-withdrawing properties. In particular, X<关于标签《 2 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 2 、X<关于标签 3 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 3 、X<关于标签 6 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 6 及びX<关于标签 7 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 7 are preferably cyano groups from the point of promoting the dense packing structure between the compounds more. X<关于标签 1 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 1 、X<关于标签 4 的说明:此处标签可能是用于特定指代或进一步说明的标识,在英文翻译中保留原样,不做翻译。 4 、X5 and X 8 In terms of ease of synthesis, it is preferable that the X of compound (1) be a hydrogen atom. 1 , X 4 , X 5 and X 8 X is a hydrogen atom, 2 , X 3 , X 6 and X 7 It is preferable that the group is a cyano group. In another embodiment, X of compound (1) 1 , X 4 , X 5 and X 8 X is a hydrogen atom, 2 , X 3 , X 6 and X 7 Each of these is independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, or a cyano group, and X 2 , X 3 , X 6 and X 7 Of these, one to three, preferably two or three, may be cyano groups. In this case, X 2 , X 3 , X 6 and X 7 The remaining part is preferably a hydrogen atom, X 2 , X 3 , X 6 and X 7 It is more preferable that one or two of them are hydrogen atoms.

[0024] In general formula (1), Y 1 ~Y 4 Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, or an ester group, Y 1 ~Y 4 Of these, at least one is an alkyl group, an alkoxy group, or an ester group. Y 1 ~Y 4 The number of carbon atoms in the alkyl group is preferably small from the standpoint of the material's conductivity. Therefore, Y 1 ~Y 4The number of carbon atoms in the alkyl group is preferably 30 or less, more preferably 20 or less, even more preferably 15 or less, and particularly preferably 10 or less. Also, Y 1 ~Y 4 The alkyl group preferably has 2 or more carbon atoms, more preferably 4 or more, even more preferably 6 or more, and particularly preferably 8 or more. The above upper and lower limits can be combined in any way. For example, Y 1 ~Y 4 The number of carbon atoms in the alkyl group may be 2 to 30, 4 to 20, 6 to 15, or 8 to 10. Y 1 ~Y 4 The alkyl group may be linear or cyclic. If the alkyl group is linear, it may be linear or branched. From the viewpoint of ease of synthesis, it is preferable that the alkyl group is linear or branched in which the carbon atom bonded to the thiophene ring is a primary carbon atom. From the viewpoint of solubility of the material, it is preferable that the alkyl group is branched in which the carbon atom bonded to the thiophene ring is a primary carbon atom, or that the alkyl group is linear, branched, or cyclic in which the carbon atom bonded to the thiophene ring is a secondary carbon atom. From the viewpoint of ease of synthesis and solubility, it is even more preferable that the alkyl group is branched in which the carbon atom bonded to the thiophene ring is a primary carbon atom.

[0025] Y 1 ~Y 4 The number of carbon atoms in the alkoxy group is preferably small from the standpoint of the conductivity of the material. Therefore, Y 1 ~Y 4 The number of carbon atoms in the alkoxy group is preferably 30 or less, more preferably 20 or less, even more preferably 15 or less, and particularly preferably 10 or less. 1 ~Y 4 The alkoxy group preferably has 2 or more carbon atoms, more preferably 4 or more, even more preferably 6 or more, and particularly preferably 8 or more. The above upper and lower limits can be combined in any way. For example, Y 1 ~Y4 The number of carbon atoms in the alkoxy group may be 2 to 30, 4 to 20, 6 to 15, or 8 to 10. An alkoxy group has a structure in which an alkyl group is bonded to an oxygen atom, and 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 linear or branched. In terms of ease of synthesis, it is preferable that the carbon atom bonded to the oxygen atom is a linear or branched alkyl group in which the carbon atom is a primary carbon atom. In terms of solubility of the material, it is preferable that the carbon atom bonded to the oxygen atom is a branched alkyl group in which the carbon atom is a primary carbon atom, or a linear, branched, or cyclic alkyl group in which the carbon atom bonded to the oxygen atom is a secondary carbon atom, more preferably a linear, branched, or cyclic alkyl group in which the carbon atom bonded to the oxygen atom is a secondary carbon atom, and even more preferably a linear or branched alkyl group in which the carbon atom bonded to the oxygen atom is a secondary carbon atom.

[0026] Y 1 ~Y 4 Examples of ester groups include monovalent groups having an ester bond. Specifically, examples include the group represented by the following general formula (i). -COO-R 1 ...(i) In general formula (i), R 1 It is an alkyl group or an aryl group. R 1 The number of carbon atoms in the alkyl group is preferably small from the standpoint of the material's conductivity. Therefore, R 1 The number of carbon atoms in the alkyl group is preferably 30 or less, more preferably 20 or less, even more preferably 15 or less, and particularly preferably 10 or less. 1 The alkyl group preferably has 1 or more carbon atoms, more preferably 4 or more, even more preferably 6 or more, and particularly preferably 8 or more. The above upper and lower limits can be combined in any way. For example, R 1The number of carbon atoms in the alkyl group may be 1 to 30, 4 to 20, 6 to 15, or 8 to 10. R 1 The alkyl group may be linear or cyclic. If the alkyl group is linear, it may be linear or branched. In terms of ease of synthesis, it is preferable that the alkyl group is linear or branched in which the carbon atom bonded to the oxygen atom is a primary carbon atom. In terms of solubility of the material, it is preferable that the alkyl group is branched in which the carbon atom bonded to the oxygen atom is a primary carbon atom, or linear, branched, or cyclic in which the carbon atom bonded to the oxygen atom is a secondary carbon atom, more preferably linear, branched, or cyclic in which the carbon atom bonded to the oxygen atom is a secondary carbon atom, and even more preferably linear or branched in which the carbon atom bonded to the oxygen atom is a secondary carbon atom.

