JP2010267557A - Dye-sensitized photoelectric conversion element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye-sensitized photoelectric conversion element capable of providing a photoelectric conversion element having efficient power generation characteristics, improving the deterioration of the power generation characteristics of the photoelectric conversion element with preservation passage of time, and ensuring superior performance even with an electrolyte containing less iodine ion, in the dye-sensitized photoelectric conversion element containing a current collecting mesh. <P>SOLUTION: The dye-sensitized photoelectric conversion element includes a photo-electrode layer containing dye-sensitized semiconductor particles, an electrolyte layer and a counter electrode layer in this order. In this dye-sensitized photoelectric conversion element, the photo-electrode layer is an electrode layer in which a substrate, a conductive layer, a current-collecting mesh with a protective layer and a dye-sensitized semiconductor particle layer are laminated in this order. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a dye-sensitized photoelectric conversion element.

In recent years, solid pn junction solar cells have been actively studied as photoelectric conversion elements that convert solar energy into electric power. The solid junction solar cell uses a silicon crystal, an amorphous silicon thin film, or a multilayer thin film of a non-silicon compound semiconductor. However, solid junction solar cells need to be manufactured at high temperature or under vacuum. For this reason, the production of solid junction solar cells has the disadvantages of high plant costs and low energy recovery with respect to the investment.

The development of organic solar cells that can be manufactured at lower temperatures and at lower costs as solar cells that generate electricity under the next-generation solar light source is expected, and dye-sensitized solar cells that can be mass-produced at low cost in the atmosphere Batteries are attracting particular attention. Patent Document 1 proposes a highly efficient photoelectric conversion method using a dye-sensitized porous semiconductor film for the dye-sensitized solar cell. A dye-sensitized solar cell is a wet solar cell that employs a solid (semiconductor) -liquid (electrolyte) junction instead of a solid (semiconductor) -solid (semiconductor) junction in a solid junction solar cell.

The dye-sensitized solar cell has a high energy conversion efficiency of 11%, and is promising as a source of electric energy. In particular, the dye-sensitized solar cell has a characteristic of having power generation capability even with a low light amount, and has characteristics different from a so-called silicon-based solar cell that generates power only outdoors (under a large light amount of a solar light source). Therefore, the present invention is described as a dye-sensitized photoelectric conversion element in terms of a power generation element that can generate power not only with a solar light source but also with a weak indoor light source (for example, a fluorescent light, an incandescent light source, and an LED light source).

General dye-sensitized photoelectric conversion elements include a photoelectrode layer (consisting of a transparent substrate, a transparent conductive layer and a dye-sensitized porous semiconductor film), an electrolyte layer and a counter electrode layer (transparent conductive layer and transparent substrate). Are formed in a stacked structure in this order. The conductive layer laid on the photoelectrode layer and the counter electrode layer is generally transparent and is formed of a metal, a conductive metal oxide, or the like, and indium-tin oxide is particularly excellent. It is known that auxiliary leads for collecting current are disposed on the transparent conductive layer of the photoelectrode layer. The auxiliary lead can be arranged by patterning, for example. It is known that the auxiliary lead is usefully formed from a low-resistance metal material (for example, copper, silver, aluminum, platinum, gold, titanium, nickel), and a network-shaped current collecting mesh is preferable.

On the other hand, an electrolytic solution used for a dye-sensitized photoelectric conversion element is generally a solution in which a redox couple and an electrolyte are dissolved in an organic solvent. As the organic solvent, aprotic polar substances (eg, carbonate, ether, lactone, nitrile, sulfoxide) are generally used (Patent Document 1). As redox pairs, iodine and iodide, bromine and bromide, ferrocyanate and ferricyanate, and ferrocene and ferricinium ions have been proposed. In general, when used as an electrolyte solution of a dye-sensitized photoelectric conversion element in a combination of iodine and iodide, which is a redox couple in principle (Patent Document 2), The problem is that the durability deteriorates.

However, it is difficult to obtain sufficient energy conversion efficiency by a method using a redox pair other than the combination of iodine and iodide. Patent Document 2 reports an experimental example in which the amount of iodine added was changed from 0 to 0.2 M (Table 1 in paragraph No. 0034). However, if no iodine was added, it would not function as a solar cell. Is described. The amount of iodine added is said to be 0.04M to 0.2M, and the electrolyte containing such a large amount of iodine volatilizes during power generation, thereby reducing the electrical output. And had a problem.

