Compound, compound manufacturing method, photoelectric conversion film, organic thin-film solar cell

Abstract

To provide a photoelectric conversion film material that exhibits strong light absorption in the near-infrared region of the solar spectrum. The present invention provides a compound represented by formula (I) (R 1 , R 2 is selected from formula (1) to formula (3). 1 , Ph.D. 2 is any one selected from a group in which one or more hydrogen atoms of a ring structure selected from formulas (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, a pyridine ring represented by formula (7), and -Cl. X is C(CN)2 or O. TIFF2026044171000028.tif66170

Description

[Technical Field]

[0001] The present invention relates to a compound, a method for producing the compound, a photoelectric conversion film containing the compound, and an organic thin-film solar cell. [Background technology]

[0002] Organic thin-film solar cells are attracting attention as the next generation of solar cells. Organic thin-film solar cells have a photoelectric conversion film between an anode and a cathode. The photoelectric conversion film structure can be a single layer type, a pn heterojunction, a bulk heterojunction, or an interpenetrating junction.

[0003] Conventionally, organic materials used in photoelectric conversion films with a bulk heterojunction structure are known to be those described in Non-Patent Document 1. Non-Patent Document 1 describes a compound of a squaraine derivative and a fullerene derivative, phenyl C 61 An organic thin-film solar cell having a bulk heterojunction structure photoelectric conversion film containing butyric acid methyl ester (PCBM) is described. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] KCDeping et al.,Phys.Chem.Chem.Phys.2012,14,8328 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional photoelectric conversion films have insufficient light absorption in the near-infrared (NIR) region of the solar spectrum, making it impossible to fully utilize solar energy. For this reason, conventional organic thin-film solar cells have required photoelectric conversion films that exhibit stronger light absorption in the near-infrared region.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a compound that can be suitably used as a material for a photoelectric conversion film that exhibits strong light absorption for light in the near-infrared region of the solar spectrum, and a method for producing the same. Another object of the present invention is to provide a photoelectric conversion film that contains the compound of the present invention and exhibits strong light absorption in the near-infrared region. Another object of the present invention is to provide an organic thin-film solar cell which includes the photoelectric conversion film of the present invention and is capable of converting solar energy in a wide range from the visible light region to the near-infrared region into electrical energy. [Means for solving the problem]

[0007] The present inventors have focused on squaraine derivatives and conducted extensive research in order to solve the above problems and realize an organic material that can be used as a material for a photoelectric conversion film that exhibits strong light absorption in the near-infrared region of the solar spectrum. As a result, they found that a compound represented by formula (1) having a squaraine skeleton in the central part of the molecule would be sufficient, and arrived at the present invention. That is, the present invention relates to the following items.

[0008] [1] A compound represented by the following general formula (I):

[0009] [ka] (In general formula (I), R 1 , R 2 are acyclic alkyl groups having 1 to 26 carbon atoms selected from the following general formulae (1) to (3), and may be the same or different. 1 , Ph.D. 2is one selected from a group in which one or more hydrogen atoms of a ring structure selected from the following formulae (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, a pyridine ring represented by the following formula (7), and -Cl, and may be the same or different. X is C(CN)2 or O.

[0010] [ka] (In general formulas (1) to (3), n is an integer.)

[0011] [ka]

[0012] [2] The R in the general formula (I) 1 and the above R 2 is the same, and 1 and the aforementioned Ph 2 The compound according to [1], wherein [3] The compound according to [1], wherein the general formula (I) is any one selected from the following formulae (I-1) to (I-7):

[0013] [ka]

[0014] [ka]

[0015] [4] A method for producing the compound according to any one of [1] to [3], 4-methyl-7-chloroquinoline and the R 1 to the nitrogen atom of the quinoline ring of 4-methyl-7-chloroquinoline, and 1a first step of producing an ammonium salt having an acyclic alkyl group bonded thereto, the acyclic alkyl group corresponding to and a second step of reacting the ammonium salt with squaric acid or a squaric acid derivative having a group corresponding to X in general formula (I) to produce a compound represented by the following general formula (II):

[0016] [ka] (In general formula (II), R 1 represents an acyclic alkyl group having 1 to 26 carbon atoms selected from the following general formulae (1) to (3). X represents C(CN)2 or O.

[0017] [ka] (In general formulas (1) to (3), n is an integer.)

[0018] [5] Furthermore, one of the chloro groups of the compound represented by the general formula (II) and Ph 1 -B(OH)2 (where Ph 1 is a group in which one or more hydrogen atoms of a ring structure selected from the formulas (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, or a pyridine ring represented by the formula (7). 2 -B(OH)2 (where Ph 2 is a group in which one or more hydrogen atoms of a ring structure selected from the formulae (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, or a pyridine ring represented by the formula (7).

[0019] [6] A photoelectric conversion film comprising the compound according to any one of [1] to [3]. [7] Phenyl C represented by the following formula (21) 61 The photoelectric conversion film according to [6], which contains either or both of butyric acid methyl ester (PCBM) and PCE10 represented by the following formula (22):

[0020] [ka] (In formula (22), n is an integer representing a repeating unit. Bu represents -CH2CH2CH2CH3. Et represents -CH2CH3.)

[0021] [8] An electron donating material that functions as an electron donor and an electron accepting material that functions as an electron acceptor, The photoelectric conversion film according to [6], which has a bulk heterojunction structure in which the electron donating material and the electron accepting material are mixed.

[0022] [9] An organic thin-film solar cell comprising a first electrode, a second electrode, and the photoelectric conversion film according to [6]. [Effects of the Invention]

[0023] The compound of the present invention is represented by general formula (I), and a thin film containing the compound of the present invention exhibits strong light absorption for light in the near-infrared region of the solar spectrum. Furthermore, the compound of the present invention can be dissolved in a solvent to form a solution, and a thin film can be easily formed by applying the solution to a surface to be formed and removing the solvent contained in the resulting coating film. Furthermore, a thin film containing the compound of the present invention exhibits strong light absorption for light in the near-infrared region of the solar spectrum, even without heat treatment after removing the solvent contained in the coating film. Furthermore, the compound of the present invention does not contain metal atoms. For these reasons, the compound of the present invention can be suitably used as a material for the photoelectric conversion film of an organic thin-film solar cell. Furthermore, according to the method for producing the compound of the present invention, the compound of the present invention that can be suitably used as a material for the photoelectric conversion film of an organic thin-film solar cell can be produced efficiently with fewer production steps.

