JP2001036110A - Semiconductor particulate, manufacture thereof and photoelectric conversion element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide semiconductor particulates used for a pigment sensitizing photoelectric conversion element which is superior in energy conversion efficiency and can be made larger in area and an optical electrochemical cell, by allowing an ester compound other than pigments to be adsorbed to a semiconductor. SOLUTION: A manufactured and color sensitized TiO2 electrode substrate is coupled with a platinum vopor-deposited glass which is as large as its size, and an electrolyte is impregnated between both glasses due to capillary phenomena, and then it is led into the TiO2 electrode, so as to obtain an optical electrochemical cell. A conductive glass 1 (a conductive agent layer 2 is formed on a glass), TiO2 layer 3, pigment layer 4, electrolyte 5, platinum layer 6, and glass 7 are laminated in sequence, to produce an optical electrochemical cell packaged with an epoxy-based sealing agent. The optical electrochemical cell is irradiated with an artificial solar light, and the electricity generated is measured by a current/voltage measuring device. As a result, a photoelectric conversion element of superior photoelectric conversion efficiency and an optical electrochemical cell can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor fine particles sensitized by a dye and a photoelectric conversion element using the same. Furthermore, the present invention relates to a method for producing semiconductor fine particles sensitized by a dye.

[0002]

2. Description of the Related Art At present, photovoltaic power generation is the main technology for practical use of single crystal silicon solar cells, polycrystalline silicon solar cells, amorphous silicon solar cells and compound solar cells such as cadmium telluride and indium copper selenide. Thus, a solar energy conversion efficiency exceeding 10% is obtained as the power generation efficiency. However, in order to popularize these materials in the future, it is necessary to overcome the problems that the energy cost for material production is high, the environmental load for commercialization is large, and the energy payback time is long for users. On the other hand, aiming for lower prices,
Many solar cells using an organic material, which can easily be made large in area, as a photosensitive material in place of silicon have been proposed so far, but have a problem that the energy conversion efficiency is as low as 1% or less and the durability is poor. Under these circumstances, Nature
(353, 737-740, 1991) and U.S. Pat.
No. 7721 and the like disclose a photoelectric conversion element and a solar cell using semiconductor fine particles sensitized by a dye, and materials and manufacturing techniques required for the fabrication. The proposed battery is a wet solar cell using a titanium dioxide porous thin film spectrally sensitized by a ruthenium complex as a working electrode.
The first advantage of this method is that an inexpensive oxide semiconductor such as titanium dioxide can be used without having to purify it to high purity, and therefore it can be provided as an inexpensive photoelectric conversion element. The absorption of the dye is broad,
Thirdly, sunlight can be converted into electricity over a wide visible light wavelength range. Thirdly, energy conversion efficiency is close to 10% under optimum conditions. However, when the dye is adsorbed on the semiconductor fine particles, there is a problem that the dye is undesirably aggregated, and the performance of the obtained photoelectric conversion element is reduced. To prevent this aggregation, a method of mixing a steroidal carboxylic acid compound with the dye solution is known as Chemical.
Communication (pages 719 to 720, 1998
Year), but the effect was not sufficient.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a dye-sensitized photoelectric conversion element which is excellent in energy conversion efficiency and can have a large area, and semiconductor fine particles used for a photoelectrochemical cell. . Another object of the present invention is to provide a method for producing the semiconductor fine particles.

[0004]

The object of the present invention has been attained by the following items which specify the present invention and preferred embodiments thereof. (1) semiconductor fine particles sensitized by a dye,
Semiconductor fine particles characterized by adsorbing an ester compound to a semiconductor in addition to a dye. (2) The semiconductor fine particles according to (1), wherein the ester compound is a compound represented by the following general formula (A). Formula (A) R ¹ -LZR ² (W) (In Formula (A), R ¹ and R ² each independently represent an alkyl group, an alkenyl group, an alkynyl group, a cyclic aliphatic group,
Represents an aromatic group or a heterocyclic group, which may have a substituent or may be condensed, and R ¹ and R ² may be linked to form a ring. L represents a single bond or a divalent linking group. Z represents an ester bond, and (W) represents a counter ion necessary to neutralize the charge of the molecule. (3) The semiconductor fine particles according to the above (2), wherein in the general formula (A), R ¹ is a substituted or unsubstituted alkyl group having 20 or less carbon atoms. (4) The semiconductor fine particles according to the above (2), wherein in the general formula (A), R ¹ is a cyclic aliphatic group having 25 or less carbon atoms. (5) The semiconductor fine particles according to (2), wherein in the general formula (A), R ¹ is an aromatic group having 13 or less carbon atoms or a heterocyclic ring. (6) The above (2) to (2), wherein Z is an ester bond of a carboxylic acid, a sulfonic acid or a phosphonic acid.
The semiconductor fine particles according to any one of (5). (7) The semiconductor fine particles according to any one of (1) to (6), wherein the dye is a dye selected from a ruthenium complex dye, a phthalocyanine dye, and a polymethine dye. (8) The semiconductor particles according to any one of (1) to (7), wherein the semiconductor particles are metal oxide particles. (9) The semiconductor particles according to any one of (1) to (8), wherein the semiconductor particles are titanium dioxide. (10) A photoelectric conversion element using the semiconductor fine particles according to any of (1) to (9). (11) A method for producing semiconductor fine particles sensitized by a dye, comprising: a) a step of immersing the semiconductor fine particles in a solution in which an ester compound coexists with the dye; b) a step of adsorbing the dye to the semiconductor fine particles; A method of immersing in a solution containing an ester compound. (12) The method for producing semiconductor fine particles according to (11) above, wherein the ester compound is a compound represented by the following general formula (A). Formula (A) R ¹ -LZR ² (W) (In Formula (A), R ¹ and R ² each independently represent an alkyl group, an alkenyl group, an alkynyl group, a cyclic aliphatic group, or an aromatic group. A heterocyclic group or a heterocyclic group, which may have a substituent or may be condensed, and R ¹ and R ² may be linked to form a ring. Represents a divalent linking group, Z represents an ester bond, (W) represents a counter ion necessary for neutralizing the electric charge of the molecule.) (13) In the step (a) of the above (11), The method for producing semiconductor fine particles according to the above (11) or (12), wherein the concentration of the ester compound in the solution in which the dye and the ester compound coexist is 1 to 1000 times in molar ratio with respect to the dye. . (14) In the step (b) of the above (11), the molar concentration of the ester compound in the immersion liquid containing the ester compound is 0.1 mM to 1M.
Or the method for producing semiconductor fine particles according to (12).

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The ester compound that can be used in the present invention may be any of a carboxylic acid ester, a phosphonic acid ester, a sulfonic acid ester, a boric acid ester and a thiocarboxylic acid ester, and is preferably a compound represented by the general formula (A). General formula (A) R ¹ -LZR ² (W) General formula (A) will be described. Where R ¹ and R
² each independently represents an alkyl group, an alkenyl group, an alkynyl group, a cyclic aliphatic group, an aromatic group or a heterocyclic group, which may have a substituent or may be condensed, , R ¹ and R ² may be linked to form a ring.
When R ¹ or R ² is an alkyl group, an alkenyl group or an alkynyl group, the number of carbon atoms is preferably 30 or less, more preferably 25 or less, and particularly preferably 20 or less. When R ¹ or R ² is a cyclic aliphatic group, it has 35 carbon atoms.
The following is preferred, more preferably 30 or less, particularly preferably 25 or less, and specifically, for example, a steroid group having a cyclopentane hydrophenanthrene ring. When R ¹ or R ² represents an aromatic group or a heterocyclic ring, it preferably has 20 or less carbon atoms, and more preferably ¹ or ² carbon atoms.
7 or less, particularly preferably 13 or less. Preferred examples of the hetero ring include pyrrole ring, thiazole ring, oxazole ring, selenazole ring, imidazole ring, tellurazole ring, 2-quinoline ring, 4-quinoline ring, thiazoline ring, oxadiazole ring and benzodiazole derivatives thereof. Of these, a pyrrole ring, a thiazole ring, an oxazole ring, a selenazole ring, an imidazole ring, a 2-quinoline ring, a 4-quinoline ring, and a ring derived from a benzo-fused ring thereof are particularly preferable. Examples of the substituent which R ¹ and R ² may have include an alkyl group (eg, methyl, ethyl, isobutyl, n-dodecyl, cyclohexyl, vinyl, allyl, benzyl, etc.) and an aryl group (eg, phenyl, tolyl, naphthyl) Etc.), heterocyclic residues (eg, pyridyl group, imidazolyl group, furyl group, thienyl group, oxazolyl group, thiazolyl group, benzimidazolyl group, quinolyl group, etc.), halogen atoms (eg, fluorine, chlorine, bromine), alkoxy groups (Eg, methoxy, ethoxy, benzyloxy, etc.), aryloxy group (eg, phenoxy, etc.), alkylthio group (eg, methylthio, ethylthio, etc.), arylthio group (eg, phenylthio, etc.), hydroxy group and oxygen anion, nitro group, cyano group , An amide group (eg, acetylamino, benzoy ), Sulfonamide groups (eg, methanesulfonylamino, benzenesulfonylamino, etc.), ureido groups (eg, 3-phenylureido, etc.), urethane groups (eg, isobutoxycarbonylamino, carbamoyloxy, etc.), ester groups (eg, acetoxy) Benzoyloxy, methoxycarbonyl, phenoxycarbonyl, etc.), carbamoyl group (eg, N-methylcarbamoyl, N, N-diphenylcarbamoyl, etc.), sulfamoyl group (eg, N-phenylsulfamoyl, etc.), acyl group (eg, acetyl, benzoyl) An amino group (amino, methylamino, anilino, diphenylamino, etc.), a sulfonyl group (eg, methylsulfonyl, etc.), a carboxylic acid group, a phosphonic acid group, a sulfonic acid group, a phosphoric acid group,
And the like. The above substituent may be further present on the carbon atom of the substituent.