As these improvements, Patent Document 2 discloses a configuration in which the metal current collecting mesh is composed of two or more layers of an inner layer and an outer layer, and the outer layer is formed of a self-assembled film. In particular, the self-assembled film contains sulfur in the terminal functional group that forms a binding site with the inner layer. Certainly, this method improves the deterioration of the metal current collector mesh over time, but the penetration of the electrolyte into the self-assembled film and the mutual reaction of the components occur over a long period of time, resulting in poor durability. It was enough. In particular, it was insufficient for improving durability at high temperatures.

US Pat. No. 4,927,721 Published Patent Publication No. 2004-327226

Thus, in the dye-sensitized photoelectric conversion element, in order to obtain a sufficiently high energy conversion efficiency, it is necessary to use a redox pair made of a combination of iodine and iodide in the electrolytic solution. However, when iodine is used, the electrolyte is colored due to the formation of triiodide ions, light is absorbed, and energy conversion efficiency decreases. Further, when the current collecting mesh is used due to the oxidative corrosion reaction of iodine, there is a problem that the deterioration of the mesh proceeds. Accordingly, a first object of the present invention is to provide a photoelectric conversion element having efficient power generation characteristics in a dye-sensitized photoelectric conversion element having a current collecting mesh. Furthermore, the second object is to improve the deterioration of the photoelectric generation element of the photoelectric conversion element due to storage aging. A third object is to provide a dye-sensitized photoelectric conversion element that is excellent even in an electrolyte solution with less iodine ions.

The present invention relates to a dye-sensitized photoelectric conversion element having a photoelectrode layer made of dye-sensitized semiconductor particles, an electrolyte solution layer, and a counter electrode layer in this order, wherein the photoelectrode layer is a substrate, a conductive layer, This was achieved by a current collecting mesh with a protective layer and a dye-sensitized photoelectric conversion element characterized in that a dye-sensitized semiconductor particle layer was sequentially laminated.

Preferred embodiments of the present invention are as follows.
(Aspect 1) In a dye-sensitized photoelectric conversion element having a photoelectrode layer composed of dye-sensitized semiconductor particles, an electrolyte layer, and a counter electrode layer in this order, the photoelectrode layer includes a substrate, a conductive layer, A dye-sensitized photoelectric conversion element comprising an electrode layer in which a current collecting mesh with a protective layer and a dye-sensitized semiconductor particle layer are sequentially laminated.

(Aspect 2) The protective layer of the current collecting mesh with a protective layer is a crosslinked resin composition comprising at least one resin selected from an epoxy resin, a urethane resin, an acrylic resin, or a (meth) acrylate resin and a crosslinking agent. The dye-sensitized photoelectric conversion element according to aspect 1, which is a resin composition.
(Aspect 3) The dye-sensitized photoelectric conversion element according to Aspect 1 or 2, wherein the current-collecting mesh of the current-collecting mesh with a protective layer and / or the protective layer thereof is formed by screen printing.

(Aspect 4) The protective layer of the current collecting mesh with the protective layer is a resin composition having a pencil hardness of 2H or more and an insulation resistance value of 10 ¹² Ω / □ or more (25 ° C., 60% RH). The dye-sensitized photoelectric conversion element according to any one of aspects 1 to 3, wherein:
(Aspect 5) The electrolyte layer has 0.05 to 5 M of aliphatic quaternary ammonium ions having 4 to 80 total carbon atoms and 4 to 43 total carbon atoms in an aprotic solvent. The dye-sensitized photoelectric conversion element according to any one of aspects 1 to 4, comprising an electrolytic solution in which imidazolium ions are dissolved in 0.05 to 5M and iodide ions are dissolved in 0.1 to 10M.

