TW201202194A - Squarylium dye, dye-sensitized solar cell using the dye, and photoelectric conversion element using the dye - Google Patents

Abstract

Disclosed are: a novel squarylium dye which is capable of improving the photoelectric conversion efficiency in the near infrared region; and a dye-sensitized solar cell and a photoelectric conversion element, each using the squarylium dye and having improved photoelectric conversion efficiency. Specifically disclosed is a squarylium dye represented by formula (1). In the formula, R1-R7 and R'1-R'7 each represents a hydrogen atom, an alkyl group, a sulfoalkyl group, a cycloalkyl group, an alkoxyl group, an aryl group, a halogen atom or the like; X and Y each represents a hydrogen atom or -COOR (wherein R represents a hydrogen atom or a C1-C12 alkyl group), with both or either of X and Y being -COOR; and R8 and/or R'8 represents a C3-C30 alkyl group, a C3-C30 halogen-substituted alkyl group, a C3-C30 hydroxycarbonylalkyl group, RCOO- or RSO3- (wherein R represents a C1-C30 alkyl group).

Description

[Technical Field] The present invention relates to a squarylium dye having a π-priming structure, a semi-squaric acid dye, a photoelectric conversion element using the same, and a dye-sensitized solar cell. [Prior Art] The photoelectric conversion element is used in a photo-electric device such as a photo sensor or a solar cell. A photoelectric conversion element using semiconductor fine particles sensitized with a dye has been found in Patent Document 1. As for the solar cell, a solar cell using a single crystal, a polycrystalline or an amorphous semiconductor has been widely used in electric appliances such as electronic computers, residential, and the like. However, in the manufacture of solar cells using such germanium semiconductors, since high-precision processes such as plasma CVD or high-temperature crystal growth processes are used, considerable energy is required, and expensive devices are required due to the necessity of vacuum, so that manufacturing is required. The cost is getting higher. Therefore, as a solar cell which can be manufactured at a low cost, for example, a dye-sensitized solar cell which is used for a material which adsorbs a photo-sensitizing dye such as a ruthenium metal complex in an oxide semiconductor such as titanium oxide has been proposed. The dye-sensitized solar cell is, for example, a transparent glass plate provided with a transparent conductive layer such as tin oxide added with indium or a transparent conductive layer such as a transparent insulating material of a transparent resin plate, and is formed on the surface by adsorption of, for example, ruthenium The titanium oxide of the pigment formed by the complex compound is used as a negative electrode of the semiconductor layer, and a transparent glass plate provided with a metal layer or a conductive layer such as platinum as a positive electrode or a transparent insulating material such as a transparent tree-5-201202194 grease plate. The electrolyte is sealed between them. Sensitization of the dye When the solar cell is illuminated, light is absorbed by the negative electrode to excite the electrons of the dye, and the excited electrons move toward the semiconductor layer, and then guided to the transparent electrode, and the electrolyte is reduced by the electrons from the conductive layer on the positive electrode. It is considered that the reduced electrolyte is oxidized by transferring electrons into the pigment, and the cycle causes the dye-sensitized solar cell to generate electricity. At present, a dye-sensitized solar cell is less effective than a tantalum solar cell in that it is low in power generation energy for irradiating light energy, and an effective dye-sensitized solar cell is becoming an important issue in manufacturing an efficiency. In view of the fact that the efficiency of the sensitized solar cell is affected by the characteristics of the various elements constituting it, and is also affected by the combination of these elements, various attempts are being made. Among them, we are working on the development of higher-efficiency sensitizing dyes for pigments that have a photosensitizing effect. As for the high-efficiency pigment currently known, there is a Ru pigment, but since the Ru of the transition metal is expensive, it is devoted to the development of a cheap and efficient dye. Further, these dyes have high photoelectric conversion efficiency in the visible light region, but have low photoelectric conversion efficiency in the near-infrared light region. Therefore, it has been desired to develop a dye having an absorption band in the vicinity of the near-infrared region. In the case of the organic dye having an absorption band in the vicinity of the near-infrared region, there are known compounds in Patent Document 1, Non-Patent Document 1, Non-Patent Document 2, and the like. Further, a dye-sensitized solar cell in which an organic dye having an absorption band in the vicinity of the near-infrared region and an organic dye having an absorption band in another region are mixed is disclosed in Patent Document 2, Non-Patent Document 3, Non-Patent Document 4, and the like. Also known as squaraine pigments are known in these documents. [Patent Document 1] Japanese Patent No. 4,148,374 [Patent Document 2] JP-A-2000-268892 (Patent Document 3) Patent No. 4000194 (Patent Document 4) Patent No. 3 6 1 6 1 Bulletin No. 73 [Non-hands [| Literature 1] Chemical Communication, 2007, p4680 -4682 Expertise (] Literature 2] J. Am. Chem. Soc., 2007, 129, p 1 0320 -10321 [梦隹专Hand IJ Document 3] New J. Chem., 2005, 29, p773-776 [Non-Patent Document 4] Angew. Chem. Int. Ed., 2008, 120, p8383- 8387 [Non-Patent Document 5] J. Am. Chem. Soc., 1 998, 120, p662 1 - 6622 [Non-Patent Document 6] J. Am. Chem. Soc., 1999, 121, pl0251 - 1 0263 Patent Document 1 discloses a photoelectric conversion element and a dye-sensitized solar cell The polymethine dye used in the above is exemplified. The polymethine pigment used in Patent Document 1 contains a large amount of a compound represented by the general formula, but among the exemplified compounds, it has a carboxyl group. (indolenine) is a squaric acid coloring matter with an ethyl group, and a squaric acid coloring matter having an N-carboxyethyl group. However, it is not illustrated. a squaric acid pigment having a benzopyroquinonecarboxylic acid, and a squaraine dye having a long-chain N-substituted alkyl group and a benzopyrudocarboxylic acid group. In this context, it is understood to mean Has a carboxyl group