[0027] R 1 The number of carbon atoms in the aryl group is preferably small from the standpoint of the material's electrical conductivity. Therefore, R 1 The number of carbon atoms in the aryl group is preferably 18 or less, more preferably 12 or less, even more preferably 10 or less, and particularly preferably 6. 1 The lower limit of the number of carbon atoms in the aryl group is 6. The above upper and lower limits can be combined arbitrarily. For example, R 1 The number of carbon atoms in the aryl group may be 6 to 18, 6 to 12, 6 to 10, or 6. R 1 The aryl group may or may not have substituents. That is, R 1 The aryl group is either unsubstituted or substituted. Examples of substituents include alkyl groups, alkoxy groups, hydroxyl groups, and amino groups.

[0028] Y 1 ~Y 4 They may be the same or different. In particular, Y is chosen because it is easy to form a lamellar structure in a film obtained using the compound of the present invention.1 and Y 3 One of them is a hydrogen atom, and the other is an alkyl group, alkoxy group, or ester group, Y 2 and Y 4 Preferably, one of the atoms is a hydrogen atom, and the other is an alkyl group, an alkoxy group, or an ester group. In terms of ease of synthesis, Y is superior to M. 1 ~Y 4 So that it is symmetric, that is, Y 1 and Y 2 It is preferable that they are the same, Y 3 and Y 4 It is preferable that they be the same, and among them in particular, Y is preferred in terms of extending the absorption wavelength. 3 and Y 4 Y is a hydrogen atom, 1 and Y 2 It is more preferable that is an alkyl group, an alkoxy group, or an ester group, Y 3 and Y 4 Y is a hydrogen atom, 1 and Y 2 It is even more preferable that the group is an alkoxy group. Furthermore, in another aspect, since the orientation of the substituents becomes parallel and it is easier to form a lamellar structure, Y is used in relation to M. 1 ~Y 4 To make it asymmetric, that is, Y 2 and Y 3 Y is a hydrogen atom, 1 and Y 4 Preferably, each of these is independently an alkyl group, an alkoxy group, or an ester group, Y 2 and Y 3 Y is a hydrogen atom, 1 and Y 4 It is more preferable that each of them is independently an alkyl group or an alkoxy group, Y 2 and Y 3 Y is a hydrogen atom, 1 and Y 4 It is even more preferable that one of the groups is an alkyl group and the other is an alkoxy group.

[0029] In general formula (1), Z 1 and Z2 Each of these is independently either an oxygen atom or a dicyanomethylene group. Compound (1) is Z 1 and Z 2 It is thought that the oxygen atom or dicyanomethylene group can act as an electron-withdrawing group in the acceptor part. 1 and Z 2 Both are preferably dicyanomethylene groups in terms of further enhancing electron-withdrawing properties. Also, in terms of ease of synthesis, Z 1 Both are dicyanomethylene groups, Z 2 Preferably, all of them are oxygen atoms.

[0030] In general formula (1), M is a nitrogen atom substituted with an alkyl group or an aryl group. Compound (1) is thought to have increased solubility because M is a nitrogen atom substituted with an alkyl group or an aryl group. A nitrogen atom substituted with an alkyl or aryl group is represented by the following general formula (ii).

[0031] [ka]

[0032] In general formula (ii), R 2 and R 3 Each of these is independently an alkyl group or an aryl group. R 2 and R 3 As for alkyl groups, Y 1 ~Y 4 In the explanation, the previously given example was R 1 Examples of alkyl groups include: R 2 and R 3 As for the aryl group, Y 1 ~Y 4 In the explanation, the previously given example was R 1 Examples include the aryl group. In terms of ease of synthesis of compound (1), it is preferable that the two alkyl or aryl groups on the nitrogen atom are identical. From the viewpoint of solubility, M is preferably a nitrogen atom substituted with an alkyl group.

[0033] As for compound (1), X in general formula (1) 1 , X 4 , X 5 and X 8 X is a hydrogen atom, 2 , X 3 , X 6 and X 7 The cyano group is Y 3 and Y 4 Y is a hydrogen atom, 1 and Y 2 The alkoxy group is Z 1 Both are dicyanomethylene groups, Z 2 Compounds in which all atoms are oxygen atoms and M is a nitrogen atom substituted with an alkyl group are preferred. In another embodiment, compound (1) is X in general formula (1). 1 , X 4 , X 5 and X 8 X is a hydrogen atom, 2 , X 3 , X 6 and X 7 The cyano group is Y 2 and Y 3 Y is a hydrogen atom, 1 and Y 4 Each of these is independently an alkyl group or an alkoxy group, Z 1 Both are dicyanomethylene groups, Z 2 Compounds in which both are oxygen atoms and M is a nitrogen atom substituted with an alkyl group are preferred, and among these, Y 1 and Y 4 A compound in which one of the groups is an alkyl group and the other is an alkoxy group is more preferable, Y 1 is an alkoxy group, Y 4 Compounds that are alkyl groups are most preferred. Specific examples of compound (1) include the compounds represented by formulas (1-1) to (1 to 35) below, but compound (1) is not limited to these. In this specification, for example, the compound represented by formula (1-1) below is also referred to as "compound (1-1)". The same applies to the compounds represented by formulas (1-2) to (1 to 35) below.