(Aspect 6) The dye-sensitized photoelectric conversion element according to aspects 1 to 5, wherein the ratio of triiodide ions to iodide ions in the electrolytic solution is less than 1 mol%.
(Aspect 7) A benzimidazole compound having a total carbon number of 7 to 47 is dissolved in an amount of 0.01 to 1 M in the solvent of the electrolytic solution, and a thiocyanate ion or an isothiocyanate ion is dissolved in an amount of 0.01 to 1 M. The dye-sensitized photoelectric conversion element according to any one of aspects 1 to 6, wherein 0.01 to 1 M of guanidinium ions having 1 to 61 carbon atoms are dissolved.
(Aspect 8) The dye-sensitized photoelectric conversion element according to any one of aspects 1 to 7, wherein the dye-sensitized photoelectric conversion element is a gas barrier substrate.
(Aspect 9) The dye-sensitized photoelectric conversion element according to any one of aspects 1 to 7, wherein the dye-sensitized photoelectric conversion element is housed in a protective packaging bag made of a transparent plastic film substrate. element.
Hereinafter, the present invention will be described.

(Mesh for current collection)
In order to fully express the characteristics of the current collecting mesh in the present invention, the current collecting mesh provided with an essential protective layer will be described first. In the present invention, electrons generated in a porous photoelectrode layer made of dye-sensitized semiconductor particles move to a uniform transparent overall conductive layer, and a current collecting mesh with a protective layer is used to collect the electrons. It is characterized by that. In that case, the protective layer of the current-collecting mesh with a protective layer is composed of a crosslinked resin composition. The protective layer of the current collecting mesh arranged as an outer layer does not hinder electron transfer between the transparent conductive layer and the electrolyte layer or the charge transfer layer, and the protective layer of the current collecting mesh is an oxide semiconductor porous film The risk of hindering electron transfer from the transparent conductive layer to the transparent conductive layer is reduced.

The current collecting mesh of the present invention is formed of a low-resistance metal material, metal oxide, or organic conductive material, and is formed of, for example, copper, silver, aluminum, platinum, gold, titanium, nickel, carbon nanofiber, polythiophene, or the like. Preferably, it is a metal material, for example, silver, platinum, copper, nickel, etc. These conductive materials may contain additives (for example, a resin as a binder, a surfactant or a polymer material as a dispersant, an ionic additive, etc.) as long as the conductivity is not significantly impaired. For example, Dotite D-362, D-500, D-550, D-753, D-723S, XC-12, FN-101, FE-107, XA-9015, XA-824, manufactured by Fujikura Kasei Kogyo Co., Ltd. D-362 etc. can be mentioned. Also, DD paste TH9910 and DD paste NF2000, which are copper pastes manufactured by Tatsuta Electric Corporation, such as DW-250H-5, DW-250H-7, DW-260H, DW-351H-30, DW manufactured by Toyobo Co., Ltd. -104H, DW-545, DW-114L-1, DWP-025, DX-152H-1, DX-153H-87, DX-116L-1, DX-150H-40, DX-280H-3, DY-200L -2, DYP-020, DWP-025, DWP-026, DYP-020, etc., C2050926D2, C20503303D1, C20100829D2, C70709D18, C10515D1, C2021031D3, C60903D5, C20903D2 SP, SD, ST, SF, SL, SI, CP, Lion paste W-310A, Lion paste W-311N, Lion paste W-356A, W-376R, Lion paste W-370C, etc., manufactured by Toyo Ink Co., Ltd. REXALPHA series of RA, FS, FD, FL, GR, etc., LS-506J, ACP-051, TU-20S, TU-10S manufactured by Asahi Chemical Research Co., Ltd. can be mentioned. The current collecting mesh has a thickness of 25 μm or less, preferably 15 μm or less, and more preferably 7 μm or less. The line width is 60 μm or less, preferably 40 μm or less, more preferably 30 μm or less, and particularly preferably 20 μm or less.

The opening on the transparent conductive film may be any shape such as a polygon such as a rectangle or a hexagon, a circle such as a circle or an ellipse, a rhombus or a parallelogram, and is not particularly limited. The openings are generally formed in the same shape, but may have different shapes or different areas. Among these, it is preferable to form the metal film in a lattice shape or a stripe shape from the viewpoint of improving the total light transmittance. Furthermore, the end of the opening may be continuous or discontinuous with the metal film. The size of the opening is preferably 20 μm to 2.5 mm.

 The current collecting mesh can be formed by a developing method such as an etching method, screen printing, an ink jet method, or a silver complex diffusion transfer method (DTR). If necessary, an electroless plating method and an electrolytic plating method can be used in combination. Among these, screen printing is particularly preferable.

