JP2011060589A - Photochemical battery including semiconductor fine particle sensitized by binuclear ruthenium complex dye and electrolyte solution containing arylamine compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photochemical battery with high efficiency of photoelectric conversion, including semiconductor fine particles sensitized by binuclear ruthenium complex dye, which has a high extinction coefficient and superior electron-transfer properties, and electrolyte solution including an arylamine compound. <P>SOLUTION: The photochemical battery includes the semiconductor fine particles sensitized by the binuclear ruthenium complex dye and the electrolytic solution including the arylamine compound represented by general formula (2). In the formula, Ar denotes an aryl group, and R<SP>1</SP>and R<SP>2</SP>, which are either the same group or may be different groups, denote hydrogen atoms or alkyl groups. Further, R<SP>1</SP>and R<SP>2</SP>may combine to form a ring. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photochemical battery comprising a photoelectric conversion element having semiconductor particles sensitized by a dinuclear ruthenium complex dye having a high extinction coefficient and excellent in electron transfer, and an electrolyte solution containing an arylamine compound.

  Solar cells are highly expected as a clean renewable energy source. Practical use of single-crystal silicon-based, polycrystalline silicon-based, amorphous silicon-based solar cells and solar cells composed of compounds such as cadmium telluride and indium copper selenide Research has been conducted with the aim of making it easier. However, in order to disseminate it as a household power source, many of the batteries that must be overcome, such as high manufacturing costs, difficulty in securing raw materials, recycling problems, and difficulty in increasing the area. I have a problem. Thus, solar cells using organic materials have been proposed with the aim of increasing the area and reducing the price, but all have a conversion efficiency of about 1%, which is far from practical use.

  Under such circumstances, in 1991, Gretzel et al. Disclosed a photoelectric conversion element and a solar cell using semiconductor fine particles sensitized with a dye in Nature, and materials and manufacturing techniques necessary for the production of the solar cell. (For example, Nature, Volume 353, page 737, 1991 (Non-Patent Document 1), JP-A-1-220380 (Patent Document 1), etc.). This battery is a wet solar cell using a porous titania thin film sensitized with a ruthenium dye as a working electrode. The advantage of this solar cell is that it can be used as an inexpensive photoelectric conversion element because it is not necessary to purify an inexpensive material with high purity, and further, the absorption of the dye used is broad, and over a wide visible light wavelength range. It can convert sunlight into electricity. However, further improvement in conversion efficiency is necessary for practical use, and development of a dye having a higher extinction coefficient and absorbing light up to a higher wavelength region is desired.

  JP 2003-261536 (Patent Document 2) by the present applicant discloses a dipyridyl ligand-containing metal mononuclear complex which is a metal complex dye useful as a photoelectric conversion element.

  In addition, the latest technology of dye-sensitized solar cells (CMC Co., Ltd., issued on May 25, 2001, page 117) (Non-Patent Document 2) discloses polynuclear β-diketonate complex dyes.

  In addition, Japanese Patent Application Laid-Open No. 2004-359677 (Patent Document 3) describes a plurality of metals and a plurality of coordinations as a novel multinuclear complex having an excellent photoelectric conversion function for extracting electrons by receiving the energy of actinic rays such as light. A binuclear complex having a coordination structure in which a bridging ligand (BL) having a conjugated group and a metal coordinated to a plurality of metals has a heteroconjugated ring and a coordination structure not having a heteroconjugated ring is disclosed.

  Furthermore, WO2006 / 038587 (Patent Document 4) discloses a binuclear metal complex having a coordination structure having a heteroconjugated ring as a metal complex dye that can provide a photoelectric conversion element having high photoelectric conversion efficiency.

