JP2003017146A - Dye sensitized photoelectric conversion element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectric conversion element with excellent conversion efficiency and low cost, and to provide a solar cell. SOLUTION: The photoelectric conversion element uses oxide semiconductor particles sensitized by the dye having a structure expressed by the formula (1). The oxide semiconductor particles include titanium dioxide as an essential component. In the formula, R1 -R5 and Rx represent hydrogen atom or substituent respectively, X represents an atom and an atomic group, or an organic residue with two valence.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photoelectric conversion element characterized by using semiconductor fine particles sensitized by a dye having the structure of the general formula (1) and a solar cell using the photoelectric conversion element.

[0002]

2. Description of the Related Art Solar cells that use sunlight as an energy resource to replace fossil fuels such as petroleum and coal are drawing attention. Currently, silicon solar cells using crystalline or amorphous silicon, compound semiconductor solar cells using gallium, arsenic, and the like are being actively studied for development such as high efficiency. However, since they require high energy and cost for production, they are difficult to use for general purpose. A photoelectric conversion element using semiconductor fine particles sensitized with a dye, or a solar cell using the same is also known, and materials and manufacturing techniques for producing the same are disclosed. (B.O'Regan and M. Gratzel Nat
ure, 353, 737 (1991), MKNazeeruddin, A.Kay, I.Ro
dicio, R. Humphry-Baker, E. Muller, P. Liska, N. Vlach
opoulos, M. Gratzel, J. Am. Chem. Soc., 115, 6382 (199
3) etc) This photoelectric conversion element is manufactured using a relatively inexpensive oxide semiconductor such as titanium oxide, and there is a possibility that a photoelectric conversion element with a lower cost than a solar cell using conventional silicon etc. can be obtained. It is getting attention. However, in order to obtain a device with high conversion efficiency, a ruthenium-based complex is used as a sensitizing dye, the cost of the dye itself is high, and there is still a problem in its supply. Further, although attempts have already been made to use organic dyes as sensitizing dyes, the conversion efficiency is low and they are not yet in practical use.

[0003]

In a photoelectric conversion element using an organic dye-sensitized semiconductor, an inexpensive organic dye is used,
It is required to develop a photoelectric conversion element having high conversion efficiency and high practicality.

Means for Solving the Problems As a result of diligent efforts to solve the above-mentioned problems, the present inventors sensitized semiconductor fine particles with a dye having a general formula (1) structure to obtain a photoelectric conversion element. It was found that a photoelectric conversion element having a high conversion efficiency can be obtained by making it, and the present invention has been completed. That is, the present invention

(1) A photoelectric conversion element characterized by using oxide semiconductor fine particles sensitized by a dye having the structure of general formula (1),

[0005]

[Chemical 2]

(R1 to R5 and Rx in the general formula (1) each represent a hydrogen atom or a substituent, and X represents a divalent atom, atomic group or organic residue.) (2) General The dye having the structure of formula (1) is characterized in that it has at least one or more of a carbonyl group such as a carboxyl group, an ester group, an amide group, a hydroxyl group, a sulfonic acid group, and a phosphoric acid group in the molecule (1) The photoelectric conversion element described in (3), a compound selected from the group consisting of at least one or more of the dye (1) described in (1) or (2), another metal complex, and an organic dye having a structure of another structure. Among them, a photoelectric conversion element using an oxide semiconductor sensitized by two or more compounds in total. (4) The photoelectric conversion device according to (1) to (3), wherein the oxide semiconductor fine particles contain titanium dioxide as an essential component, (5) The dye is supported on the oxide semiconductor fine particles in the presence of an inclusion compound (1 ) To (4), and (6) A solar cell using the photoelectric conversion element of (1) to (5).

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The photoelectric conversion device of the present invention uses an oxide semiconductor sensitized with a dye having the structure of general formula (1).

[0007]

[Chemical 3]

[0008] In the general formula (1), R1 to R5 and Rx each represent a hydrogen atom or a substituent. Rx is R1 compared to general formula (1)
~ R5, X, and a single or plural substituents which can be substituted at a site other than oxygen atom. X represents a divalent atom or atomic group or an organic residue.