L represents a single bond or a divalent linking group. 2
Valent linking groups include carbon, oxygen, sulfur, nitrogen, silicon, phosphorus and
And linking groups formed by atoms selected from halogen atoms
Is preferred, and the number of carbon atoms is preferably 0 to 10, more preferably
Preferably it is 0 to 8. Specifically, oxygen (ether
), Sulfur (thioether), substituted or unsubstituted
A mino group or a substituted or unsubstituted alkylene group,
Or two or more linking groups selected from these are linked in series
Group. The substituent here is the aforementioned R ¹Or
R^TwoIs the same as the substituent which may be possessed. Especially as L
Preferably, a single bond or -O-, -S-, -OCH
_Two-, -CH_Two-, -OCH_TwoCH_Two-, -OCH_TwoCH_TwoC
H_Two-Or -SCH_TwoCH_Two-Is a linking group.

Z represents an ester bond, specifically, —C
(O) O- group, -C (S) S- group,-(O) S (O) O
— Group, —P (O) (OR ³ ) O— group, —B (OR ⁴ ) O—
Group. Here, R ³ and R ⁴ are each hydrogen or an alkyl group having 10 or less carbon atoms. Z is preferably -C (O) O- group,-(O) S (O) O- group or -P
(O) (OR ³⁾ a O- group, and most preferably -C
(O) O- group.

(W) represents a counter ion necessary for neutralizing the electric charge of the molecule. It is determined whether the compound of the general formula (A) is a cation, an anion, or has a net ionic charge. Depends on the substituent. When the substituent has a dissociable group, it may dissociate and have a negative charge, and in this case also, the charge of the entire molecule is neutralized by W. Typical cations are inorganic or organic ammonium ions (eg, tetraalkylammonium ions, pyridinium ions) and alkali metal ions, while the anions are specifically either inorganic or organic anions. Frequently, for example, halogen anions (eg, fluoride, chloride, bromide, iodide), substituted aryl sulfonate (eg, p-
Toluenesulfonate ion, p-chlorobenzenesulfonate ion, aryldisulfonate ion (for example,
1,3-benzenedisulfonate ion, 1,5-naphthalenedisulfonic acid ion, 2,6-naphthalenedisulfonic acid ion), alkyl sulfate ion (for example, methyl sulfate ion), sulfate ion, thiocyanate ion, perchlorate ion , Tetrafluoroborate ion, picrate ion, acetate ion and trifluoromethanesulfonic acid ion. Further, an ionic polymer or a metal complex ion (for example, bisbenzene-1,2-dithiolatonickel (III)) can be used as a charge balancing counter ion.

The ester compound to be used is added for the purpose of preventing undesired aggregation of the dye, and is substantially colorless from the viewpoint of effective use of light, that is, has substantially no absorption in the visible region. preferable. Hereinafter, specific examples of the ester compound used in the present invention are shown, but the present invention is not limited thereto.

[0010]

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[0011]

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An object of the present invention is to dissolve or disperse the above-mentioned ester compound in a dye solution when the dye is adsorbed on the semiconductor fine particles, or to dissolve or disperse the ester compound after adsorbing the dye on the semiconductor. Can also be achieved by processing semiconductors. In the latter case, specifically, the semiconductor on which the dye is adsorbed may be immersed in the solution of the ester compound of the present invention. The concentration of the ester compound when dissolved in the dye solution is 0.01 to 1 in a molar ratio to the dye.
000 times, preferably 0.1 to 5,000 times
Times, particularly preferably 1 to 1,000 times. Further, the concentration of the ester compound in the solution when treating the semiconductor on which the dye is adsorbed is preferably 0.1 mM to 1.0 M, and preferably 1 mM to 1.0 M.
mM to 0.5M is more preferred. Further, the adsorption amount of the ester compound to the semiconductor may be at least slightly adsorbed, and is preferably not more than the dye adsorption amount by weight, particularly preferably not more than 1/100 of the dye adsorption amount.

Next, the structure and materials of the photoelectric conversion element of the present invention will be described in detail. In the present invention, the dye-sensitized photoelectric conversion element includes a conductive support, a semiconductor film (photosensitive layer) sensitized by a dye or the like provided on the conductive support, a charge transfer layer, and a counter electrode. A photoelectrochemical cell that can use this photoelectric conversion element for a battery that works in an external circuit is used. The photosensitive layer is designed according to the purpose, and may have a single-layer structure or a multilayer structure. Light incident on the photosensitive layer excites a dye or the like. The excited dye or the like has high-energy electrons. The electrons are transferred from the dye or the like to the conduction band of the semiconductor fine particles, and reach the conductive support by diffusion. At this time, molecules such as dyes are oxidized. In a photoelectrochemical cell, electrons on a conductive support return to an oxidized substance such as a dye through a counter electrode and a charge transfer layer while working in an external circuit, and the dye or the like is regenerated. The semiconductor film functions as a negative electrode of this battery. In the present invention, at the boundary between the layers (for example, the boundary between the conductive layer and the photosensitive layer of the conductive support, the boundary between the photosensitive layer and the charge transfer layer, the boundary between the charge transfer layer and the counter electrode, etc.), the constituent components of each layer They may be mutually diffused and mixed.

In the present invention, the semiconductor is a so-called photoreceptor, and plays a role of absorbing light to separate charges and generate electrons and holes. In a dye-sensitized semiconductor, light absorption and the resulting generation of electrons and holes mainly occur in the dye, and the semiconductor is responsible for receiving and transmitting the electrons.

As the semiconductor, besides a simple semiconductor such as silicon and germanium, a III-V compound semiconductor, a metal chalcogenide (eg, oxide, sulfide, selenide, etc.) or a compound having a perovskite structure is used. can do. Preferably as a metal chalcogenide titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium or tantalum oxide, cadmium, zinc, lead, silver,
Examples include antimony, sulfide of bismuth, cadmium, selenide of lead, and telluride of cadmium. Other compound semiconductors include phosphides such as zinc, gallium, indium and cadmium, gallium arsenide, copper-indium-selenium compounds, copper-indium-sulfur compounds and the like. Further, as the compound having a perovskite structure, strontium titanate, calcium titanate, sodium titanate, barium titanate, and potassium niobate are preferably exemplified.

More preferably, the semiconductor used in the present invention is specifically Si, TiO ₂ , SnO ₂ , Fe ₂ O ₃ , WO ₃ , Zn
O, Nb ₂ O ₅ , CdS, ZnS, PbS, Bi ₂ S ₃ , CdSe, CdTe, GaP, I
nP, GaAs, CuInS ₂ and CuInSe ₂ are mentioned. More preferably _{TiO 2, ZnO, SnO 2,} Fe 2 O 3, WO 3, Nb 2 O 5, CdS, Pb
S, CdSe, InP, GaAs, a CuInS _2, CuInSe _2, particularly preferably a TiO ₂ or Nb ₂ O _5, and most preferably TiO
₂

The semiconductor used in the present invention may be single crystal or polycrystal. Although a single crystal is preferable as the conversion efficiency, a polycrystal is preferable in terms of manufacturing cost, securing of raw materials, energy payback time, and the like, and a fine particle semiconductor having a nanometer to micrometer size is particularly preferable.

The particle size of these semiconductor fine particles is preferably 5 to 200 nm as a primary particle as an average particle size using the diameter when the projected area is converted into a circle, and particularly preferably 8 to 200 nm.
Preferably it is 100 nm. The average particle size of the semiconductor fine particles (secondary particles) in the dispersion is 0.01 to
It is preferably 100 μm.

Further, two or more kinds of fine particles having different particle size distributions may be mixed and used. In this case, the average size of the small particles is preferably 5 nm or less. Also, in order to improve the light capture rate by scattering incident light,
Semiconductor particles having a large particle size, for example, about 300 nm may be mixed.

The method for producing semiconductor fine particles is described in Sol-gel described in "Sol-gel method science" by Agaku Shofusha (1988) by Sakuhana Sakubana, "Thin-film coating technology by sol-gel method" (1995) by Technical Information Association. Tadao Sugimoto, "Synthesis of Monodisperse Particles by New Synthetic Gel-Sol Method and Size Morphology Control" Materia, Vol. 35, No. 9, 1012
The gel-sol method described on pages 10 to 1018 (1996) is preferred.

It is also preferable to use a method developed by Degussa to produce an oxide by hydrolyzing a chloride in an oxyhydrogen flame at a high temperature.

In the case of titanium oxide, the above-mentioned sol-gel method, gel-sol method, and high-temperature hydrolysis method of chloride in an oxyhydrogen flame are all preferable, but furthermore, Manabu Kiyono's "Titanium oxide physical properties and applied technology", published by Gihodo ( 1997) can also be used.

In the case of titanium oxide, among the sol-gel methods described above, in particular, "Journal of American
Ceramic Society Vol. 80, No. 12, 31
Pages 57 to 3171 (1997) "and Burnside et al.," Chemical Materials Vol. 10, No. 9, pages 2419 to 2425 "
The described method is preferred.

As the conductive support, use is made of a support such as metal, which has conductivity, or a glass or plastic support having a conductive layer (conductive agent layer) containing a conductive agent on the surface. Can be. In the latter case, preferred conductive agents include metals (for example, platinum, gold, silver, copper, aluminum, rhodium, indium, etc.), carbon, or conductive metal oxides (indium-tin composite oxide, tin oxide doped with fluorine). And the like). The conductive agent layer preferably has a thickness of about 0.02 to 10 μm.

The lower the surface resistance of the conductive support, the better. The preferred range of the surface resistance is 100 Ω / □ or less, and more preferably 40 Ω / □ or less. The lower limit is not particularly limited, but is usually about 0.1 Ω / □.

Preferably, the conductive support is substantially transparent. Substantially transparent means that the light transmittance is 10%
The above means that it is preferably at least 50%, particularly preferably at least 70%. As the transparent conductive support, a support obtained by coating a conductive metal oxide on glass or plastic is preferable. Of these, conductive glass in which a conductive layer made of tin dioxide doped with fluorine is deposited on a transparent substrate made of low-cost soda-lime float glass is particularly preferable. Further, it is preferable to use a transparent polymer film provided with the above conductive layer for a low-cost flexible photoelectric conversion element or solar cell.
Transparent polymer films include tetraacetyl cellulose (TAC), polyethylene terephthalate (PET),
Polyethylene naphthalate (PEN), syndioctatic polysterene (SPS), polyphenylene sulfide (PPS), polycarbonate (PC), polyarylate (PAr), polysulfone (PSF), polyester sulfone (PES), polyetherimide (PE
I), cyclic polyolefin, brominated phenoxy and the like. When a transparent conductive support is used, it is preferable that light is incident from the support side. In this case, the coating amount of the conductive metal oxide is preferably 0.01 to 100 g per 1 m ² of a glass or plastic support.