[0034] [ka]

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] [ka]

[0039] Among the compounds mentioned above, Y 1 ~Y 4 Compounds in which at least one of the rings is an alkoxy group, and in that 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 (i.e., compounds in which the alkoxy group bonded to the thiophene ring is branched at position 1) exhibit particularly excellent solubility. Examples of such compounds include compounds (1-1) to (1-16) and (1-33) to (1-35).

[0040] The method for producing compound (1) is not particularly limited, but as an example of a method for producing compound (1), the method for producing compound (A) shown in the following formula will be specifically explained. In compound (A), Y is the same as Y in compound (1). 1 ~Y 4 It corresponds to one of the following, and Z in compound (A) is Z in compound (1). 1 It corresponds to this.

[0041] [ka]

[0042] First, the compound (B), which is a 3-substituted thiophene, is reacted with lithium diisopropylamide (LDA) in a reaction solvent, and then N,N-dimethylformamide is reacted further to obtain the compound (C) shown below.

[0043] [ka]

[0044] The preferred ratio of raw materials is 0.9 to 1.5 equivalents of LDA and 0.9 equivalents or more of N,N-dimethylformamide relative to compound (B). 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 compound. 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.

[0045] Compound (B) may be synthesized by known methods, or a commercially available product may be used. For example, compound (B), in which Y is an alkoxy group, the alkyl group bonded to the oxygen atom in the alkoxy group is linear, branched, or cyclic, and the carbon atom bonded to the oxygen atom is a secondary carbon atom, can be obtained by reacting commercially available 3-methoxythiophene with a secondary alcohol in a reaction solvent. Here, the secondary alcohol may be synthesized by known methods, or a commercially available product may be used. The preferred ratio of raw materials is 0.9 to 1.5 equivalents of secondary alcohol and 0.1 to 0.5 equivalents of sodium bisulfate relative to 3-methoxythiophene. The reaction solvent is not particularly limited as long as it does not react with the starting compound; for example, aromatic hydrocarbon solvents such as toluene and xylene can be used. The reaction temperature is preferably between room temperature and reflux temperature. The reaction time is preferably 1 to 24 hours.

[0046] Next, compound (C) and N-bromosuccinimide (NBS) are reacted in a reaction solvent to obtain compound (D) shown in the following formula.

[0047] [ka]

[0048] The ratio of raw materials is preferably 0.9 to 1.2 equivalents of NBS relative to compound (C), and more preferably 0.9 to 1.05 equivalents. Bromine may be used instead of NBS. The reaction solvent is not particularly limited as long as it does not react with the starting compound, and examples include saturated aliphatic hydrocarbon solvents such as hexane; ether solvents such as tetrahydrofuran (THF); aromatic hydrocarbon solvents such as toluene and xylene; halogenated solvents such as chloroform; and N,N-dimethylformamide. The reaction temperature is preferably -78 to 50°C. The reaction time is preferably 10 minutes to 24 hours after adding NBS.

[0049] In the preparation of compound (A), compound (E) shown below may be used instead of compound (D). Compound (E) can be obtained, for example, as follows.

[0050] Specifically, first, compound (B) and lithium diisopropylamide (LDA) are reacted in a reaction solvent, and then 1,2-dibromo-1,1,2,2-tetrachloroethane is reacted further to obtain compound (D') shown in the following formula.

[0051] [ka]

[0052] The preferred ratio of raw materials is 0.9 to 1.5 equivalents of LDA relative to compound (B), and 0.9 equivalents or more of 1,2-dibromo-1,1,2,2-tetrachloroethane. The reaction solvent is not particularly limited as long as it does not react with the starting compound. 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 1,2-dibromo-1,1,2,2-tetrachloroethane.

[0053] Next, compound (D') and lithium diisopropylamide (LDA) are reacted in a reaction solvent, and then N,N-dimethylformamide is further reacted to obtain compound (E) shown in the formula below.

[0054] [ka]

[0055] The preferred ratio of raw materials is 0.9 to 1.5 equivalents of LDA and 0.9 equivalents or more of N,N-dimethylformamide relative to compound (D'). 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 compound. 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.

[0056] Next, in the reaction solvent, a cross-coupling reaction is carried out between at least one of compound (D) and compound (E) and compound (F) of the following formula to obtain compound (G) of the following formula. The method for producing compound (G) is not particularly limited, but for example, compound (G) can be produced by a method similar to the method described in Chinese Patent Application Publication No. 114106581, Japanese Patent Publication No. 7448103, and Japanese Patent Publication No. 2022-030124. An example of specific production conditions is as follows.

