WO2007052681A1

WO2007052681A1 - Photoelectrochemical cell

Info

Publication number: WO2007052681A1
Application number: PCT/JP2006/321807
Authority: WO
Inventors: Kunihito Miyake
Original assignee: Sumitomo Chemical Company, Limited
Priority date: 2005-10-31
Filing date: 2006-10-25
Publication date: 2007-05-10

Abstract

Disclosed is a photoelectrochemical cell obtained by sealing a multilayer body, which includes a conductive substrate, semiconductor particles on which a photosensitizing dye is adsorbed, a charge transporting layer and a counter electrode, with a sealing agent. This photoelectrochemical cell is characterized in that the sealing agent contains a resin having a hydroxyl group.

Description

Technical details Photoelectrochemical cell technology field,

The present invention relates to a photoelectrochemical cell. Background art

Recently, reduction of C_〇 ₂ released into the atmosphere in order to prevent global warming is demanded. As an effective means of reducing C_〇 _2, for example, a solar using photoelectrochemical cell such as a silicon solar cell of the pn junction type can installed in the roof of the house -. System utilization promotion have been proposed. However, the single crystal, polycrystal and amorphous silicon used in the above silicon-based photoelectrochemical zero pond have a problem of high cost due to the necessity of high temperature and high vacuum conditions during the manufacturing process.

On the other hand, Nature (p. 7 37-740, '3 53 卷, .1 99.1) describes a photoelectric conversion in which a thin film of titanium oxide with a photosensitizing dye adsorbed on its surface is laminated on a conductive substrate. A photoelectrochemical cell including an element, a charge transfer layer, and a counter electrode has been proposed. Compared with conventional silicon-based solar cells, the photoelectrochemical cell can be manufactured at a lower cost because many of the materials used are cheaper and high temperature and high vacuum conditions are not required in the manufacturing process. Expected.

By the way, the charge transfer layer proposed in Nature (No. 7 37-740, pp. 3 53, 1 99 1) uses iodine, fluoride, etc. as an electrolyte, and uses acetonitrile as a solvent. If a long-term use is required, a sealant is used to prevent the charge transfer layer from volatilizing.

Also, in Nature material (2nd line from bottom left column on page 406, 2nd year, 2003), BYNEL (registered trademark, DuPont), an adhesive of polyethylene resin, is used as a sealant. The proposed photoelectrochemical cell has been proposed. The present inventors have provided a photoelectrochemical cell obtained using iodine / iodide as an electrolyte contained in a charge transfer layer, using acetonitrile as a solvent, and using the adhesive as a sealant. 8 When stored at 5T: Iodine disappeared, indicating that the durability was not sufficient. Disclosure of the invention

As a result of examining the sealant for photoelectrochemical cells, it was found that a photoelectrochemical cell obtained using a sealant containing a certain kind of resin is excellent in durability. An object of the present invention is to provide a photoelectrochemical cell excellent in durability. That is, the present invention provides the following [1] to [5].

[1]. In a photoelectrochemical cell in which a laminate including a conductive substrate, semiconductor fine particles adsorbed with a photosensitizing dye, a charge transfer layer and a counter electrode is sealed with a sealant, the sealant is a hydroxyl group A photoelectrochemical cell containing a resin comprising:

[2] The resin containing a hydroxyl group is at least one resin selected from the group consisting of an ethylene-vinyl alcohol copolymer, a partially saponified polyvinyl alcohol, and a fully saponified polypinyl alcohol. ] The photoelectrochemical cell described in [3] The photoelectrochemical cell according to [1] or [2], wherein the semiconductor fine particles are titanium oxide. '

[4] The photoelectrochemical cell according to any one of [1] to [3], wherein the charge transfer layer is a combination of ₁₂ and iodide. ,

[5]. Photoelectrochemical cell containing a resin containing at least one hydroxyl group selected from the group consisting of ethylene-vinyl alcohol copolymer, partially genated polyvinyl alcohol and fully saponified polyvinyl alcohol. ¾ Sealant. Brief Description of Drawings

FIG. 1 is a schematic cross-sectional view of wet photoelectrochemistry of the present invention.