It is preferable to use metal leads for the purpose of lowering the resistance of the transparent conductive substrate. The material of the metal lead is preferably a metal such as aluminum, copper, silver, gold, platinum, and nickel, and particularly preferably aluminum and silver. It is preferable that the metal lead is provided on a transparent substrate by vapor deposition, sputtering, or the like, and a transparent conductive layer made of tin oxide doped with fluorine or an ITO film is provided thereon. It is also preferable to provide a metal lead on the transparent conductive layer after providing the transparent conductive layer on a transparent substrate. The decrease in the amount of incident light due to the installation of metal leads is 1 to 10%, more preferably 1 to 5%.
It is.

Examples of the method of applying the semiconductor fine particles on the conductive support include a method of applying a dispersion or colloid solution of the semiconductor fine particles on the conductive support, and the above-mentioned sol-gel method. In consideration of mass production of photoelectric conversion elements, liquid physical properties, and flexibility of a support, a wet film forming method is relatively advantageous. As a wet type film applying method, a coating method and a printing method are typical.

As a method for preparing a dispersion of semiconductor fine particles, in addition to the above-described sol-gel method, a method of grinding with a mortar, a method of dispersing while grinding with a mill, or a method of synthesizing a semiconductor in a solvent when synthesizing a semiconductor. A method of precipitating it as fine particles and using it as it is may be mentioned. Examples of the dispersion medium include water and various organic solvents (eg, methanol, ethanol, isopropyl alcohol, dichloromethane, acetone, acetonitrile, ethyl acetate, etc.). When dispersing,
If necessary, a polymer, a surfactant, an acid, a chelating agent or the like may be used as a dispersing aid.

The application method includes a roller method and a dip method as an application system, an air knife method and a blade method as a metering system, and a method in which application and metering can be performed in the same part.
No. 4,589,294, U.S. Pat. No. 2,761,419, and U.S. Pat.
A slide hopper method, an extrusion method, a curtain method and the like described in US Pat. As a general-purpose machine, a spin method or a spray method is also preferably used.

As the wet printing method, three types of printing methods, namely, relief printing, offset printing and gravure printing, intaglio printing, rubber printing and screen printing have been conventionally preferred.

From the above methods, a preferred film forming method is selected depending on the liquid viscosity and the wet thickness.

The liquid viscosity is greatly affected by the type and dispersibility of the semiconductor fine particles, the type of solvent used, and additives such as a surfactant and a binder. High viscosity liquid (for example, 0.01 to 500 Po
In ise), an extrusion method or a casting method is preferable, and in a low-viscosity liquid (for example, 0.1 Poise or less), a slide hopper method, a wire bar method, or a spin method is preferable, and a uniform film can be formed.

In the case of applying a low-viscosity liquid by the extrusion method, the application is possible if the applied amount is a certain amount.

Screen printing is often used for applying a high-viscosity paste of semiconductor fine particles, and this technique can also be used.

As described above, a method of applying a wet film may be appropriately selected in accordance with parameters such as the liquid viscosity of the coating liquid, the coating amount, the support, and the coating speed.

Further, the semiconductor fine particle-containing layer need not be limited to a single layer. It is also possible to apply a multi-layer coating of dispersion liquids having different particle diameters, and different types of semiconductors.
Alternatively, the coating layers having different compositions of the binder and the additives can be applied in multiple layers, and the multilayer coating is effective even when the film thickness is insufficient by one application. The extrusion method or the slide hopper method is suitable for multilayer coating. In the case of multi-layer coating, multi-layer coating may be performed at the same time, or several to dozens of times may be sequentially applied. Furthermore, a screen printing method can also be preferably used in the case of successive coating.

In general, as the thickness of the layer containing semiconductor fine particles increases, the amount of dye carried per unit projected area increases, so that the light capture rate increases. However, the diffusion distance of generated electrons increases, so that the loss due to charge recombination also increases. growing. Therefore, the semiconductor fine particle-containing layer has a preferable thickness, but is typically 0.1 to 100 μm. When used as a photoelectrochemical cell, the thickness is preferably 1 to 30 μm, and more preferably 2 to 25 μm. The coating amount of the semiconductor fine particles per 1 m ² of the support is 0.5 to 400.
g, more preferably 5 to 100 g.

The semiconductor fine particles are preferably subjected to a heat treatment in order to electronically contact the particles after being applied to the conductive support, and to improve the strength of the coating film and the adhesion to the support. The preferred range of the heat treatment temperature is 40 ° C. or more and less than 700 ° C., more preferably 1 ° C.
It is not less than 00 ° C and not more than 600 ° C. The heat treatment time is 1
It is about 0 minutes to 10 hours. When a support having a low melting point or softening point, such as a polymer film, is used, high-temperature treatment is not preferable because it causes deterioration of the support. It is preferable that the temperature is as low as possible from the viewpoint of cost. The lowering of the temperature can be achieved by the above-mentioned combination of small semiconductor particles of 5 nm or less, heat treatment in the presence of a mineral acid, and the like.

After the heat treatment, chemical plating using, for example, an aqueous solution of titanium tetrachloride for the purpose of increasing the surface area of the semiconductor particles, increasing the purity near the semiconductor particles, and increasing the efficiency of injecting electrons from the dye into the semiconductor particles. Alternatively, electrochemical plating using an aqueous solution of titanium trichloride may be performed.

The semiconductor fine particles preferably have a large surface area so that many dyes can be adsorbed. Therefore, the surface area when the semiconductor fine particle layer is coated on the support is preferably at least 10 times, more preferably at least 100 times the projected area. The upper limit is not particularly limited, but is usually about 1000 times.

The dye used in the present invention is preferably a metal complex dye or a methine dye. In the present invention, two or more dyes can be mixed in order to widen the wavelength range of photoelectric conversion as much as possible and to increase the conversion efficiency. Dyes to be mixed and their proportions can be selected so as to match the wavelength range and intensity distribution of the target light source. These dyes are suitably linked to the surface of the semiconductor fine particles (interlocki).
ng group). Preferred binding groups include COOH, SO ₂ H, cyano, -P (O) (OH)
₂ groups, -OP (O) (OH) ₂ groups, or oxime, dioxime,
Chelating groups having π conductivity such as hydroxyquinoline, salicylate and α-keto enolate. Among them, COOH group, -P (O) (OH) ₂ group, -OP (O) (OH ₎ 2
Groups are particularly preferred. These groups may form a salt with an alkali metal or the like, or may form an inner salt. In the case of a polymethine dye, if the methine chain contains an acidic group as in the case of forming a squarylium ring or a croconium ring, this portion may be used as a bonding group.

The dyes preferably used in the present invention will be specifically described below. When the dye used in the present invention is a metal complex dye, a ruthenium complex dye is preferable, and a dye represented by the following formula (I) is more preferable. Wherein _{(I) (A 1) p} RuB a B b B c formula (I), p is 0 to 2, preferably 2.
Ru represents ruthenium. A ₁ is Cl, SCN, H ₂ O,
A ligand selected from Br, I, CN, NCO, and SeCN. B _a, B _b, B _c is an organic ligand selected from the following B-1 to B-8 independently.

[0044]

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Where Ra is a hydrogen atom, a halogen atom,
A substituted or unsubstituted alkyl group having 1 to 12 carbon atoms (hereinafter referred to as C number), an aralkyl group substituted or unsubstituted with 7 to 12 carbon atoms, or a substituted or unsubstituted with 6 to 12 carbon atoms Represents an aryl group. The above alkyl group,
The alkyl portion of the aralkyl group may be linear or branched, and the aryl portion of the aralkyl group may be monocyclic or polycyclic (condensed ring, ring assembly). .

The ruthenium complex dyes used in the present invention include, for example, US Pat.
Complex dyes described in 5084365, 5350644, 5463057, 5525440 and JP-A-7-249790.

Preferred specific examples of the metal complex dye used in the present invention are shown below, but the present invention is not limited to these.

[0048]

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[0049]

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[0050]

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When the dye used in the present invention is a methine dye, the following formulas (II), (III) and (IV)
Alternatively, a dye represented by the formula (V) is preferable.

[0052]

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In the formula, R _b and R _f each represent a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, and R _{c to} R _e
Represents a hydrogen atom or a substituent. R _{b to} R _f may combine with each other to form a ring. X ₁₁ and X ₁₂ each represent nitrogen, oxygen, sulfur, selenium, or tellurium. n ₁₁ and n
₁₃ represents an integer of 0 to 2; n ₁₂ represents an integer of 1 to 6; The compound represented by the formula (II) may have a counter ion depending on the charge of the whole molecule.

The above alkyl group, aryl group and heterocyclic group may have a substituent. The alkyl group may be linear or branched, and the aryl group and the heterocyclic group may be monocyclic or polycyclic (condensed ring, ring assembly). The ring formed by R _{b to} R _f may have a substituent and may be a single ring or a condensed ring.

[0055]

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[0056] In the formula, Z _a represents a non-metallic atomic group necessary for forming a nitrogen-containing heterocyclic ring. R _g is an alkyl group or an aryl group. Q _a represents a methine group or a polymethine group necessary for the compound represented by the formula (III) to form a methine dye. X ₁₃ represents a charge balancing counter ion, and n ₁₄ represents a number from 0 to 10 required to neutralize the charge of the molecule.

[0057] nitrogen-containing heterocyclic ring formed by the above Z _a may have a substituent, may be a condensed ring may be a single ring. Further, the alkyl group and the aryl group may have a substituent, the alkyl group may be linear or branched, and the aryl group may be monocyclic or polycyclic (condensed ring, Ring set).

The dye represented by the formula (III) is represented by the following formula (III)
The dyes represented by -a) to (III-d) are preferable.