R1 and R2 may be the same or different from each other, and each is a hydrogen atom, an oxygen atom, a saturated or unsaturated hydrocarbon group which may be substituted, an aromatic group which may be substituted or a heterocyclic group which may be substituted. Respectively. The saturated hydrocarbon group is a C1 to C22 linear, branched or cyclic alkyl group having 1 to 22 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an octyl group, an octadecyl group, an isopropyl group and a cyclohexyl group. To be As an unsaturated hydrocarbon group, C2 ~
C22 is a linear, branched or cyclic alkenyl group and alkynyl group having 2 to 22 carbon atoms, vinyl group, propenyl group, pentynyl group, butenyl group, hexenyl group, hexadienyl group, isopropenyl group, isohexenyl group, cyclo Examples thereof include a hexenyl group, a cyclopentadienyl group, an ethynyl group, a propynyl group, a pentynyl group, a hexynyl group, an isohexynyl group and a cyclohexynyl group. Further, as an aromatic group, a C6 to C40 aromatic ring having 6 to 40 carbon atoms, a heterocyclic group is a C4 to C40 heterocyclic ring having 4 to 40 carbon atoms, and as the aromatic ring, a phenyl group, a naphthyl group, an anthracenyl group, etc. However, as the heterocycle, a pyridine group, a bipyridine group, an indole group,
Examples thereof include a benzothiazole group, a benzothiadiazole group, a benzimidazole group, and a benzoxazole group. Further, as the substituent which may be substituted with these, a halogen atom such as iodine, bromine and chlorine, an acryloylalkyl group, a methacryloylalkyl group, an acryloyl group,
Carbonyl groups such as methacryloyl group, carboxyalkyl group, carboxyl group, ester group, carbamoyl group, aldehyde group, acyl group, acylamino group, amide group, alkylamide group, aromatic amide group, alkyl group,
Halogenated alkyl group, cyanoalkyl group, hydroxyalkyl group, vinylalkyl group, cycloalkyl group, alkoxyalkyl group, phenoxyalkyl group, phenyl group, phenoxy group, vinyl group, alkoxy group, alkoxyalkoxy group, hydroxyl group, sulfonic acid group , Sulfonic acid ester group, sulfoamide group, phosphoric acid group, phosphoric acid ester group, mercapto group, tosyl group, cyano group, isocyano group, thiocyanato group, isothiocyanato group, nitro group,
Examples thereof include a nitrosyl group, an amino group, an alkyl-substituted amino group, an aromatic-substituted amino group, a tosyl group, a biphenyl group and an aryl group. These substituents may substitute for the hydrocarbon group and the aromatic group alone or in combination. R1 and
Preferred as R2 are a hydroxyl group, an alkoxy group, a cyano group, a phenyl group, a carboxyl group, an amino group, a halogen atom such as iodine, bromine and chlorine, and an alkyl group substituted with a phenyl group, a hydrogen atom, a methyl group, Examples thereof include ethyl group, propyl group, octyl group, octadecyl group, alkoxyalkyl group, hydroxyalkoxyalkyl group and phenyl group. When the substituent is an acidic group or a hydroxyl group, it may form a salt. The salt here is a lithium salt, a sodium salt, a metal salt such as a potassium salt, a tetramethylammonium salt, a tetrabutylammonium salt,
An organic salt such as an imidazolium salt is shown.