[Explanation of symbols]

-1 Basics

2 Conductive layer

3 Semiconductor particle layer

4 Photosensitizing dye

5 Electrolyte

6 Conductive layer

7 Board

8 Conductive board

9 Counter electrode

1 0 Sealant Mode for carrying out the invention

Hereinafter, the present invention will be described in detail.

The photoelectrochemical cell of the present invention is a photoelectrochemical cell formed by sealing a laminate including a conductive substrate, semiconductor fine particles adsorbed with a photosensitizing dye, a charge transfer layer and a counter electrode with a sealant. It is.

In wet photoelectrochemical cells, an electrolyte is filled between a conductive substrate in contact with a layer of semiconductor fine particles adsorbed with a photosensitizing dye (hereinafter also referred to as a dye adsorbing semiconductor particle layer) and a counter electrode. Yes.

In dry photoelectrochemical cells, the conductive substrate and the counter electrode are stacked via a solid hole transport material, and the semi-fine particles adsorbed with the photosensitizing dye are solid hole transport materials. It is contained in. The wet photoelectrochemical cell of the present invention will be described below as an example. A specific example is shown in Fig. 1. A conductive substrate (8), a counter electrode (9) opposite to the conductive substrate (8), and a semiconductor fine particle layer (3) adsorbed with a photosensitizing dye (4) exist between them. To do. In the case of a wet photoelectrochemical cell, the semiconductor particle layer (3) (with the dye adsorbed) is filled with the electrolytic solution (5) and sealed with a sealing material (10).

The conductive substrate (8) is composed of a substrate (1) and a conductive layer (2) in order from the top. The counter electrode (9) consists of a substrate (7) and a conductive layer (6) in order from the bottom. The conductive substrate (8) used in the photoelectrochemical cell of the present invention and the conductive layer in the counter electrode (9) ((2) for the conductive substrate, (6) for the counter electrode) The lower the resistance, the better. In addition, the conductive layer (2) of the conductive substrate has a high transmittance in the high wavelength region, specifically, a region longer than 350 nm, specifically, a transmittance of 80% or more. It is preferable.

Examples of the conductive material used in the conductive layer include iron, nickel, chromium, titanium, aluminum, platinum, gold, silver, cobalt, palladium, .copper, tantalum, ruthenium, tungsten, zinc, tin, and the like; Metal alloy: Conductive metal oxide such as indium-muth tin complex oxide (ITO), tin oxide doped with fluorine: Conductivity such as carbon, polyethylene dioxythiophene (EDOT), poly'diphosphorus, etc. A functional polymer. The conductive polymer is usually doped with para-toluenesulfonic acid or the like.

Specific examples of the conductive layer include a conductive substance itself, or a non-conductive substrate, and a thin film of a conductive substance formed on the surface of the non-conductive substrate by vapor deposition, sputtering, adhesion, or the like. '.

The conductive substrate (8) preferably has a textured structure on the surface of the conductive material in order to confine incident light and use it effectively. Non-conductive substrate in conductive substrate (8) and counter electrode (9). (1) for conductive substrate and (7) for counter electrode include glass or plastic.