[0024] The photoelectric conversion film of the present invention contains the compound of the present invention. Therefore, the photoelectric conversion film of the present invention exhibits strong light absorption in the near-infrared region and can be suitably used as a photoelectric conversion film for organic thin-film solar cells. The photoelectric conversion film of the present invention can be produced by applying a solution in which the compound of the present invention is dissolved in a solvent, and can be produced without heat treatment. Therefore, the photoelectric conversion film of the present invention can be produced efficiently with fewer production steps. The organic thin-film solar cell of the present invention includes the photoelectric conversion film of the present invention, and therefore the organic thin-film solar cell of the present invention can convert solar energy over a wide range from the visible light region to the near-infrared region into electrical energy, thereby achieving high solar light utilization efficiency. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a cross-sectional view showing an example of an organic thin-film solar cell according to this embodiment. [Figure 2] Fig. 2(a) is a graph showing the relationship between the absorption coefficient ε and wavelength of the compound solution of Example 1. Fig. 2(b) is a graph showing the relationship between the index α of the optical absorption intensity of the thin film of Example 1 and wavelength, where the solid line shows the result for the thin film before heat treatment and the dotted line shows the result for the thin film after heat treatment. [Figure 3] Fig. 3(a) is a graph showing the relationship between the absorption coefficient ε and wavelength of the compound solution of Example 2. Fig. 3(b) is a graph showing the relationship between the index α of the optical absorption intensity of the thin film of Example 2 and wavelength, where the solid line shows the result for the thin film before heat treatment and the dotted line shows the result for the thin film after heat treatment. [Figure 4] Fig. 4(a) is a graph showing the relationship between the absorption coefficient ε and wavelength of the compound solution of Example 3. Fig. 4(b) is a graph showing the relationship between the index α of the optical absorption intensity of the thin film of Example 3 and wavelength, where the solid line shows the result for the thin film before heat treatment and the dotted line shows the result for the thin film after heat treatment. [Figure 5]Fig. 5(a) is a graph showing the relationship between the absorption coefficient ε and wavelength of the compound solution of Example 4. Fig. 5(b) is a graph showing the relationship between the index α of the optical absorption intensity of the thin film of Example 4 and wavelength, where the solid line shows the result for the thin film before heat treatment and the dotted line shows the result for the thin film after heat treatment. [Figure 6] Fig. 6(a) is a graph showing the relationship between the absorption coefficient ε and wavelength of the compound solution of Example 5. Fig. 6(b) is a graph showing the relationship between the index α of the optical absorption intensity of the thin film of Example 5 and wavelength, where the solid line shows the result for the thin film before heat treatment and the dotted line shows the result for the thin film after heat treatment. [Figure 7] Fig. 7(a) is a graph showing the relationship between absorbance (intensity) and wavelength of the compound solution of Example 6. Fig. 7(b) is a graph showing the relationship between absorbance (intensity) and wavelength of the thin film of Example 6 before heat treatment. [Figure 8] Fig. 8(a) is a graph showing the relationship between absorbance (intensity) and wavelength for the compound solution of Example 7. Fig. 8(b) is a graph showing the relationship between absorbance (intensity) and wavelength for the thin film of Example 7, where the solid line shows the result for the thin film before heat treatment and the dotted line shows the result for the thin film after heat treatment. [Figure 9] FIG. 9 is a graph showing the relationship between current density and voltage of the organic thin-film solar cell of Example 1. [Figure 10] FIG. 10 is a graph showing the measurement results of the spectral sensitivity spectrum of the organic thin-film solar cell of Example 1. [Figure 11] Fig. 11 is a graph showing the results of measuring the absorption spectrum of the organic thin-film solar cell of Example 1 and the results of measuring the absorption spectrum of a thin film before heat treatment of the compound represented by formula (I-1) produced in Example 1. The dotted line in Fig. 11 shows the results of the organic thin-film solar cell of Example 1, and the solid line shows the results of the thin film before heat treatment. DETAILED DESCRIPTION OF THE INVENTION

[0026] The compound of the present invention, the method for producing the compound, the photoelectric conversion film, and the organic thin-film solar cell will be described in detail below. The scope of the present invention is not limited to the embodiment described here, and various modifications can be made without departing from the spirit of the present invention. Furthermore, when multiple upper and lower limit values ​​are described for a specific parameter, any upper and lower limit values ​​can be combined to form a suitable numerical range.

[0027] [Compound] The compound of this embodiment is represented by the following general formula (I).

[0028] [ka] (In general formula (I), R 1 , R 2 are acyclic alkyl groups having 1 to 26 carbon atoms selected from the following general formulae (1) to (3), and may be the same or different. 1 , Ph.D. 2 is one selected from a group in which one or more hydrogen atoms of a ring structure selected from the following formulae (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, a pyridine ring represented by the following formula (7), and -Cl, and may be the same or different. X is C(CN)2 or O.

[0029] [ka] (In general formulas (1) to (3), n is an integer.)

[0030] [ka]

[0031] The compound of the present embodiment represented by formula (I) is a squaraine derivative having a squaraine skeleton in the center of the molecule. In formula (I), X is C(CN)2 or O. Compounds in which X is C(CN)2 or O can be used as materials capable of forming thin films that exhibit strong light absorption in the near-infrared region of the solar spectrum.

[0032] Furthermore, a compound in which X is C(CN)2 is preferred because, when used as a material for a photoelectric conversion film, it produces a photoelectric conversion film with high electron-accepting properties compared to a compound in which X is O. On the other hand, when a compound in which X is O is used as a material for a photoelectric conversion film, a photoelectric conversion film with shallower HOMO and LUMO energy levels is formed compared to a compound in which X is C(CN)2. Therefore, depending on the type of organic compound other than the compound represented by formula (I) used as a material for the photoelectric conversion film, the use of a compound in which X is O may result in better compatibility in energy levels compared to a compound in which X is C(CN)2. When a compound represented by formula (I) is used as a material for a photoelectric conversion film, X is appropriately determined depending on the type of organic compound used as a material for the photoelectric conversion film together with the compound represented by formula (I).

[0033] R in formula (I) 1 , R 2 R is an acyclic alkyl group having 1 to 26 carbon atoms selected from general formulas (1) to (3), and may be the same or different. 1 and R 2 are preferably the same, since this makes it easier to prepare the compound represented by formula (I). 1 and R 2 However, since it is an acyclic alkyl group having 26 or less carbon atoms, the raw materials are readily available, and the compound represented by formula (I) can be easily produced.

[0034] R 1 and R 2 is preferably an acyclic alkyl group having 10 to 20 carbon atoms. 1 and R 2When R is an acyclic alkyl group having 10 or more carbon atoms, the compound represented by formula (I) has high solubility in organic solvents, and a thin film can be easily formed by coating a solution of the compound represented by formula (I) in an organic solvent. 1 and R 2 However, if R is an acyclic alkyl group having 20 or less carbon atoms, the raw materials are easily available, and the compound represented by formula (I) can be produced more easily, which is preferable. 1 and R 2 is more preferably an acyclic alkyl group having 12 to 18 carbon atoms.

[0035] R in formula (I) 1 and R 2 When R is an acyclic alkyl group of general formula (1), n ​​is preferably 10 to 16. 1 and R 2 When R is an acyclic alkyl group of general formula (2), n is preferably 12 to 18. 1 and R 2 When is an acyclic alkyl group of general formula (3), n is preferably 14 to 20.

[0036] R in formula (I) 1 and R 2 is preferably an acyclic alkyl group represented by general formula (2) or general formula (3), and more preferably an acyclic alkyl group represented by general formula (3). The reason for this is that the compound represented by formula (I) has high solubility in organic solvents, and by dissolving the compound represented by formula (I) in an organic solvent, a solution containing the compound represented by formula (I) can be easily formed.

[0037] Ph in formula (I) 1 , Ph.D. 2is one selected from a group in which one or more hydrogen atoms of any of the ring structures selected from formulas (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, a pyridine ring represented by the following formula (7), and -Cl, and may be the same or different. Ph 1 and Ph 2 are preferably the same, since this makes it easier to prepare the compound represented by formula (I).

[0038] Ph 1 and / or Ph 2 However, the compound having any one of the ring structures selected from the formulas (4) to (6) is Ph 1 and / or Ph 2 The extended π-conjugation resulting from the presence of the compound is preferred because it allows the formation of a thin film that exhibits light absorption in the longer wavelength region. Furthermore, a compound having one or more hydrogen atoms in a ring structure selected from formulas (4) to (6) substituted with a substituent selected from -CHO, -CN, and -F has a substituent selected from -CHO, -CN, and -F, and therefore, when used as a material for a photoelectric conversion film, a photoelectric conversion film having high electron-accepting properties can be obtained.

[0039] Ph 1 and / or Ph 2 However, compounds having a ring structure represented by formula (4) are preferred because raw materials are readily available and, due to their extended conjugation length, they are easily formed into thin films that exhibit light absorption in the long wavelength region. In the ring structure represented by formula (4), the position to which any of the substituents selected from -CHO, -CN, and -F is bonded is preferably away from the position at which the quinoline ring of the squaraine skeleton is bonded to the ring structure represented by formula (4). This is because the compound represented by formula (I) can be easily produced.