S 201202194 False 吲哚 structure and squaraine pigment with N substituent. Patent Document 4 discloses a silver halide salt photographic light-sensitive material, and exemplifies a polymethine coloring matter used therefor. The polymethine dye used in Patent Document 4 contains a large amount of a compound represented by the general formula, but the compound exemplified has a methyl phthalocyanine dye having a carboxyl anion of a carboxy fluorene structure as a component internal salt. However, a method of forming an intramolecular salt or a method of forming an alkaline earth metal and a salt is not described, and only the N substituent in the nitrogen-containing heterocyclic ring is exemplified as a C1 alkyl group. In Non-Patent Document 1 and Non-Patent Document 2, a methyl group, an ethyl group, and a C8 alkyl group are exemplified as the N substituent in the nitrogen-containing hetero ring, and one of them has a carboxyl group and the other has a pseudoanthracene skeleton. Squaric acid pigment, but the conversion efficiency is low. In Non-Patent Document 2 and Non-Patent Documents 3 and 4, a dye-sensitized solar cell in which a short-wavelength region dye and a long-wavelength region dye are mixed is exemplified, but the disclosure of the squaraine dye is almost the same as in Patent Document 1. Non-patent documents 5 and 6 exemplify a synthesis method of a substituted oxime, but a benzofluorene compound having an ester group is not disclosed. [Summary of the Invention] The squaric acid dye is generally easy to aggregate, and it is considered that energy transfer between the dyes is likely to occur as a photoelectric conversion element or a pigment for a solar cell. In the case where the N substituent is a short alkyl group, there is a tendency to aggregate and cause energy transfer between the dyes to be deactivated. Further, the acid dye having a carboxyindolenine skeleton has a short absorption wavelength and cannot sufficiently absorb light. -8-201202194 The present invention has been made in view of the above problems, and an object thereof is to provide a novel dye which can improve photoelectric conversion efficiency in a near-infrared region, and to provide a dye-sensitized solar cell and a photoelectric conversion element using the same. Further, it is an object of the present invention to provide a simple synthesis method which provides a squaraine dye suitable for a near-infrared region which is not easily deactivated. Further, an object of the present invention is to provide a dye-sensitized solar cell and a photoelectric conversion element which can improve photoelectric conversion efficiency in a wide range of regions. The present invention relates to a squaraine dye represented by the following formula (1). 【化1】

In the formula, Ri~R7, and R'i~R'7 are independently a gas atom, a C1~C12 alkyl group, a C1-C4 sulfoalkyl group, a C4~C12 cycloalkyl group, a C1~C12 alkane. An oxy group, an aryl group of C5 to C12, an aromatic alkoxy group of C6 to C12 or a halogen atom, and X and Y independently represent a hydrogen atom or -COOR (R is hydrogen or an alkyl group of C1 to C12), and at least one Is -COOR, R8 and R's independently represent a C1 to C30 alkyl group, a C1-C30 halogen-substituted alkyl group, a C1-C30 hydroxycarbonylalkyl group or a RCOO- or RS03- (R is a C1 to C30 alkyl group). , but at least one is a C3 to C30 alkyl group, a C3 to C30 halogen-substituted alkyl group, a C3-C30 hydroxycarbonylalkyl group or a RCOO- or RS〇3_ (R is a C1 to C30 alkyl group) 201202194 In the formula (1), RrR?, and R'^R'7 are independently a hydrogen atom, an alkyl group of C1 to C12, a sulfoalkyl group of C1 to C4, a cycloalkyl group of C4 to C12, and a C1 to C12. Alkoxy, C5-C12 aryl, C6-C12 aromatic alkoxy or halogen atom, X and Y are independently hydrogen or -COOR (R is hydrogen or C1 to C12 alkyl), and at least one Is -COOR, R8 and R'8 are independently C3~C30 alkyl, C3~C30 halogen substituted alkyl, C3~C30 hydroxy Or a carbonyl group or RCOO- RS03- (R is alkyl group of C1 ~ C30) preferred. The squaric acid dye is a squaric acid dye represented by the following formula (2):

Wherein 'Rl~R_5, R'l~R'5, ~R7, R'6~R'7, X, Y, and R'8 are synonymous with formula (1) ·", RrRs, and R' ^R'5 is independently a hydrogen atom or a halogen atom, R6~R7 and R'6~R'7 are independently a C1~C12 alkyl group, a C1~C4 sulfoalkyl group, a C4~C12 cycloalkyl group, a C1~ An alkoxy group of C12, an aryl group of C5 to C12, an aromatic alkoxy group of C6 to C12 or a halogen atom. Further, the present invention relates to a half acid color represented by the following formula (3) -10- 201202194 [Chemical 3]

In the formula, Ri to R7 independently represent a hydrogen atom, a C1-C12-based group, a C1-C4 sulfoalkyl group, a C4-C12 cycloalkyl group, a C1-C12 alkoxy group, a C5-C12 aryl group, and a C6 group. -C12 aromatic alkoxy or halogen atom, X means COOR (R is ammonia or C1~C12). R8 indicates not C3~C30, C3~C30 halogen substituted alkyl, C3 ～C30 hydroxycarbonylalkyl or RCOO- or RS0.3- (R is a C1 to C30 alkyl group). R9 represents a hydrogen atom or an alkyl group of C1 to C12, but when X is other than -COOH, R9 is a hydrogen atom. The above-mentioned semi-squaric acid dye is a squaraine dye represented by the following formula (4):

In the formula, R, ~R8, R9, and X are synonymous with the formula (3). Further, the present invention relates to a dye-sensitized solar cell or a photoelectric conversion element characterized in that a dye used in a dye-sensitized solar cell or a photoelectric conversion element using a dye is the above-described squaraine dye or a semi-squaric acid dye. Here, _ -11 - 201202194 , the above squaric acid dye can be used together with the above-mentioned semi-squaric acid dye. The substituted benzo[e]indole compound represented by the following formula (5) is a novel compound which can be used as an intermediate of the above-described squary pigment or semi-squaric acid. 【化5】

(5) where Ri~R7 is synonymous with formula (1). X is synonymous with the formula (3) "r1" is an alkyl group of C1 to C30' and the carbon adjacent to the ring is a - or a secondary carbon. It is more advantageous to use the above-mentioned substituted benzo[e]fluorene compound represented by the following formula (6).

In the formula, R broad R?, Rio and X are synonymous with formula (5). It is preferably a methyl group. The salt of the substituted benzo[e] D-extracted -12-201202194 compound represented by the above formulas (5) and (6) is similarly a novel compound which can be used as the above-mentioned squaraine pigment or half. An intermediate of squaraine pigment. These salts are represented by the following formula (7), and are advantageously represented by the formula (8). [化7] Ri

Wherein the 'RrRs' is synonymous with the formula (i). Rl{) and X are synonymous with equation (5). Redundant _ indicates that it is a relatively anionic halogen ion, BF4- or CCl〇4. However, when Κ·8 is RCOO - or rs〇3·, Z· does not exist. 【化8】

In the formula, R丨~R8, Rw, z- and X are synonymous with the formula (7). Ri〇 is preferably a methyl group. The above-mentioned substituted benzoquinone [e] fluorene compound can be produced by sequentially performing the following steps: a compound of the following formula (9) and a compound of the following formula (1 〇) in palladium acetate and 2, 2' - bis(diphenylphosphonium)_〗 ",_binaphthyl acetate £_13-201202194 In the next reaction, an esterified aryl hydrazine of the following formula (11) is produced, followed by esterification The step of reacting an aryl hydrazine with a ketone of the following formula (12) in the presence of p-toluenesulfonic acid monohydrate. 【化9】

(9) (11)