Plastics include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PP S), poly force—bonate (PC), polypropylene (PP), polyimide (PI), rear Cetylcellulose (TAC), Syndiotactic polystyrene (SPS), Polyarylate (PAR); Aton (registered trademark of JSR), Zeonex (■ registered trademark of Nippon Zeon), Zeonor (registered trademark of Nippon Zeon), Cyclic polyolefin (COP) such as Abel (registered trademark of Mitsui Chemicals) and Topas (registered trademark of T icona); Polyester monosulfone (PES), Polyether imide (P, EI), Polysulfone (PSF) And polyamide (PA). As the conductive substrate (8) and the counter electrode (9), glass or plastic coated with a conductive metal oxide is preferable. Among them, conductive glass with a conductive layer made of tin dioxide doped with fluorine and conductive film with a conductive layer made of indium-tin composite oxide (ITO) have low electrical resistance and light transmission. It is particularly preferable because of its excellent properties and availability. The semiconductor fine particles used in the present invention are fine particles having a semiconductor characteristic with a primary particle size of about 1 to 5000 nm, preferably about 5 to 500 nm. For the purpose of improving the photoelectric conversion efficiency by reflection, semiconductor fine particles having different primary particle diameters may be mixed. Tubes and hollow fine particles may be used. Examples of the material of the semiconductor fine particles (2) include titanium oxide, tin oxide, zinc oxide, iron oxide, tungsten oxide, zirconium oxide, hafnium oxide, strontium oxide, indium oxide, cerium oxide, yttrium oxide, lanthanum oxide, Metal oxides such as vanadium oxide, niobium oxide, tantalum oxide, gallium oxide, nickel oxide, strontium titanate, barium titanate, potassium niobate and sodium tantalite; Metal halides such as silver iodide, silver bromide, copper iodide, copper bromide, etc .; zinc sulfide, titanium sulfide, indium sulfide, bismuth sulfide, cadmium sulfide, zirconium sulfide, tantalum sulfide, molybdenum sulfide, silver sulfide, Metal sulfides such as copper sulfide, tin sulfide, sulfurized tungsten, and antimony sulfide;

Metal selenides such as cadmium selenide, zirconium selenide, zinc selenide, titanium selenide, indium selenide, tungsten selenide, molybdenum selenide, bismuth selenide, lead selenide;

Metal tellurides such as cadmium telluride, tungsten telluride, molybdenum telluride, zinc telluride, bismuth telluride;

Metal phosphides such as zinc phosphide, gallium phosphide, indium phosphide, cadmium phosphide;

Examples include gallium arsenide, copper indium monoselenide, copper indium monosulfide, silicon, germanium, and the like.

Further, it may be a mixture of two or more of zinc oxide, Z tin oxide, tin oxide, titanium oxide and the like.

Among them, titanium oxide, tin oxide, zinc oxide, iron oxide, tan oxide, gusten, zirconium oxide, hafnium oxide, strontium oxide, indium oxide, cerium oxide, yttrium oxide, lanthanum oxide, vanadium oxide, niobium oxide, oxide Metal oxides such as tantalum, gallium oxide, nickel iodide, strontium titanate, barium titanate, potassium niobate, sodium tantalate, zinc oxide / oxide, tin, tin oxide, titanium oxide, etc. are available at relatively low prices It is preferable because it is easy to absorb and the photosensitizing dye is easily adsorbed. Particularly, titanium oxide is suitable. On the surface of the semiconductor fine particles, chemical plating using a titanium tetrachloride aqueous solution or electrochemical using a titanium trichloride aqueous solution. You may perform a target treatment. As a result, the surface area of the semiconductor fine particles is increased, the purity in the vicinity of the semiconductor fine particles is increased, impurities such as iron existing on the surface of the conductive fine particles are obscured, or the connectivity and integrity of the semiconductor fine particles. Can be increased.

The semiconductor fine particles preferably have a large surface area so that many photosensitizing dyes can be adsorbed. Therefore, the surface area of the semiconductor fine particle (2) layer applied on the substrate is preferably 10 times or more, more preferably 100 times or more the projected area. This upper limit is usually around 100 times.

The layer of semiconductor fine particles (2) may be a single layer of semiconductor fine particles, but in the case of a wet photoelectrochemical cell, which is usually a layer composed of a plurality of semiconductor fine particles and a plurality of semiconductor fine particles having different particle diameters. After the semiconductor fine particle layer is formed on the conductive substrate, the photosensitizing dye is adsorbed on the fine particles of the layer.

As a method of forming a semiconductor fine particle layer on a conductive substrate, a method of directly forming a semiconductor fine particle as a thin film on a conductive substrate by spray spraying or the like; electrically depositing a semiconductor fine particle thin film using the conductive substrate as an electrode Examples of the method include: a method in which a slurry of semiconductor fine particles is applied on a conductive substrate and then dried, cured, or baked. The method for applying the semiconductor fine particle slurry onto the conductive substrate will be described in more detail. Examples thereof include a doctor blade, squeegee, spin coating, date coating, and screen printing. In these methods, the average particle diameter in the dispersed state of the semiconductor fine particles in the slurry is preferably 0, 0 1 nm to 100 m. ,

The dispersion medium for dispersing the slurry is not particularly limited as long as the semiconductor fine particles can be dispersed.Water, ethanol, isopropanol, t-butano.