[0040] Ph 1 and / or Ph 2However, compounds having a ring structure represented by formula (5) are preferred because the raw materials are easily available and, when used as a material for a photoelectric conversion film, a photoelectric conversion film having high electron-accepting properties is obtained. In the ring structure represented by formula (5), the position to which any of the substituents selected from -CHO, -CN, and -F is bonded may be any position in the ring structure represented by formula (5). Regardless of the position to which the substituent is bonded in the ring structure represented by formula (5), the effect of improving electron-accepting properties can be obtained.

[0041] The position at which the ring structure represented by formula (5) is bonded to the quinoline ring of the squaraine skeleton may be any position on the quinoline ring, but is preferably a position away from the position at which the squaraine skeleton is bonded to the quinoline ring, because this makes the compound represented by formula (I) easier to produce.

[0042] Ph 1 and / or Ph 2 However, compounds having a ring structure represented by formula (6) are preferred because the raw materials are easily available and, when used as a material for a photoelectric conversion film, a photoelectric conversion film having high electron-donating properties is obtained. In the ring structure represented by formula (6), the position to which any of the substituents selected from -CHO, -CN, and -F is bonded may be any position in the ring structure represented by formula (6). Regardless of the position to which the substituent is bonded in the ring structure represented by formula (5), the effect of improving electron-accepting properties can be obtained.

[0043] The position at which the ring structure represented by formula (6) is bonded to the quinoline ring of the squaraine skeleton may be any position on the quinoline ring, and is preferably a position away from the position at which the squaraine skeleton is bonded to the quinoline ring, because this makes the compound represented by formula (I) easier to produce.

[0044] Ph 1 and / or Ph 2 is a group substituted with -CHO, it is preferable because the effect of improving the electron accepting property due to -CHO can be obtained.1 and / or Ph 2 is a group substituted with -CN, this is preferable because it has the effect of improving the electron-accepting property due to -CN. 1 and / or Ph 2 is a group substituted with -F, this is preferable because the effect of improving the electron-accepting property due to -F can be obtained.

[0045] Ph 1 and / or Ph 2 The number of any one of the substituents selected from -CHO, -CN, and -F that each of Ph has is preferably 1 to 3. 1 and / or Ph 2 When Ph is a group substituted with -CHO, the number of substituents is preferably one, since this facilitates production. 1 and / or Ph 2 When Ph is a group substituted with -CN, the number of substituents is preferably one, since this makes production easier. 1 and / or Ph 2 is a group substituted with -F, it is preferable that the number is 3, since raw materials are easily available.

[0046] Ph 1 and / or Ph 2 However, the compound having the pyridine ring represented by formula (7) can be used in the same manner as the compound having any one of the ring structures selected from formulas (4) to (6). 1 and / or Ph 2 The extended π conjugation resulting from the presence of the compound is preferable because it allows the material to be formed into a thin film that exhibits light absorption in the longer wavelength region.

[0047] Furthermore, the position at which the pyridine ring represented by formula (7) is bonded to the quinoline ring of the squaraine skeleton is preferably a position at which the nitrogen atom of the pyridine ring represented by formula (7) is separated from the quinoline ring, and most preferably the 4-position of the pyridine ring represented by formula (7). This is because the conjugation length is extended by bonding the pyridine ring represented by formula (7) to the quinoline ring. The position at which the pyridine ring of formula (7) is bonded to the quinoline ring of the squaraine skeleton may be any position on the quinoline ring, but is preferably a position away from the position at which the squaraine skeleton is bonded to the quinoline ring, because this makes the compound of formula (I) easier to produce.

[0048] Also, Ph 1 and / or Ph 2 Compounds where is -Cl are, for example, Ph 1 and Ph 2 is compared with a compound having any one of the ring structures selected from formulas (4) to (6), Ph 1 and Ph 2 This suppresses the effect of steric hindrance caused by the presence of Ph 1 and / or Ph 2 A compound in which is —Cl is preferred because, when used as a material for a photoelectric conversion film, a photoelectric conversion film having high electron-accepting properties can be obtained.

[0049] Specific examples of the compound represented by formula (I) include compounds represented by the following formulae (I-1) to (I-7). The compounds represented by formulae (I-1) to (I-7) can be suitably used as materials for photoelectric conversion films. This is because, when used as materials for the photoelectric conversion film of an organic thin-film solar cell, a photoelectric conversion film that exhibits stronger light absorption for light in the near-infrared region of the solar spectrum can be obtained.

[0050] [ka]

[0051] [ka]

[0052] The compound represented by formula (I) can be dissolved in an organic solvent, such as chloroform, tetrahydrofuran (THF), dichloromethane, or chlorobenzene.

[0053] [Method of manufacturing the compound] Next, a method for producing the compound of the present embodiment represented by formula (I) will be described. The compound of this embodiment represented by formula (I) can be produced, for example, by a method in which the following steps 1 and 2 are carried out in this order. Furthermore, in the production method of this embodiment, step 3 and / or step 4 are carried out after step 2, as necessary.

[0054] (1st step) 4-methyl-7-chloroquinoline and R in formula (I) 1 By refluxing in a solvent, the nitrogen atom of the quinoline ring of 4-methyl-7-chloroquinoline is reacted with an iodide having an acyclic alkyl group corresponding to R in formula (I). 1 The ammonium salt having the corresponding alkyl group bonded thereto is produced.

[0055] Examples of the solvent used in the first step include tetrahydrofuran (THF), acetonitrile, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), etc. The solvent used in the first step may be one type alone or a mixture of two or more types. The reaction temperature and reaction time in the first step are determined by the reaction temperature and reaction time of the compound R 1 The reaction temperature can be appropriately determined depending on the type of iodide having an acyclic alkyl group corresponding to the formula (I) and the type and amount of solvent used.

[0056] 4-Methyl-7-chloroquinoline, which is used as a starting material in the first step, can be produced by a known method. Specifically, 4-methyl-7-chloroquinoline can be produced, for example, by the following method: 4,7-Dichloroquinoline is reacted with methylmagnesium bromide (CHMgBr) in a solvent using iron(III) acetylacetonate as a catalyst by a known method.

[0057] (2nd process) Next, the ammonium salt produced in the first step is reacted with squaric acid or a squaraine derivative having a group corresponding to X in formula (I) by refluxing in a solvent to produce a compound represented by the following general formula (II). The compound represented by general formula (II) can be obtained by reacting the ammonium salt produced in the first step with squaric acid or a squaraine derivative having a group corresponding to X in formula (I) by refluxing in a solvent to produce a compound represented by the following general formula (II). 1 and R 2 is the same, and Ph 1 and Ph 2 is -Cl and X is C(CN)2 or O.

[0058] [ka] (In general formula (II), R 1 represents an acyclic alkyl group having 1 to 26 carbon atoms selected from the following general formulae (1) to (3). X represents C(CN)2 or O.

[0059] [ka] (In general formulas (1) to (3), n is an integer.)

[0060] Examples of the solvent used in the second step include toluene, n-butanol, isopropanol, chlorobenzene, etc. The solvent used in the second step may be one type alone or a mixture of two or more types. The reaction temperature and reaction time in the second step can be appropriately determined depending on the types of squaric acid or squaraine derivative having a group corresponding to X in formula (I), ammonium salt, and solvent used in the second step, as well as the amounts of these used.

[0061] In the second step, squaric acid represented by formula (11) or a squaraine derivative having a group corresponding to X in formula (I) is used as a raw material. Examples of squaraine derivatives having a group corresponding to X in formula (I) include triethylamine salts of squaric acid derivatives having -C(CN)2 represented by formula (12) (HN + (C2H5)3), triethylamine salts of squaric acid derivatives with O (HN + (C2H5)3) can be used.