°2 (10) Ο B2 (12) where 'Αι~Α6 and Βι~Β2 are hydrogen I atoms, C1~C12 sulfhydryl groups' C1~C4 sulfoalkyl groups, C4~C12 cycloalkyl groups, C1~ An alkoxy group of C12, an aryl group of C6-C12, an aromatic alkoxy group of C6-C12 or a halogen atom, and, at least one of A, -A6 is a COOH group or COOR (R is hydrogen or C1 to C12) alkyl). 01~02 is (: C12 alkyl group, C4~C12 cycloalkyl group, or C6-C12 aryl group. Among them, Ai~A6 system obtains R^Rs, Βι~Β2 system in formula (7) Κ·6~Κ·7. [Embodiment] The photoelectric conversion element or the dye-sensitized solar cell of the present invention contains the squarylium dye represented by the formula (1), the semi- squaric acid dye represented by the formula (3), or both. In addition, since the dye-sensitized solar cell is a photoelectric conversion element, the description of the two is common, and the common -14-201202194 description will be described with a dye-sensitized solar cell as a representative. The squaraine dye of the present invention is described by the formula (1). In the formula (1), Ri to R7 and R, 1 to R, 7 independently represent a hydrogen atom and a C1-C12 alkane. a sulfoalkyl group of C1 to C4, a cycloalkyl group of C4-C12, an alkoxy group of C1-C12, an aryl group of C5-C12, an aromatic alkoxy group of C6-C12 or a halogen atom, but preferably a hydrogen atom, an alkyl group of C1 to C6, a sulfoalkyl group of C1 to C4, a cycloalkyl group of C4 to C6, an alkoxy group of C1 to C6, an aryl group of C6 to C8, and an aromatic hydrocarbon of C6 to C8. Or a halogen atom. More preferably, RrRs, and a ruler '1~foot'5 are a hydrogen atom or a halogen atom, 116~7, and a ruler '6~11'7 is a C1~C12 alkyl group, C1~C4 a sulfoalkyl group, a C4 to C12 cycloalkyl group, a C1 to C12 alkoxy group, a C6 to C12 aryl group, a C6 to C12 aromatic alkoxy group or a halogen atom. Further preferably, R1 to R> And R'1~R'5 are a hydrogen atom, R6~R>7, and R'6~R'7 are a methyl group. In the formula (1), R8 and R'8 independently represent an alkyl group of C1 to C30, a dentate-substituted alkyl group of C1-C30, a C1-C30 hydroxycarbonylalkyl group or RCOO- or RS03-. Further, at least one of 118 and 11, 8 is a C3 to C30 alkyl group, and a C3-C30 group. A halogen-substituted alkyl group, a C3 to C30 hydroxycarbonylalkyl group or RCOO- or RS03- wherein R in 'RCOO- or RS03- is an alkyl group of C1 to C30, preferably an alkyl group of C3 to C20. The rulers 8 and 11'8 may be the same or different. If any of 118 and R'8 is a base of C3 or more, the other may be a base of Η or C1 〜2. If & 8 and 11'8 In the same case, there are advantages of synthesis and purification. ^ In the formula (1), at least one of R8 and R's is C4 to C20. -15- 201202194 base, C4~C20 halogen-substituted alkyl, C4-C20 hydroxycarbonylalkyl or RCOO- or RS〇3-, preferably C4~C20, C4~C20 fluoride Substituted alkyl. Wherein R is preferably an alkyl group of C1 to C6. Further, Rs and R'8 are preferably independently a C3 to C30 alkyl group, a C3 to C30 halogen-substituted alkyl group, a C3 to C30 hydroxycarbonylalkyl group or RCOO- or RS〇3-. Wherein R is an alkyl group of C1 to C30, preferably an alkyl group of C3 to C20, more preferably an alkyl group of C1 to C6. When R8 and R'8 are a substituted alkyl group, a halogen-substituted alkyl 'hydroxycarbonylalkyl group is preferred. When the substituent has carbon, its carbon is contained in the aforementioned carbon number. Preferably, R8 and R'8 are exemplified by a branched or linear alkyl group or a fluorine-substituted alkyl group of C3 to C30, more preferably an η-alkyl group or a fluorine-substituted η-alkyl group. Among them, at least one of r8 and r'8 is preferably the above-mentioned substituted alkyl group, but more preferably both. In the formula (1), X and Y independently represent hydrogen or -C〇OR (R is hydrogen or an alkyl group of C1 to C12), and either or both of X and Y are -COOR. When R is hydrogen, it becomes a carboxyl group. Wherein R is preferably hydrogen or a C1 to C6 alkyl group. More preferably, either X or Y is -COOH' and the other is -COOH or hydrogen. The squaraine dye represented by the formula (1) is preferably a squaric acid dye represented by the formula (2). In the formula (2), Ri~Rs, R'rR, 'R6~R7, r, 6~r, 7, χ, γ, r8 and r,s are synonymous with the formula (i). Preferably, in the formula (2), Ri~Rs and R'^R'5 are independently a hydrogen atom or a halogen atom, and R6~R7 and R'6~R'7 are independently a C1~C12 alkyl group, C1~ a sulfoalkyl group of C4, a cycloalkyl group of C4-C12, an alkoxy group of C1 to C12, an aryl group of C5 to C12, an aromatic alkoxy group of C6 to C12 or a halogen atom. -16-201202194 Next, the semi-squaraine dye of the present invention will be described. The semi-squaric acid dye of the present invention is represented by the formula (3). The compound represented by the formula (3) is a compound having a structure in which one of the two benzofluorene skeletons of the squary pigment represented by the formula (1) is removed, and has a similar structure. The semi-squaric acid dye represented by the formula (3) can be obtained as an intermediate of the squarylium dye represented by the formula (1). The semi-squaric acid dye can be used in the same application as the squaraine dye represented by the formula (1). More preferably, it can be used together with the squaric acid dye represented by the formula (1). Among the semi-squaric acid dyes represented by the formula (3), preferred are the semi-squaric acid dyes represented by (4). In the formulas (3) and (4), the same symbols have the same meaning. Therefore, 1^~118 has the same meaning as the formula (1) 2R1 to R8. X represents -C〇〇R (R is hydrogen or a C1-C12 alkyl group). R9 is hydrogen or an alkyl group of Cl~C12 when X is COOH, and hydrogen when X is other than COOH. Preferably, X is COOH and 119 is hydrogen. The substituted benzo[e]fluorene compound represented by the formulas (5), (6), (7) and (8) or a salt thereof is represented by the formula (1), (2), (3) or (4) An intermediate represented by a squaraine or a semi-squaric acid. Therefore, the substituents of the same symbols have the same meaning. The reason for the correctness is not certain, but it is considered that the long-chain alkyl group of C3 to C3 0 can prevent the aggregation of the squaraine pigment, and can reduce the charge separation loss caused by the energy movement between the pigments. The synthesis of the squaraine dye represented by the formula (1) can be synthesized from a decylnaphthalene carboxylate as a raw material, followed by reaction with a halogenated alkane, and -17-201202194 is a benzopyrocarboxylic acid. An alkylating salt of an ester. Next, the salt is reacted with a squaric acid to partially hydrolyze the ester to synthesize. The synthesis of carboxy fluorene is described in Bioconjugate Chem., 2003, Vol. 14, 1 048-1 051. [化1 0]