[0057] [ka]

[0058] Here, compound (F) may be synthesized by known methods (for example, Chinese Patent Application Publication No. 114106581, Japanese Patent No. 7448103, or Journal of Materials Chemistry, 2011, Vol. 21, p. 3895), or a commercially available product may be used. Alternatively, compound (F) may be used depending on the cross-coupling reaction (where "L" in compound (F) is an alkyltin group, boric acid, boric acid ester group, zinc halide, magnesium halide, or silyl group, etc.). The type of cross-coupling reaction between compound (D) and compound (E) and compound (F) is not particularly limited, and 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, nickel catalyst, or copper catalyst. When compound (D) or compound (E) is reacted with compound (F) by Stille coupling reaction, the preferred ratio of raw materials is 1.9 to 3.0 equivalents of compound (D) or compound (E) relative to compound (F). When compound (D) and compound (E) are reacted with compound (F) by Stille coupling reaction, the preferred ratio of raw materials is 0.9 to 1.1 equivalents each of compound (D) and compound (E) relative to compound (F). Furthermore, it is preferable to use a palladium catalyst in the Stille coupling reaction, and the palladium content in the catalyst is preferably 0.1 to 50 mol%. The reaction solvent is not particularly limited as long as it does not react with the starting compound, and examples include saturated aliphatic hydrocarbon solvents such as hexane; ether solvents such as diethyl ether, cyclopentyl methyl ether, tetrahydrofuran (THF), and 1,4-dioxane; aromatic hydrocarbon solvents such as toluene and xylene; and N,N-dimethylformamide (DMF), dimethyl sulfoxide, and N-methyl-2-pyrrolidone. The reaction temperature is preferably between 20°C and the reflux temperature of the reaction solvent. The reaction time is preferably 1 to 24 hours.

[0059] Next, compound (G) and compound (I) are reacted in a reaction solvent in the presence of an acid catalyst to obtain compound (A). The method for producing compound (A) is not particularly limited, but for example, compound (A) can be produced by a method similar to the method described in Japanese Patent Publication No. 2022-511781 and Japanese Patent Publication No. 2023-500815. An example of specific production conditions is as follows.

[0060] [ka]

[0061] Here, compound (I) can be synthesized by known methods (for example, Japanese Patent Publication No. 2022-511781, Japanese Patent Publication No. 2023-500815). Examples of acid catalysts include p-toluenesulfonic acid hydrate (PTSA·H2O). The preferred ratio of raw materials is 1.9 to 10 equivalents of compound (I) relative to compound (G). The preferred amount of p-toluenesulfonic acid hydrate is 2.1 to 11 equivalents. The reaction solvent is not particularly limited as long as it does not react with the starting compound. For example, an alcohol-based solvent such as methanol or ethanol may be mixed with an aromatic hydrocarbon solvent such as toluene or xylene. The reaction temperature is preferably between room temperature and reflux temperature. The reaction time is preferably 1 to 6 hours.

[0062] In this way, compound (A) can be produced. Here, Y in compound (A) is the same as Y in compound (1). 1 ~Y 4 It will be one of the following, and Z in compound (A) is Z in compound (1). 1 This is the result.

[0063] The compound of the present invention is suitable as an n-type semiconductor material (light-absorbing material and electron-transporting material) used in photoelectric conversion elements because it can suppress the dark current of the photoelectric conversion element while extending the absorption wavelength. The applications of the compounds of the present invention are not limited to those described above. For example, since the compounds of the present invention also have excellent luminescence properties, they can be used in bioimaging, organic EL, near-infrared luminescent dyes for wavelength conversion films and compositions, etc.

[0064] [Composition] The composition of the present invention contains the above-described compound (1). Compound (1) may be used alone, or two or more compounds may be used in any proportion and combination. 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 high in terms of light absorption, and preferably low in terms of carrier balance. Therefore, the content of compound (1) in the composition of the present invention is preferably 10% by mass or more, more preferably 25% by mass or more, and even more preferably 40% by mass or more, relative to the total amount (total mass) of all components other than the solvent. Furthermore, the content of compound (1) in the composition of the present invention 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, relative to the total amount (total mass) of all components other than the solvent. The above upper and lower limits can be combined arbitrarily. For example, the content of compound (1) may be 10 to 100% by mass, 10 to 90% by mass, 25 to 75% by mass, or 40 to 60% by mass.

[0065] The composition of the present invention may further contain a solvent. A composition containing compound (1) and a solvent is suitable as an ink (active layer forming composition) for forming the photoelectric conversion layer (active layer) of a photoelectric conversion element. As a solvent, a liquid that does not react with compound (1) but dissolves compound (1) is preferred, such as aromatic hydrocarbon solvents like toluene and xylene; and halogenated solvents like dichloromethane and chloroform. If the composition of the present invention contains a solvent, the solvent may be used alone or two or more solvents in any proportion or combination. If 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 even more preferably 1% by mass or more, based on the total mass of the composition of the present invention. Furthermore, the content of compound (1) is preferably 5% by mass or less, more preferably 3.5% by mass or less, and even more preferably 2% by mass or less, based on the total mass of the composition of the present invention. The above upper and lower limits can be combined arbitrarily. For example, the content of compound (1) may be 0.1 to 5% by mass, 0.5 to 3.5% by mass, or 1 to 2% by mass.

[0066] When the composition of the present invention is used as an active layer forming composition, it is preferable that the composition 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 is used in the photoelectric conversion layer of an organic photoelectric conversion element, but examples include polymers described in the literature (ACS Energy Lett., 2019, Vol. 4, p. 1401. and 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 two or more types may be used in any proportion and combination. The mass ratio of compound (1) to the p-type semiconductor material (compound (1) / p-type semiconductor material) is preferably 0.1 or higher, more preferably 0.5 or higher, and even more preferably 0.75 or higher. Furthermore, the mass ratio of compound (1) to the p-type semiconductor material is preferably 3 or less, more preferably 2 or less, and even more preferably 1.5 or less. The above upper and lower limits can be combined arbitrarily. For example, the mass ratio of compound (1) to the p-type semiconductor material may be 0.1 to 3, 0.5 to 2, or 0.75 to 1.5.