[0062] [ka]

[0063] The squaraine derivative having a group corresponding to X in formula (I) used as a raw material in the second step can be produced by a known method. For example, the squaraine derivative having a group corresponding to X in formula (I) is a triethylamine salt (HN + (C2H5)3) can be produced, for example, by placing 3,4-diethoxy-3-cyclobutane-1,2-dione, malononitrile (CH2(CN)2), and triethylamine ((CH3CH2)3N) in a solvent and subjecting them to a Knoevenagel condensation reaction.

[0064] (3rd step) In this embodiment, step 3 is carried out as necessary after step 2. In step 3 of this embodiment, a compound represented by formula (II) is used as an intermediate compound. First, one of the chloro groups of the compound represented by formula (II) and Ph 1 -B(OH)2 (where Ph 1is a group in which one or more hydrogen atoms of a ring structure selected from the formulas (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, or a pyridine ring represented by the formula (7).) is refluxed in a solvent to cause a reaction (Miyaura reaction).

[0065] Then, the other chloro group of the compound represented by formula (II) and Ph 2 -B(OH)2 (where Ph 2 is a group in which one or more hydrogen atoms of a ring structure selected from the formulas (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, or a pyridine ring represented by the formula (7).) is refluxed in a solvent to cause a reaction (Miyaura reaction).

[0066] The reaction temperature and reaction time in the first and second reactions of the third step depend on the type of compound represented by formula (II) used as a raw material in the third step, Ph 1 -B(OH)2 (where Ph 1 is a group in which one or more hydrogen atoms of any of the ring structures selected from the formulas (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, or a pyridine ring represented by the formula (7). 2 -B(OH)2 (where Ph 2 is a group in which one or more hydrogen atoms of any of the ring structures selected from the formulas (4) to (6) are substituted with any of the substituents selected from -CHO, -CN, and -F, or a pyridine ring represented by the formula (7). The amount of the substituted or unsubstituted group can be determined appropriately depending on the type of the substituted or unsubstituted group, the type of catalyst, the amount of the substituted or unsubstituted group, and the like.

[0067] Ph used in the third step 1 -B(OH)2 and Ph 2-B(OH)2 can be produced by a known method. Specifically, for example, it can be produced by a method of reacting a boron compound with a halide having a group in which one or more hydrogen atoms in a ring structure selected from formulas (4) to (6), such as 1-bromo-4-formylbenzene, are substituted with a substituent selected from -CHO, -CN, and -F. 1 -B(OH)2 and Ph 2 -B(OH)2 may be produced, for example, by reacting a boron compound with a halide such as 4-bromopyridine, in which one hydrogen atom on the pyridine ring represented by formula (7) is substituted with a halogen. Ph used in the third step 1 -B(OH)2 and Ph 2 As -B(OH)2, commercially available compounds may be used.

[0068] Examples of solvents used in the first and second reactions in the third step include tetrahydrofuran (THF), N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). The solvents used in the first and second reactions may be the same or different. The solvents used in the first and second reactions may each be a single type or a mixture of two or more types.

[0069] The first and second reactions are preferably carried out using a catalyst. Ph 1 When the ring structure represented by formula (4) is present, in the first reaction (or Ph 2 has a ring structure represented by formula (4), in the second reaction, it is preferable to use, as a catalyst, one or more selected from the group consisting of tetrakis(triphenylphosphine)palladium (Pd(PPh3)4), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos), and potassium carbonate.

[0070] Ph1 In any case where the compound has a ring structure represented by formula (5), a ring structure represented by formula (6), or a pyridine ring represented by formula (7), in the first reaction (or Ph 2 In the second reaction, Ph 1 The same catalysts as those in the case where the ring structure represented by formula (4) is used can be used.

[0071] Using the production method of this embodiment, Ph in the compound represented by formula (I) 1 and Ph 2 When a compound different from Ph is produced, the mole number of the compound represented by formula (II) used in the first reaction and the mole number of Ph are 1 -Adjust the ratio with the number of moles of B(OH)2. In addition, Ph in the compound represented by formula (I) 1 and Ph 2 When producing a compound different from the above, one equivalent of Ph is used for one of the two chloro groups of the compound represented by formula (II). 1 After the first reaction with -B(OH)2, Ph 2 A second reaction may be carried out using -B(OH)2.

[0072] By using these methods, in the first reaction, one of the chloro groups of the compound represented by formula (II) and Ph 1 -B(OH)2 (where Ph 1 is a group in which one or more hydrogen atoms of a ring structure selected from the formulas (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, or a pyridine ring represented by the formula (7). 2 -B(OH)2 (where Ph 2is a group in which one or more hydrogen atoms of any ring structure selected from the formulas (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, or a pyridine ring represented by the formula (7).

[0073] In this embodiment, an example has been described in which the first reaction is carried out followed by the second reaction, but the first reaction may also be carried out after the second reaction. In addition, the production method of this embodiment can be used to obtain Ph in the compound represented by formula (I). 1 and Ph 2 When the first and second reactions are to produce the same compound, the first and second reactions can be carried out simultaneously.

[0074] After the second step, the third step is carried out to obtain R 1 and R 2 is the same, and Ph 1 and Ph 2 is a group in which one or more hydrogen atoms of any of the ring structures selected from formulas (4) to (6) are substituted with any of the substituents selected from -CHO, -CN, and -F, and may be the same or different, and a compound of the present embodiment in which X is C(CN)2 or O is obtained.

[0075] (4th step) In this embodiment, after the third step, the fourth step is carried out as necessary. In the fourth step of this embodiment, the R produced in the third step is 1 and R 2 R of the compound represented by general formula (I) 1 and R 2 One of the acyclic alkyl groups is reacted with a compound having a desired alkyl group by a known method.

[0076] After the third step, the fourth step is carried out to obtain the compound represented by general formula (I) 1 and R 2 is different, Ph 1 and Ph 2is a group in which one or more hydrogen atoms of any of the ring structures selected from formulas (4) to (6) are substituted with any of the substituents selected from -CHO, -CN, and -F, and may be the same or different, and a compound of the present embodiment in which X is C(CN)2 or O is obtained.

[0077] In this embodiment, the fourth step is performed after the third step, but the fourth step may be performed before the third step.

[0078] The compound of this embodiment is represented by general formula (I), and a thin film containing the compound of the present invention exhibits strong light absorption for light in the near-infrared region of the solar spectrum. Furthermore, the compound represented by formula (I) can be dissolved in a solvent to form a solution, and a thin film can be easily formed by applying the solution to a surface to be formed and removing the solvent contained in the resulting coating film. Furthermore, a thin film containing the compound represented by formula (I) exhibits strong light absorption for light in the near-infrared region of the solar spectrum, even without heat treatment after removing the solvent contained in the coating film. Furthermore, the compound represented by formula (I) does not contain metal atoms. For these reasons, the compound represented by formula (I) can be suitably used as a material for the photoelectric conversion film of an organic thin-film solar cell.

[0079] Furthermore, according to the method for producing the compound represented by formula (I) of this embodiment, the compound represented by formula (I) can be produced efficiently with fewer production steps by carrying out steps 1 and 2 and, optionally, steps 3 and / or 4.

[0080] The use of the compound represented by formula (I) of this embodiment is not limited to materials for photoelectric conversion films of organic thin-film solar cells. The compound represented by formula (I) can also be preferably used for, for example, near-infrared detectors, near-infrared filters, etc.

[0081] [Photoelectric conversion film] Next, the photoelectric conversion film of this embodiment will be described. The photoelectric conversion film of this embodiment contains a compound represented by formula (I) of this embodiment. The photoelectric conversion film of this embodiment contains, for example, an electron donating material that functions as an electron donor (donor) and an electron accepting material that functions as an electron acceptor (acceptor). The electron donating material and the electron accepting material contained in the photoelectric conversion film of this embodiment may each be of only one type, or two or more types.