COOR4 can be synthesized from the esterified naphthalene bromide with reference to Non-Patent Documents 4 and 5, and the compound 6 of the following formula is synthesized. In the formula, hydrazine is 2,2'-bis(diphenylphosphinodecyl)-1,1'-binaphthyl. [1 1]

Me02C

Pd(OAc) 2 (1 mol%) BINAP (1 mol%)

(1.0 eq), NatOBu (1.4 eq) toluene, 80 C. overnight Me02C Ο (2.〇eq)

Total yield 30%

TsOH (5.0 eq), EtOH, overnight reflux N-hospital residue benzopyridinium sulfonium salt can be synthesized by reference to Dyes and Pigments, 11, 1989, p21-35. An N-alkylcarboxybenzopyridinium salt having a different carbon number can be synthesized by using a halogenated alkane having a changed alkyl carbon number. -18- 201202194 【化1 2】

The squaric acid coloring matter represented by the formula (1) is an N-alkyl carboxy sulfonium salt and a squaric acid, and is synthesized by reference to Dyes and Pigments, 11, 1 989, p2 卜 35 [Chemical 1 3]

Further, the squarylium dye represented by the formula (2) can be synthesized by referring to Non-Patent Document 2. In the following formula, R is an alkyl group of C3 to C30. £ -19- 201202194 【化1 4】