-Alcohol solvents such as lujaterbineol; organic solvents such as ketone solvents such as aceton are used. These water and organic solvent may be a mixture. The dispersion includes a polymer such as polyethylene glycol; a surfactant such as T r i, t o n—X

An organic acid or an inorganic acid such as acetic acid, formic acid, nitric acid or hydrochloric acid; and a cleansing agent such as acetylacetone.

It is preferable to form a semiconductor fine particle layer by firing a conductive substrate coated with a slurry of semiconductor fine particles. The firing temperature is usually lower than the melting point of the conductive layer or substrate, and the upper limit of the firing temperature is 1200, preferably 600: or less. The firing time is usually within 10 hours. The thickness of the semiconductor fine particle layer on the conductive substrate is usually from 0.:! To 2 0 0, preferably :! ~ 50. Other methods for forming a semiconductor fine particle layer on a conductive substrate at a relatively low temperature include, for example, a hydrothermal method in which a porous semiconductor fine particle layer is formed by hydrothermal treatment (dye-sensitized photoelectric for practical use). Chemical Battery, 2nd Lecture (Hideki Kajiura), pages 6 3 to 65, published by NTS (2 0 0 3)), Electrophoretic electrodeposition method for electrodeposition of dispersed semiconductor particles on a dispersion liquid substrate ( T. Miyasaka et al., Ceni. Let t., 1250 (2002)), applying a semiconductor paste to a substrate, pressing it after drying (a dye-sensitized photoelectrochemical cell for practical use, No. 1 2 lectures (Takehiko Tsuji) 3 1 2-3 1 3 pages, published by NTS (2 0 3)). The photosensitizing dye used in the present invention has absorption in the visible light region and / or infrared light region, and various metal complexes can be used as one or more organic dyes. For photosensitizing dyes, photosensitizing dyes having functional groups such as force lpoxyl group, hydroxyalkyl group, hydroxyl S., sulfone group, force lpoxyalkyl group in the molecule tend to be adsorbed to semiconductors quickly. It is preferably used because of its presence. In addition, a metal complex is preferably used because of excellent photoelectric conversion efficiency and durability. Examples of the metal complex include copper phthalocyanine, metal phthalocyanine such as titanyl phthalocyanine, chlorophyll, hemin, and those described in JP-A No. 1 2 2 0 3 80 and JP-A-5-5 0 4 0 2 3 Ruthenium, osmium, iron, zinc complex, etc. can be used. A more detailed example of a ruthenium complex is c / s-bis (isothiocyanate) bis (2,2'-bibilidyl-4,4'-dicarboxylate) -ruthenium (II) bis-tetrabutyl Ammonium, bis (isothiocyanate) bis (2,2'-bibilyl-4,4'-dicarboxylate) -ruthenium (11), tris (isothiocyanate) monoruthenium (II)- 2, 2 ': 6', 2 "-Te-pyridine-4,4 ', 4" -tricarboxylic acid tristetratetramethyl ammonium, cis-bis (isothiocyanate) (2, 2'-bipyridyl-4 , 4'-dicarboxylate) (2,2'-bibilidyl-4,4'-dinonyl) ruteni Um (II). Examples of organic dyes include metal-free phthalocyanine, cyanine dyes, merocyanine dyes, xanthene dyes, triphenylmethane dyes, squalium dyes, and the like. :.

Specific examples of cyanine dyes include NK 1 1 94, .NK 342 2 (both manufactured by Nippon Photosensitivity Laboratories).

Specific examples of merocyanine dyes include NK242 6 and NK 2 5 0 1 (both manufactured by Nippon Photosensitivity Laboratories).

Examples of xanthene dyes include uranin, eosin, rose bengal, rhodamine B, and dibromofluorescein.

Examples of the triphenylmethane dye include malachite green and crystal violet.

Examples of the coumarin dye include NKX-267 7 (produced by Hayashibara Biochemical Research Institute) (see the following structural formula).