[0059]

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In the formulas (III-a) to (III-d), R _{11 to} R
₁₅ , R _{21 to} R ₂₄ , R _{31 to} R ₃₃ , and R _{41 to} R ₄₃ each independently represent a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group, and Y ₁₁ , Y ₁₂ , Y ₂₁ , Y ₂₂ , Y ₃₁ ~
Y ₃₅ and Y _{41 to} Y ₄₆ each independently represent oxygen, sulfur,
Selenium, tellurium, -CR ₁₆ R ₁₇ -, or -NR ₁₈ - represents a. R _{16 to} R ₁₈ each independently represent a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group. Y ₂₃ is O-,
S-, Se-, Te-, or -NR ₁₈ - represents a.

V ₁₁ , V ₁₂ , V ₂₁ , V ₂₂ , V ₃₁ , and V
₄₁ independently represents a substituent, and n ₁₅ , n ₃₁ and n
₄₁ independently represents an integer of 1 to 6; Formula (III-
The compounds represented by a) to (III-d) may have a counter ion depending on the charge of the whole molecule.

The alkyl group, aryl group and heterocyclic group in the above may have a substituent, the alkyl group may be linear or branched, and the aryl group and heterocyclic group may be a single group. It may be a ring or a polycyclic (condensed ring, ring assembly).

Specific examples of the above polymethine dyes are described in M.
Organic Co. by Okawara, T. Kitao, T. Hirasima, M. Matuoka
lorants (Elsevier) and the like.

[0064]

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[0065] In the formula (IV), Q _b represents an atomic group necessary to complete a nitrogen-containing heterocyclic ring of 5- or 6-membered, Q _b
May be condensed and may have a substituent. Preferred examples of the heterocycle completed by Q _b include:
Benzothiazole nucleus, benzoxazole nucleus, benzoselenazole nucleus, benzotellurazole nucleus, 2-quinoline nucleus, 4-quinoline nucleus, benzimidazole nucleus, thiazoline nucleus, indolenine nucleus, oxadiazole nucleus, thiazole nucleus, imidazole nucleus Among them, more preferred are a benzothiazole nucleus, a benzoxazole nucleus, a benzimidazole nucleus, a benzoselenazole nucleus, a 2-quinoline nucleus, a 4-quinoline nucleus and an indolenine nucleus, and particularly preferred are a benzothiazole nucleus and a benzoxazole nucleus. , 2-
They are a quinoline nucleus, a 4-quinoline nucleus, and an indolenine nucleus. Examples of the substituent on the ring include a carboxylic acid group, a phosphonic acid group, a sulfonic acid group, a halogen atom (F, Cl, Br, I), a cyano group, an alkoxy group (e.g., methoxy, ethoxy, methoxyethoxy), an aryloxy group ( Phenoxy),
Alkyl group (methyl, ethyl, cyclopropyl, cyclohexyl, trifluoromethyl, methoxyethyl, allyl, benzyl etc.), alkylthio group (methylthio, ethylthio etc.), alkenyl group (vinyl, 1-propenyl etc.), aryl group or Heterocyclic groups (phenyl, thienyl, toluyl, chlorophenyl and the like) and the like.

Z _b represents an atomic group composed of atoms selected from a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom and a hydrogen atom, which is necessary for completing a 3- to 9-membered ring. The ring completed by Z _b is preferably a ring whose skeleton is formed by 4 to 6 carbon atoms, more preferably a ring represented by the following (A) to (E), and most preferably (A) A).

[0067]

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L ₁ , L ₂ , L ₃ , L ₄ and L ₅ each independently represent a methine group which may have a substituent. As the substituent, a substituted or unsubstituted alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 7 carbon atoms, for example, methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, 2-carboxy) A substituted or unsubstituted aryl group (preferably having 6 to 10 carbon atoms, more preferably 6 to 8 carbon atoms, for example, phenyl, toluyl, chlorophenyl, o-carboxyphenyl), a heterocyclic ring Groups (eg, pyridyl, thienyl, furanyl, pyridyl, barbituric acid), halogen atoms (eg, chlorine, bromine), alkoxy groups (eg, methoxy, ethoxy), amino groups (preferably having 1 to 12 carbon atoms,
More preferably those of 6 to 12, for example,
Diphenylamino, methylphenylamino, 4-acetylpiperazin-1-yl), oxo group and the like. The substituents on these methine groups may be linked to each other to form a ring such as a cyclopentene ring, a cyclohexene ring, a squarylium ring, or a ring with an auxochrome.

N ₅₁ represents an integer from 0 to 4, preferably from 0 to 3. n ₅₂ is 0 or 1.

R ₅ represents a substituent. The substituent is preferably an aromatic group which may have a substituent or an aliphatic group which may have a substituent. The number of carbon atoms of the aromatic group is preferably 1 to 16, more preferably 5 to 5. Or 6
It is. The number of carbon atoms in the aliphatic group is preferably 1 to 1
0, more preferably 1 to 6. Examples of the unsubstituted aliphatic group and aromatic group include a methyl group, an ethyl group, n
-Propyl group, n-butyl group, phenyl group, naphthyl group and the like.

W ₁ represents a counter ion when a counter ion is required to neutralize the charge. Whether a dye is a cation, an anion, or has a net ionic charge depends on its auxochrome and substituents. When the substituent has a dissociable group, it may dissociate and have a negative charge,
Also in this case, the charge of the whole molecule is neutralized by W ₁ . Typical cations are inorganic or organic ammonium ions (eg, tetraalkylammonium ions, pyridinium ions) and alkali metal ions,
On the other hand, the anion may specifically be either an inorganic anion or an organic anion, such as a halogen anion (for example, a fluoride ion, a chloride ion, a bromide ion, or an iodide ion), or a substituted aryl. Sulfonate ion (for example, p-toluenesulfonate ion, p-
Chlorobenzenesulfonic acid ion), aryldisulfonic acid ion (for example, 1,3-benzenedisulfonic acid ion, 1,5-naphthalenedisulfonic acid ion, 2,6
-Naphthalenedisulfonic acid ion), alkyl sulfate ion (for example, methyl sulfate ion), sulfate ion, thiocyanate ion, perchlorate ion, tetrafluoroborate ion, picrate ion, acetate ion, and trifluoromethanesulfonic acid ion. Can be

Further, an ionic polymer or another dye having a charge opposite to that of the dye may be used as the charge balancing counter ion, or a metal complex ion (for example, bisbenzene-
1,2-Dithiolatonickel (III)) is also possible.

[0073]

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In the formula (V), D represents an aromatic group having at least four functional groups, and X ₁ and X ₂ each independently represent a sulfur atom, a selenium atom, CR ₆₃ R ₆₄ or CR ₆₅ ＣＲCR ₆₆ . Here, R _{63 to} R ₆₆ are each a hydrogen atom or an alkyl group. R ₆₁ and R ₆₂ each represent an alkyl group or an aromatic group, and P ₁ and P ₂ each independently represent a nonmetallic atom group necessary for forming a polymethine dye. W ₂ represents a counter ion when a counter ion is required to neutralize the charge.

The formula (V) will be described in more detail. In the formula (V), D represents at least a tetrafunctional or higher aromatic group. Examples of such aromatic groups include, as aromatic hydrocarbons from which these groups are derived, benzene, naphthalene,
Anthracene, phenanthrene and the like are mentioned, and the aromatic hetero ring is anthraquinone, carbazole, pyridine, quinoline, thiophene, furan, xanthene, thianthrene and the like, and these may have a substituent other than the connecting portion. . The aromatic group represented by D is preferably a group derived from an aromatic hydrocarbon, and more preferably a group derived from benzene or naphthalene.

X ₁ and X ₂ are preferably a sulfur atom or C
R ₆₃ R ₆₄ , most preferably CR ₆₃ R ₆₄ .

P ₁ and P ₂ each independently represent a group of nonmetallic atoms necessary for forming a polymethine dye. Although any methine dye can be formed by P ₁ and P ₂ , preferred examples include a cyanine dye, a merocyanine dye, a rhodocyanine dye, a trinuclear merocyanine dye, an allopolar dye, a hemicyanine dye, and a styryl dye. In this case, the cyanine dyes include those in which the substituent on the methine chain forming the dye forms a squarium ring or a croconium ring. For more information on these dyes, see
Heterocyclic Compounds-Cyanin by FM Harmer, Heterocyclic Compounds-Cyanin Soybeans and Related Compounds
e Dyes and Related Compounds), John Wiley & Sons, New York, London, 1964, D.M.
(DMSturmer), Heterocyclic Compounds-Special topi
cs in heterocyclic chemistry) ”, Chapters 18, 14
, 482-515, etc. The formulas of the cyanine dye, merocyanine dye and rhodocyanine dye are preferably those shown in (XI), (XII) and (XIII) of U.S. Pat. No. 5,340,694, Nos. 21 and 22. Further, a polymethine dye formed by P ₁ and P ₂ preferably has a squarylium ring in at least one of the methine chain portions, and more preferably has a squarylium ring in both.

R ₆₁ and R ₆₂ are an aromatic group or an aliphatic group, and these may have a substituent. The number of carbon atoms of the aromatic group is preferably 5 to 16, more preferably 5 to 6. The number of carbon atoms in the aliphatic group is preferably 1 to 10, more preferably 1 to 6. Examples of the unsubstituted aliphatic group and aromatic group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a phenyl group, and a naphthyl group.

In the formula (V), it is preferable that at least one of R ₆₁ , R ₆₂ , P ₁ and P ₂ has an acidic group. Here, the acidic group is a substituent having a dissociable proton, for example, carboxylic acid, phosphonic acid, sulfonic acid,
Boric acid and the like are preferable, and carboxylic acid is preferable.
Further, such an acidic group may be in a form of dissociating by releasing a proton. W ₂ has the same meaning as W _{1 in} formula (IV).

Preferred specific examples of the polymethine dyes represented by formulas (II) to (V) are shown below, but the present invention is not limited to these.