In the above, the squaric acid dye represented by the formula (1) and the semi- squaric acid dye represented by the formula (3) may be used singly or in combination with the photoelectric conversion element or the dye-sensitized solar cell of the present invention. Since the semi-squaric acid dye represented by the formula (3) has an absorption region on the relatively short wavelength side, it is excellent as a photoelectric conversion element in a short-wavelength region or a dye for a dye-sensitized solar cell. Further, by using the squarylium dye represented by the formula (1), a photoelectric conversion element having good light absorption in a wide range of regions is obtained. Further, since the semi-squaric acid dye represented by the formula (3) is also an intermediate of the squarylium dye represented by the formula (1), it has the advantages of being able to be synthesized by the same raw material, and the properties are similar, so that it is useful. It is not easy to produce an interaction and cause problems such as deterioration. When the squaric acid dye represented by the formula (丨) is used in combination with the semi-squaric acid dye represented by the formula (3), it is preferably used in the ratio of (1) / (3) to 〇·3 to 10, More preferably in the range of 1 to 4, the absorption wavelength region of the sensitizing dye can be selected depending on the light source when the dye-sensitized solar cell is used. The skeleton can be selected in accordance with the wavelength region of the light source that meets the purpose. The pigment preferably has an appropriate binding group (interlocking group) to the surface of the semiconductor fine particles. Preferred binders are exemplified by COOH group, S03H group, cyano group, -P(〇)(〇H)2 group, -0Ρ(0)(0Η)2 group, -OH group or hydrazine, diterpene, hydroxyquine. A chelating group having a π conductivity of hydrazine, a salicylate, and an α-ketoenoic acid ester. Among these, a COOH group is preferred, and the squaraine dye represented by the above formulas (1) and (3) preferably has a COOH group. The basic constitution of a photoelectric conversion element or a dye-sensitized solar cell using the pigment of the present invention. An example will be described with reference to FIG. 1 is a cross-sectional view showing an example of a photoelectric conversion element, which is configured to have a semiconductor layer 3 on which a conductive layer 2 and an adsorption layer containing a sensitizing dye are adsorbed on a semiconductor layer composed of one or more layers on a substrate 1. The laminated surface electrode 10 and the counter electrode 11 provided with the conductive layer 5 on the substrate 4, and the electrolyte layer 6 are disposed between the two electrodes. The dye-adsorbed semiconductor layer 3 means a semiconductor electrode constituting a part of the electrode. The adsorbed dye semiconductor layer 3 is formed by coating and sintering a layer of titanium oxide or metal oxide fine particles, or a layer formed by coating and sintering a plurality of times, and is a semiconductor layer to which a pigment is adsorbed. The metal oxide particles such as titanium oxide particles are composed of a sensitizing dye which is present on the surface of the particles. Further, the light is incident from the side of the surface electrode 1 . Therefore, the dye-sensitized solar cell of the present invention has the same basic structure as described above - 21 - 201202194 and is an external circuit worker. Therefore, the method of using the dye-photoelectric conversion element as the dye-sensitized solar cell is known from the above-mentioned Patent Documents 1 to 2 and the like, and these methods may be used. The substrate 1' is not particularly limited as long as it is a transparent insulating material, and is exemplified by, for example, a general glass plate or a plastic plate, and may be bent, for example, as a PET resin, but is preferably resistant. About 500. The heat resistant material in the step of sintering the titanium oxide having an upper limit is exemplified by a transparent glass plate. Next, a conductive layer 2 is formed on the surface of the substrate 1 so as not to impair the transparency of the substrate. However, the conductive layer is preferably ITO, FTO, tantalum or a combination known as a so-called transparent electrode, and particularly It is a metal layer that does not damage the thickness of the transparency. The method of providing the conductive layers is not particularly limited, and spin coating, vapor deposition (including CVD and PVD), spray coating, laser ablation, or spin coating of various materials using paste, bar coating, and mesh may be used. A well-known technique such as the printing method. Among them, a spray method or a vapor deposition method or a vapor deposition method is preferred. The semiconductor layer 3 on which the dye is adsorbed is disposed thereon. Usually, after forming a layer of a metal oxide as a semiconductor layer, a sensitizing dye is adsorbed thereon. As the metal oxide, those known as photoelectric conversion materials can be used, and examples thereof include titanium oxide, zinc oxide, and tungsten oxide. Among them, titanium oxide is preferred. The titanium oxide may be titanium hydroxide or hydrous titanium oxide in addition to titanium oxide such as anatase type, rutile type or brookite type. Further, at least one of the elements of Nb, V or Ta is preferably doped so as to have a weight concentration (calculated as a metal element) of 30 ppm to 5% with respect to the titanium oxide. In the case of such a metal oxide, -22 to 201202194 may be used in the present invention, but it is preferably a fine particle having an average particle diameter of 5 to 500 nm, preferably 10 to 2 Å Onm. A metal oxide layer is formed on the conductive layer 2, and the method is not particularly limited, and various methods such as spin coating, printing, and spray coating of a metal oxide can be used. Further, sintering of a metal oxide such as titanium oxide after film formation may be fired according to the purpose. Then, a dye for sensitization is adsorbed on the metal oxide as a metal oxide for adsorbing the dye to form a semiconductor layer 3 for adsorbing the dye. The present invention is characterized by having a sensitizing dye, and the other layers or materials may be conventional structures or materials, and are not limited to the configuration shown in Fig. 1. The material constituting the adsorption dye semiconductor layer 3 is a semiconductor and a dye. However, the semiconductor is usually a metal oxide, preferably titanium oxide. Therefore, the semiconductor is represented by a metal oxide or titanium oxide. Further, the dye used for dye sensitization is the above-described squarylium dye represented by the formula (1) and/or the formula (3). Since the above-mentioned squary pigment is large in the number of alkyl groups substituted for N, a good photoelectric conversion element and a dye-sensitized solar cell can be obtained. The pigment is dissolved in the solvent which is dissolved and adsorbed on the titanium dioxide semiconductor layer. The adsorption solvent can be used as long as it is a solvent capable of dissolving the dye. Specifically, a nitrile solvent such as methanol, ethanol, propanol or n-butanol such as 'acetonitrile' propionitrile, a ketone such as acetone or methyl ethyl ketone, dimethyl carbonate or diethyl carbonate can be used. Carbonates, lactones, caprolactams. It is preferably methanol, ethanol or acetonitrile. It can also be used in a pigment solution to dissolve a dye solution of a co-adsorbent such as deoxycholic acid (De〇Xych〇liC acid) or bile acid (DCA), and is attached by suction -23-201202194. The pigment can also be dissolved in a supercritical fluid or a pressurized fluid for adsorption. Specifically, it is preferably adsorbed by using carbon dioxide or a solution of an entrainer added to carbon dioxide. The metal oxide which adsorbs the pigment can further adsorb the carboxylic acid in the C02 supercritical fluid. The effect of adsorbing a carboxylic acid is known from Non-Patent Document J. Photochem. and Photobio. A. Chem. 164. (2004) 117. However, as with the dye adsorption or washing treatment, it is important to effectively adsorb into the inside of the fine pores of the metal oxide such as titanium oxide. The CO 2 supercritical fluid formed by placing the metal oxide of the adsorbed dye (which may also be a substrate having a metal oxide layer adsorbing the dye) and the carboxylic acid in a pressure range of 5 to 30 MPa and a temperature range of 40 to 60 ° C. In medium or pressurized CO 2 , the carboxylic acid can be effectively adsorbed. As the carboxylic acid, benzoic acid, acetic acid, anisic acid or nicotinic acid is preferred. The carboxylic acid is preferably used in a state of being dissolved in an alcohol containing at least one of methanol, ethanol, propanol and butanol, and the concentration of the carboxylic acid is preferably in the range of 0.01 to 10 mol/L. The surface electrode 10 composed of the substrate 1, the conductive layer 2, and the semiconductor layer 3 for adsorbing the dye as described above functions as a negative electrode. The other electrode (opposing electrode) 11 serving as a positive electrode is disposed opposite to the surface electrode 10 as shown in Fig. 1 . The electrode as the positive electrode may be a conductive metal or the like, and a conductive layer 5 such as a metal film or a carbon film may be applied to the substrate 4 such as a general glass plate or a plastic plate. An electrolyte layer 6 is provided between the surface electrode 10 as a negative electrode and the counter electrode 11 as a positive electrode. The type of the electrolyte constituting the electrolyte layer 6 is not particularly limited as long as it is a redox species which is used to reduce the color of the dye which is excited by the photoexcited semiconductor, and is not a liquid electrolyte. A gel electrolyte obtained by kneading a pseudo-solid obtained by a conventional gelling agent (polymer or low-molecular gelling agent) or an ionic liquid and a metal oxide may be added thereto. For example, examples of the electrolyte used in the solution electrolyte are iodine and iodide (metal iodide such as Lil, Nal, KI, Csl, Cal2, quaternary ammonium compound such as tetraalkylammonium iodide, pyridinium iodide, imidazole iodine, etc.) Combination of iodine salt, etc., combination of bromine and bromide (metal bromide such as LiBr, NaBr, KBr, CsBr, CaBr2, tetraalkylammonium bromide, quaternary ammonium compound bromine salt such as pyridine bromine, etc.) A sulfur compound such as sodium, an alkylthiol or an alkyl disulfide; a phosphorous dye, hydroquinone or hydrazine. The electrolyte can also be used in combination. Further, the electrolyte is preferably a molten salt electrolyte having a high boiling point. When the semiconductor electrode is composed of a titanium oxide layer which adsorbs a dye, it is combined with a molten salt electrolyte to exhibit particularly excellent battery characteristics. The molten salt electrolyte composition contains a molten salt. The molten salt electrolyte composition is preferably a liquid at normal temperature. The molten salt of the main component is an electrolyte which is liquid at room temperature or has a low melting point, and a general example thereof is "electrochemistry", pyridine described in 1971, Vol. 65, No. 11, p. 923, etc. Key salts, imidazole salts, trisazo salts, and the like. The molten salt may be used singly or in combination of two or more. Further, an alkali metal salt such as Lil, Nal, KI, LiBF4, CF3COOLi 'CF3COONa, LiSCN or NaSCN may be used in combination. Usually, the molten salt electrolyte composition contains iodine. The molten salt electrolyte composition preferably has a lower volatility and preferably contains no solvent -25-201202194. The molten salt electrolyte composition can also be used by gelation. When a solvent is used in the electrolytic solution, a compound which exhibits low viscosity, exhibits high mobility, and exhibits excellent ion conductivity is desired. Examples of such a compound are a heterocyclic compound such as a carbonate compound such as ethylene carbonate or propylene carbonate, a methylene compound such as methyl-2-oxazole, an etherification such as dioxane or diethyl ether, or an ethylene glycol dialkyl ether or a propylene glycol. Chain ethers such as alkyl ether, polyethylene glycol dioxane, polypropylene glycol dialkyl ether, methanol, ethanol, ethylene dialkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether, polypropylene Alcohols such as alkyl ethers, polyhydric alcohols such as ethylene glycol, propylene glycol, polyethylene glycol, polypropylene, and glycerin; nitrile compounds such as acetonitrile, glutaronitrile, methoxyacetonitrile, and propyl benzonitrile; Aprotic polarity, water, etc. such as ring code. These solvents can also be used in combination. The method of providing the electrolyte layer 6 is not particularly limited. For example, a film-shaped separator 7 may be disposed between the electrodes to form a gap, and a method of depositing a substance between the gaps may be applied, and an appropriate interval of an electrolyte or the like may be applied to the inner surface of the negative electrode. The method of placing and mounting the positive electrode. It is preferable to encapsulate the electrodes and the periphery thereof without allowing the electrolyte, but the method of packaging or the material of the package is not particularly limited. [Examples] Hereinafter, the present invention will be described in more detail based on examples and comparative examples. Synthesis Examples 1 to 9 and 13 are to be understood as examples (except for the dye D-6). Synthesis Example 1 Ionic solvent, 3-ester ether, alcohol, monoglycol, glycol, nitrile, substance, electricity, electricity, and effluent, -26-201202194 [Chem.