[0010] R3, R5, and Rx represent substituents which may be the same or different from each other. Further, a plurality of Rx may be present in the molecule as the same or different substituents. Specific examples of the substituent include an acryloylalkyl group, a methacryloylalkyl group, an acryloyl group, a methacryloyl group, a carboxyalkyl group, a carboxyl group, an ester group, a carbamoyl group, an aldehyde group, an acyl group, an amide group, an alkylamide group, and an aromatic group. Amido group, carbonyl group such as hydrogen atom, alkyl group, halogen atom, halogenated alkyl group, cyanoalkyl group, hydroxyalkyl group, vinylalkyl group, cycloalkyl group, alkoxyalkyl group, phenoxyalkyl group, phenyl group, phenoxy Group, vinyl group, alkoxy group, hydroxyl group, sulfonic acid group,
Sulfonic acid ester group, sulfamido group, phosphoric acid group, phosphoric acid ester group, mercapto group, tosyl group, cyano group,
Isocyanato group, thiocyanato group, isothiocyanato group,
Acylamino group, nitro group, nitrosyl group, amino group,
Examples thereof include an alkyl-substituted amino group, an aromatic-substituted amino group, a biphenyl group and an aryl group, and a carboxyalkyl group, a carboxyl group, an ester group, a carbamoyl group, an acyl group, an amide group, an alkylamide group, an aromatic amide group, hydrogen. Atom, alkyl group, halogen atom, cyanoalkyl group, alkoxyalkyl group, phenyl group, alkoxy group, hydroxyl group, sulfonic acid group, sulfonic acid ester group,
Phosphoric acid group, phosphoric acid ester group, cyano group, isocyano group, thiocyanato group, isothiocyanato group, alkyl-substituted amino group, aromatic-substituted amino group and the like are preferable, and carboxyalkyl group, carboxyl group, ester group, carbamoyl group, amide group , Alkylamide group, aromatic amide group, hydrogen atom, alkyl group, alkoxyalkyl group, phenyl group, alkoxy group, hydroxyl group, sulfonic acid group, sulfonate ester group, cyano group, isocyano group, thiocyanato group, isothiocyanato group, alkyl A substituted amino group,
An aromatic substituted amino group and the like are more preferable. Further, when the substituent is an acidic group or a hydroxyl group, it may form a salt.
The salt here refers to metal salts such as lithium salt, sodium salt and potassium salt, and organic salts such as tetramethylammonium salt, tetrabutylammonium salt and imidazolium salt.

In addition to the above, examples of the substituent Rx include the followings.

[0012]

[Chemical 4]

The above R has the same meaning as R1 and R2. Also,
When the substituent is an acidic group such as a carboxyl group, a sulfonic acid group, a phosphoric acid group or a hydroxyl group, it may form a salt. The salt here refers to metal salts such as lithium salt, sodium salt and potassium salt, and organic salts such as tetramethylammonium salt, tetrabutylammonium salt and imidazolium salt.

Further, among these, the following substituents Rx are more preferable.

[0015]

[Chemical 5]

The above R has the same meaning as R1 and R2. Also,
When the substituent is an acidic group such as a carboxyl group, a sulfonic acid group, a phosphoric acid group or a hydroxyl group, it may form a salt. The salt here refers to metal salts such as lithium salt, sodium salt and potassium salt, and organic salts such as tetramethylammonium salt, tetrabutylammonium salt and imidazolium salt.

R4 is a hydrogen atom, a nitro group, a carboxyl group,
Ester group, cyano group, isocyano group, thiocyanato group, isothiocyanato group, acyl group, acylamino group and the like, nitro group, carboxyl group, ester group,
Cyano group, isocyanato group, thiocyanato group, isothiocyanato group and the like are preferable, carboxyl group, ester group,
A cyano group is more preferred. Further, when the substituent is an acidic group, it may form a salt. The salt here refers to metal salts such as lithium salt, sodium salt and potassium salt, and organic salts such as tetramethylammonium salt, tetrabutylammonium salt and imidazolium salt.

[0018] R1 and R5, R2 and R3, and R1 and R2 may form a ring. The ring formed by R1 and R5 or R2 and R3 may be, for example, saturated or unsaturated and may be substituted.
Examples include a 5-membered ring and a 6-membered ring. As the 5-membered ring, an imidazole ring, a thiazole ring, a dithiazolium ring, an oxazole ring, a pyrrole ring, a pyrrolidone ring, a pyridone ring, a pyrazinone ring, a pyrazole ring and the like, a 6-membered ring, a pyridine ring, a pyrazine ring, a piperidone ring, Examples thereof include a piperidine ring, a pyrimidine ring, a pyridazine ring, a morpholine ring and an indolizine ring. Also preferred are julolidine and tetramethyljulolidine in which both R1 and R11 and R2 and R3 form a 6-membered ring.

[0019] Examples of the ring formed by R1 and R2 include a saturated or unsaturated 5-membered ring which may be substituted, 6-membered ring, and 7
A member ring is mentioned. Examples of 5-membered ring include carbazole ring and indole ring, and examples of 6-membered ring include pyridine ring, pyrazine ring, piperidone ring, piperidine ring, pyrimidine ring, pyridazine ring, morpholine ring and indolizine ring. Examples of the 7-membered ring include an azepine ring and the like.