[0067] The composition of the present invention may further contain components other than compound (1), a p-type semiconductor material, and a solvent (optional components), as long as they do not impair the effects of the present invention. Optional components include, for example, 1,8-diiodoctane and 1-chloronaphthalene. If the composition of the present invention contains optional components, these optional components may be used alone or in any combination of two or more components in any proportion. When an optional component is included, a higher content of the optional component is preferable in that the effects of including the optional component are more likely to manifest. On the other hand, a higher content of compound (1) is preferable in that the composition of the present invention is more likely to maintain suitable physical properties as a photoelectric conversion element. Therefore, when the composition of the present invention includes an optional component, the content of the optional component is preferably 0.1% by mass or more, and more preferably 0.3% by mass or more, relative to the total amount (total mass) of all components other than the solvent in the composition of the present invention. Furthermore, the content of the optional component is preferably 2% by mass or less, and more preferably 1% by mass or less, relative to the total amount (total mass) of all components other than the solvent in the composition of the present invention. The above upper and lower limits can be combined arbitrarily. For example, the content of the optional component may be 0.1 to 2% by mass, or 0.3 to 1% by mass.

[0068] The compositions of the present invention can be obtained, for example, by dissolving compound (1) in a solvent and, if necessary, a p-type semiconductor material and one or more optional components. Furthermore, by removing the solvent from the obtained composition, a solvent-free composition of the present invention can be obtained.

[0069] The composition of the present invention is suitable as an ink (active layer forming composition) for forming the photoelectric conversion layer (active layer) of a photoelectric conversion element.

[0070] [film] The film of the present invention is a film containing the above-mentioned compound (1), and is also called 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 that contains the solvent. Specifically, it can be obtained by coating the composition of the present invention containing the solvent onto a substrate and then drying it. The content of compound (1) in the membrane is the same as the content of compound (1) relative to the total amount (total mass) of all components other than the solvent in the composition of the present invention described above. That is, the content of compound (1) relative to the total mass of the membrane is preferably 10% by mass or more, more preferably 25% by mass or more, and even more preferably 40% by mass or more. Furthermore, the content of compound (1) relative to the total mass of the membrane 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. The above upper and lower limits can be combined arbitrarily. For example, the content of compound (1) may be 10 to 100% by mass, 10 to 90% by mass, 25 to 75% by mass, or 40 to 60% by mass.

[0071] In terms of light absorption, a thicker film thickness is preferable. On the other hand, in terms of 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, a thinner film thickness is preferable. Therefore, the film thickness is preferably 10 nm or more, and more preferably 100 nm or more. Furthermore, the film thickness is preferably 2000 nm or less, and more preferably 1000 nm or less. The above upper and lower limits can be combined arbitrarily. For example, the film thickness may be 10 to 2000 nm, or 100 to 1000 nm. The film thickness can be adjusted by the amount of composition applied to the substrate.

[0072] The method of applying the composition is not particularly limited, but examples include brush application, bar coating, spray coating, dip coating, spin coating, and curtain coating. The drying temperature after application is preferably 20 to 250°C. The drying time is preferably between 10 minutes and 5 hours.

[0073] The film of the present invention is suitable as a photoelectric conversion layer (active layer) of a photoelectric conversion element.

[0074] [Photoelectric conversion element] The photoelectric conversion element of the present invention is an element comprising the film of the present invention as described above, and is also called an organic photoelectric conversion element. Specifically, the photoelectric conversion element of the present invention comprises the film of the present invention as a 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, refer to Japanese Patent Application Publication No. 2007-324587. The specific structure is not particularly limited, but 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 used.

[0075] An example of the photoelectric conversion element of the present invention will be described below with reference to Figure 1. Please note that, for the sake of clarity, the drawings used in the following description may show enlarged versions of key features, and the dimensional ratios of each component may differ from those of the actual components. Furthermore, the materials, dimensions, etc., exemplified in the following description are merely examples, and the present invention is not limited to them. It can be implemented with appropriate modifications without altering its essence.

[0076] The photoelectric conversion element 10 shown in Figure 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 stacked in this order on a transparent substrate 11. Furthermore, the hole transport layer 13 and the electron transport layer 15 may be swapped in their positions. 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 stacked on a transparent substrate in that order.

[0077] The transparent substrate 11 may be a substrate having an average transmittance of 80% or more in visible light of 450 nm or higher. Examples of materials for forming the transparent substrate 11 include glass; and plastics such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, and polyethylene sulfide.

[0078] The transparent electrode 12 is an electrode having an average transmittance of 80% or more in visible light of 450 nm or higher. The material used to form the transparent electrode 12 is not particularly limited as long as it can form the transparent electrode 12, but examples include tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), tungsten-doped indium oxide (IWO), zinc-aluminum oxide (AZO), indium oxide (In2O3), zinc oxide (ZnO), and titanium oxide (TiO2).

[0079] The metal electrode 16 is an electrode that is paired with the transparent electrode 12. The material constituting the metal electrode 16 is not particularly limited, but examples include metals or alloys thereof such as gold, platinum, silver, aluminum, nickel, titanium, magnesium, calcium, barium, sodium, chromium, copper, and cobalt. The metal electrode 16 is preferably a transparent electrode or a reflective electrode. That is, the photoelectric conversion element is preferably a laminated structure in which a photoelectric conversion layer (active layer) is sandwiched between a pair of electrodes (transparent or metal), and more preferably 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 forming the electrodes may be of the same type or of different types. The film thickness of the metal electrode 16 is not particularly limited, but approximately 10 nm is preferred from the viewpoint of improving transparency. If transparency is not required, for example, considering durability, 40 nm or more is preferred, and 100 nm or more is more preferred.