Pd(OAc)2(1 mol%) BINAP(1mol%) H2Nn 1 (1.Oeq), NatOBu(1,4eq) °1 °2 toluene, 80C, overnight

O χ^γΚ«(2.0θς)

Rt.

TsOH (5.0 eq), EtOH, overnight reflux

Ethoxycarbonylbenzopyrazine is 1-bromo-4-ethoxycarbonylnaphthalene, benzophenone oxime, palladium acetate, BINAP, sodium butoxide, methyl isopropyl, p-toluenesulfonic acid Commercially available reagents are synthesized. The bromo-4-ethoxycarbonylnaphthalene 78.87rnm〇l was dissolved in a toluene solvent, palladium acetate and BINAp were added, followed by the addition of benzopyrene 78.8 7 mol, sodium butoxide, and reacted overnight at 80°C. Subsequently, 123.46 mmol of methyl isopropyl ketone and p-toluic acid monohydrate were added, and the reaction was carried out overnight in an ethanol solvent to obtain the title phenylhydrazine pseudodecyl ester in a yield of 30%. Synthesis Example 2

The synthesis of N-n-alkylethoxycarbonyl benzopyridinium salt is 2,3,3-trimethyl-6-ethoxycarbonylbenzopyrazine.1111〇1 and 1_Iodination Ethane was dissolved in 20 ml of ethanol and reacted for 7 hours while refluxing. The solid component was filtered to obtain b-ethylethyl-2,3,3-trimethyl-6-ethoxycarbonylbenzimidium iodide in a yield of 55 %. S -27- 201202194 Synthesis Example 3 Synthesis of N-n-alkylethoxycarbonyl benzopyridinium salt 2,3,3-trimethyl-6-ethoxycarbonylbenzopyrazine iodide The alkane was dissolved in 2 mL of ethanol and reacted under reflux for 48 hours. The solid component was filtered to obtain 1-n-butyl-2,3,3-trimethyl-6-ethoxycarbonylbenzoquinone in a yield of 55 %. Synthesis Example 4 Synthesis of N-n-alkylethoxycarbonylbenzopyrazine salt 2,3,3-trimethyl-6-ethoxycarbonylbenzopyrazine (^丨^^丨 and 丨- Iodinated octane was dissolved in 20 ml of ethanol and reacted for 72 hours while refluxing. The solid component was filtered to obtain 1-n-octyl-2,3,3-trimethyl-6-ethoxyl in a yield of 55%. The carbonyl benzopyrene iodine. Synthesis Example 5 The synthesis of the squaric acid pigment is 1-n-butyl-2,3,3-trimethyl-5-ethoxymercaptobenzopyrene 0.7 mmol of iodine and 3 mmol of squaric acid were dissolved in a solvent of benzene:butanol 1:4 in a volume ratio of 40 ml, and 1 ml of porphyrin was added thereto, and the reaction was refluxed for 15 hours while removing water, cooled to room temperature, and the solid component was filtered. The solid component was washed with diethyl ether to obtain an ester of squaraine pigment. After purification by a column, it was hydrolyzed with an aqueous solution of sodium hydroxide to obtain the squaraine dye D-1 of the title compound. Synthesis Example 6 -28- 201202194 Synthesis of ethoxycarbonylbenzene In the case of the salt, the squaric acid dyes D-2 and D-6 were obtained in the same manner as in the synthesis example 5, except that 1-iodooctane or 1-iodide was used instead of 1-iodobutane. The IR spectrum of acid dye D-2 is shown in Figure 2. Example 7 An asymmetric squaric acid coloring dye reacts a carboxy fluorenyl salt with 1 equivalent of a square acid ester to synthesize a semi-squaric acid. Next, another pseudo sulfonium salt is reacted to synthesize an asymmetric squaraine dye. And a sulfonium salt was used in the synthesis of the synthesis example 2, and as a further benzopyridinium salt, the synthesis was carried out using 1-bromonaphthalene instead of 1-bromo-4-ethoxycarbonylnaphthalene in Synthesis Example 1. Benzo-pseudo-purine, which is obtained by alkylation of 1-iodized octane to a benzopyridinium salt, is described in J. Am. Chem. Soc., 129, pl0320-1 032 1 Synthetic Asymmetric Squaric acid dye D-3 Synthesis Example 8 As a carboxyindolenine salt, a carboxyindolenine salt obtained by using 1-iodated octane in Synthesis Example 3, and as a further benzopyridinium salt are synthesized and synthesized. In Example 1, a benzopyrazine obtained by substituting 1-bromonaphthalene for bromo-4-ethoxycarbonylnaphthalene, and then alkylating it with 1-iodized octane, is obtained. An asymmetric squaraine dye D-4 was synthesized by J. Am. Chem. Soc., 129, pl0320-10321. Synthesis Example 9 2^ -29- 201202194 Aqueous sodium hydroxide solution was used as a carboxy group. The squaryphthyl sulfonium salt obtained by using 1-iodide butane in Synthesis Example 2 is hydrolyzed with the squarylate obtained using butyl sulphate to synthesize the semi-squaric acid dye D-5. 1 0 was obtained using the synthesis example 4 as a carboxy sulfonium salt, and the other was obtained by synthesizing an asymmetric squaric acid in the same manner as in Synthesis Example 8 using an iodide salt obtained by ethylating methyl morphine. Pigment D-7. Synthesis Example 1 1 As a carboxyindolenine salt, in Synthesis Example 1, ethyl 4-bromobenzoate was used instead of 1-bromo-4-ethoxycarbonylnaphthalene, and in Synthesis Example 3, 1 was used. The symmetrical squary pigment D-8 was synthesized in the same manner as in Synthesis Example 5 except that ethane iodide was used instead of 1-iodide. Synthesis Example 1 2 As a carboxyindolenine salt, in Synthesis Example 1, ethyl 4-bromobenzoate was used instead of 1-bromo-4-ethoxycarbonylnaphthalene, and in Synthesis Example 3, 1-propidium iodide was used instead of 1 The symmetrical squaric acid dye D-9 was synthesized in the same manner as in Synthesis Example 5 by iodinating butane. Synthesis Example 1 3 As a carboxy fluorene, in Synthesis Example 3, 1,1,1-trifluoro-4-iodide butane was used instead of 1-iodide butane, and synthesized in the same manner as in Synthesis Example 5 - 30- 201202194 Symmetric squaric acid pigment D-10. Specific examples of the squaraine dye or the semi-squaric acid dye of the present invention are Structural Formulas 21 to 37, and are shown in Tables 1 to 3. In Tables 1 to 3, R9, R1(), X and Y correspond to symbols attached to the structural formula. 【化1 6】

C -31 - 201202194 [Chem. 1 7]