[0020] X represents a divalent atom and atomic group or an organic residue. Specific examples include an oxygen atom, a sulfur atom, a selenium atom, an imino group, an alkyl-substituted imino group, a phenyl-substituted imino group and the like, and the following as a structure (= X) via a double bond.

[0021]

[Chemical 6]

R that may be substituted for X may be the same as R1 and R2. Further, when X has an acidic group such as a carboxyl group, a sulfonic acid group, a phosphoric acid group or a hydroxyl group, it may form a salt. The salt here refers to metal salts such as lithium salt, sodium salt and potassium salt, and organic salts such as tetramethylammonium salt, tetrabutylammonium salt and imidazolium salt.

[0023] Further, among these, X is more preferably an oxygen atom, a sulfur atom, an imino group and the following.

[0024]

[Chemical 7]

The above R has the same meaning as R1 and R2. Also, X
When has an acidic group such as a carboxyl group, a sulfonic acid group, a phosphoric acid group or a hydroxyl group, a salt may be formed. The salt here refers to metal salts such as lithium salt, sodium salt and potassium salt, and organic salts such as tetramethylammonium salt, tetrabutylammonium salt and imidazolium salt.

The benzopyran dye represented by the dye having the structure of the general formula (1) is produced, for example, by the method represented by the following formula (West German Patent Application Publication No. 1619567 and Japanese Patent Publication No. 54-13257). . It is also possible to introduce a substituent by forming a benzopyran structure and then performing a substituent introduction reaction such as sulfonation.

[0027]

[Chemical 8]

[0028] Furthermore, the dye having the structure of the general formula (1) can be quaternized to obtain a compound having a substituent RY on the nitrogen atom and an anion on the counter ion. It can also be used for a photoelectric conversion element.

[0029]

[Chemical 9]

The substituent Ry here may be the same as R1 and R2, and specific examples thereof include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a hexyl group, an octyl group, an octadecyl group,
Examples include isopropyl group, alkyl group such as t-butyl group, methoxyethyl group, ethoxyethyl group, phenyl group, or phenyl group substituted with methyl group, ethyl group, t-butyl group, amino group, and the like. Of these, a methyl group, an ethyl group, a propyl group, a hexyl group, an octyl group, a t-butyl group, a phenyl group and the like are preferable, and a methyl group, an ethyl group, a propyl group and a phenyl group are more preferable.

[0031] A represents an anion. Specific examples thereof include F-, Cl-, Br-, I-, ClO4-, BF4-, PF6-, OH-, CH3SO3-, C6H5.
SO3-, p-CH3C6H5SO3- and the like, Br-, I-, ClO4-, BF4
-, PF6-, C6H5SO3-, p-CH3C6H5SO3-, etc. are preferred, and I-, B
r-, C6H5SO3-, p-CH3C6H5SO3- and the like are more preferable. Further, when neutralized intramolecularly or between two molecules with a basic group or the like, A may not be present.

Specific examples of the dye having the structure of the general formula (1) are listed below (the substituents Rx in the general formula (1) are assigned to R6 to R11, and are exemplified as the general formula (2)).

[0033]

[Chemical 10]

In the table, Me is a methyl group, Et is an ethyl group, pro is a propyl group, Bu is a butyl group, Hex is a hexyl group, and Ph is a phenyl group.

[0035]

【table 1】

[0036] Continuation of Table 1

[0037]

[0038] Specific examples of these other dyes include the followings.

[0039]

[Chemical 11]

[0040]

[0041]

[0042] When these dyes have an acidic group or a hydroxyl group, they may form a salt. The salt here refers to metal salts such as lithium salt, sodium salt and potassium salt, and organic salts such as tetramethylammonium salt, tetrabutylammonium salt and imidazolium salt.