[0080] The method for forming the transparent electrode 12 and the metal electrode 16 is not particularly limited, but they can be formed by, for example, a dry process such as vacuum deposition or sputtering; or a wet process using conductive ink or the like.

[0081] There are no particular restrictions on the components and manufacturing methods when a hole transport layer 13 and an electron transport layer 15 are provided, and known technologies can be used. For example, the components and manufacturing methods described in International Publication No. 2013 / 171517, International Publication No. 2013 / 180230, and Japanese Patent Application Publication No. 2012-191194 can be used.

[0082] The photoelectric conversion layer 14 is a layer that absorbs light and separates electric 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 above-described composition of the present invention onto a layer that will be beneath the photoelectric conversion layer 14, such as the hole transport layer 13, and then drying it.

[0083] 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 on a transparent substrate 11 in this order.

[0084] The photoelectric conversion element of the present invention has a photoelectric conversion layer 14 containing compound (1), which allows for the absorption wavelength to be extended while suppressing dark current, and thus provides high sensor sensitivity on the longer wavelength side.

[0085] [CMOS image sensor] The CMOS image sensor of the present invention comprises 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. For example, one can refer to Japanese Patent Application Publication No. 2021-57422, and is not particularly limited. More specifically, an example of a CMOS image sensor is a structure in which metal wiring, the photoelectric conversion element of the present invention, a color filter, and a microlens are stacked in this order on a substrate such as a silicon substrate. [Examples]

[0086] The present invention will be described in more detail below with reference to examples, but the following examples are not intended to limit the scope of the present invention.

[0087] [Synthesis of compound (1-1)] Compound (B-1) shown below was synthesized using the same method as described in the publicly available literature (New J. Chem., 2020, Vol. 44, p. 8032). Using the obtained compound (B-1), compound (C-1) was synthesized using the same method as described in the publicly available literature (J.Mater.Chem.A, 2020, Vol. 8, p. 5163). Compound (B-1) 1 The 1H-NMR measurement data is shown below. 1H-NMR (400MHz, solvent: CDCl3, ppm): δ7.14(dd,1H), 6.74(dd,1H), 6.21(dd,1H), 4. 00(quin,1H), 1.71-1.58(m,4H), 1.50-1.28(m,6H), 0.95(t,3H), 0.88(t,3H). Compound (C-1) 1 The 1H-NMR measurement data is shown below. 1 H-NMR (400MHz, solvent: CDCl3, ppm): δ9.81(s,1H), 7.40(dd,1H), 6.73(m,1H), 4.0 3(quin,1H), 1.72-1.57(m,4H), 1.45-1.29(m,6H), 0.96(t,3H), 0.87(t,3H).

[0088] [ka]

[0089] Next, 4.99 g (20.7 mmol) of compound (C-1) was dissolved in 40 mL of acetonitrile. 3.73 g (20.9 mmol) of N-bromosuccinimide was slowly added. After stirring at room temperature for 1 hour, water and hexane were added, and the organic layer was washed three times with water. After drying over anhydrous sodium sulfate, the compound was purified by silica gel chromatography to obtain the compound (yield 98%). 1 1H-NMR analysis confirmed that the obtained compound was compound (D-1). 1 The 1H-NMR measurement data is shown below. 1 H-NMR (400MHz, solvent: CDCl3, ppm): δ9.70(s,1H), 7.33(s,1H), 4.10(quin,1H), 1.73-1.59(m,4H), 1.45-1.29(m,6H), 0.96(t,3H), 0.88(t,3H).

[0090] [ka]

[0091] Separately, using commercially available compounds, the compound (F-1) shown below was synthesized by the same method as described in the publicly available literature (Journal of Materials Chemistry, 2011, Vol. 21, p. 3895). Compound (F-1) 1 The 1H-NMR measurement data is shown below. 1 H-NMR (400MHz, solvent: CDCl3, ppm): δ6.99(s,2H), 4.45(sep,1H), 2.07-1.98(m,2H), 1.86-1.79(m,2H), 1.34-1.06(m,24H), 0.84(t,6H), 0.34(s,18H).

[0092] [ka]

[0093] Next, 1.70 g (2.29 mmol) of compound (F-1) and 1.50 g (4.7 mmol) of compound (D-1) were reacted, referring to the method described in Japanese Patent Publication No. 2022-030124. After removing the solvent under reduced pressure, the mixture was purified by silica gel column chromatography to obtain the compound (yield 93%). 1 1H-NMR analysis confirmed that the obtained compound was compound (G-1). 1 The 1H-NMR measurement data is shown below. 1 H-NMR (400MHz, solvent: CDCl3, ppm): δ9.75(s,2H), 7.42(s,2H), 7.40(s,2H), 4.29(quin,2H), 4.19(sep,1H), 2.10- 1.95(m,2H), 1.90-1.74(m,10H), 1.54-1.34(m,4H), 1.34-1.16(m,32H), 1.04(t,6H), 0.89(t,6H), 0.81(t,6H).