-32- 201202194 【化1 8】

Π

Π

C -33- 201202194 R9, R1(), X and Y of the squaraine dye or the semi-squaric acid dyes D-1 to D-10 obtained in Synthesis Examples 1 to 13 and the maximum absorption wavelength (Xmax) in the ultraviolet visible region Shown in Table 1. [Table 1] Pigment formula r9 XR 1 0 Y Λ max (nm) D-1 21 C4H9 C00H C4H9 COOH 674 D-2 21 C8H17 C00H C8H17 COOH 674 D-3 21 C2H5 C00H C8H17 H 668 D-4 21 C8H17 COOH C8H17 — 668 D-5 22 C4H9 C00H — — 452 D-6 21 C2H5 C00H C2H5 COOH 668 D-7 23 C8H17 COOH C2H5 — 674 D-8 24 C2H5 COOH C2H5 COOH 644 D-9 24 C2H4C00H Η C2H4C00H H 620 D-10 21 CF3C3H6 COOH CF3C3H6 COOH 674 -34- 201202194

[Table 2] Pigment type r9 XR 1 0 Y D-ll 21 C3H7 C00H C3H7 COOH D-12 21 C6H13 C00H C6H13 COOH D-13 21 C12H25 COOH C12H25 COOH D-14 21 C16H33 COOH C16H33 COOH D-15 21 C18H37 COOH C18H37 COOH D-16 21 C30H61 COOH C30H61 COOH D-17 21 C3H7 COOH C8H17 COOH D-18 25 C3H7 COOH C3H7 COOH D-19 25 C4H9 COOH C4H9 COOH D-20 25 C6H13 COOH C6H13 COOH D~21 25 C8H17 COOH C8H17 COOH D -22 25 C12H25 COOH C12H25 COOH D-23 25 C16H33 COOH C16H33 COOH D-24 25 C18H37 COOH C18H37 COOH D-25 25 C30H61 COOH C30H61 COOH D-26 26 C3H7 COOH C3H7 COOH D-27 26 C4H9 COOH C4H9 COOH D-28 26 C6H13 COOH C6H13 COOH D-29 26 C8H17 COOH C8H17 COOH D-30 26 C12H25 COOH C12H25 COOH D-31 26 C16H33 COOH C16H33 COOH D-32 26 C18H37 COOH C18H37 COOH D-33 26 C30H61 COOH C30H61 COOH D-34 27 C3H7 COOH C3H7 COOH D-35 27 C4H9 COOH C4H9 COOH D-36 27 C6H13 COOH C6H13 COOH D-37 27 C8H17 COOH C8H17 COOH D-38 27 C12H25 COOH C12H25 COOH D-39 27 C16H33 COOH C16H33 COOH D-40 27 C18H37 COOH C18H37 COOH c -35- 201202194 Table 3] Pigment type r9 XR 1 0 Y D-41 27 C30H61 C00H C30H61 COOH D-42 28 C4H9 C00H C4H9 COOH D-43 28 C8H17 C00H C8H17 COOH D-44 29 C4H9 C00H C4H9 COOH D-45 29 C8H17 C00H C8H17 COOH D-46 30 C4H9 C00H C4H9 COOH D-47 30 C8H17 C00H C8H17 COOH D-48 31 C4H9 COOH C4H9 COOH D-49 31 C8H17 C00H C8H17 COOH D-50 32 C4H9 C00H C4H9 COOH D-51 32 C8H17 COOH C8H17 COOH D- 52 33 C4H9 COOH One D-53 33 C8H17 COOH — — D-54 34 C4H9 COOH — — D-55 34 C8H17 COOH — One D-56 35 C4H9 COOH — — D-57 35 C8H17 COOH — A D-58 36 C4H9 COOH — — D-59 36 C8H17 COOH — A D-60 37 C4H9 COOH — — D-61 37 C8H17 COOH — — Example 1 FTO (Fluoride-doped tin oxide) film made of Japanese plate glass A glass substrate (trade name: low-E glass) was used as a glass substrate to which a transparent conductive film was attached at 30 mm x 25 mm x 3 mm. Next, a titanium oxide film is formed on the conductive film of the substrate to which the conductive film is attached. As the titanium oxide, a commercially available titanium oxide paste (D paste manufactured by SOLARONIX Co., Ltd.) was used. It is applied by extrusion printing to a conductive film of a substrate to which a conductive film is attached in a range of 5 mm x 5 mm -36 to 201202194, dried, and fired at 450 ° C to form a thickness of 15#. A layer of titanium oxide of m is obtained to obtain a laminate. Use D-Ι as the color. Make it 3xl (T4mol/L., DCA becomes 3 xl (T3mol/L is dissolved in ethanol. The adsorption of the pigment dissolves the pigment in the solvent to form a dye solution, and the dye solution is placed in the container, and then the configuration The laminate having the above titanium oxide layer is formed, and after standing for 2 hours, the adsorbent-pigmented laminate is taken out from the container. - On the peripheral sides of the 5 mm x 5 mm of the titanium oxide film formed on the laminate, an electrolyte can be injected In a manner, a sheet-shaped thermoplastic adhesive composed of an ionic polymer resin having a thickness of 50/zm is attached to a gap of about 1 mm at two positions of the peripheral portion (trade name of Mitsui Dupon Polychemical Co., Ltd.; HIGH) MILAN SHEET). The thermoplastic adhesive agent acts as a packaging material and also acts as a separator between the two poles. Next, a platinum film having a thickness of 10 nm is formed as a glass substrate of the positive electrode by a sputtering method to make the uranium side It is bonded to the thermoplastic adhesive film in such a manner as to oppose the titanium oxide side. From the gap of the thermoplastic adhesive film, the capillary phenomenon 'will contain Li, 0.5 M of t- A acetonitrile solution containing butylpyridine and 0.05 M iodine as a main component was filled between the substrate and the positive electrode. Immediately after the electrolyte was filled, the gap was immediately sealed with an epoxy resin to obtain a photoelectric conversion element. Examples 2 to 5 Except for D-2, D-3, D-4 or D-5, the remainder is the same as in the first embodiment,