Japanese Patent Laid-Open No. 1-220380 JP 2003-261536 A Japanese Patent Application Laid-Open No. 2004-359677 International Publication No. 2006/038587 Pamphlet

Nature, 353, 737, 1991 The latest technology of dye-sensitized solar cells (CMC Corporation, issued on May 25, 2001, page 117)

  An object of the present invention is to provide a photochemistry with high photoelectric conversion efficiency, comprising a semiconductor fine particle sensitized by a dinuclear ruthenium complex dye having a high extinction coefficient and excellent electron transfer, and an electrolyte solution containing an arylamine compound. To provide a battery.

The present invention relates to the following matters.
1. A photochemical battery comprising semiconductor fine particles sensitized by a dinuclear ruthenium complex dye represented by the following general formula (1) and an electrolyte solution containing an arylamine compound represented by the following general formula (2).

(In the formula, X ^N- represents an N-valent anion which is a counter ion (where N is 1 or 2),

Is a nitrogen-containing bidentate ligand having two carboxyl groups,

Is a nitrogen-containing tetradentate ligand,

Represents a nitrogen-containing bidentate ligand. n shows the integer of 0-2. p represents the number of counter ions necessary to neutralize the charge of the complex. The carboxyl group (COOH) may be deprotonated (H ⁺ ) to become a carboxy ion (COO ⁻ ). )

2. X ^N-is, hexafluorophosphate ion, tetrafluoroborate ion, photochemical cell of claim 1, wherein the nitrate ion or iodide ion.

  3. Nitrogen-containing bidentate ligand is 2,2′-bipyridine, 2,2 ′-(4,4′-dimethyl) bipyridine, 2,2 ′-(4,4′-di-t-butyl) bipyridine, 2. The photochemical cell as described in 1 above, which is 2,2 ′-(4,4′-di-n-nonyl) bipyridine or 1,10-phenanthroline.

  4). 2. The photochemical cell according to 1 above, wherein the nitrogen-containing bidentate ligand having two carboxyl groups is 2,2'-bipyridine-4,4'-dicarboxylic acid.

  5. 2. The photochemical cell according to 1 above, wherein the nitrogen-containing tetradentate ligand is 2,2'-biimidazole or 2,2'-bibenzimidazole.

  6). 2. The photochemical battery according to 1 above, wherein the semiconductor fine particles are titanium oxide, zinc oxide, tin oxide, or a mixture thereof.

  7. The arylamine compound represented by the following general formula (2) is at least one selected from the group consisting of aniline, dimethylaniline, di-n-butylaniline, di-n-hexylaniline, and di-n-octylaniline. 2. The photochemical battery according to 1 above.

(In the formula, Ar represents an aryl group, and R ¹ and R ² may be the same or different and represent a hydrogen atom or an alkyl group. R ¹ and R ² are bonded to form a ring. May be.)

  8). 2. The photochemical cell according to 1 above, wherein the electrolyte solution contains a redox pair.

  9. 2. The above 1, having a photoelectric conversion element in which semiconductor fine particles sensitized by the dinuclear ruthenium complex dye are fixed on an electrode and a counter electrode, and having a layer of an electrolyte solution containing the arylamine compound therebetween. Photochemical battery.

According to the present invention, there is provided a photochemical battery having a high photoelectric conversion efficiency, comprising a semiconductor fine particle sensitized by a dinuclear ruthenium complex dye having a high extinction coefficient and excellent in electron transfer, and an electrolyte solution containing an arylamine compound. Can be provided. This photochemical battery can obtain a higher photoelectric conversion efficiency than a battery that does not contain an arylamine compound.

  Semiconductor fine particles sensitized with the dinuclear ruthenium complex dye of the present invention can be obtained by bringing the dinuclear ruthenium complex and semiconductor fine particles into contact with each other.