[0094] [ka]

[0095] Separately, compound (I-1) of the following formula was synthesized by the method described in Japanese Patent Publication No. 2023-500815. 0.42 g (0.47 mmol) of compound (G-1) and 0.35 g (1.42 mmol) of compound (I-1) were placed in a reaction vessel, dissolved in 6.9 mL of toluene and 13.8 mL of ethanol, and then 0.40 g (2.12 mmol) of p-toluenesulfonic acid monohydrate was added, and the mixture was stirred at 65°C for 4 hours. After cooling, the organic layer was extracted with ethyl acetate and water, the extract was dried over sodium sulfate, and the solvent was removed from the solution after removing the solids by filtration to obtain the crude product. The obtained crude product was purified using silica gel chromatography to obtain 0.46 g of the solid compound (yield 72%). 1 1H-NMR analysis confirmed that the obtained compound was compound (1-1). 1 The 1H-NMR measurement data is shown below. 1 H-NMR (400MHz, solvent: CDCl3, ppm): δ8.66(s,2H), 8.60(s,2H), 7.87(s,2H), 7.44-7.52(br.s.,4H), 4.41-4.47(quin,2H), 4.21-4. 29(m,1H), 2.06-2.17(m,2H), 1.79-2.04(m,10H), 1.46-1.59(m,4H), 1.15-1.42(m,32H), 1.10(t,6H), 0.91(t,6H), 0.81(t,6H).

[0096] [ka]

[0097] [Synthesis of compound (N-1)] Compound (G-1) was synthesized in the same manner as compound (1-1). Separately, compound (I-2) was synthesized using the method described in Adv. Mater., 2017, Vol. 29, p. 1703080. 0.30 g (0.34 mmol) of compound (G-1) and 0.21 g (0.81 mmol) of compound (I-2) were placed in a reaction vessel, dissolved in 8.6 mL of chloroform, and then 0.34 mL of pyridine was added. The mixture was stirred at 60°C for 3 hours. After cooling, the solvent was removed by distillation to obtain the crude product. The crude product was purified using silica gel chromatography to obtain 0.43 g of the solid compound (yield 93%). 1 1H-NMR analysis confirmed that the obtained compound was compound (N-1). 1 The 1H-NMR measurement data is shown below. 1 H-NMR (400MHz, CDCl3, ppm): δ8.71(s,2H), 8.86(s,2H), 7.90(s,2H), 7.57(s,2H), 7.49(br.s.,2H), 4.41-4.47(quin,2H), 4.22-4 .29(m,1H), 2.03-2.14(m,2H), 1.77-2.01(m,10H), 1.46-1.59(m,4H), 1.15-1.40(m,32H), 1.08(t,6H), 0.91(t,6H), 0.81(t,6H).

[0098] [ka]

[0099] [Synthesis of compound (N-2)] Compound (G-1) was synthesized in the same manner as compound (1-1). Separately, compound (I-3) was synthesized according to the method described in Angew. Chem. Int. Ed., 2017, Vol. 56, p. 3045. 0.30 g (0.34 mmol) of compound (G-1) and 0.19 g (0.81 mmol) of compound (I-3) were placed in a reaction vessel, dissolved with 8.6 mL of chloroform, and then 0.34 mL of pyridine was added and the mixture was stirred at 60°C for 3 hours. After cooling, the solvent was removed by distillation to obtain the crude product. The crude product was purified using silica gel chromatography to obtain 0.39 g of the solid compound (yield 89%). 1 1H-NMR analysis confirmed that the obtained compound was compound (N-2). 1 The 1H-NMR measurement data is shown below. 1 H-NMR (400MHz, CDCl3, ppm): δ8.64(s,2H), 8.45(dd,2H), 7.64(t,2H), 7.54(s,2H), 7.48(br.s.,2H), 4.40-4.46(quin,2H), 4.21- 4.28(m,1H), 2.04-2.15(m,2H), 1.77-2.00(m,10H), 1.44-1.61(m,4H), 1.14-1.40(m,32H), 1.09(t,6H), 0.91(t,6H), 0.81(t,6H).

[0100] [ka]

[0101] [Example 1] <Manufacturing of photoelectric conversion elements> (Formation of hole transport layer) The surface of an ITO substrate, on which a transparent conductive film of indium tin oxide (ITO) was patterned onto a glass substrate as a transparent substrate and used as a transparent electrode, was treated with ozone for 10 minutes using an ultraviolet ozone cleaning machine (manufactured by Japan Laser Electronics Co., Ltd., product name "NL-UV253"). Separately, a composition for forming a hole transport layer was prepared by dissolving 60 mg of a polytriarylamine compound (hole transport polymer) represented by the following formula (H-1) in 1 mL of anisole. A hole transport layer-forming composition was spin-coated onto a transparent electrode of an ozone-treated ITO substrate at a rotation speed of 1000 rpm for 60 seconds, and then heated and dried at 240°C for 30 minutes to form a hole transport layer with a thickness of 300 nm.

[0102] [ka]

[0103] (Formation of the photoelectric conversion layer) As the p-type semiconductor material, a compound represented by the following formula (P-1) (weight-average molecular weight 80,000) was used. Compound (1-1) was used as the n-type semiconductor material. An active layer-forming composition, which is an organic semiconductor ink, was prepared by dissolving 0.11 g of p-type semiconductor material and 0.13 g of n-type semiconductor material in 9.68 mL of o-xylene. In the active layer-forming composition, the mass ratio of the n-type semiconductor material to the p-type semiconductor material (n-type semiconductor material / p-type semiconductor material) was 1.2. The solid content concentration of the active layer-forming composition was 25 mg / mL. Using the obtained active layer-forming composition, the hole transport layer was spin-coated at 1000 rpm per minute, followed by heat treatment (thermal annealing) at 120°C for 10 minutes to form a photoelectric conversion layer (active layer) consisting of an organic thin film with a thickness of 150 nm.