The dye-sensitized photoelectric conversion element of the present invention is one in which, for example, oxide semiconductor fine particles are used to produce a thin film of an oxide semiconductor on a substrate, and then the thin film is loaded with a dye.
As the oxide semiconductor fine particles, a metal oxide is preferable,
Specific examples thereof include oxides of titanium, tin, zinc, tungsten, zirconium, gallium, indium, yttrium, niobium, tantalum, vanadium and the like. Among these, titanium, tin, zinc, niobium,
Oxides such as tungsten are preferred, of which titanium oxide is most preferred. These oxide semiconductors can be used alone or in a mixture. The average particle size of the fine particles of the oxide semiconductor is usually 1 to 500 nm, preferably 5 to 100 nm. It is also possible to use a mixture of fine particles having a large particle diameter and fine particles having a small particle diameter. The oxide semiconductor thin film is a method of directly forming oxide semiconductor fine particles as a thin film on a substrate by spray spraying, a method of electrically depositing a semiconductor fine particle thin film using the substrate as an electrode, and applying a slurry of semiconductor fine particles described below on the substrate. And then dry,
It can be manufactured by curing or baking. From the performance of the oxide semiconductor electrode, a method using a slurry or the like is preferable. In the case of this method, the slurry is obtained by dispersing secondary-aggregated oxide semiconductor fine particles in a dispersion medium by an ordinary method so that the average primary particle diameter becomes 1 to 200 nm. The dispersion medium for dispersing the slurry may be any as long as it can disperse the semiconductor fine particles, and water or alcohols such as ethanol, ketones such as acetone and acetylacetone, or organic solvents such as hydrocarbons such as hexane are used. You may mix and use,
The use of water is preferable in that the viscosity change of the slurry is reduced. The firing temperature of the substrate coated with the slurry is generally lower than the melting point (softening point) of the base material, and usually the upper limit is 900 ° C, preferably 600 ° C or lower. The firing time is not particularly limited, but is preferably within 4 hours. The thickness of the thin film on the substrate is usually 1 to 200 μm, preferably 5 to 50 μm.

[0044] The oxide semiconductor thin film may be subjected to a secondary treatment.
That is, for example, alkoxide of the same metal as the semiconductor,
It is also possible to improve the performance of the semiconductor thin film by directly immersing the thin film together with the substrate in a solution of chloride, nitrate, sulfide or the like and drying or rebaking. Examples of the metal alkoxide include titanium ethoxide, titanium isopropoxide, titanium t-butoxide, n-dibutyl-diacetyltin and the like, and an alcohol solution thereof is used. Examples of chlorides include titanium tetrachloride, tin tetrachloride,
Examples thereof include zinc chloride and the aqueous solution thereof is used.

[0045] Next, a method for supporting a dye on the oxide semiconductor thin film will be described. As a method of supporting the dye, a solution obtained by dissolving the dye in a solvent capable of dissolving the dye, or, in the case of a dye having low solubility, a dispersion obtained by dispersing the dye, the above oxide A method of immersing a substrate provided with a semiconductor thin film can be mentioned. The concentration in the solution or dispersion is appropriately determined depending on the dye. The semiconductor thin film formed on the substrate is immersed in the solution. Immersion time is generally from room temperature to the boiling point of the solvent, and immersion time is about 1 to 48 hours. Specific examples of the solvent that can be used to dissolve the dye include methanol, ethanol, acetonitrile, dimethyl sulfoxide, dimethylformamide and the like. The dye concentration of the solution is usually 1 × 10 ^-6 M ~
1M is preferable, and 1 × 10 ⁻⁴ M to ¹ × 10 ⁻¹ M is preferable. In this way, a photoelectric conversion device of a thin film of oxide semiconductor fine particles sensitized with the dye having the structure of the general formula (1) is obtained. The dye to be carried may be one kind or a mixture of several kinds. When mixed, the dyes having the structure of the general formula (1) of the present invention may be mixed with each other, or other dyes or metal complex dyes may be mixed. In particular, by mixing dyes having different absorption wavelengths, a wide absorption wavelength can be used, and a solar cell with high conversion efficiency can be obtained. There is no particular limitation on the example of the metal complex, but J. Am. Chem. Soc., 115, 6382 (1993) and JP-A-2.
The ruthenium complex shown in 000-26487, phthalocyanine, porphyrin and the like are preferable, and as the organic dye, metal-free phthalocyanine, porphyrin and cyanine, methine dye such as merocyanine, oxonol and triphenylmethane, xanthene dye, azo dye and the like. Examples thereof include dyes of the system type and anthraquinone type. Preferred are methine dyes such as ruthenium complex and merocyanine. When the dye having the structure of the general formula (1) is carried on the thin film of the oxide semiconductor fine particles, it is effective to carry the dye in the coexistence of the inclusion compound in order to prevent the dyes from associating with each other. Examples of the inclusion compound include steroid compounds such as cholic acid, crown ether, cyclodextrin, polyethylene oxide, and the like, with preference given to cholic acid and polyethylene oxide. Further, the surface of the semiconductor electrode may be treated with an amine compound such as 4-t-butylpyridine after supporting the dye. As a treatment method, for example, a method of immersing a substrate provided with a semiconductor fine particle thin film carrying a dye in an ethanol solution of amine is used.