The binuclear ruthenium complex used in the present invention is represented by the general formula (1).
In the general formula (1), X ^N− represents an N-valent anion (where N is 1 or 2) which is a counter ion. X ^- include, for example, hexafluorophosphate ion, perchlorate ion, tetraphenylborate ion, tetrafluoroborate ion, trifluoromethanesulfonate ion, thiocyanate ion, sulfate ion, nitrate ion, chloride ion, Examples include halide ions such as iodide ions, preferably hexafluorophosphate ions, tetrafluoroborate ions, nitrate ions, halide ions, and more preferably hexafluorophosphate ions, tetrafluoroborate acids. Ions, nitrate ions, and iodide ions. Examples of X ²⁻ include sulfate ion, sulfite ion, thiosulfate ion, carbonate ion, monohydrogen phosphate ion, and preferably sulfate ion.

  or,

Represents a nitrogen-containing bidentate ligand having two carboxyl groups. The carboxyl group (COOH) may be deprotonated (H ⁺ ) to become a carboxy ion (COO ⁻ ). Two nitrogen-containing bidentate ligands having two carboxyl groups are contained in the complex, but they may be the same or different.
Examples of the nitrogen-containing bidentate ligand having two carboxyl groups include a ligand represented by the following formula (1-A).

In the formula, H in —COOH may be eliminated, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom or a substituted or unsubstituted linear or branched group It represents an alkyl group, or two or more of these together form a substituted or unsubstituted aromatic hydrocarbon ring with the carbon atom to which they are attached.
As an alkyl group, a C6 or less thing is preferable and a methyl group and an ethyl group are more preferable.

In addition, R ² and R ³ , R ⁴ and R ⁵ , R ¹ and R ⁶ are combined together and a carbon atom to which they are bonded together with a 6-membered aromatic hydrocarbon ring (which may have a substituent) It is also preferable to form. Examples of the substituent of the aromatic hydrocarbon ring include an alkyl group (such as a methyl group and an ethyl group) and an alkoxy group (such as a methoxy group and an ethoxy group).

R ^{1 to} R ⁶ are all hydrogen atoms, or R ¹ and R ⁶ are hydrogen atoms, and R ² and R ³ , R ⁴ and R ⁵ are joined together with the carbon atom to which they are bonded together. It is preferable to form an aromatic hydrocarbon ring, and it is particularly preferable that all of R ^{1 to} R ⁶ are hydrogen atoms.

Examples of the nitrogen-containing bidentate ligand having two carboxyl groups include 2,2′-bipyridine-4,4′-dicarboxylic acid, 1,10-phenanthroline-4,7-dicarboxylic acid, 2- (2- (4-Carboxypyridyl))-4-carboxyquinoline, 2,2′-biquinoline-4,4′-dicarboxylic acid and the like are mentioned, and preferably 2,2′-bipyridine-4,4′-dicarboxylic acid. is there. In addition, the carboxyl group (COOH) in these ligands may be deprotonated (H ⁺ ) to be a carboxy ion (COO ⁻ ).

  Furthermore,

Represents a nitrogen-containing tetradentate ligand.
Examples of the nitrogen-containing tetradentate ligand include a ligand represented by the following formula (1-B1).

In the formula, each of R ³¹ , R ³² and R ³³ independently represents a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group, or two or more of these are combined to form a bond A substituted or unsubstituted aromatic hydrocarbon ring together with the carbon atoms to be represented, and each of R ³⁴ , R ³⁵ and R ³⁶ independently represents a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group. Or two or more of these together form a substituted or unsubstituted aromatic hydrocarbon ring with the carbon atom to which they are attached.

  As an alkyl group, a C6 or less thing is preferable and a methyl group and an ethyl group are more preferable.

It is also preferable that two adjacent R ^{31 to} R ³⁶ are joined together to form a 6-membered aromatic hydrocarbon ring (which may have a substituent) together with the carbon atom to which they are bonded. . Examples of the substituent of the aromatic hydrocarbon ring include an alkyl group (such as a methyl group and an ethyl group) and an alkoxy group (such as a methoxy group and an ethoxy group).

R ^{31 to} R ³⁶ are preferably hydrogen atoms or methyl groups, and it is particularly preferable that R ^{31 to} R ³⁶ are all hydrogen atoms.
In addition, examples of the nitrogen-containing tetradentate ligand include a ligand represented by the following formula (1-B2).