[0082] In this embodiment, as a preferred example of the photoelectric conversion film, a case where the photoelectric conversion film has a bulk heterojunction structure in which an electron donating material and an electron accepting material are mixed in a phase-separated state will be described. When the photoelectric conversion film of this embodiment has a bulk heterojunction structure, it is preferable because an organic thin-film solar cell including the photoelectric conversion film of this embodiment has high energy conversion efficiency.

[0083] The photoelectric conversion film of this embodiment may contain a compound represented by formula (I), and the structure of the photoelectric conversion film is not limited to a bulk heterojunction structure. The structure of the photoelectric conversion film of this embodiment may be, for example, a single layer, a pn heterojunction, or an interpenetrating junction. When the photoelectric conversion film of this embodiment has a pn heterojunction structure, it may be formed by stacking, for example, a layer containing an electron-donating material and a layer containing an electron-accepting material.

[0084] The compound represented by formula (I) contained in the photoelectric conversion film of this embodiment may be contained as an electron-donating material that functions as an electron donor (donor), or may be contained as an electron-accepting material that functions as an electron acceptor (acceptor), and this is determined depending on the type of organic compound other than the compound represented by formula (I) that is used as a material for the photoelectric conversion film.

[0085] The electron donating material contained in the photoelectric conversion film of this embodiment may be a known electron donating material. Examples of the electron donating material include PCE10 represented by the following formula (22), poly((6,7-difluoro((2-hexyldecyl)oxy)-5,8-quinoxalinidinyl)-2,5-thiophenedyl)), and poly((2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophenyl)-benzo[1,2-b:4,5-b'))-5,5'-(5,8-bis(4-(2-butyloctyl)thiophenyl)dithienobenzothiadiazole).

[0086] [ka] (In formula (22), n is an integer representing a repeating unit. Bu represents -CH2CH2CH2CH3. Et represents -CH2CH3.)

[0087] The electron-accepting material contained in the photoelectric conversion film of this embodiment may be a known material that accepts electrons donated from an electron-donating material. The electron-accepting material may be a compound different from the electron-donating material contained in the photoelectric conversion film of this embodiment, such as a phenyl C represented by the following formula (21): 61 butyric acid methyl ester (PCBM), 2,2'-((2Z,2Z'-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydrothiadiazolothienothienopyrrolothienothienoindole-2,10-diyl)bis(metallinylidene)bis(5,6-difluoro-3-oxo-2,3-dihydroindene-2,1-diylidene)dimanolonitrile, and the like.

[0088] [ka]

[0089] The photoelectric conversion film of this embodiment contains PCE10 represented by formula (22) as an electron donating material and phenyl C represented by formula (21) as an electron accepting material. 61It is preferable that the photoelectric conversion film contains butyric acid methyl ester (PCBM), because this will result in an organic thin-film solar cell including the photoelectric conversion film of this embodiment having high energy conversion efficiency.

[0090] The ratio of the electron donating material to the electron accepting material contained in the photoelectric conversion film of this embodiment is preferably, for example, 0.5 to 2 moles of the electron accepting material per mole of the electron donating material, and can be determined appropriately depending on the type of the electron donating material and the type of the electron accepting material. For example, the electron donating material is only the compound represented by formula (I) and PCE10 represented by formula (22), and the electron accepting material is phenyl C 61 When only butyric acid methyl ester (PCBM) is used, it is preferable to contain 0.5 to 2 moles of the electron-accepting material per mole of the total of the electron-donating materials.

[0091] The content of the compound represented by formula (I) relative to 1 mole of the total of the electron donating material and the electron accepting material contained in the photoelectric conversion film of this embodiment is preferably 0.3 mole to 0.7 mole.

[0092] The photoelectric conversion film of this embodiment may contain not only the electron donating material and the electron accepting material, but also other known materials as necessary. When the photoelectric conversion film of this embodiment contains materials other than the electron donating material and the electron accepting material, the proportion of the materials other than the electron donating material and the electron accepting material contained in the photoelectric conversion film is preferably 0.1% by mass to 10% by mass, and more preferably 1% by mass to 5% by mass.

[0093] [Method of manufacturing photoelectric conversion film] Next, a method for producing the photoelectric conversion film of this embodiment will be described. When the photoelectric conversion film of this embodiment has a bulk heterojunction structure, it can be produced, for example, by the method shown below. First, a compound represented by formula (I), an electron-accepting material, an electron-donating material other than the compound represented by formula (I) which is contained as needed, and other materials which are contained as needed are dissolved in a solvent using a known method to prepare a coating material (solution) for a photoelectric conversion film.

[0094] As a solvent that can be used as a material for the coating material for the photoelectric conversion film, for example, one or more selected from chloroform, 1,8-diiodooctane, diphenyl ether, 1,2-dibromobenzene, chloronaphthalene, and the like can be used. By using 1,8-diiodooctane together with chloroform as a solvent, a coating material for a photoelectric conversion film can be obtained that is likely to produce a photoelectric conversion film in which an electron donating material containing a compound represented by formula (I) and an electron accepting material are mixed in a preferred phase-separated state.

[0095] Next, the coating material for the photoelectric conversion film is applied to the surface on which the photoelectric conversion film is to be formed to form a coating film. A known method can be used to apply the coating material for the photoelectric conversion film. Specific examples of the method for applying the coating material for the photoelectric conversion film include immersion, inkjet, dip coating, die coating, spray coating, spin coating, roll coating, screen printing, flexographic printing, and screen printing.

[0096] Next, the coating film formed on the surface on which the photoelectric conversion film is to be formed is dried by a known method to remove the solvent contained in the coating film. Through the above steps, the photoelectric conversion film of this embodiment made of a thin film is obtained. The photoelectric conversion film of this embodiment contains the compound represented by formula (I), and therefore exhibits strong light absorption for light in the near-infrared region even without heat treatment after removing the solvent contained in the coating film, and can be suitably used as a photoelectric conversion film for an organic thin-film solar cell.

[0097] In the method for producing a photoelectric conversion film according to the present embodiment, after removing the solvent contained in the coating film, a heat treatment may be carried out as necessary. By carrying out the heat treatment, a photoelectric conversion film for an organic thin-film solar cell that exhibits stronger absorption in a wider range from the visible light region to the near-infrared region may be obtained. When the photoelectric conversion film is subjected to heat treatment, the heat treatment can be performed, for example, at a temperature of 60°C to 150°C for 1 minute to 60 minutes, preferably at a temperature of 80°C to 100°C for 5 minutes to 10 minutes, and can be appropriately determined depending on the thickness of the photoelectric conversion film, etc.

[0098] The photoelectric conversion film of this embodiment contains a compound represented by formula (I). Therefore, the photoelectric conversion film of this embodiment exhibits strong light absorption in the near-infrared region and can be suitably used as a photoelectric conversion film for organic thin-film solar cells. Furthermore, the photoelectric conversion film of this embodiment can be produced by a method of applying a solution in which the compound represented by formula (I) is dissolved in a solvent, and can be produced without heat treatment. Therefore, the photoelectric conversion film of this embodiment can be produced efficiently with fewer production steps.

[0099] [Organic thin film solar cell] Next, the organic thin-film solar cell of this embodiment will be described in detail with reference to the drawings. Fig. 1 is a cross-sectional view showing an example of an organic thin-film solar cell according to this embodiment. As shown in Fig. 1, an organic thin-film solar cell 10 according to this embodiment has a plate-like shape.

[0100] As shown in FIG. 1, the organic thin-film solar cell 10 of this embodiment includes a substrate 1, a first electrode 2a formed on the substrate 1, a photoelectric conversion film 3 formed on the first electrode 2a, and a second electrode 2b formed on the photoelectric conversion film 3. In the organic thin-film solar cell 10 of this embodiment, the photoelectric conversion film 3 includes the photoelectric conversion film of this embodiment having a bulk heterojunction structure.