The solar cell of the present invention is composed of a photoelectric conversion element electrode in which the dye having the structure of the general formula (1) is carried on the above oxide semiconductor thin film, a counter electrode, a redox electrolyte or a hole transport material. The redox electrolyte may be a solution in which a redox couple is dissolved in a solvent, a gel electrolyte impregnated in a polymer matrix, or a solid electrolyte such as a molten salt. Examples of the hole transport material include materials using an amine derivative, a conductive polymer such as polyacetylene, polyaniline and polythiophene, and a discotic liquid crystal phase such as polyphenylene. The counter electrode used is preferably one having conductivity and catalytically acting on the reduction reaction of the redox electrolyte. For example, glass, or a polymer film obtained by vapor deposition of platinum, carbon, rhodium, ruthenium, or the like, or by coating conductive fine particles can be used. As the redox electrolyte used in the solar cell of the present invention, a halogen redox electrolyte composed of a halogen compound and a halogen molecule having a halogen ion as a counter ion, a metal complex such as ferrocyanate-ferricyanate or ferrocene-ferricinium ion. Metal redox electrolytes such as, alkylthiol-alkyl disulfide, viologen dyes, aromatic redox electrolytes such as hydroquinone-quinone, and the like,
Halogen redox based electrolytes are preferred. Examples of the halogen molecule in the halogen redox electrolyte composed of a halogen compound-halogen molecule include iodine molecules and bromine molecules, and iodine molecules are preferred. Further, as the halogen compound having a halogen ion as a counter ion, for example, a metal halide such as LiI, NaI, KI, CsI, CaI2 or a tetraalkylammonium iodide, pyridinium iodide, an organic halogen such as imidazolium iodide. Examples thereof include quaternary ammonium salts, and salt compounds having an iodine ion as a counter ion are preferable. Examples of the salt compound having an iodine ion as a counter ion include lithium iodide, sodium iodide, potassium iodide,
Examples include trimethylammonium iodide salt and the like.

When the redox electrolyte is formed in the form of a solution containing the redox electrolyte, an electrochemically inactive one is used as the solvent. For example, acetonitrile, propylene carbonate, ethylene carbonate, 3-methoxypropionitrile, methoxyacetonitrile, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, γ-butyrolactone,
Dimethoxyethane, diethyl carbonate, diethyl ether, diethyl carbonate, dimethyl carbonate, 1,2-dimethoxyethane, dimethylformamide, dimethyl sulfoxide, 1,3-dioxolane, methyl formate, 2-methyltetrahydrofuran, 3-methoxy-
Oxaziridin-2-one, sulfolane, tetrahydrofuran, water and the like, among them, especially, acetonitrile, propylene carbonate, ethylene carbonate, 3-methoxypropionitrile, methoxyacetonitrile, ethylene glycol, 3-methoxyoxaziridine- 2-on and the like are preferable. You may use these individually or in combination of 2 or more types. In the case of a gel electrolyte, a matrix using a polyacrylate or polymethacrylate resin may be used. The concentration of the redox electrolyte is usually 0.01 to 99% by weight, preferably 0.1 to 90%.
It is about% by weight. The counter electrode is arranged so as to sandwich the electrode of the photoelectric conversion element in which the dye is carried on the oxide semiconductor thin film on the substrate. A solar cell of the present invention can be obtained by filling a solution containing a redox electrolyte in the meantime.