(Protective layer of current collecting mesh)
Next, the resin composition layer which is a protective film for the current collecting mesh of the present invention will be described below. The resin composition for a protective layer of the present invention is not particularly limited as long as it is a resin, but it is particularly preferable if the resin is crosslinked by some method. Among them, epoxy resin, urethane resin, acrylic resin or methacrylate resin, ester resin, polyvinyl acetal resin, acrylic-olefin copolymer xylene resin, styrene resin, acrylic resin, formaldehyde resin and phenol are preferable among them. Examples thereof include at least one resin composition selected from the group consisting of resins. Moreover, an epoxy resin, a urethane resin, an acrylic resin, a methacrylate resin, or an ester resin is preferable. Furthermore, among these, it is bridge | crosslinked, especially a crosslinked epoxy resin and a crosslinked urethane resin are preferable, and also a crosslinked epoxy resin is preferable. These materials are described in, for example, Japanese Patent Application Laid-Open No. 2008-201894. The preferable resin composition is described below.

(Epoxy resin)
As the epoxy resin, as a compound containing at least one epoxy group in the molecule, for example, (1) carbon number 2 such as butyl glycidyl ether, octyl glycidyl ether, decyl glycidyl ether, aryl glycidyl ether, phenyl glycidyl ether, etc. -20 glycidyl ethers of alcohol;

 (2) polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether dibromoneopentyl glycol diglycidyl ether, Polyglycidyl ethers of polyols such as glycerol triglycidyl ether, trimethylolpropane triglycidyl ether diglycerol tetraglycidyl ether, polyglycerol polyglycidyl ether;

 (3) 2,6-diglycidyl phenyl glycidyl ether, 2,6,2 ′, 6′-tetramethyl-4,4′-biphenyl glycidyl ether, bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, Bisphenol F type epoxy resin, hydrogenated bisphenol F type epoxy resin, bisphenol S type epoxy resin, hydrogenated type bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, halogenated phenol novolak type epoxy resin, Glycidyl ether type epoxy compounds such as brominated epoxy resins;

(4) Cyclic aliphatic epoxy compounds such as alicyclic diepoxy acetal, alicyclic diepoxy adipate, vinylcyclohexene dioxide;
(5) Unsaturated acid glycidyl esters such as glycidyl (meth) acrylate, tetrahydroxyphthalic acid diglycidyl ester, sorbic acid glycidyl ester, oleic acid glycidyl ester, linolenic acid glycidyl ester; butyl glycidyl ester, octyl glycidyl ester hexahydrophthal Alkyl carboxylic acid glycidyl esters such as acid diglycidyl ester;

(6) Aromatic carboxylic acid glycidyl esters such as benzoic acid glycidyl ester, o-phthalic acid diglycidyl ester, diglycidyl p-oxybenzoic acid, dimer acid glycidyl ester;
(7) Tetraglycidyldiaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, diglycidylaniline, diglycidyltoluidine, tetraglycidyl-m-xylylenediamine, diglycidyltribromoaniline, tetraglycidylbis Glycidylamine type epoxy compounds such as aminomethylcyclohexane;

(8) Heterocyclic epoxy compounds such as diglycidyl hydantoin, glycidyl glycidoxyalkylhydantoin, and triglycidyl isocyanurate are exemplified.
Among these, polyglycidyl ethers of polyols, phenol novolac type epoxy resins, and cresol novolac type epoxy resins are preferable, and bisphenol A type epoxy resins, bisphenol F type epoxy resins, and alkylcarboxylic acid glycidyl esters are particularly preferable. Commercially available products can be used as the epoxy resin. Examples of the commercially available products include Etoto YD128 and YD8125 manufactured by Tohto Kasei, Epicron 840S, 850S, 1050, and 830 manufactured by Dainippon Ink and Chemicals, Asahi Chemical Co., Ltd. Co., Ltd. Coated Paste CR-20T is included.

(Curing agent)
Although the resin composition of the present invention itself may be crosslinked during the reaction, it can be made into an effective crosslinked resin composition by adding a crosslinking agent. For example, as a curing agent that reacts with an epoxy resin, a compound having a functional group that reacts with two or more epoxy groups in one molecule (referred to as a curing agent in the present invention) is used. Examples of the functional group in such a curing agent include a functional group such as a carboxyl group, a hydroxyl group, an amino group, and a thiol group.