In the formula, each of R ⁴¹ and R ⁴² independently represents a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group, or a group that is substituted or unsubstituted together with a carbon atom to which they are bonded together. Forming a substituted aromatic hydrocarbon ring, R ⁴³ and R ⁴⁴ each independently represent a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group, or they are taken together; A substituted or unsubstituted aromatic hydrocarbon ring is formed with the carbon atom to which they are bonded.

  As an alkyl group, a C6 or less thing is preferable and a methyl group and an ethyl group are more preferable.

R ⁴¹ and R ⁴² , R ⁴³ and R ⁴⁴ together form a 6-membered aromatic hydrocarbon ring (which may have a substituent) together with the carbon atom to which they are bonded. Is also preferable. Examples of the substituent of the aromatic hydrocarbon ring include an alkyl group (such as a methyl group and an ethyl group) and an alkoxy group (such as a methoxy group and an ethoxy group).

R ^{41 to} R ⁴⁴ are preferably hydrogen atoms or methyl groups, and it is particularly preferable that R ^{41 to} R ⁴⁴ are all hydrogen atoms. R ⁴¹ and R ⁴² , R ⁴³ and R ⁴⁴ together form a 6-membered aromatic hydrocarbon ring (which may have a substituent such as a methyl group) together with the carbon atom to which they are bonded. It is also particularly preferable, for example, a ligand represented by the following formula (1-B3) is preferable.

In the formula, R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ each independently represent a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group, and R ⁵⁵ , R ⁵⁶ , R ⁵⁷ and R ⁵⁸ are Each independently represents a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group.

  As an alkyl group, a C6 or less thing is preferable and a methyl group and an ethyl group are more preferable.

R ^{51 to} R ⁵⁸ are preferably a hydrogen atom or a methyl group, and R ^{51 to} R ⁵⁸ are all hydrogen atoms, or R ⁵² , R ⁵³ , R ⁵⁶ and R ⁵⁷ are methyl groups, R ⁵¹ , R ⁵⁴ , R ⁵⁵ and R ⁵⁸ are particularly preferably hydrogen atoms, and it is more preferable that R ^{51 to} R ⁵⁸ are all hydrogen atoms.
Examples of the nitrogen-containing tetradentate ligand include 2,2′-bipyrimidine, 2,2′-biimidazole, 2,2′-bibenzimidazole, etc., preferably 2,2′-biimidazole, 2,2′-bibenzimidazole, more preferably 2,2′-bibenzimidazole.

Represents a nitrogen-containing bidentate ligand. Two such nitrogen-containing bidentate ligands are contained in the complex, but they may be the same or different.
Examples of the nitrogen-containing bidentate ligand include a ligand represented by the following formula (1-C).

In the formula, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group, Or two or more of these together form a substituted or unsubstituted aromatic hydrocarbon ring with the carbon atom to which they are attached.

  As an alkyl group, a C18 or less thing is preferable, and a methyl group, t-butyl group, and a nonyl group are more preferable.

Further, (which may have a substituent) two adjacent, or R ¹¹ and R ¹⁸ together aromatic 6-membered together with the carbon atoms to which they are bonded hydrocarbon ring R ¹¹ to R ¹⁸ It is also preferable to form. Examples of the substituent of the aromatic hydrocarbon ring include an alkyl group (such as a methyl group and a t-butyl group) and an alkoxy group (such as a methoxy group and an ethoxy group).