C -37- 201202194 Obtained photoelectric conversion elements. Example 6 In addition, the dye D-1 was dissolved in ethanol in a manner of 2.25×1 (T4 mol/L, D-5 was 0.75×10_4 mol/L, and DCA was 3.0×1 〇-3 mol/L), and two pigments were mixed and adsorbed. The photoelectric conversion element was obtained as in Example 1. Example 7 A photoelectric conversion element was obtained in the same manner as in Example 1 except that the dye D-10 was used. Comparative Example 1 to 4 In addition to the use of the dye D- 6. In addition to the dye D-1, D-7, D-8 or D-9, the photoelectric conversion element was obtained as in Example 1. The photoelectric conversion element produced in the examples and the comparative examples was used as a dye-sensitized solar cell. The characteristics of the battery were evaluated using the curve tracer characteristic using a sunlight simulator AM 1.5 using a simulated sunlight of 100 mW/cm2. The conversion efficiency (%), short-circuit current (Jsc: mA/cm2), open voltage were measured. The characteristics of (Voc: V) and the charging factor (ff: shape factor) are shown in Table 4. In the table, η is the conversion efficiency, Xmax is the maximum absorption wavelength, and λ〇 is the absorption end wavelength. -38- 201202194 [Table 4] Pigment Π (%) Voc (V) Jsc (mA/cm2) ff into max (did) long 0 (did) Example 1 D-1 3.47 0.55 9. 70 0. 65 720 830 Example 2 D-2 2. 89 0.57 7.80 0. 65 690 830 Example 3 D-3 3.49 0.59 9.09 0. 65 690 790 Example 4 D -4 3.42 0. 60 8.51 0. 67 690 810 Example 5 D-5 2. 89 0. 63 7. 17 0. 64 495 520 Example 6 D-1+D-5 5. 10 0. 61 13. 1 0. 64 720 830 Example 7 D-10 3.23 0. 63 7.46 0. 69 688 758 Comparative Example 1 D-6 0. 83 0.56 1.97 0. 75 690 770 Comparative Example 2 D-7 0. 95 0. 49 3.04 0. 64 690 835 Comparative Example 3 D-8 1. 67 0. 59 4. 35 0. 65 650 727 Comparative Example 4 D-9 0. 14 0. 44 0.56 0. 56 660 737 [Industrial use possible The photoelectric conversion element using the squarylium dye or the semi-squaric acid dye of the present invention or the dye-sensitized solar cell comprising the same has high photoelectric conversion efficiency in the near-infrared region. Further, by using a semi-squaric acid dye together with the squaric acid dye, light from 400 nm to 830 nm can be absorbed, and an expensive Ru dye is not used, and the photoelectric conversion efficiency can be further improved by the multiplication effect of the two dyes. Further, the squaraine dye of the present invention can obtain a photoelectric conversion element having high photoelectric conversion efficiency or a dye-sensitized solar cell comprising the same. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing an example of a dye-sensitized solar cell. 2 is an IR spectrum of the squaraine dye d-2 of the present invention. β ς -39- 201202194 [Explanation of main components] 1 : Substrate 2 : Conductive layer 3 : Semiconductor layer 4 for adsorbing pigment: Substrate 5 : Conductive layer 6 : Electrolyte layer 7 : separator I 0 : surface electrode II : counter electrode -40

Claims (1)

201202194 VII. Patent application scope: 1. A squaraine pigment represented by the following formula (1), [Chemical 1] Where is RrR·/, and R’^R’? Independently represents a hydrogen atom, an alkyl group of C1 to C12, a sulfoalkyl group of C1-C4, a cycloalkyl group of C4 to C12, an alkoxy group of C1 to C12, an aryl group of C5 to C12, and an aromatic hydrocarbon of C6 to C12. An oxy or a halogen atom, X and Y independently represent a hydrogen atom or -COOR (R is hydrogen or an alkyl group of C1 to C12), and at least one of them is -COOR, and R8 and R'8 independently represent a C1 to C30 alkyl group. a halogen-substituted alkyl group of C1 to C30, a hydroxycarbonylalkyl group of C1 to C30 or RCOO- or RS03- (R is a hospital group of C1 to C30), but at least one is a C3 to C30 alkyl group, C3 a C-substituted alkyl group of C30, a hydroxycarbonylalkyl group of C3~C30 or RCOO- or RS03- (R is an alkyl group of Cl~C30) 〇2. The squaraine pigment of the first item of the patent application scope, Wherein, in the formula, Ri~R7, and R'^R, independently a hydrogen atom, an alkyl group of C1 to C12, a sulfoalkyl group of C1 to C4, a cycloalkyl group of C4 to C12, and an alkoxy group of C1-C12. a group, an aryl group of C5 to C12, an aromatic alkoxy group of C6 to C12 or a halogen atom, and X and Y are independently hydrogen or -COOR (R is hydrogen or an alkyl group of C1 to C12), and at least s -41 - 201202194 One is -COOR, 118 and 11,8 are independently C3~C30 alkyl, C3-C30 Halogen-substituted alkyl group, C3~C30 hydroxycarbonylalkyl group or RC〇〇- or RS03- (R is a hospital base of C1 to C30) 3. The squaric acid coloring matter of the first aspect of the patent application is below Equation (2) means: [Chemical 2] In the formula, Ri - Rs, R'rR'5, R6 to R7, R'6 to R, 7, X, Y, r8 and R'8 have the same meanings as in the formula (1). 4. For the squaric acid pigment in the third paragraph of the patent application, in the formula (2), Ri~R5 and R'rR's are independently hydrogen atoms or halogen atoms, and R6~R7 and R'6~R'7 are independently C1-C12 alkyl group, C1-C4 sulfoalkyl group, C4-C12 cycloalkyl group, C1-C12 alkoxy group, C5-C12 aryl group, C6-C12 aromatic alkoxy group or halogen atom . A photoelectric conversion element characterized in that it is a photoelectric conversion element using a squaric acid coloring matter, wherein the squaric acid coloring matter is a squaric acid coloring matter as in the first aspect of the patent application. 6. A dye-sensitized solar cell characterized in that it is composed of a photoelectric conversion element as in the fifth item of the patent application. 7·- a semi-squaric acid dye represented by the following formula (3), -42- 201202194 [Chemical 3] In the formula, R!~R7 independently represents a hydrogen atom, an alkyl group of C1 to C12, a dilating group of C1 to C4, a ring group of C4 to C12, an alkoxy group of C1 to C12, an aryl group of C5 to C12, Aromatic oxy or _ atom of 'C6~C12' X represents COOR (R is hydrogen or a hospital base of C1~C12), R8 represents an alkyl group of C3~C30, a halogen substituted alkyl of C3~C30, C3 to C30 hydroxycarbonylalkyl or RCOO- or RS03- (R is an alkyl group of C1 to C30), 119 represents a hydrogen atom or an alkyl group of C1 to C12, and when X is other than -COOH, R9 is a hydrogen atom. 8. The semi-square acid dye according to item 7 of the patent application, which is represented by the following formula (4): In the formula, Ri~Rs, R_9, and X are synonymous with the formula (3). -43-201202194 9. A photoelectric conversion element characterized by using a photoelectric conversion element of a pigment, wherein the pigment is a semi-squaric acid dye, and the semi-squaric acid dye is a half-acid acid dye as in the seventh item of the patent application. 10. The photoelectric conversion element according to item 5 of the patent application, which is a photoelectric conversion element using a pigment, wherein a squaraine dye as in the first aspect of the patent application and a semi- squaric acid dye as in the seventh aspect of the patent application are used together. . A dye-sensitized solar cell characterized by using a photoelectric conversion element according to the ninth or tenth aspect of the patent application. -44-