Examples of indoline-based organic dyes include D 149 (manufactured by Mitsubishi Paper Industries) (see the following structural formula). '

(D149) Examples of the method of adsorbing the photosensitizing dye to the semiconductor fine particles laminated on the conductive substrate include a well-dried semiconductor fine particle layer and a conductive material in a solution containing the photosensitizing dye of the present invention. The method of immersing the laminated body which consists of a board | substrate for several hours is mentioned. Adsorption of the photosensitizing dye may be performed at room temperature (at 25), may be performed under heating, or may be performed while refluxing a solution containing the photosensitizing dye.

The photosensitizing dye can be adsorbed before the semiconductor fine particle layer is formed on the conductive substrate, or the semiconductor fine particles and the photosensitizing dye may be applied to the conductive substrate at the same time. There is a method of adsorbing a photosensitizing dye to the formed semiconductor fine particle layer. More preferred. When the semiconductor fine particle layer is heat-treated, it is preferable that the photosensitizing dye adsorption is performed after the heat treatment. After the heat treatment, the photosensitizing dye is adsorbed before water is adsorbed on the surface of the semiconductor fine particle layer. Particularly preferred is a method of making them. 'It is preferable to remove the unadsorbed photosensitizing dye by washing in order to suppress the reduction of the sensitizing effect due to floating of the photosensitizing dye not adhering to the semiconductor fine particles. ■ One type of photosensitizing dye can be adsorbed or a mixture of several types can be used. When the application is a photoelectrochemical cell, it is preferable to select a photosensitizing dye to be mixed so that the wavelength range of photoelectric conversion of irradiation light such as sunlight is as wide as possible. In addition, the adsorption amount of the photosensitizing dye to the semiconductor fine particles is 0.1. A millimolar is preferred. With such a dye amount, a sufficient sensitizing effect is obtained in the semiconductor fine particles, and there is a tendency to suppress a reduction in the sensitizing effect due to the floating of the dye not attached to the semiconductor fine particles. To preferred. ..

The photosensitizing dye adsorbed on the semiconductor fine particle layer (2) may be the same or different. For example, the first layer adsorbs a photosensitizing dye of 300 nm to '500 nm, and the second layer adsorbs a photosensitizing dye of 500 nm to 700 nm. Alternatively, a photosensitizing dye having a different absorption wavelength may be adsorbed to each layer, for example, a photosensitizing dye having a wavelength of 700 to 90 nm is adsorbed to the third layer.

'

A colorless compound may be co-adsorbed for the purpose of suppressing interactions such as association and aggregation between photosensitizing dyes. Examples of the hydrophobic compound after co-adsorption include a steroid compound having a strong lpoxyl group (for example, chenodeoxycholic acid) and the like. For the purpose of promoting the removal of excess dye, the surface of the semiconductor fine particles may be treated with amines after adsorbing the dye. Preferred amines include, for example, pyridine, 4-tert-butylpyridine, polyvinyl pyridine and the like. When these are liquids, they may be used as they are, or when they are solids, they may be dissolved in an organic solvent. Examples of the electrolyte contained in the charge transfer layer of the present invention include combinations of ₁₂ and various iodides, combinations of Br ₂ and various bromides, and combinations of ferrocyanate-ferricyanate metal complexes. , Combinations of metal complexes of phenoxy and ferricinium ions, combinations of alkyl compounds of alkylthio-l-alkyldisulfides, combinations of alkylviologens and their reduced forms, combinations of polyhydroxybenzenes and their oxidants, etc. Can be mentioned.

Here, the ® © product that may be combined with I _2, for example, L i I, N a I , KI, C s I and C a I ₂ of a metal such as iodides; 1-propyl one 3-methylimidazo Riumuai Examples include iodine salts of quaternary imidazolium compounds such as iodine, 1-propyl-2,3-dimethyldimethylimidazole, iodine salts of quaternary pyridinium compounds, iodine salts of tetraalkylammonium compounds, and the like.

The iodide may be combined with B r _2, for example, L i B r, N a B r, KB r, C s B r and C a B r _2, etc. of the metal bromide; tetraalkyl ammonium Niu beam blow amide Ya pyridinium Examples include bromine salts of quaternary ammonium compounds such as zinc bromide.