R ^{11 to} R ¹⁸ are preferably a hydrogen atom, a methyl group, a t-butyl group, or a nonyl group, and R ^{11 to} R ¹⁸ are all hydrogen atoms, or R ¹² and R ¹⁷ are a methyl group, t-butyl. Group, nonyl group, and R ¹¹ , R ^{13 to} R ¹⁶ and R ¹⁸ are particularly preferably hydrogen atoms. R ¹¹ and R ¹⁸ are combined to form a 6-membered aromatic hydrocarbon ring (which may have a substituent such as a methyl group) together with the carbon atom to which they are bonded, and R ¹² It is particularly preferable that R ¹⁷ is a hydrogen atom or a methyl group, a t-butyl group, a nonyl group, more preferably a hydrogen atom. Further, R ¹³ and R ¹⁴ , and R ¹⁵ and R ¹⁶ together form a 6-membered aromatic hydrocarbon ring (which may have a substituent such as a methyl group) together with the carbon atom to which they are bonded. R ¹¹ , R ¹² , R ¹⁷ and R ¹⁸ are particularly preferably a hydrogen atom or a methyl group, a t-butyl group, a nonyl group, more preferably a hydrogen atom.

  Examples of the nitrogen-containing bidentate ligand include 2,2′-bipyridine, 2,2′-4,4′-dimethyl-bipyridine, and 2,2′-4,4′-di-t-butyl-bipyridine. 2,2′-4,4′-dinonyl-bipyridine, 1,10-phenanthroline, 2- (2-pyridinyl) quinoline, 2,2′-biquinoline, etc., preferably 2,2′-bipyridine. 2,2′-4,4′-dimethyl-bipyridine, 2,2′-4,4′-di-t-butyl-bipyridine, 2,2′-4,4′-dinonyl-bipyridine, 1,10 -Phenanthroline.

  In addition, n represents the valence of a cation and is an integer of 0-2 normally, Preferably it is 1 or 2, More preferably, it is 1. P represents the number of counter ions necessary to neutralize the charge of the complex.

  Specific examples of the binuclear ruthenium complex used in the present invention as described above include the following compounds (D-1) to (D-17), preferably (D-4). , (D-5), (D-9), (D-10), (D-11), (D-13), (D-16) and (D-17) are used. Note that H of —COOH in formulas (D-1) to (D-17) may be eliminated.

  In addition, you may use these binuclear ruthenium complexes individually or in mixture of 2 or more types. These dinuclear ruthenium complexes can be synthesized by a known method (see, for example, International Publication No. 2006/038587).

  Examples of the semiconductor fine particles used in the present invention include metal oxides such as titanium oxide, zinc oxide, tin oxide, indium oxide, niobium oxide, tungsten oxide, vanadium oxide; strontium titanate, calcium titanate, barium titanate. Compound oxides such as potassium niobate; metal sulfides such as cadmium sulfide and bismuth sulfide; metal selenides such as cadmium selenide; metal tellurides such as cadmium telluride; metal phosphides such as gallium phosphide; Although metal arsenides such as gallium arsenide are mentioned, metal oxides are preferable, and titanium oxide, zinc oxide, and tin oxide are more preferable. The primary particle size of the semiconductor fine particles is not particularly limited, but those having a particle size of preferably 1 to 5000 nm, more preferably 2 to 500 nm, and particularly preferably 3 to 300 nm are used. These semiconductor fine particles may be used alone or in admixture of two or more.

  As a method for adsorbing a binuclear metal complex dye on semiconductor fine particles, a semiconductor layer (semiconductor fine particle film) containing semiconductor fine particles is formed on a conductive support and then immersed in a solution containing the binuclear metal complex dye. (For example, refer to WO 2006/038587). The semiconductor layer can be formed by applying a paste of semiconductor fine particles on a conductive support and heating and baking. And after immersing in a pigment | dye solution, the electroconductive support body in which this semiconductor layer was formed is wash | cleaned and dried.

  Examples of the solvent for the dye solution include alcohols such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol and ethylene glycol; nitriles such as acetonitrile and propionitrile; N, N-dimethylacetamide, N, N-dimethylformamide and the like Amides; ureas such as N-methylpyrrolidone; sulfoxides such as dimethyl sulfoxide, and the like, preferably isopropyl alcohol, t-butanol, and acetonitrile. These organic solvents may be used alone or in combination of two or more.