[0081]

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[0082]

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[0083]

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[0084]

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[0085]

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[0086]

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[0087]

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[0088]

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[0089]

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[0090]

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[0091]

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[0092]

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[0093]

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[0094]

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[0095]

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[0096]

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[0097]

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[0098]

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[0099]

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[0100]

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[0101]

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The compounds represented by the formulas (II) and (III) are described in FMHarmer, "Heterocyclic Compounds-Cyanine Soybean and
Related Compounds (Heterocyclic Compounds
-Cyanine Dyes and Related Compounds), John Wiley & Sons, Inc.- New York, London, 1964, DMSturmer, Heterocyclic Compounds-Special Topics. In Heterocyclic Compounds-Specia
l topics in heterocyclic chemistry), Chapter 18,
Section 14, Sections 482-515, John Willie
John Wiley & Sons, New York, London, 1977, "Rodd's Chemistry of Carbon Compounds"
Carbon Compounds) '' 2nd.Ed.vol.IV, partB, 1977
Published in Chapter 15, Chapters 369-422, Elsevier Science Public Company, Inc.
(Science Publishing Company Inc.), New York, UK Patent No. 1,077,611, and the like.

The synthesis of the compound represented by the formula (IV) used in the present invention is described in Dyes and Pigments, Vol. 21, 227 to 23.
This can be done by referring to the description of documents such as four pages. The synthesis of the compound represented by the formula (V) is described in Ukrainskii Khimich
eskii Zhurnal Vol. 40, No. 3, pp. 253-258, Dyes and
Pigments, Vol. 21, pp. 227 to 234, and descriptions of documents cited in these documents can be referred to.

The method of adsorbing the dye on the semiconductor fine particles can be carried out by immersing the working electrode containing the semiconductor particles which are well dried in the dye solution, or by applying the dye solution to the semiconductor fine particle layer and adsorbing it. . In the former case, a dipping method, a dipping method, a roller method, an air knife method, or the like can be used. In the case of the immersion method, the dye may be adsorbed at room temperature or may be heated and refluxed as described in JP-A-7-249790. As the latter application method,
There are a wire bar method, a slide hopper method, an extrusion method, a curtain method, a spin method, and a spray method. Examples of the printing method include letterpress, offset, gravure, and screen printing.

The solvent can be appropriately selected according to the solubility of the dye. For example, water, alcohols (methanol, ethanol, t-butanol, benzyl alcohol, etc.), nitriles (acetonitrile, propionitrile, 3-methoxypropionitrile, etc.), nitromethane, halogenated hydrocarbons (dichloromethane, dichloroethane, chloroform) , Chlorobenzene, etc.), ethers (diethyl ether, tetrahydrofuran, etc.), dimethyl sulfoxide, amides (N, N-dimethylformamide, N, N
-Dimethylacetamide, etc.), N-methylpyrrolidone,
1,3-dimethylimidazolidinone, 3-methyloxazolidinone, esters (ethyl acetate, butyl acetate, etc.), carbonates (diethyl carbonate, ethylene carbonate,
Propylene carbonate), ketones (acetone, 2-butanone, cyclohexanone, etc.), hydrocarbons (hexane, petroleum ether, benzene, toluene, etc.) and mixed solvents thereof.

As in the case of the formation of the semiconductor fine particle layer, the viscosity of the liquid is the same as in the formation of the semiconductor fine particle layer. In addition to the extrusion method for a high-viscosity liquid (for example, 0.01 to 500 Poise), various printing methods are used. A slide hopper method, a wire bar method, or a spin method is suitable, and a uniform film can be obtained.

As described above, the viscosity of the dye coating solution, the coating amount,
An application method may be appropriately selected according to parameters such as a support and a coating speed. The time required for dye adsorption after coating should be as short as possible in consideration of mass production.

Since the presence of unadsorbed dye causes disturbance of device performance, it is preferable to remove the dye by washing immediately after adsorption. It is preferable to perform cleaning with a polar solvent such as acetonitrile and an organic solvent such as an alcohol solvent using a wet cleaning tank. Further, in order to increase the amount of the adsorbed dye, it is preferable to perform the heat treatment before the adsorption. After the heat treatment, in order to avoid the adsorption of water on the surface of the semiconductor fine particles, it is also preferable to quickly adsorb the dye at 40 to 80 ° C. without returning to normal temperature.

The total amount of the dye used is preferably 0.01 to 100 mmol per 1 m ² of the support. The amount of the dye adsorbed on the semiconductor fine particles is preferably 0.01 to 1 mmol per 1 g of the semiconductor fine particles. With such an amount of the dye, a sensitizing effect in the semiconductor can be sufficiently obtained. On the other hand, if the amount of the dye is small, the sensitizing effect becomes insufficient, and if the amount of the dye is too large, the dye not adhering to the semiconductor floats and causes a reduction in the sensitizing effect.

For the purpose of accelerating the removal of excess dye, the surface of the semiconductor fine particles may be treated with an amine after adsorbing the dye. Preferred amines include pyridine, 4-tert-butylpyridine, polyvinylpyridine and the like. When these are liquids, they may be used as they are or may be used by dissolving them in an organic solvent.

Hereinafter, the charge transfer layer and the counter electrode will be described in detail. The charge transfer layer is a layer having a function of replenishing an oxidized dye with electrons. Examples of typical charge transfer layers that can be used in the present invention include a liquid in which a redox couple is dissolved in an organic solvent (electrolyte solution) and a so-called gel in which a liquid in which a redox couple is dissolved in an organic solvent is impregnated in a polymer matrix. Examples of the electrolyte include an electrolyte and a molten salt containing a redox couple.
Further, a solid electrolyte or a hole transporting material can be used.

The electrolyte used in the present invention comprises an electrolyte, a solvent,
And additives. The electrolyte of the present invention is a combination of I ₂ and iodide (for the iodide, a metal iodide such as LiI, NaI, KI, CsI, or CaI ₂ , or a tetraalkylammonium iodide, pyridinium iodide, imidazolium iodide or the like). Iodine salts of secondary ammonium compounds), B
Combination of r ₂ and bromide (bromide is LiBr,
NaBr, KBr, CsBr, metal bromide such as CaBr _2, or tetraalkylammonium bromide, pyridinium bromine salts of di-bromide and quaternary ammonium compounds). In addition, ferrocyanate - ferricyanide or ferrocene - ferricinium ion such as Metal complex, sodium polysulfide, sulfur compounds such as alkylthiol-alkyldisulfide, viologen dyes, hydroquinone-quinone, and the like.
Among them, an electrolyte in which I ₂ is combined with LiI, an iodine salt of a quaternary ammonium compound such as pyridinium iodide, imidazolium iodide, or the like is preferable in the present invention.
The above-mentioned electrolytes may be used as a mixture. The electrolyte is EP-718288, WO95 / 18456, J. Electrochem.Soc.,
Vol.143, No. 10, 3099 (1996), Inorg. Chem. 1996, 35, 11
A salt in a molten state at room temperature (molten salt) described in 68-1178 can also be used. When a molten salt is used as an electrolyte, a solvent need not be used.

The preferred electrolyte concentration is 0.1 M or more and 15 M or less, more preferably 0.2 M or more and 10 M or less. In addition, when iodine is added to the electrolyte, the preferable concentration of iodine is 0.01M or more and 0.5M or less.

The solvent used for the electrolyte in the present invention is a compound capable of exhibiting excellent ionic conductivity by lowering the viscosity and improving the ionic mobility or increasing the dielectric constant and improving the effective carrier concentration. Desirably. Examples of such a solvent include carbonate compounds such as ethylene carbonate and propylene carbonate, 3-methyl-
Heterocyclic compounds such as 2-oxazolidinone, dioxane, ether compounds such as diethyl ether, ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, chain ethers such as polypropylene glycol dialkyl ether, methanol, ethanol,
Alcohols such as ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl ether, and polypropylene glycol monoalkyl ether; polyhydric alcohols such as ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, and glycerin; acetonitrile; Nitrile compounds such as glutaronitrile, methoxyacetonitrile, propionitrile, and benzonitrile; aprotic polar substances such as dimethylsulfoxide (DMSO) and sulfolane; and water can be used.

Further, in the present invention, J. Am. Ceram. Soc.,
80 (12) 3157-3171 (1997), ter-butylpyridine, and basic compounds such as 2-picoline and 2,6-lutidine can also be added. The preferred concentration range when adding a basic compound is 0.05M or more and 2M or less.

In the present invention, the electrolyte may be gelled (solidified) by a method such as addition of a polymer, addition of an oil gelling agent, polymerization containing a polyfunctional monomer, and crosslinking reaction of the polymer. When gelling by adding a polymer, use the Polymer Electrolyte Review-1 and 2
(Co-edited by JR MacCallum and CA Vincent, ELSEVIER APPLI
Compounds described in ED SCIENCE) can be used, and particularly, polyacrylonitrile and polyvinylidene fluoride can be preferably used. When gelling by adding an oil gelling agent, use J. Chem Soc. Japan, Ind.
Chem.Sec., 46,779 (1943), J. Am. Chem. Soc., 111,5
542 (1989), J. Chem. Soc., Chem. Commun., 1993, 39
0, Angew. Chem. Int. Ed. Engl., 35, 1949 (1996), Che
m. Lett., 1996, 885, J. Chm. Soc., Chem. Commun., 1
Although the compounds described in 997,545 can be used, preferred compounds are compounds having an amide structure in the molecular structure.