Examples of the alkyl viologen include methyl viologen chloride, hexyl viologen promide, and benzyl viologen tetrafluoroborate. Examples of the polyhydroxybenzes and diols include, for example, hyde mouth quinone and naphthohyde mouth quinone.

The electrolyte is preferably a combination of I ₂ and an iodide, and in particular, a metal iodide, an iodine salt of a quaternary imidazolium compound, an iodine salt of a quaternary pyridinium compound, and an iodine salt of a tetraalkylammonium compound. A combination of at least one iodide selected from the group consisting of and I ₂ is preferred. When the photoelectrochemical cell of the present invention is wet, the charge transfer layer contains an electrolyte. Examples of the electrolytic solution include water and an organic solvent that dissolves the electrolyte. Examples of the organic solvent include nitrile solvents such as acetonitrile and methotisacetonitrile pionitrile; carbonate solvents such as ethylene power and propylene carbonate; Lactone solvents such as lolactone; Amide solvents such as N ,, N-dimethylformamide i 1-Methyl-3 —propylimidazolium ioidaid 1-methyl-3 —hexylimidazole An ionic liquid such as mu-iodide; 1-ethyl-3-methylimidazolium-bis (trifluoromethanesulfonic acid) imide. ..,

The electrolysis ¾ may be gelled with a low molecular gelling agent shown in polyacrylonitrile, polyvinylidene fluoride, poly-4-vinylpyridine, or Chemistry Letters, 1 2 4 1 (1 9 9 8). . When the photoelectrochemical cell of the present invention is dry, a solid electrolytic layer such as a solid hole transport material is used for the charge transfer layer.

Solid hole transport materials include those made of p-type inorganic semiconductors containing monovalent copper such as Cu I and Cu SCN, and Synthetic M etl, 8 9, 2 1 5 (1 9. 9 7) And aromatic, amines such as those shown by Nature, 3 95, 5 8 3 (1 9 9 8); polythiophene and its derivatives; polypyrrole and its derivatives; poly 7 phosphorus and its derivatives; And (2) vinylene) and derivatives thereof; poly (ρ-phenylenepinylene) and derivatives thereof, and the like. The sealing agent used in the present invention contains a resin containing a hydroxyl group. By using the resin as a sealing agent, when a volatile solvent such as acetonitrile or iodine is used as an electrolytic solution, they are In particular, it is difficult to volatilize at high temperatures, so durability is significantly improved.

As the resin containing a hydroxyl group, a thermoplastic resin is preferable because of easy handling. As a specific example of a resin containing a hydroxyl group, an ethylene-vinyl alcohol copolymer obtained by hydrolyzing an acetate ester of an ethylene-vinyl acetate copolymer is used. Resin structure such as polyvinyl acetate, partially saponified polyvinyl alcohol partially hydrolyzed with vinyl acetate, and fully saponified polyvinyl alcohol with approximately 98 mol% or more of polyvinyl acetate hydrolyzed Examples thereof include those containing a structural unit obtained by hydrolysis of vinyl ester as a unit.

The resin containing a hydroxyl group can be used as a film, and when used as a film, the film may be stretched. Among these, from the viewpoint of ease of sealing by thermocompression bonding using an electrothermal press, etc. Of these, ethylene-vinyl alcohol copolymer is preferably used.

Examples of the ethylene-vinyl alcohol copolymer include Kuraray's Ever, Lu (registered trademark), Nippon Synthetic Chemical's Soanol (registered trademark), Soarlite (registered trademark), and the like. Any grade in the EVAL RE SI N & F I LM catalog (issued in May 2006) can be used. For example, L, F, T, J, H, E, E, G with different ethylene polymerization ratios. Any grade can be used. Also; these films may contain a lubricant. .

In addition, ethylene-vinyl alcohol copolymer, partially saponified polyvinyl alcohol, fully saponified polyvinyl alcohol are polyethylene terephthalate (PET), polyamide: (PA), polyethylene (PE), polypropylene (PP) , they may form a multi-layered structure of aluminum S I_〇 ₂ film.