 Specific examples of curing agents include polyfunctional carboxylic acid compounds such as terephthalic acid, bifunctional phenol compounds such as bisphenol A, bisphenol F, bisphenol S, resorcinol derivatives, and catechol derivatives, phenol resins such as phenol novolac resins and cresol novolac resins. And polyfunctional amino compounds such as amino resins, 1,3,5-triaminotriazine, and 4,4′-diaminodiphenylsulfone. Among these, a compound having at least one of a hydroxyl group and an amino group as a functional group that reacts with an epoxy group is preferably used as a curing agent.

 As the addition amount of the curing agent, the ratio of the functional group of the curing agent to the epoxy group in the epoxy resin (solid content of the curing agent (g) / curing agent equivalent) / (solid content of the epoxy resin (g) / Epoxy equivalent) is preferably 0.1 to 5.0, more preferably 0.3 to 2.0. In the above definition formula, the equivalent means the number of functional groups per molecule, the number of functional groups that react with an epoxy group as a curing agent, and the number of epoxy groups as an epoxy resin.

Moreover, as said crosslinking agent, an oxazoline type crosslinking agent is also used suitably. Examples of the oxazoline-based crosslinking agent include EPOCROSS series K-1000, K-2000, WS-500, WS-700 manufactured by Nippon Shokubai Co., Ltd., and the like.

(Urethane resin)
Next, a urethane resin that is a protective layer for a current collecting mesh preferable in the present invention will be described. The urethane resin can be produced mainly by reacting an organic polyisocyanate with a polyol, or by reacting a terminal isocyanate group-containing urethane prepolymer with a polyamine curing agent.

Examples of the organic polyisocyanate used in the present invention include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and tolidine. Examples include diisocyanate, paraphenylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hexamethylene diisocyanate, and terminal isocyanate group-containing urethane prepolymers obtained by reacting these polyisocyanates with polyols. It is done. Among these, a terminal isocyanate group-containing urethane prepolymer is preferable in terms of physical properties, reactivity, and storage stability.

As the polyol used as a raw material for the terminal isocyanate group-containing urethane prepolymer, a high molecular weight polyol alone or a combination of a high molecular weight polyol and a low molecular weight polyol is preferable. Examples of the high molecular weight polyol used as a raw material for the terminal isocyanate group-containing urethane prepolymer include polyether polyols such as poly (oxyalkylene) glycol and poly (oxytetramethylene) glycol, polyester polyols, polylactone polyols, and polyether ester polyols. , Polycarbonate polyols, and high molecular weight polyols such as polybutadiene polyols.

Examples of the low molecular weight polyol used as a raw material for the terminal isocyanate group-containing urethane prepolymer include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, 2, -methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, glycerin, Examples include trimethylolpropane, diethylene glycol, triethylene glycol, and tetraethylene glycol.

Examples of the polyol used for the reaction with the organic polyisocyanate include ethylene oxide, propylene oxide as a starting material having at least two hydroxyl groups such as 1,2-propylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, and the like. Polyether polyols such as poly (oxyalkylene) glycol and poly (oxytetramethylene) glycol obtained by addition polymerization of alkylene oxide such as butylene oxide; adipic acid, sebacic acid, azelaic acid, succinic acid, maleic acid, phthalic acid Polyhydric carboxylic acid such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 6-hexanediol, 1,8-octanediol, neopentyl glycol, 2, -methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, glycerin, trimethylolpropane, diethylene glycol, triethylene glycol, Polyester polyols obtained by polycondensation of polyhydric alcohols such as tetraethylene glycol; and polylactone polyols, polyether ester polyols, polycarbonate polyols, and polybutadiene polyols. Among these, polyether polyol and polyester polyol are preferable. The number average molecular weight of these polyols is preferably 500 to 10000, more preferably 1000 to 5000.

 Here, as the urethanization catalyst of the protective film for the current collecting mesh of the present invention, organic acid metal salts such as stannous octoate and dibutyltin dilaurate; triethylenediamine, triethylamine, N-ethylmorpholine, dimethylethanolamine And amines such as pentamethyldiethylenetriamine and palmityldimethylamine.