[0048]

EXAMPLES The present invention will be described more specifically based on the following examples, but the present invention is not limited to these examples. In the examples, parts are parts by weight unless otherwise specified. Synthesis Example 1 3-benzimidazolyl- (2 ')-7-diethylamino-2-iminocoumarin 5 parts and dinitril malonate 1 part were refluxed for 2 hours in 45 parts of glycol monoethyl ether, and then at 5 ° C.
The precipitate formed is cooled by suction filtration with suction, and methanol is added.
It was washed with 10 parts and vacuum dried at 70 ° C. to obtain 3.4 parts of the compound (117). Synthesis Example 1 200 parts of compound (117) in 20 parts of 25% fuming sulfuric acid for 2 hours at 60 ° C.
The reaction solution was poured into 200 parts of water. The precipitate formed is suction filtered, 10 parts of cold water,
Wash with 5 parts cold methanol and vacuum dry at 70 ° C
(24) 180 parts were obtained (λmax = 520 nm (H ₂ O)).

[0049]

[Chemical 12]

[0050] Example 7 dyes having the structure of the general formula (1) 3 × 10 ^-4 ~ 5 × 10 ^-4 M
Dissolved in EtOH. A porous substrate (semiconductor thin film electrode obtained by sintering porous titanium oxide on a transparent conductive glass electrode) is immersed in this solution at room temperature for 3 hours to overnight to support the dye on the porous substrate, and then washed with a solvent. , Dried,
A dye-sensitized semiconductor thin film photoelectric conversion device was obtained. Further, in Examples 5 and 8, 9 0.2M titanium tetrachloride aqueous solution was added dropwise to the titanium oxide thin film portion of the semiconductor thin film electrode, and at room temperature 24
The dye was similarly loaded using the titanium tetrachloride-treated semiconductor thin film electrode obtained by rinsing at 450 ° C. for 30 minutes after standing still for a period of time. Furthermore, in Example 4, when the dye was loaded, cholic acid was added as an inclusion compound so that the concentration of the dye was 3 × 10 ⁻² M to prepare the above dye solution, and the dye solution was loaded on a semiconductor thin film, and the cholic acid-treated dye-sensitized semiconductor was loaded. A thin film was obtained. A conductive glass, the surface of which was sputtered with platinum, was fixed so as to sandwich it, and a solution containing an electrolyte was injected into the void. Three types of solutions containing electrolytes were prepared. The electrolyte of A is 3-methoxypropionitrile, iodine / lithium iodide / 1,2-dimethyl-3.
-n-Propylimidazolium iodide / t-butyl pyridine dissolved to 0.1M / 0.1M / 0.6M / 1M respectively, B electrolyte is a solution of ethylene carbonate and acetonitrile 6: 4 iodine / Tetra-n-propylammonium iodide was dissolved at 0.02M / 0.5M to prepare. The size of the battery to be measured was 0.25 cm ² in the actual part. A 500 W xenon lamp was used as a light source, and 100 mW / cm ² was passed through an AM1.5 filter. Short-circuit current, release voltage, conversion efficiency, and form factor were measured using potentio galvanostat.

[0051]

[Table 2]

[0052]

INDUSTRIAL APPLICABILITY In the dye-sensitized photoelectric conversion element of the present invention, by using the dye having the structure of the general formula (1), a solar cell having high conversion efficiency can be provided.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5F051 AA09 AA14 FA01 FA30 GA03                 5H032 AA06 AS16 CC17 EE16 EE17

Claims (6)

[Claims] 1. A photoelectric conversion device comprising oxide semiconductor fine particles sensitized with a dye having a structure of general formula (1). [Chemical 1] (R1 to R5 and Rx in the general formula (1) each represent a hydrogen atom or a substituent, and X represents a divalent atom, atomic group or organic residue.) 2. The dye having the structure of the general formula (1) has at least one or more of a carbonyl group such as a carboxyl group, an ester group and an amide group, a hydroxyl group, a sulfonic acid group and a phosphoric acid group in the molecule. The photoelectric conversion element according to claim 1, which is characterized in that. 3. A compound selected from the group consisting of at least one or more of the dyes (1) according to claims 1 and 2, another metal complex and an organic dye having a structure of another structure, in total 2 A photoelectric conversion element comprising an oxide semiconductor sensitized with one or more compounds. 4. The photoelectric conversion device according to claim 1, wherein the oxide semiconductor fine particles contain titanium dioxide as an essential component. 5. The photoelectric conversion device according to claim 1, wherein the dye is carried on the oxide semiconductor fine particles in the presence of the inclusion compound. 6. A solar cell using the photoelectric conversion element according to claim 1.