  The concentration of the dye in the solution can be determined as appropriate, but since the dye can be adsorbed in a short time, a higher concentration is preferable, and a saturated solution is preferable.

  The temperature at which the dye is adsorbed is usually 0 to 80 ° C., preferably 20 to 40 ° C. The time for adsorbing the dye (time for immersing in the dye solution) can be appropriately determined, and is, for example, about 1 to 40 hours, preferably about 5 to 20 hours. If the adsorption time is longer than this, the amount of dye adsorbed will not change much, while the photoelectric conversion efficiency may decrease.

  The photoelectric conversion element of the present invention includes semiconductor fine particles sensitized with a dinuclear ruthenium complex dye. Specifically, for example, the semiconductor fine particles sensitized with the ruthenium complex dye are fixed on an electrode. Is.

  The electrode is a conductive electrode, preferably a transparent electrode formed on a transparent substrate. Examples of the conductive agent include metals such as gold, silver, copper, platinum, and palladium, indium oxide compounds represented by indium oxide (ITO) doped with tin, and tin oxide (FTO) doped with fluorine. Examples thereof include tin oxide compounds and zinc oxide compounds.

  The photochemical cell of the present invention can be produced using semiconductor fine particles sensitized with the aforementioned binuclear ruthenium complex dye.

  Specifically, the photochemical cell of the present invention has the above-described photoelectric conversion element of the present invention and a counter electrode as electrodes, and an electrolyte solution layer therebetween. Note that at least one of the electrode and the counter electrode used in the photoelectric conversion element of the present invention is a transparent electrode.

  The counter electrode functions as a positive electrode when combined with a photoelectric conversion element to form a photochemical battery. As the counter electrode, a substrate having a conductive layer can be used as in the case of the conductive electrode. However, if the metal plate itself is used, the substrate is not necessarily required. As the conductive agent used for the counter electrode, for example, a conductive metal oxide such as tin oxide doped with a metal such as platinum or carbon or fluorine is preferably used.

  In the present invention, an electrolyte solution containing an arylamine compound is used as the electrolyte of the photochemical battery. This electrolyte solution contains an arylamine compound and a redox couple (redox couple). An arylamine compound may be used independently and may be used in combination of 2 or more type.

  As the arylamine compound used in the present invention, an aniline compound represented by the following formula (E) is preferably used.

However, R ¹ and R ² in the formula (E) may be the same or different and each represents a hydrogen atom or an alkyl group. R ¹ and R ² may combine to form a ring.

  The concentration of the aniline compound used in the present invention in the electrolyte solution is preferably in the range of 0.001 mol / l to 5 mol / l, more preferably in the range of 0.5 mol / l to 1 mol / l, particularly 0.5 mol / l. preferable.

  Examples of the aniline compound include aniline, dimethylaniline, and di-n-butyl represented by the following formulas (E-1a), (E-1b), (E-1c), (E-1d), and (E-1e). It is preferably at least one selected from the group consisting of aniline, di n-hexyl aniline and di n-octyl aniline, and di n-hexyl aniline is particularly preferable.