[0104] [ka]

[0105] (Formation of electron transport layer and metal electrode) A 40 nm thick electron transport layer was formed on a photoelectric conversion layer by depositing C60 fullerene (manufactured by Frontier Carbon Co., Ltd.) as an electron transport material in a vacuum. Next, aluminum was deposited in a vacuum as a metal electrode material on the electron transport layer to form a 100 nm thick metal electrode, thereby obtaining a photoelectric conversion element. The obtained photoelectric conversion elements were evaluated as follows.

[0106] <Rating> (Evaluation of external quantum efficiency (EQE)) The photoelectric conversion element was irradiated with a xenon lamp under a -5V applied voltage, and the external quantum efficiency was measured using an action spectrum measuring device (PEC-S20, manufactured by Pexel Technologies, Inc.). As a result, we were able to confirm the photoelectric conversion capability using light ranging from the visible range to 1200 nm.

[0107] (Measurement of dark current) The dark current was measured using a photoelectric converter when -5V was applied. A high-precision current measuring device (Keithley Instruments, product name "Keithley 6482") was used to measure the dark current. The results are shown in Table 1. The values ​​shown in Table 1 are relative values ​​(relative dark current values) when the dark current in the photoelectric conversion element obtained in Comparative Example 2, described later, is set to 1.00.

[0108] [Comparative Example 1] A photoelectric conversion element was manufactured in the same manner as in Example 1, except that a compound represented by the following formula (N-1) was used as the n-type semiconductor material, and the external quantum efficiency was measured when -5V was applied. As a result, the photoelectric conversion ability was confirmed with light from the visible range to 1200 nm. Furthermore, the dark current of the obtained photoelectric conversion element was measured when -5V was applied, in the same manner as in Example 1. The results are shown in Table 1. Note that the values ​​shown in Table 1 are relative values ​​(relative dark current values) when the dark current of the photoelectric conversion element obtained in Comparative Example 2, described later, is set to 1.00.

[0109] [Comparative Example 2] A photoelectric conversion element was manufactured in the same manner as in Example 1, except that a compound represented by the following formula (N-2) was used as the n-type semiconductor material, and the external quantum efficiency was measured when -5V was applied. As a result, the photoelectric conversion ability was confirmed with light from the visible range to 1200 nm. Furthermore, the dark current of the obtained photoelectric conversion element was measured when -5V was applied, in the same manner as in Example 1.

[0110] [Table 1]

[0111] As is clear from the results in Table 1, the photoelectric conversion element obtained in Example 1 had a significantly lower dark current and significantly less noise than the photoelectric conversion elements obtained in Comparative Examples 1 and 2. From these results, it was shown that the compound (1) of the present invention can achieve both high sensor sensitivity in the long wavelength region of the absorption wavelength and a low reduction in dark current.

Industrial Applicability

[0112] The compound of the present invention can suppress the dark current of a photoelectric conversion element while increasing the absorption wavelength to a longer wavelength, and is useful as a semiconductor material used for a photoelectric conversion element.

Explanation of Reference Numerals

[0113] 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). 【Chemistry 1】 In the general formula (1), X １ to X ８ are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom or a cyano group, and among X １ to X ８ , at least one is a cyano group. Y １ to Y ４ are each independently a hydrogen atom, an alkyl group, an alkoxy group or an ester group, and among Y １ to Y ４ , at least one is an alkyl group, an alkoxy group or an ester group. Z １ and Z ２ are each independently an oxygen atom or a dicyanomethylene group, and M is a nitrogen atom substituted with an alkyl group or an aryl group.

2. Z in the general formula (1) １ Both are dicyanomethylene groups, Z ２ The compound according to claim 1, wherein all of them are oxygen atoms.

3. X in the general formula (1) １ , X ４ , X ５ and X ８ X is a hydrogen atom, ２ , X ３ , X ６ and X ７ The compound according to claim 1, wherein the group is a cyano group.

4. The compound according to claim 1, wherein M in the general formula (1) is a nitrogen atom substituted with an alkyl group.

5. Y in the general formula (1) １ and Y ３ One of them is a hydrogen atom, and the other is an alkyl group, an alkoxy group, or an ester group, Y ２ and Y ４ The compound according to claim 1, wherein one of the atoms is a hydrogen atom and the other is an alkyl group, an alkoxy group, or an ester group.

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

7. X in the general formula (1) １ , X ４ , X ５ and X ８ X is a hydrogen atom, ２ , X ３ , X ６ and X ７ The cyano group is Y ３ and Y ４ This is a hydrogen atom, Y １ and Y ２ is an alkoxy group, Z １ Both are dicyanomethylene groups, Z ２ The compound according to claim 1, wherein all of are oxygen atoms and M is a nitrogen atom substituted with an alkyl group.

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

9. X in the general formula (1) １ , X ４ , X ５ and X ８ X is a hydrogen atom, ２ , X ３ , X ６ and X ７ The cyano group is Y ２ and Y ３ This is a hydrogen atom, Y １ and Y ４ Each of these is independently an alkyl group or an alkoxy group, Z １ Both are dicyanomethylene groups, Z ２ The compound according to claim 1, wherein all of are oxygen atoms and M is a nitrogen atom substituted with an alkyl group.

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

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

12. A photoelectric conversion element comprising the film described in claim 11.

13. A CMOS image sensor comprising the photoelectric conversion element described in claim 12.

Images