 Examples of the polyamine curing agent include 4,4′-diamino-3,3′-dichlorodiphenylmethane (referred to as MBOCA), trimethylenebis (4-aminobenzoate), and methylenebis (2-ethyl-6-methylaniline). And polyaminochlorophenylmethane compounds such as methylenebis (2,3-dichloroaniline), toluenediamine, 4,4′-diaminodiphenylmethane, and the like.

(Ester resin)
As the ester resin, a polyester obtained from the following polybasic acid component and diol component can be used. That is, as the polyvalent base component, for example, terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, Examples include pyromellitic acid, dimer acid, and 5-sodium sulfoisophthalic acid. As the polyester resin constituting the polymer binder, it is preferable to use a copolymerized polyester using two or more kinds of dicarboxylic acid components. The polyester resin may contain an unsaturated polybasic acid component such as maleic acid or itaconic acid, or a hydroxycarboxylic acid component such as p-hydroxybenzoic acid, if it is in a slight amount.

Examples of the diol component of the ester resin include ethylene glycol, 1,4-butanediol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylene glycol, dimethylolpropane, and the like ( Examples thereof include ethylene oxide) glycol and poly (tetramethylene oxide) glycol.

(acrylic resin)
The acrylic resin can be obtained by copolymerizing monomers exemplified below. That is, alkyl acrylate, alkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, cyclohexyl, etc.); Hydroxy-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate and 2-hydroxypropyl methacrylate; Epoxy group-containing monomers such as glycidyl acrylate, glycidyl methacrylate and allyl glycidyl ether; acrylic acid and methacrylic acid Carboxy groups such as itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene sulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.) Monomers having salts thereof: acrylamide, methacrylamide, N-alkyl acrylamide, N-alkyl methacrylamide, N, N-dialkyl acrylamide, N, N-dialkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl Group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, etc.),

 N-alkoxyacrylamide, N-alkoxymethacrylamide, N, N-dialkoxyacrylamide, N, N-dialkoxymethacrylamide (alkoxy groups include methoxy, ethoxy, butoxy, isobutoxy, etc.), acryloylmorpholine, Monomers having an amide group such as N-methylolacrylamide, N-methylolmethacrylamide, N-phenylacrylamide, N-phenylmethacrylamide; monomers of acid anhydrides such as maleic anhydride and itaconic anhydride; 2-vinyl-2- Oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2- Isopropenyl-5- Oxazoline group-containing monomers such as til-2-oxazoline; methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, vinyl isocyanate, allyl isocyanate, styrene, α-methylstyrene, vinyl methyl ether, vinyl ethyl ether, vinyl trialkoxysilane, alkyl maleic acid Monoester, alkyl fumaric acid monoester, alkyl itaconic acid monoester, acrylonitrile, methacrylonitrile, vinylidene chloride, ethylene, propylene, vinyl chloride, vinyl acetate, butadiene.

These resins are used as a protective layer for the current collecting mesh. In that case, a solution obtained by dissolving the preferred resin of the present invention in a solvent or the like is applied on the conductive mesh of the current collecting mesh and dried. Thus, a substrate for a photoelectrode having a current collecting mesh with a protective layer is produced. As the applying method, screen printing is particularly preferable. Further, a photoelectrode layer substrate, a photoelectrode layer conductive layer, a color dye-sensitized semiconductor particle layer, an electrolyte layer, a counter electrode layer, and a counter electrode layer transparent substrate will be described in this order. More preferably, the cross-linking is completed at a high temperature after the protective film is formed. In this case, the post-treatment temperature is preferably 50 ° C. or higher and 200 ° C. or lower, more preferably 80 ° C. or higher and 160 ° C., particularly 100 ° C. or higher and 150 ° C. or lower. The heating time is not particularly limited, but is preferably 0.5 minutes or more and 60 minutes or less, more preferably 1 minute or more and 30 minutes or less, and particularly preferably 2 minutes or more and 20 minutes or less. In addition, it is not particularly limited to perform other surface treatment or to insert a functional layer between the layers forming the photoelectrode layer, and examples thereof include a surface treatment of a substrate described later, an undercoat layer, and the like. It is also preferable to provide a new layer.