When the gel electrolyte is formed by polymerization of polyfunctional monomers, a solution is prepared from the polyfunctional monomers, a polymerization initiator, an electrolyte, and a solvent, and the solution is prepared by a method such as a casting method, a coating method, a dipping method, or an impregnation method. A method in which a sol-like electrolyte layer is formed on an electrode supporting a dye and then gelled by radical polymerization is preferable. The polyfunctional monomer is preferably a compound having two or more ethylenically unsaturated groups, for example, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and triethylene glycol dimethacrylate. Ethylene glycol diacrylate, triethylene glycol dimethacrylate,
Preferred examples include pentaerythritol triacrylate and trimethylolpropane triacrylate. The monomers constituting the gel electrolyte may include a monofunctional monomer in addition to the above, and may include acrylic acid or α-
Esters or amides derived from alkylacrylic acids (such as methacrylic acid) (such as Nis
o-propylacrylamide, acrylamide, 2-acrylamide-2-methylpropanesulfonic acid, acrylamidopropyltrimethylammonium chloride,
Methyl acrylate, hydroxyethyl acrylate,
n-propyl acrylate, n-butyl acrylate,
2-methoxyethyl acrylate, cyclohexyl acrylate, etc.), vinyl esters (eg, vinyl acetate), esters derived from maleic acid or fumaric acid (eg, dimethyl maleate, dibutyl maleate, diethyl fumarate, etc.), maleic acid, Fumaric acid,
p-styrenesulfonic acid sodium salt, acrylonitrile, methacrylonitrile, dienes (eg, butadiene, cyclopentadiene, isoprene), aromatic vinyl compound (eg, styrene, p-chlorostyrene, sodium styrenesulfonate), nitrogen-containing heterocycle A vinyl compound having a quaternary ammonium salt,
N-vinylformamide, N-vinyl-N-methylformamide, vinyl sulfonic acid, sodium vinyl sulfonate, vinylidene fluoride, vinylidene chloride, vinyl alkyl ethers (eg, methyl vinyl ether), ethylene, propylene, 1-butene, isobutene, N-phenylmaleimide and the like can be preferably used. The preferred weight composition range of the polyfunctional monomer in the total amount of the monomers is preferably from 0.5% by weight to 70% by weight, more preferably from 1.0% by weight to 50% by weight.
% By weight or less.

The above-mentioned monomers are generally described in Takatsu Otsu and Masayoshi Kinoshita: Experimental Methods for Polymer Synthesis (Chemical Doujin) and Takatsu Otsu: Lecture Polymerization Reaction Theory 1 Radical Polymerization (I) (Chemical Doujin) It can be polymerized by radical polymerization, which is a simple polymer synthesis method. The monomer for a gel electrolyte that can be used in the present invention can be radically polymerized by heating, light, electron beam, or electrochemically, but it is particularly preferable to radically polymerize by heating. The polymerization initiator preferably used when the crosslinked polymer is formed by heating,
For example, 2,2'-azobis (isobutyronitrile),
Azo initiators such as 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate), peroxide initiators such as benzoyl peroxide, etc. It is. The preferable addition amount of the polymerization initiator is 0.01% by weight or more based on the total amount of the monomers.
0% by weight or less, more preferably 0.1% by weight or more and 10% by weight or less.

The weight composition range of the monomers in the gel electrolyte is preferably 0.5% by weight or more and 70% by weight or less, more preferably 1.0% by weight or more and 50% by weight or less.

When the electrolyte is gelled by a crosslinking reaction of the polymer, it is desirable to use a polymer having a crosslinkable reactive group and a crosslinking agent together. In this case, a preferable crosslinkable reactive group is a nitrogen-containing heterocyclic ring (for example, a pyridine ring, an imidazole ring, a thiazole ring, an oxazole ring, a triazole ring, a morpholine ring, a piperidine ring, a piperazine ring, etc.), and a preferable crosslinking agent. Is a bifunctional or higher functional reagent capable of electrophilic reaction with a nitrogen atom (for example, alkyl halide, aralkyl halide, sulfonic acid ester, acid anhydride, acid chloride, isocyanate, etc.).

In the present invention, an organic or organic material is used instead of the electrolyte.
Use a hole transport material that is inorganic or a combination of both.
Can be used. Organic hole transport applicable to the present invention
Materials include N, N'-diphenyl-N, N'-bis (4-meth
(Xyphenyl)-(1,1'-biphenyl) -4,4'-diamine
(J. Hagen et al., Synthetic Metal 89 (1997) 215-22
0), 2,2 ', 7,7'-tetrakis (N, N-di-p-methoxyphenyl)
Ruamine) 9,9'-spirobifluorene (Nature, Vol. 395,
 8 Oct. 1998, p583-585 and WO97 / 10617), 1,1-bis
{4- (di-p-tolylamino) phenyl} cyclohexane
Aromatic Diamine Linked with Tertiary Aromatic Amine Unit
Compound (JP-A-59-194393), 4,4-bis
[(N-1-naphthyl) -N-phenylamino] biphenyl
Condensation of two or more containing two or more tertiary amines represented
Aromatic amine having an aromatic ring substituted by a nitrogen atom
-234681), a derivative of triphenylbenzene
Aromatic triamine having terburst structure (US Patent
No. 4,923,774, JP-A-4-308688), N, N'-di
Phenyl-N, N'-bis (3-methylphenyl)-(1,1'-bi
Aromatic diamines such as phenyl) -4,4'-diamine (US
Patent No. 4,764,625), α, α, α ′, α′-tetramethy
-Α, α'-bis (4-di-p-tolylaminophenyl) -p-
Xylene (JP-A-3-269084), p-phenylene
Amine derivatives, sterically asymmetric trif as a whole molecule
Phenylamine derivatives (JP-A-4-129271),
Compounds in which a plurality of aromatic diamino groups are substituted for a benzyl group (particularly
JP-A-4-175395), tertiary aromatic amine with ethylene group
Unit-linked aromatic diamine (JP-A-4-264189)
Japanese Patent Application Laid-Open (JP-A) No. 6-64, and aromatic diamine having a styryl structure
JP-A-4-290851), benzylphenyl compounds (JP-A
JP-A-4-364153), connecting a tertiary amine with a fluorene group
(JP-A-5-25473), triamine compound
(JP-A-5-239455), pisdipyridylaminobi
Phenyl (JP-A-5-320634), N, N, N-trif
Phenylamine derivatives (JP-A-6-1972), phenoamines
Aromatic diamine having a xazazine structure (Japanese Patent Application Laid-Open No. 7-138562)
No.), diaminophenylphenanthridine derivative (JP-A
Aromatic amines, α-octane shown in
Tilthiophene and α, ω-dihexyl-α-octylchi
Offen (Adv. Mater. 1997, 9, N0.7, p557), hexadode
Sild decithiophene (Angew. Chem. Int. Ed. Engl. 1
995, 34, No. 3, p303-307), 2,8-dihexylanthra [2,
3-b: 6,7-b '] dithiophene (JACS, Vol120, N0.4,1998, p66
Oligothiophene compounds such as 4-672), polypyrrole (K.
 Murakoshi et al.,; Chem. Lett. 1997, p471), ¨ Ha
ndbook of Organic Conductive Molecules and Polymer
s Vol.1,2,3,4¨ (by NALWA, published by WILEY)
Polyacetylene and its derivatives, poly (p-phenylene)
Len) and its derivatives, poly (p-phenylene vinylene)
And its derivatives, polythienylenevinylene and
Derivatives, polythiophenes and their derivatives, polya
Nirin and its derivatives, polytoluidine and its derivatives
Conductive polymers such as conductors can be preferably used
You. In addition, Nature, Vo
l. 395, 8 Oct. 1998, as described in p583-585
Tris (4) to control dopant level
-Bromophenyl) aminium hexachloroantimonate
Addition of compounds containing cation radicals such as salts
Control of the oxide semiconductor surface
Li [(CF _ThreeSO_Two)_TwoN]
It may be added.

The organic hole transporting material can be introduced into the inside of the electrode by a method such as a vacuum evaporation method, a casting method, a coating method, a spin coating method, an immersion method, an electrolytic polymerization method, and a photoelectrolytic polymerization method. When a hole transport material is used in place of the electrolyte, it is used to prevent a short circuit. Electorochim. Acta 40, 643-652
(1995), it is preferable to apply a thin layer of titanium dioxide as an undercoat layer using a technique such as spray pyrolysis.

When an inorganic solid compound is used instead of the electrolyte, copper iodide (p-CuI) (J. Phys. D: Appl. Phys. 31
(1998) 1492-1496), copper thiocyanate (Thin Solid Film)
s 261 (1995) 307-310, J. Appl. Phys. 80 (8), 15 Octobe
r 1996, p4749-4754, Chem. Mater. 1998, 10, 1501-150.
9, Semicond. Sci. Technol. 10, 1689-1693) can be introduced into the inside of the electrode by a method such as a casting method, a coating method, a spin coating method, a dipping method, and an electrolytic plating method.

There are two methods for forming the charge transfer layer. One is a method in which a counter electrode is first stuck on a semiconductor fine particle-containing layer carrying a sensitizing dye, and a liquid charge transfer layer is sandwiched in the gap. Another one
One is to apply the charge transfer layer directly on the semiconductor fine particle-containing layer, and the counter electrode is applied thereafter.

As the method of sandwiching the charge transfer layer in the former case, a normal pressure process utilizing a capillary phenomenon by immersion or the like and a vacuum process of replacing the gas phase with a liquid phase at a pressure lower than normal pressure can be used.

In the latter case, the wet charge transfer layer is provided with a counter electrode in an undried state, and measures are taken to prevent liquid leakage at the edge. In the case of a gel electrolyte, there is also a method of applying it by a wet method and solidifying it by a method such as polymerization. In this case, a counter electrode can be provided after drying and fixing. As a method for applying a wet organic hole transport material or a gel electrolyte in addition to the electrolytic solution, the immersion method, the roller method, the dipping method, the air knife method, the extrusion method, and the slide method are the same as the method for applying the semiconductor fine particle-containing layer and the dye. A hopper method, a wire bar method, a spin method, a spray method, a casting method, various printing methods and the like can be considered. In the case of a solid electrolyte or a solid hole (hole) transport material, the charge transfer layer can be formed by a dry film forming process such as a vacuum evaporation method or a CVD method, and then a counter electrode can be provided.

In consideration of mass production, in the case of an electrolyte that cannot be solidified or a wet hole transport material, it is possible to cope by sealing the edge portion immediately after coating, but it is possible to solidify the material. In the case of a hole transport material, it is more preferable to solidify the layer by a method such as photopolymerization or thermal radical polymerization after forming the hole transport layer by wet application. As described above, the film application method may be appropriately selected depending on the physical properties of the liquid and the process conditions.

The water content in the charge transfer layer was 10,
2,000 ppm or less, more preferably 2,0 ppm
It is at most 00 ppm, particularly preferably at most 100 ppm.