The electrolyte solution of the present invention preferably contains a redox pair (redox pair). The redox pair to be used is not particularly limited.
(1) iodine and iodide (for example, metal iodides such as lithium iodide and potassium iodide; quaternary ammonium compounds such as tetrabutylammonium iodide, tetrapropylammonium iodide, pyridinium iodide and imidazolium iodide) (Iodide) combinations,
(2) Bromine and bromides (for example, metal bromides such as lithium bromide and potassium bromide; bromides of quaternary ammonium compounds such as tetrabutylammonium bromide, tetrapropylammonium bromide, pyridinium bromide and imidazolium bromide) A combination of
(3) Combination of chlorine and chloride (for example, metal chloride such as lithium chloride and potassium chloride; chloride of quaternary ammonium compound such as tetrabutylammonium chloride, tetrapropylammonium chloride, pyridinium chloride, imidazolium chloride),
(4) Combination of alkyl viologen and its reduced form,
(5) quinone / hydroquinone, iron (II) ion / iron (III) ion, copper (I) ion / copper (II) ion, manganese (II) ion / manganese (III) ion, cobalt ion (II) / cobalt Transition metal ion pairs such as ions (III)),
(6) Ferrocyanian / ferricyan, cobalt tetrachloride (II) / cobalt tetrachloride (III), cobalt tetrabromide (II) / cobalt tetrabromide (III), iridium hexachloride (II) / iridium hexachloride ( III), ruthenium hexacyanide (II) / ruthenium hexacyanide (III), rhodium hexachloride (II) / rhodium hexachloride (III), rhenium hexachloride (III) / rhenium hexachloride (IV), rhenium hexachloride A combination of complex ions such as (IV) / rhenium hexachloride (V), osmium hexachloride (III) / osmium hexachloride (IV), osmium hexachloride (IV) / osmium hexachloride (V),
(7) Complexes formed of transition metals such as cobalt, iron, ruthenium, manganese, nickel, rhenium, and complex conjugate rings such as bipyridine and derivatives thereof, terpyridine and derivatives thereof, phenanthroline and derivatives thereof, and derivatives thereof,
(8) Complexes of cyclopentadiene such as ferrocene / ferrocenium ion, cobaltcene / cobaltcenium ion, ruthenocene / ruthenoceum ion, etc. and their derivatives and metals,
(9) Porphyrin-based compounds can be mentioned, and preferably the redox couples mentioned in (1) above are used. In addition, you may use these redox pairs individually or in mixture of 2 or more types. The amount of use of these redox pairs can be determined as appropriate.

The photochemical cell of the present invention can be manufactured by a conventionally applied method, for example,
(1) A semiconductor fine particle paste such as an oxide is applied on a transparent electrode and heated and fired to produce a thin film of semiconductor fine particles.
(2) Next, when the thin film of semiconductor fine particles is titania, baking is performed at a temperature of 400 to 550 ° C. for 0.5 to 1 hour.
(3) The transparent electrode with the obtained thin film is immersed in a dye solution, and a dinuclear ruthenium dye is supported to produce a photoelectric conversion element.
(4) The obtained photoelectric conversion element is combined with a transparent electrode on which platinum or carbon is vapor-deposited as a counter electrode, and an electrolyte solution is put therebetween.
The photochemical battery of the present invention can be manufactured by performing the operation described above.

  Next, the present invention will be specifically described with reference to examples, but the scope of the present invention is not limited thereto. In addition, the photoelectric conversion efficiency of the photochemical cell was measured by irradiating simulated sunlight from a solar simulator (manufactured by Eihiro Seiki Co., Ltd.). The binuclear ruthenium complex dye was synthesized with reference to International Publication No. 2006/038587.

Example 1
(Preparation of porous titania electrode)
Using titania paste PST-18NR (manufactured by JGC Catalysts & Chemicals Co., Ltd.) for the transparent layer and PST-400C (manufactured by JGC Catalysts & Chemicals Co., Ltd.) for the diffusion layer, on the transparent conductive glass electrode (manufactured by Asahi Glass Co., Ltd.) It was applied using a screen printer. The obtained film was aged for 5 minutes in an atmosphere of 25 ° C. and a relative humidity of 60%, and the aged film was baked at 440 to 460 ° C. for 30 minutes. By repeating this operation, a 16 mm ² porous titania electrode was produced.

(Preparation of porous titania electrode adsorbed with dye)
A dinuclear ruthenium complex dye (D-4) was added to a mixed solvent of t-butanol / acetonitrile (= 1: 1 (volume ratio)) to prepare a saturated dye solution of the ruthenium complex dye. Next, the porous titania electrode was immersed in the saturated dye solution in an incubator with an internal temperature of 30 ° C. for 20 hours to produce a porous titania electrode adsorbing the dye.