For example, Kuraray's Kuraray Poval, Japan, Synthetic Chemical's Gosensenol, Shiramoto Vinegar Bipoval's J-Poval, 'Ryoke Chemical Company's Denka Poval, Examples include Unitika Poval manufactured by Unitica. The poval may contain a plasticizer. '.

In order to keep the distance between the conductive substrate (8) and the counter electrode (9) constant in these resins, the spacers of .. • further suppress the evaporation of volatile solvents such as acetonitrile and iodine. In order to achieve this, a filler such as S i 0 T i '0 ₂ or A 1 ₂ 0 ₃ may be mixed. „In addition, the sealing agent of the present invention includes Hi-Milan (registered trademark, Mitsui DuPont Polychemi). Ionomer resins such as Calf); Glass frits; Hot mesole adhesives such as SX 1 1 70 (Solaronix); Adhesives such as Amo si 1 4 (So 1 aronix); B YNE L (DuPont) Anhydrous-modified LLDPE (made by modifying linear low density polyethylene with an acid anhydride such as maleic anhydride) or epoxy adhesive may be used in combination. For example, pre-molded shapes such as films and sheets, or water before sealing Comprise a liquid, to drying during sealing 'shall and the like ¾ ease of handling, film, sealing such sheets -. Those preformed in a shape to be sealed are preferred.

The thickness of the film is usually about 1 m to 1 mm. As a method for sealing using a molded sealant, a method in which a sealant is sandwiched between a working electrode and a counter electrode and bonded by an electric heating press can be mentioned. The bonding temperature may be at a temperature higher than the temperature at which the resin melts, and is usually between 50 and 300.

The sealing material portion may be locally heated and melted and bonded using laser light or the like. When sealing a cell in which a dye is already installed, it is preferable to adjust the heating time within a range where the dye does not deteriorate with heat. Since the photoelectrochemical cell of the present invention is sealed with a volatile solvent such as acetonitrile or a sealing agent that can prevent the evaporation of electrolyte such as iodine, the electrolyte contained in the charge transfer layer even when stored at high temperature The charge transfer layer such as water and solvent is not lost and it has excellent durability. Examples, ■

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples; needless to say t. (Example 1):

The conductive surface of a conductive glass with a tin oxide film doped with fluorine (made by Nippon Sheet Glass Co., Ltd., 10 Ω / D) is a titanium oxide dispersion. Name, manufactured by Solaronix) was applied using a doctor blade, fired at 500, the glass was cooled, and a semiconductor fine particle layer was formed on a conductive substrate. Subsequently, a solution of -bis (isothiocyanate) bis (2; 2'-bipyridyl-4,4'-dicarboxylate) -ruthenium (II) bis-tetraptylammonium (concentration is 0 0003 mol / liter, the solvent is a mixed solvent of 1 butyl alcohol / acetonitrile = 1/1): 16 hours soaked, taken out from the solution, filtered with acetoni small rill, then air dried A laminate of a semiconductor fine particle layer adsorbing a conductive substrate and a photosensitized dye (the area of the titanium oxide electrode was 7 cm ² ) was obtained. Next, a 50-thick ethylene-vinyl alcohol copolymer resin (EVAL (registered trademark of Kuraray Co., Ltd.) F 1 0 1) film was installed around the layer as a sealant, A conductive glass with a tin oxide film and pre-deposited with platinum was overlaid with a hole drilled beforehand. After thermocompression bonding with an electrothermal brace machine, the electrolyte solution is passed through a hole in the counter electrode previously opened (solvent is acetonitrile; iodine concentration in the solvent is 0.05 mol liter, and the concentration of lithium iodide is also 0.1 mol) A 4-liter tert-butylpyridine concentration of 0 ... 5 mol liters and a 1-propyl-1,3-dimethylimidazolium iodide concentration of 0.6 mol / liter) were injected into the cell. Then, ethylene-vinyl alcohol copolymer resin (Eval (registered trademark of Kuraray Co., Ltd.) F 1 0 1) was placed on the hole and sealed by thermocompression using an electric heat press to seal the hole. A stopped photoelectrochemical cell was obtained.