The counter electrode functions as a positive electrode of the photoelectrochemical cell when the photoelectric conversion element is a photoelectrochemical cell. As the counter electrode, a support having a conductive layer can be used as in the case of the above-described conductive support. However, the support is not necessarily required in a configuration in which the strength and the sealing property are sufficiently maintained. Specifically, as the conductive material used for the counter electrode, a metal (for example, platinum, gold, silver, copper, aluminum, rhodium,
Indium, etc.), carbon, or a conductive metal oxide (indium-tin composite oxide, tin oxide doped with fluorine, or the like). The thickness of the counter electrode is not particularly limited, but is preferably 3 nm or more and 10 μm or less. If it is a metal material, its thickness is preferably 5 μm.
m, more preferably 5 nm or more and 3 μm or less.

For light to reach the photosensitive layer, at least one of the conductive support and the counter electrode must be substantially transparent. In the photoelectrochemical cell of the present invention,
It is preferable that the conductive support is transparent and sunlight is incident from the support side. In this case, it is more preferable that the counter electrode has a property of reflecting light. In the present invention, as the counter electrode, glass or plastic on which a metal or a conductive oxide is deposited, or a metal thin film can be used.

As described in the application of the charge transfer layer, there are two types of application of the counter electrode, that is, the application on the charge transfer layer and the application on the semiconductor fine particle containing layer first. In either case, depending on the type of counter electrode material and the type of charge transfer layer,
The counter electrode material can be appropriately formed on the charge transfer layer or the semiconductor fine particle-containing layer by a method such as coating, laminating, vapor deposition, or bonding. For example, in the case of attaching a counter electrode, a substrate provided as a conductive layer can be attached by a method such as application, evaporation, or CVD of the above conductive material. When the charge transfer layer is solid, the above-mentioned conductive material is directly applied thereon, plated, PVD, CV
The counter electrode can be formed by a technique such as D.

Further, it is also possible to provide a layer having other necessary functions such as a protective layer and an antireflection film on the conductive support or the counter electrode of the working electrode. When such layers are separated in function by multiple layers, simultaneous multilayer coating or sequential coating can be performed, but simultaneous multilayer coating is more preferable in terms of productivity. In the simultaneous multi-layer coating, the slide hopper method and the extrusion method are suitable in consideration of productivity and uniformity of film formation. In addition, these functional layers can be provided by a technique such as vapor deposition or pasting depending on the material.

In the photoelectrochemical cell of the present invention, it is preferable to seal the side surface of the cell with a polymer, an adhesive or the like in order to prevent deterioration of components and volatilization of contents.

Next, a cell structure and a module structure when the photoelectric conversion element of the present invention is applied to a so-called solar cell will be described.

The structure inside the cell of the dye-sensitized solar cell is as follows:
It is basically the same as the above-mentioned photoelectric conversion element or photoelectrochemical cell, but various forms are possible according to the purpose as shown in FIG. 2 or FIG. When roughly divided into two, a structure that allows light to enter from both sides [FIGS. 2 (a) and (d), FIG.
(G)] and a type that can be used only from one side [FIG. 2 (b)
(C) and FIGS. 3 (e) (f) (h)].

FIG. 2A shows a dye-adsorbed TiO ₂ layer 10 which is a layer containing dye-adsorbed semiconductor fine particles between transparent conductive layers 12.
And the charge transfer layer 11. FIG.
(B), a metal lead 9 is partially provided on a transparent substrate 13;
Further, a transparent conductive layer 12 is provided, an undercoat layer 14, a dye-adsorbed TiO ₂ layer 10, a charge transfer layer 11 and a metal layer 8 are provided in this order, and a support substrate 15 is further provided.
FIG. 2 (c) shows that a metal layer 8 is further provided on a support substrate 15, a dye-adsorbed TiO ₂ layer 10 is provided via an undercoat layer 14, and a charge transfer layer 11 and a transparent conductive layer 12 are further provided.
This is a structure in which a transparent substrate 13 partially provided with a metal lead 9 is arranged with the metal lead 9 side inside. FIG. 2 (d)
Has a structure in which a metal lead 9 is partially provided on a transparent substrate 13, and an undercoat layer 14, a dye-adsorbed TiO ₂ layer 10, and a charge transfer layer 11 are interposed between a transparent conductive layer 12 and a transparent conductive layer 12. FIG. 3 (e) has a transparent conductive layer 12 on a transparent substrate 13, a dye-adsorbed TiO ₂ layer 10 is provided via an undercoat layer 14, and a charge transfer layer 11 and a metal layer 8 are further provided thereon. This is a structure in which a support substrate 15 is arranged. FIG.
(F) has a metal layer 8 on a support substrate 15, a dye-adsorbed TiO ₂ layer 10 is provided via an undercoat layer 14, a charge transfer layer 11 and a transparent conductive layer 12 are further provided, and a transparent substrate 13 is arranged. FIG. 3 (g) shows a transparent conductive layer 1 between transparent substrates 13 having a transparent conductive layer 12.
2 on the inside, the undercoat layer 14, the dye-adsorbed TiO ₂ layer 1
0 and the charge transfer layer 11 are interposed. FIG.
(H), a metal layer 8 is provided on a support substrate 15, a dye-adsorbed TiO ₂ layer 10 is provided via an undercoat layer 14, a solid charge transfer layer 16 is further provided, and a part of the metal layer 8 or This is a structure having metal leads 9.

The module structure of the dye-sensitized solar cell of the present invention can have basically the same structure as a conventional solar cell module. Generally, a cell is formed on a supporting substrate such as a metal or ceramic, and the cell is covered with a filling resin or a protective glass or the like, and light can be taken in from the opposite side of the supporting substrate. It is also possible to use a transparent material such as tempered glass for the substrate, form a cell thereon, and take in light from the transparent support substrate side. Specifically, a module structure called a superstrate type, a substrate type, or a potting type, or a module structure such as an integrated substrate type used in an amorphous silicon solar cell or the like is possible. These module structures can be appropriately selected depending on the purpose of use and the place of use (environment). FIG. 4 shows an example in which the element of the present invention is formed into a module with an integrated substrate.

The structure shown in FIG. 4 has a transparent conductive layer 12 on one surface of a transparent substrate 13, on which a dye-adsorbed Ti
A cell provided with an O ₂ layer 10, a solid charge transfer layer 16 and a metal layer 8 is modularized and comprises a transparent substrate 13.
An anti-reflection layer 17 is provided on the other surface. In this case, in order to increase the utilization efficiency of incident light, it is preferable to increase the area ratio of the dye-adsorbed TiO ₂ layer 10 as the photosensitive portion (the area ratio when viewed from the transparent substrate 13 side which is the light incident surface). preferable.

In a typical structure of a superstrate type or a substrate type, cells are arranged at a fixed interval between supporting substrates which are transparent on one or both sides and have been subjected to an anti-reflection treatment, and metal leads or adjacent cells are provided between adjacent cells. They are connected by a flexible wiring or the like, and have a structure in which current collecting electrodes are arranged on the outer edge to take out generated power to the outside. Various types of plastic materials such as ethylene vinyl acetate (EVA) can be used between the substrate and the cell in the form of a film or a filling resin, depending on the purpose, in order to protect the cell and increase current collection efficiency. When using in places where it is not necessary to cover the surface with a hard material, such as places where there is little external impact, make the surface protective layer a transparent plastic film or cure the above-mentioned filling and sealing material. It is also possible to provide a protection function and eliminate the support substrate on one side. The periphery of the support substrate is fixed in a sandwich shape with a metal frame in order to seal the inside and ensure the rigidity of the module, and the space between the support substrate and the frame is hermetically sealed with a sealing material.

If a flexible material is used for the cell itself, the support substrate, the filler and the sealing member, a solar cell can be formed on a curved surface. In this way, solar cells having various shapes and functions according to the purpose of use and environment of use can be manufactured.

A super-straight type solar cell module is, for example, a method in which a front substrate sent out from a substrate supply device is conveyed by a belt conveyor or the like, and a cell is placed thereon with a sealing material, an inter-cell connection lead wire, and a back surface sealing. After laminating sequentially with materials and the like, a back substrate or a back cover can be placed, and a frame can be set on the outer edge to make it.

On the other hand, in the case of the substrate type, while the support substrate sent out from the substrate supply device is conveyed by a belt conveyor or the like, the cells are sequentially laminated thereon with the lead wires for cell connection, the sealing material, and the like. It can be manufactured by placing a front cover and setting a frame on the periphery.

In the module having the structure shown in FIG. 4, selective plating, selective etching, and CVD are performed so that a transparent electrode, a photosensitive layer, a charge transfer layer, a back surface electrode, and the like are arranged three-dimensionally at regular intervals on a supporting substrate.・ Laser scribing or plasma CVM (Solar Ener) after semiconductor process technology such as PVD, or pattern application or wide application
gy Materials and Solar Cells, 48, p373-381) or a mechanical method such as grinding or the like, and a desired module structure can be obtained.

Hereinafter, other members and steps will be described in detail. Examples of the sealing material include liquid EVA (ethylene vinyl acetate), a mixture of a vinylidene fluoride copolymer and an acrylic resin, and a film-like EVA, which provide weather resistance, electric insulation, light collection efficiency, and cell protection. Various materials can be used according to the purpose of (impact resistance) improvement and the like.

These are fixed on the cell according to the physical properties of the sealing material. For film-like materials, heat contact after roll pressing or heat contact after vacuum pressing, or for liquid or paste-like materials, There are various methods such as coating, bar coating, spray coating, screen printing and the like.

In addition, a transparent filler can be mixed into the sealing material to increase the strength and the light transmittance.

The space between the outer edge of the module and the frame surrounding the peripheral edge is preferably sealed with a resin having high weather resistance and moisture resistance.

When a flexible material such as PET or PEN is used as the support substrate, a roll-shaped support is drawn out to form cells thereon, and then the sealing layer is continuously laminated by the above-described method. And a highly productive process can be made.

In order to increase the power generation efficiency, the surface of the substrate (generally tempered glass) on the light intake side of the module is subjected to an anti-reflection treatment. This includes a method of laminating an antireflection film and a method of coating an antireflection layer.

Further, by treating the surface of the cell by a method such as grooving or texturing, it is possible to increase the utilization efficiency of incident light.