(Production of photochemical battery)
The dye adsorbing porous titania electrode obtained as described above and a platinum plate (counter electrode) were superposed. Next, an electrolyte solution (3-methoxypropionitrile and lithium iodide, iodine, 1,2-dimethyl-3-propylimidazolium iodide, and dimethylaniline, 0.1, 0.05, 0.6, In addition, a photochemical battery was manufactured by soaking the gap between the two electrodes using a capillary phenomenon.

(Measurement of photoelectric conversion efficiency)
The photoelectric conversion efficiency of the obtained photochemical battery was measured by irradiating 100 mW / cm ² of artificial sunlight using a solar simulator manufactured by Eihiro Seiki Co., Ltd.

Examples 2-8, Comparative Examples 1-7
A photochemical battery was prepared in the same manner as in Example 1 except that the type and concentration of the additive in the electrolyte solution were changed, and the photoelectric conversion efficiency was measured. The results are shown in Table 1. 4-t-butylpyridine is a compound known as an additive that gives the best results.

  From the above results, it was found that the use of an arylamine compound as an additive of the electrolytic solution markedly improves the photoelectric conversion efficiency as compared with the case where no additive or a heteroaryl compound is added. It was also confirmed that the effect of adding 4-t-butylpyridine, which is known as an additive that gives the best results, is equal to or higher than that.

  According to the present invention, there is provided a photochemical battery having a high photoelectric conversion efficiency, comprising a semiconductor fine particle sensitized by a dinuclear ruthenium complex dye having a high extinction coefficient and excellent in electron transfer, and an electrolyte solution containing an arylamine compound. Can be provided.

Claims (9)

The following general formula (1)

(In the formula, X ^N- represents an N-valent anion which is a counter ion (where N is 1 or 2),

Is a nitrogen-containing bidentate ligand having two carboxyl groups,

Is a nitrogen-containing tetradentate ligand,

Represents a nitrogen-containing bidentate ligand. n shows the integer of 0-2. p represents the number of counter ions necessary to neutralize the charge of the complex. The carboxyl group (COOH) may be deprotonated (H ⁺ ) to become a carboxy ion (COO ⁻ ). )
Semiconductor fine particles sensitized by a dinuclear ruthenium complex dye represented by formula (2):

(In the formula, Ar represents an aryl group, and R ¹ and R ² may be the same or different and represent a hydrogen atom or an alkyl group. R ¹ and R ² are bonded to form a ring. May be.)
And an electrolyte solution containing an arylamine compound represented by the formula: X ^N-is, hexafluorophosphate ion, tetrafluoroborate ion, photochemical cell of claim 1 wherein the nitrate ion or iodide ion.   Nitrogen-containing bidentate ligand is 2,2′-bipyridine, 2,2 ′-(4,4′-dimethyl) bipyridine, 2,2 ′-(4,4′-di-t-butyl) bipyridine, The photochemical cell according to claim 1, which is 2,2 '-(4,4'-di-n-nonyl) bipyridine or 1,10-phenanthroline.   The photochemical battery according to claim 1, wherein the nitrogen-containing bidentate ligand having two carboxyl groups is 2,2'-bipyridine-4,4'-dicarboxylic acid.   The photochemical cell according to claim 1, wherein the nitrogen-containing tetradentate ligand is 2,2'-biimidazole or 2,2'-bibenzimidazole.   The photochemical cell according to claim 1, wherein the semiconductor fine particles are titanium oxide, zinc oxide, tin oxide, or a mixture thereof.   The photochemical battery according to claim 1, wherein the arylamine compound is at least one selected from the group consisting of aniline, dimethylaniline, di-n-butylaniline, di-n-hexylaniline, and di-n-octylaniline.   The photochemical battery according to claim 1, wherein the electrolyte solution contains a redox pair.   A photoelectric conversion element in which semiconductor fine particles sensitized with the dinuclear ruthenium complex dye are fixed on an electrode and a counter electrode, and an electrolyte solution layer containing an arylamine compound therebetween. The photochemical battery according to any one of 8.