[0101] As the substrate 1, for example, a known light-transmitting substrate such as a glass substrate or a resin substrate can be used. The first electrode 2a functions as an anode. The first electrode 2a can be made of a known light-transmitting conductive material such as indium-tin oxide (ITO). The first electrode 2a can be formed by a known method. The second electrode 2b functions as a cathode. The second electrode 2b can be made of a known conductive material such as silver or aluminum. The second electrode 2b can be formed by a known method.

[0102] In the organic thin-film solar cell 10 of this embodiment, a hole transport layer (not shown) made of a known material such as molybdenum oxide (MoO) or poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT:PSS) may be provided between the first electrode 2a and the photoelectric conversion film 3. A known method can be used to form the hole transport layer, and the method can be appropriately determined depending on the material of the hole transport layer, etc.

[0103] In the organic thin-film solar cell 10 of this embodiment, an electron transport layer (not shown) made of a known material such as zinc oxide (ZnO) may be provided between the second electrode 2b and the photoelectric conversion film 3. A known method can be used to form the electron transport layer, and the method can be appropriately determined depending on the material of the electron transport layer, etc.

[0104] 1 includes a photoelectric conversion film having the bulk heterojunction structure of this embodiment as the photoelectric conversion film 3. Therefore, the organic thin-film solar cell 10 of this embodiment can convert solar energy over a wide range, from the visible light region to the near-infrared region, into electrical energy, and has high solar light utilization efficiency.

[0105] The organic thin-film solar cell of the present invention is not limited to the organic thin-film solar cell 10 of this embodiment shown in Fig. 1. Specifically, the shape of the organic thin-film solar cell is not limited to a plate-like shape, and may have, for example, a curved surface shape that follows the shape of the installation surface, or may have a folded surface shape.

[0106] Although the embodiment of the present invention has been described above, the present invention is not limited to this and can be modified as appropriate within the scope of the technical idea of ​​the invention. [Example]

[0107] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. [Example 1] The compound represented by formula (I-1) was produced by the method shown below.

[0108] [ka]

[0109] (1st step) First, 4-methyl-7-chloroquinoline represented by formula (32) was produced as a starting material in the first step. Specifically, 5.55 g of 4,7-dichloroquinoline represented by formula (31) and 3.91 g of methylmagnesium bromide (CH3MgBr) were placed in a solvent and reacted for 4 hours at room temperature (20°C) using iron(III) acetylacetonate (Fe(acac)3) as a catalyst. A mixed solvent containing tetrahydrofuran (THF) and N-methyl-2-pyrrolidone (NMP) in a volume ratio of 4:1 (THF:NMP) was used as the solvent. This resulted in the production of 4-methyl-7-chloroquinoline represented by formula (32) (yield: 83%).

[0110] Next, 0.53 g of 4-methyl-7-chloroquinoline and dodecyl iodide (C 12 H 25 The reaction was carried out by refluxing for 5 days in acetonitrile, and a dodecyl group (-C) was attached to the nitrogen atom of the quinoline ring of 4-methyl-7-chloroquinoline. 12 H 25 ) was bound to the ammonium salt represented by formula (33) (yield 80%).

[0111] (2nd process) Next, 0.284 g of the ammonium salt represented by formula (33) prepared in the first step and a triethylamine salt of a squaric acid derivative having —C(CN)2 represented by formula (12) (HN + The reaction was carried out by refluxing 0.087 g of (C2H5)3 in a solvent for 20 hours. The solvent used was a mixed solvent containing toluene and n-butanol in a volume ratio of 1:1 (toluene:n-butanol). This gave the compound represented by formula (34) (yield: 20%).

[0112] The triethylamine salt of the squaric acid derivative having —C(CN)2 represented by formula (12) (HN + (C2H5)3) was prepared by the following method. 1.46 g of 3,4-diethoxy-3-cyclobutane-1,2-dione, 0.52 g of malononitrile (CH2(CN)2), and 0.87 g of triethylamine ((CH3CH2)3N) were added to a benzene solvent and reacted at room temperature (20°C) for 3 hours to obtain the triethylamine salt represented by formula (12) (yield: 83%).

[0113] (3rd step) Next, 0.040 g of the compound represented by formula (34) produced in the second step was reacted with 0.019 g of hydroxide represented by formula (35) (5-Formylbenzene-2-boronic acid; manufactured by Angene International Limited), which contains a phenyl group having one -CHO substituent, in tetrahydrofuran (THF) as a solvent under reflux for 16 hours using tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) as a catalyst, 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos), and an aqueous potassium carbonate solution. This produced the target compound represented by formula (I-1) (yield 65%).

[0114] The compound represented by formula (I-1) thus produced was analyzed by nuclear magnetic resonance (NMR) using a nuclear magnetic resonance (NMR) instrument (trade name: JNM-ECZ400, manufactured by JEOL Ltd.). 1 H-NMR measurement was carried out, and the structure was identified from the following results. 1 H-NMR(500MHz, CDCl3, TMS)δ 0.85(t, J=6.5Hz, 6H), 1.24~1.50(m, 36H) 1.91(m, 4H), 4.26(brt, 4H), 6.78(brs, 2H), 7.35~7.37(brd, 2H), 7.55(s, 2H), 7.64~7 .66(brd, 2H), 7.77~7.79(d, J=8.0Hz, 4H), 7.88~7.90(d, J=8.0Hz, 4H), 8.14~8.16(d, J=9.5Hz, 2H), 8.51(brs, 2H), 9.96(s, 2H) As a result, it was confirmed that the compound synthesized in Example 1 was the compound represented by formula (I-1).

[0115] [Example 2] The compound represented by formula (I-2) was produced by the following method. That is, in the second step, a triethylamine salt of a squaric acid derivative having —C(CN)2 represented by formula (12) (HN + The compound represented by formula (I-2) was produced in a 20% yield in the same manner as in Example 1, except that 0.034 g of squaric acid represented by formula (11) was used instead of (C2H5)3).

[0116] The compound represented by formula (I-2) thus prepared was subjected to the same procedure as in Example 1. 1 H-NMR measurement was carried out, and the structure was identified from the following results. 1H-NMR (500 MHz, CDCl3, TMS) δ 0.85~0.88(t, J=6.5Hz, 6H), 1.24~1.44(m, 36H), 1.86~1.92(m, 4H), 4.11 (t, J=7.0Hz, 4H), 6.58(s, 2H), 7.19~7.25(brd, 2H), 7.48(s, 2H), 7.58~7. 60(d, J=9.0Hz, 2H), 7.80~7.82(d, J=8.5Hz, 4H), 8.00~8.02(d, J=8.5Hz, 4 H), 8.30~8.32(d, J=9.0Hz, 2H), 8.71~8.73(d, J=7.5Hz, 2H), 10.09(s, 2H) As a result, it was confirmed that the compound synthesized in Example 2 was the compound represented by formula (I-2).

[0117] [Example 3] The compound represented by formula (I-3) was prepared by the following method. That is, in the third step, the compound represented by formula (I-3) was produced (yield 69%) in the same manner as in Example 2, except that in place of the hydroxide represented by formula (35), 0.023 g of a hydroxide having one —CN as a substituent in place of —CHO in formula (35) (5-cyanobenzene-2-boronic acid; manufactured by Angene International Limited) was used.

[0118] The compound represented by formula (I-3) thus prepared was subjected to the same procedure as in Example 1. 1 H-NMR measurement was carried out, and the structure was identified from the following results. 1H-NMR (500 MHz, CDCl3, TMS) δ 0.86~0.88(t, J=7.0Hz, 6H), 1.24~1.43(m, 36H), 1.86~1.89(m, 4H), 4.0 9~4.12(t, J=7.5Hz, 4H), 6.57(s, 2H), 7.21~7.23(brd, 2H), 7.43(s, 2H) , 7.53~7.56(d, J=8.5Hz, 2H), 7.73~7.74(d, J=6.5Hz, 4H), 7.78~7.80(d, J=6.5Hz, 4H), 8.30~8.31(d, J=9.0Hz, 2H), 8.71~8.72(d, J=7.0Hz, 2H) As a result, it was confirmed that the compound synthesized in Example 3 was the compound represented by formula (I-3).