In order to increase the power generation efficiency, it is most important that the light is taken into the module without loss. However, the light that has passed through the photoelectric conversion layer and reached the inside thereof is reflected and efficiently returned to the photoelectric conversion layer side. It is also important. For this purpose, after mirror-polishing the surface of the supporting substrate, a method of depositing or plating Ag or Al or the like, a method of providing an alloy layer such as Al-Mg or Al-Ti as a reflective layer on the lowermost layer of the cell,
Alternatively, there is a method in which a texture structure is formed in the lowermost layer by annealing to increase the reflectance.

In order to increase the power generation efficiency, it is important to reduce the connection resistance between cells in order to suppress the internal voltage drop.

Although connection is generally made by wire bonding or a conductive flexible sheet, a method of using a conductive pressure-sensitive adhesive tape or conductive adhesive to have both a cell fixing function and an electrical connection function, a conductive hot melt Is applied to a desired position in a pattern.

In the case of a solar cell using a flexible support such as a polymer film, the cells are sequentially formed and cut into a desired size by the method described in the description of the coating of the semiconductor while feeding the roll-shaped support. In addition, the periphery can be sealed with a flexible and moisture-proof material to produce a battery body. Also, Solar Energy Materials andSo
LAR Cells, 48, p383-391, and a module structure called “SCAF” can also be used.

In the case of a solar cell having a flexible support, it can be further used by bonding it to a curved glass or the like.

[0156]

The present invention will be specifically described below with reference to examples showing comparative examples. Dyes used in Examples and Comparative Examples are as shown below.

[0157]

Embedded image

[Example 1] 1. Preparation of Titanium Dioxide Dispersion Titanium dioxide (Nippon Aerosil Co., Ltd.)
Degussa P-25) 15 g, water 45 g, dispersant (Triton X-100, manufactured by Aldrich) 1
g of zirconia beads having a diameter of 0.5 mm (manufactured by Nikkato Co., Ltd.), and dispersed for 2 hours at 1500 rpm using a sand grinder mill (manufactured by Imex). The zirconia beads were removed by filtration from the dispersion. In this case, the average particle size of the titanium dioxide was 2.5 μm. The particle size at this time was measured with a master sizer manufactured by MALVERN.

[0159] 2. Preparation of TiO ₂ electrode adsorbing dyes Conductive glass coated with fluorine-doped tin oxide (TCO glass-U manufactured by Asahi Glass Co., Ltd. cut into a size of 20 mm x 20 mm) using a glass rod on the conductive surface side To apply the above dispersion. At this time, adhesive tape is applied to a part (3 mm from the end) on the conductive surface side as a spacer,
Arrange the glass so that the adhesive tape is
It was applied one by one. After application, the adhesive tape was peeled off and air-dried at room temperature for one day. Next, this glass was placed in an electric furnace (muffle furnace FP-32 manufactured by Yamato Scientific Co., Ltd.) and heated at 450 ° C. for 3 hours.
After baking for 0 minutes, a TiO ₂ electrode was obtained. Using this electrode, a dye-adsorbing electrode was prepared by the following two methods. (Method 1) After taking out the electrode and cooling, a solution of the dye and the ester compound of the present invention in DMSO / ethanol (volume ratio 2.5 / 97.5) (dye: 1 × 10 ^−4).
Mol / l) for 15 hours. (Method 2) After taking out the electrode and cooling, the dye was DM
It was immersed in a solution (dye: 1 × 10 ⁻⁴ mol / l) dissolved in SO / ethanol (volume ratio 2.5 / 97.5) for 15 hours. Then, DMSO / ethanol (volume ratio 2.
5 / 97.5) to the ester compound of the present invention (10 mM)
Was immersed in the solution to which was added. Thereafter, the TiO ₂ electrode on which the dye was dyed was immersed in 4-tert-butylpyridine for 15 minutes, washed with ethanol, and air-dried. The thickness of the photosensitive layer thus obtained was 10 μm, and the coating amount of the semiconductor fine particles was 20 g / m ² . The surface resistance of the conductive glass was about 30Ω / □. Table 1 shows combinations of dyes, ester compounds, addition methods, and addition amounts (in the case of Method 1, represented by a molar ratio to the dye) used in the manufactured electrode. Comparative batteries 1 and 2 shown in Table 1 were produced in the same manner as in Example except that no ester compound was used.

[0160] 3. Preparation of Photoelectrochemical Cell The color-sensitized TiO ₂ electrode substrate (2 cm × 2 cm) prepared as described above was overlaid with platinum-deposited glass of the same size. Next, an electrolytic solution (i.e., 0.65 mol / liter of 1-methyl-3-hexylimidazolium iodide as an electrolyte in methoxypropionitrile and 0.05 mol / liter of iodine was used as an electrolyte in the gap between the two glasses by using capillary action). Was added to the mixture and introduced into a TiO ₂ electrode to obtain a photoelectrochemical cell. According to this embodiment, FIG.
As shown in the figure, a conductive glass 1 (having a conductive agent layer 2 provided on the glass), a TiO ₂ layer 3, a dye layer 4, an electrolytic solution 5, a platinum layer 6, and a glass 7 are laminated in this order to obtain an epoxy-based resin. A photoelectrochemical cell sealed with a sealant was produced.

4. Measurement of Photoelectric Conversion Efficiency The photoelectric conversion efficiency of the photoelectric conversion element of the present invention was measured as follows. A 500 W xenon lamp (Ushio) is used to filter the light through a spectral filter (Oriel A).
M1.5) and sharp cut filter (Kenko)
L-42) to generate simulated sunlight containing no ultraviolet light. The intensity of this light was 86 mW / cm ² . The fabricated photoelectrochemical cell is irradiated with simulated sunlight,
The generated electricity is measured by a current-voltage measuring device (Keisley SMU23
8). Table 1 shows the conversion efficiency (η) of the photoelectrochemical cell thus obtained.

[0162]

[Table 1]

[0163]

According to the present invention, a photoelectric conversion element and a photoelectrochemical cell having excellent photoelectric conversion efficiency can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a photoelectrochemical cell prepared in an example.

FIG. 2 is a cross-sectional view showing a basic configuration example of a photoelectrochemical cell.

FIG. 3 is a cross-sectional view illustrating a basic configuration example of a photoelectrochemical cell.

FIG. 4 is a cross-sectional view showing an example of a module configuration of a substrate integrated type.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 conductive glass 2 conductive agent layer 3 TiO ₂ layer 4 dye layer 5 electrolytic solution 6 platinum layer 7 glass 8 metal layer 9 metal lead 10 dye-adsorbed TiO ₂ layer 11 charge transfer layer 12 transparent conductive layer 13 transparent substrate 14 undercoat layer 15 Support substrate 16 Solid charge transfer layer 17 Antireflection layer

Continued on the front page (72) Inventor Masaki Okazaki 210 Nakanakanuma, Minamiashigara-shi, Kanagawa Prefecture Fuji Photo Film Co., Ltd. F-term (reference) 5F051 AA14 5H032 AA06 AS16 BB00 BB05 EE02 EE16 EE17 HH00 HH01

Claims (14)

[Claims] 1. Semiconductor fine particles sensitized by a dye, wherein an ester compound is adsorbed on the semiconductor in addition to the dye. 2. The ester compound represented by the following general formula (A)
2. The semiconductor fine particles according to claim 1, which is a compound represented by the formula: Formula (A) R ¹ -LZR ² (W) (In Formula (A), R ¹ and R ² each independently represent an alkyl group, an alkenyl group, an alkynyl group, a cyclic aliphatic group,
Represents an aromatic group or a heterocyclic group, which may have a substituent or may be condensed, and R ¹ and R ² may be linked to form a ring. L represents a single bond or a divalent linking group. Z represents an ester bond, and (W) represents a counter ion necessary to neutralize the charge of the molecule. ) 3. In the general formula (A), R ¹ has 2 carbon atoms.
3. The semiconductor fine particles according to claim 2, wherein the substituted or unsubstituted alkyl group is 0 or less. 4. In the general formula (A), R ¹ has 2 carbon atoms.
3. The semiconductor fine particles according to claim 2, wherein the number of cyclic aliphatic groups is 5 or less. 5. In the general formula (A), R ¹ has ¹ carbon atom.
3. The semiconductor fine particles according to claim 2, wherein the number of the aromatic fine particles is 3 or less. 6. The method according to claim 2, wherein Z is an ester bond of a carboxylic acid, a sulfonic acid or a phosphonic acid.
Any one of the semiconductor fine particles according to any one of (1) to (5). 7. The semiconductor fine particles according to claim 1, wherein said dye is a dye selected from a ruthenium complex dye, a phthalocyanine dye and a polymethine dye. 8. The semiconductor fine particles according to claim 1, wherein said semiconductor fine particles are metal oxide fine particles. 9. The semiconductor fine particles according to claim 1, wherein said semiconductor fine particles are titanium dioxide. 10. A photoelectric conversion element using the semiconductor fine particles according to claim 1. 11. A method for producing semiconductor fine particles sensitized by a dye, comprising: a) a step of immersing the semiconductor fine particles in a solution in which an ester compound is present together with the dye; and b) adsorbing the dye to the semiconductor fine particles. A method of immersing the semiconductor fine particles in a solution containing an ester compound. 12. The method according to claim 11, wherein the ester compound is a compound represented by the following general formula (A). Formula (A) R ¹ -LZR ² (W) (In Formula (A), R ¹ and R ² each independently represent an alkyl group, an alkenyl group, an alkynyl group, a cyclic aliphatic group, or an aromatic group. A heterocyclic group or a heterocyclic group, which may have a substituent or may be condensed, and R ¹ and R ² may be linked to form a ring. Represents a divalent linking group, Z represents an ester bond, and (W) represents a counter ion necessary for neutralizing the charge of the molecule.) 13. The method according to claim 11, wherein the concentration of the ester compound in the solution in which the dye and the ester compound coexist is 1 to 1000 times in molar ratio with respect to the dye in the step of a). The method for producing semiconductor fine particles according to claim 11 or 12, wherein 14. The method according to claim 1, wherein in the step (b), the molar concentration of the ester compound in the immersion liquid containing the ester compound is 0.1 mM to 1M.
13. The method for producing semiconductor fine particles according to 1 or 12.