The photoelectrochemical cell produced in this way was put into a xenon weathering tester and irradiated with light. (Light quantity: 0.48W / m ² (340nm), black panel temperature: 83, humidity: 50% RH , No rain), observed the change in conversion efficiency over time. The conversion efficiency was measured using a solar simulator manufactured by Yamashita Denso.

Table 1 shows the retention of conversion efficiency after 3.50 hours when the initial efficiency is 1.

(Comparative Example 1)

A photoelectrochemical cell was obtained in the same manner as in Example 1 except that B YNEL (registered trademark, manufactured by DuPont), which is an anhydride-modified LLDPE, was used as the sealant. Next, the change with time in photoelectric conversion efficiency was measured in the same manner as in Example 1. The results are shown in Table 1. table 1

(Example 2)

Around the glass plate, a 50-thick ethylene-vinyl alcohol sealant Copolymer resin (Eval (registered trademark of Kuraray Co., Ltd.) F 1 0 1) After the film was placed, a glass plate with holes drilled in advance was superposed. After thermocompression bonding with an electric heat press machine, the electrolyte solution (the solvent is acetonitrile, the iodine concentration in the solvent is 0.05 mol liters, the concentration of lithium niobate is 5 mol 0.1 mol noritol, 4 tert-butyl lysine concentration is 0.5 mol Z. liter, 1 propyl 1, 2, 3 — dimethylimidazolium iodide concentration is 0.6 'mol Z liter) Injected into. Then, to seal the hole, ethylene-vinyl alcohol copolymer resin. (Eval (registered trademark of Kura, Le Co., Ltd.)) F 1 0 1) After installing the film and glass plate on the hole, Then heat-pressed and sealed.

The glass plate encapsulating the electrolyte was aged in an oven at 85 t: and the time course of the amount of iodine was measured at an absorbance of 36 2 nm. Table 2 shows the absorbance retention when the initial absorbance is 1. Absorbance is high ^, which means that the iodine retained in the photoelectrochemical cell is high. ''

1 5

(Example 3) '.

It was carried out in the same manner as in Example 2 except that 40-m thick polyvinyl alcohol resin (Poval (registered trademark of Kuraray Co., Ltd.) V L-F) was used as the sealant.

20 (Comparative Example 2)

A glass plate encapsulating an electrolyte solution was obtained in the same manner as in Example 2 except that BYNEL (registered trademark, manufactured by DuPont), which is an anhydride-modified LLDPE, was used as the sealant. Next, the change in absorbance over time was measured in the same manner as in Example 2. The results are shown in Table 2.

,twenty five

Table 2

Industrial applicability

The photoelectrochemical cell of the present invention has a significant loss of electrolytes such as iodine and volatile solvents even when used at high temperatures or for long periods of time compared to the case of using a conventional sealant.

30 Since it is reduced, it has excellent durability. Because of these excellent characteristics, it can be used for solar cells using sunlight, and photoelectrochemical cells using artificial light in tunnels and indoors. In addition, the photoelectrochemical cell of the present invention can be used as an optical sensor because current flows upon receiving light irradiation.

35

Claims

The scope of the claims

1. In a photoelectrochemistry battery formed by sealing a conductive substrate, a semiconductor fine particle adsorbed with a photosensitizing dye, a charge transfer layer, and a counter electrode with a sealant, the sealant is water. A photoelectrochemical cell containing a resin containing an acid group. .

2. The resin according to claim 1, wherein the hydroxyl group-containing resin is at least one resin selected from the group consisting of ethylene-vinyl alcohol copolymer, polymer, partially saponified polyvinyl alcohol, and fully genated polyvinyl alcohol. Photoelectrochemical cell

3 .. The photoelectrochemical cell according to claim 1 or 2, wherein the conductive fine particles are titanium oxide. ...

. 4 charge transfer layer, Kumiawasedea Ru claims I ₂ and iodide:.! Photoelectrochemical cell according to any one of 1-3. ·

5. For photoelectrochemical cells containing at least one resin selected from the group consisting of ethylene-vinyl alcohol copolymer, partially saponified polypinyl alcohol and fully saponified polyvinyl alcohol Sealant.