[0119] [Example 4] The compound represented by formula (I-4) was prepared by the following method. That is, in the third step, the compound represented by formula (I-4) was produced in the same manner as in Example 2, except that in place of the hydroxide represented by formula (35), 0.027 g of a hydroxide having three -F as substituents at positions far from the position bonded to boron in the phenyl group ((3,4,5-Trifluorophenyl)boronic acid; manufactured by Angene International Limited) was used instead of -CHO in formula (35).

[0120] The compound represented by formula (I-4) thus prepared was subjected to the same procedure as in Example 1. 1 H-NMR measurement was carried out, and the structure was identified from the following results. 1H-NMR(500MHz, CDCl3, TMS)δ 0.85~0.88(t, J=7.5Hz, 6H), 1.24~1.43(m, 36H), 1.85~1.88(m, 4H), 4.08~4.11(t, J=7.0Hz, 4H), 6.54(s, 2H), 7.18~7.20 (brd, 2H), 7.25(s, 4H), 7.33(s, 2H), 7.44~7.46(d, J=9.0Hz, 2H), 8.26~8.28(d, J=9.0Hz, 2H), 8.69~8.71(d, J=7.5Hz, 2H) As a result, it was confirmed that the compound synthesized in Example 4 was the compound represented by formula (I-4).

[0121] [Example 5] The compound represented by formula (I-5) was prepared by the following method. That is, in the first step, dodecyl iodide (C 12 H 25 I) acyclic alkyl group (-C 12 H 25 The compound represented by formula (I-5) was produced in a 42% yield in the same manner as in Example 1, except that an iodide having an acyclic alkyl group in which n is 8 in formula (3) was used instead of formula (I-4).

[0122] The compound represented by formula (I-5) thus prepared was subjected to the same procedure as in Example 1. 1 H-NMR measurement was carried out, and the structure was identified from the following results. 1 H-NMR(500MHz, CDCl3, TMS)δ 0.82~0.85(t, J=7.0Hz, 12H), 1.21~1.43(m, 54H), 1.86~1.92(m, 4H), 4.24~4.27(t, J=7.5Hz, 4H), 6.54(s, 2H), 7.37~7.38(d, J=7.0Hz, 4H), 7.54(s, 2H), 7.61~7.62(d, J=8.5Hz, 4H), 7.76~7.79(m, 8H), 8.02~8.04(d, J=9.5Hz, 4H), 8.40~8.42(d, J=7.5Hz, 4H), 9.86(s, 2H) As a result, it was confirmed that the compound synthesized in Example 5 was the compound represented by formula (I-5).

[0123] [Example 6] The compound represented by formula (I-6) was prepared by the following method. That is, in the first step, dodecyl iodide (C 12 H 25 I) acyclic alkyl group (-C 12 H 25 The compound represented by formula (I-6) was produced in a 60% yield by carrying out the steps up to the second step in the same manner as in Example 1, except that an iodide having an acyclic alkyl group in which n is 8 in formula (3) was used instead of formula (I-6).

[0124] The compound represented by formula (I-6) thus prepared was subjected to the same procedure as in Example 1. 1 H-NMR measurement was carried out, and the structure was identified from the following results. 1 H-NMR(500MHz, CDCl3, TMS)δ 0.86~0.89(m, 12H), 1.21~1.33(m, 54H), 1.76~1.81(m, 4H), 3.98~4.02(brt, 4H), 6.65(s, 2H), 7.13(s, 2H), 7. 15~7.17(d, J=9.0Hz, 2H), 7.34~7.35(d, J=7.0Hz, 2H), 7.84~7.86(d, J=9.0Hz, 2H), 8.50~8.51(d, J=7.0Hz, 2H) As a result, it was confirmed that the compound synthesized in Example 6 was the compound represented by formula (I-6).

[0125] [Example 7] The compound represented by formula (I-7) was prepared by the following method. That is, in the third step, the compound represented by formula (I-7) was produced in the same manner as in Example 1, except that 0.016 g of 4-pyridineboronic acid (manufactured by BLD Pharmatech Co., Ltd.) was used instead of the hydroxide represented by formula (35) (yield 25%).

[0126] The compound represented by formula (I-7) was synthesized in the same manner as in Example 1. 1 H-NMR measurement was carried out, and the structure was identified from the following results. 1 H-NMR(500MHz, CDCl3, TMS)δ 0.87(t, J=7.0Hz, 6H), 1.24~1.45(m, 36H), 1.87~1.91(m, 4H), 4.23(brs, 4H), 6.72(brs, 2H), 7.33~7.34(d, J=7.0Hz, 2 H), 7.48~7.49(dd, J=6.0Hz, 4H), 7.52(s, 2H), 8.14~8.16(d, J=9.0Hz, 2H), 8.46(brs, 2H), 8.59~8.60(d, J=6.0Hz, 4H) As a result, it was confirmed that the compound synthesized in Example 7 was the compound represented by formula (I-7).

[0127] The compounds represented by formula (I-1) to formula (I-7) of Examples 1 to 7 thus obtained were each dissolved in chloroform to a concentration of 0.00015% by mass to prepare a compound solution, and the absorption spectrum was measured using an ultraviolet-visible (UV-vis) spectrophotometer (trade name: Cary 8454 UV-vis, manufactured by Agilent Technologies, Inc.).

[0128] Furthermore, the compound solutions of Examples 1 to 7 were each applied to a quartz substrate by spin coating at a concentration of 0.0001 mL / mm 2 For each of the thin films of Examples 1 to 7 thus obtained, the absorption spectrum was measured using an ultraviolet-visible-near-infrared (UV-vis-NIR) spectrophotometer (product name: UV-3100S, manufactured by Shimadzu Corporation).

[0129] Furthermore, the thin films of Examples 1 to 5 and Example 7 were each heat-treated for 10 minutes at a temperature of 100° C. Then, the absorption spectra of the thin films of Examples 1 to 5 and Example 7 after the heat treatment were measured in the same manner as for the thin films before the heat treatment.

[0130] The measurement results of the absorption spectra of the compound solutions and the thin films before and after heat treatment in Examples 1 to 5 are shown in Figures 2 to 6. Figure 2 shows the results of Example 1, Figure 3 shows the results of Example 2, Figure 4 shows the results of Example 3, Figure 5 shows the results of Example 4, and Figure 6 shows the results of Example 5. Figures 2(a), 3(a), 4(a), 5(a), and 6(a) are graphs showing the relationship between the absorption coefficient ε of the compound solutions and wavelength. Figures 2(b), 3(b), 4(b), 5(b), and 6(b) are graphs showing the relationship between the index α of the optical absorption intensity of the thin films and wavelength. The solid line shows the results for the thin films before heat treatment, and the dotted line shows the results for the thin films after heat treatment.

[0131] The measurement results of the absorption spectra of the compound solution of Example 6 and the thin film before heat treatment are shown in Figure 7. Figure 7(a) is a graph showing the relationship between the absorbance (intensity) and wavelength of the compound solution of Example 6. Figure 7(b) is a graph showing the relationship between the absorbance (intensity) and wavelength of the thin film of Example 6 before heat treatment.

[0132] The measurement results of the absorption spectra of the compound solution of Example 7 and the thin film before and after heat treatment are shown in Figure 8. Figure 8(a) is a graph showing the relationship between the absorbance (intensity) and wavelength of the compound solution of Example 7. Figure 8(b) is a graph showing the relationship between the absorbance (intensity) and wavelength of the thin film of Example 7, where the solid line shows the result for the thin film before heat treatment and the dotted line shows the result for the thin film after heat treatment.

[0133] 2 to 8, it was confirmed that the compound solutions and the thin films before heat treatment in Examples 1 to 7 all exhibited strong optical absorption for light in the near-infrared region. Furthermore, as shown in Figures 2 to 6 and 8, it was confirmed that by subjecting the thin films in Examples 1 to 5 and 7 to heat treatment, they exhibited even stronger optical absorption for light in the near-infrared region.

[0134] [Organic thin film solar cell] The organic thin-film solar cell of Example 1 was produced by the method described below. A glass substrate (manufactured by Furuuchi Chemical Co., Ltd.) with a first electrode made of indium-tin oxide (ITO) formed on its surface was prepared. Then, a 30-nm-thick electron transport layer made of zinc oxide (ZnO) was formed on the first electrode by a known sol-gel method.

[0135] Next, a photoelectric conversion film having a bulk heterojunction structure containing the compound represented by formula (I-1) produced in Example 1 was formed on the electron transport layer by the method described below. First, the electron-accepting material, phenyl C represented by formula (21), 61 6 mg of butyric acid methyl ester (PCBM) and 4 mg of the electron donor material PCE10 represented by formula (22) were added to 400 mL of chloroform as a solvent and stirred at 50°C for 3 hours using a hot stirrer to obtain a chloroform solution.

[0136] To the resulting chloroform solution, 0.7 mg of the compound represented by formula (I-1) prepared in Example 1 was added, and the mixture was stirred at 50°C using a hot stirrer for 30 minutes to dissolve the compound represented by formula (I-1). Then, 9 mL of 1,8-diiodooctane as a solvent was added to the chloroform solution in which the compound represented by formula (I-1) had been dissolved, and the mixture was stirred at 50°C for 60 minutes using a hot stirrer to obtain a coating material for a photoelectric conversion film.

[0137] The coating material for the photoelectric conversion film obtained in this manner was applied by spin coating to a substrate on which each layer up to the electron transport layer had been formed, for 35 seconds while rotating at a rotation speed of 400 rpm, to obtain a photoelectric conversion film consisting of a thin film with a thickness of 100 nm.

[0138] Next, a 10-nm-thick hole transport layer made of molybdenum oxide (MoO3) was formed on the photoelectric conversion film by vacuum deposition, and then a 600-nm-thick second electrode made of silver was formed on the hole transport layer by vacuum deposition. Through the above steps, the organic thin-film solar cell of Example 1 was obtained.

[0139] Next, the organic thin-film solar cell of Example 1 was irradiated with artificial sunlight using a solar simulator (trade name: XES-40S1, manufactured by Minaga Electric Mfg. Co., Ltd.), and the current flowing during the above-mentioned light irradiation was measured while applying a voltage using an I-V meter (trade name: ADCMAT6242, manufactured by ADC Corporation.) The JV curve, which is the relationship between current density and voltage obtained from this measurement result, is shown in Figure 9.

[0140] As shown in FIG. 9, it was confirmed that the organic thin-film solar cell of Example 1 had photoelectric conversion properties.

[0141] The short-circuit current density Jsc of the organic thin-film solar cell of Example 1 calculated from the above measurement results was 1.4 mA / cm 2 The open circuit voltage Voc was 0.3 V, the fill factor FF was 0.5, and the photoelectric conversion efficiency PCE was 0.2%. From these results, it was confirmed that the organic thin-film solar cell of Example 1 has power generation performance.

[0142] Furthermore, the spectral sensitivity spectrum (IPCE) was measured using an action spectrum measurement system (product name: SM-250GTD, manufactured by Bunkoukeiki Co., Ltd.) for the organic thin-film solar cell of Example 1. The results are shown in FIG. 10, it was confirmed that the organic thin-film solar cell of Example 1 can convert a wide range of solar energy from the visible light region to the near-infrared region into electrical energy. In addition, a peak of 2.3% was confirmed at 1100 nm in the near-infrared region.

[0143] Furthermore, the absorption spectrum of the organic thin-film solar cell of Example 1 was measured using an ultraviolet-visible-near-infrared (UV-vis-NIR) spectrophotometer (product name: UV-3600, manufactured by Shimadzu Corporation). The results are shown in Figure 11. Figure 11 also shows the absorption spectrum of the thin film of the compound represented by formula (I-1) produced in Example 1 before heat treatment. The dotted line in Figure 11 shows the result of the organic thin-film solar cell of Example 1, and the solid line shows the result of the thin film before heat treatment.

[0144] As shown in FIG. 11, it was confirmed that the organic thin-film solar cell of Example 1 exhibits strong light absorption for light in the near-infrared region of the solar light spectrum, and can absorb solar light energy over a wide range from the visible light region to the near-infrared region. [Explanation of symbols]

[0145] 10... Organic thin film solar cell, 1... Substrate, 2a... First electrode, 2b... Second electrode, 3... Photoelectric conversion film.

Claims

1. A compound represented by the following general formula (I): 【Chemistry 1】 (In general formula (I), R １ , R ２ are acyclic alkyl groups having 1 to 26 carbon atoms selected from the following general formulas (1) to (3), and may be the same or different. １ , Ph ２ is a group in which one or more hydrogen atoms of a ring structure selected from the following formulae (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, a pyridine ring represented by the following formula (7), and -Cl, and may be the same or different. X is C(CN) ２ Or O.) 【Chemistry 2】 (In general formulas (1) to (3), n is an integer.) 【Transformation 3】

2. The R in the general formula (I) １ and the above R ２ are the same, and １ and the aforementioned Ph ２ The compound of claim 1 , wherein

3. The compound according to claim 1, wherein the general formula (I) is any one selected from the following formulas (I-1) to (I-6): 【Chemistry 4】 【Transformation 5】

4. A method for producing the compound according to any one of claims 1 to 3, comprising: 4-methyl-7-chloroquinoline and the R １ to the nitrogen atom of the quinoline ring of 4-methyl-7-chloroquinoline, and an iodide having an acyclic alkyl group corresponding to the R １ a first step of producing an ammonium salt having an acyclic alkyl group attached thereto, which corresponds to and a second step of reacting the ammonium salt with squaric acid or a squaric acid derivative having a group corresponding to X in general formula (I) to produce a compound represented by the following general formula (II): 【Transformation 6】 (In general formula (II), R １ is an acyclic alkyl group having 1 to 26 carbon atoms selected from the following general formulas (1) to (3): X is C(CN) ２ Or O.) 【Transformation 7】 (In general formulas (1) to (3), n is an integer.)

5. Furthermore, one of the chloro groups of the compound represented by the general formula (II) and Ph １ -B(OH) ２ (Ph in the formula １ is a group in which one or more hydrogen atoms of a ring structure selected from the formulas (4) to (6) are substituted with a substituent selected from -CHO, -CN, and -F, or a pyridine ring represented by the formula (7). ２ -B(OH) ２ (Ph in the formula ２ is a group in which one or more hydrogen atoms of a ring structure selected from the formulae (4) to (6) are substituted with a substituent selected from —CHO, —CN, and —F, or a pyridine ring represented by the formula (7).

6. A photoelectric conversion film comprising the compound according to any one of claims 1 to 3.

7. Phenyl C represented by the following formula (21) ６１ The photoelectric conversion film according to claim 6, comprising either or both of butyric acid methyl ester (PCBM) and PCE10 represented by the following formula (22): 【Transformation 8】 (In formula (22), n is an integer indicating a repeating unit. Bu is —CH ２ CH ２ CH ２ CH ３ Et represents -CH ２ CH ３ Indicates.)

8. an electron donating material that functions as an electron donor and an electron accepting material that functions as an electron acceptor; The photoelectric conversion film according to claim 6 , which has a bulk heterojunction structure in which the electron donating material and the electron accepting material are mixed.

9. An organic thin-film solar cell comprising a first electrode, a second electrode, and the photoelectric conversion film according to claim 6 .

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