(Photoelectrode layer substrate)
The substrate for a photoelectrode layer of the present invention is preferably a transparent glass plate or a polymer film. A polymer film having flexibility is preferable to a glass plate. Examples of polymers are polyethylene terephthalate (PET), polyethylene naphthalate (PEN), syndiotactic polystyrene (SPS), polyphenylene sulfide (PPS), polycarbonate (PC), polyarylate (PAr), polysulfone (PSF), polyester sulfone. (PES), polyetherimide (PEI) and polyimide (PI). Polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are most preferred. The thickness is not particularly limited, but is preferably 10 μm to 2 mm, more preferably 20 μm to 500 μm, more preferably 50 μm to 300 μm, and particularly preferably 70 μm to 300 μm. These transparent substrates can be easily purchased as commercial products.

Furthermore, these substrates may be provided with various surface treatments and undercoat layers in order to strengthen the adhesion with the conductive layer laminated thereon. For example, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be used. The glow discharge treatment also indicates so-called low temperature plasma that occurs under a low pressure gas of 10 ^{−3 to} 20 Torr, but may be a glow discharge treatment under atmospheric pressure. First, glow discharge treatment under low pressure is described in U.S. Pat. Nos. 3,462,335, 3,761,299, 4,072,769 and British Patent 891,469. ing. In addition, a specific gas such as an inert gas, nitrogen oxides, or an organic compound gas is also introduced. When the surface of the film is subjected to glow discharge treatment, it may be at atmospheric pressure or under reduced pressure. You may implement, introducing various gas and water like oxygen, nitrogen, helium, or argon in the atmosphere of a glow discharge process.

 Next, an ultraviolet irradiation method is also preferably used in the present invention. The mercury lamp used is a high-pressure mercury lamp made of a quartz tube and preferably has an ultraviolet wavelength of 180 to 380 nm. Further, corona discharge treatment is also preferable as the surface treatment, and as the corona discharge treatment apparatus, a solid state corona treatment machine manufactured by Pillar, a LEPEL type surface treatment machine, a VETAPHON type treatment machine, or the like can be used. Next, the flame treatment will be described. The gas used may be natural gas, liquefied propane gas, or city gas, but the mixing ratio with air is important.

 In order to bond the base material and the conductive layer of the present invention, after the surface activation treatment described above or without the surface treatment, a primer layer (adhesive layer) is provided and the conductive layer is applied thereon. is there. Various contrivances have also been made for the constitution of the undercoat layer, and a layer that is often adjacent to the support (hereinafter abbreviated as the undercoat first layer) is provided as the first layer, and a functional layer is provided as the second layer thereon. There is a so-called multi-layer method in which an undercoat second layer that adheres well is applied.

 In the single layer method, examples of the undercoat polymer include water-soluble polymers, latex polymers, and water-soluble polyesters. In the undercoat first layer in the multi-layer method, for example, vinyl chloride, vinylidene chloride, butadiene, methacrylic water-soluble polymers include gelatin, gelatin derivatives, casein, agar, sodium alginate, starch, polyvinyl alcohol, polyacrylic acid copolymer, And maleic anhydride copolymer. Examples of the latex polymer include a vinyl chloride-containing copolymer, a vinylidene chloride-containing copolymer, an acrylate ester-containing copolymer, a vinyl acetate-containing copolymer, and a butadiene-containing copolymer. Starting with copolymers starting from monomers selected from acids, acrylic acid, itaconic acid, maleic anhydride, etc., oligomers such as polyethyleneimine, epoxy resin, grafted gelatin, nitrocellulose, etc. There are polymers.

The base layer of the present invention may contain inorganic or organic fine particles to such an extent that the undercoat layer optionally applied does not substantially impair the transparency of the functional layer. Silica (SiO ₂ ), titanium dioxide (TiO ₂ ), calcium carbonate, magnesium carbonate and the like can be used as the inorganic fine particle matting agent. The undercoating liquid is generally a well-known coating method, such as a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, It can be applied by a gravure coating method, a slide coating method, or an extrusion coating method using a hopper described in US Pat. No. 2,681,294.

(Conductive layer for photoelectrode layer)
The conductive layer of the photoelectrode layer is preferably transparent, metal (eg, platinum, gold, silver, copper, aluminum, indium, titanium), carbon, conductive metal oxide (eg, tin oxide, indium oxide, Zinc oxide) or composite metal oxides (eg, indium-tin oxide, indium-zinc oxide). The surface resistance value is preferably 35Ω / □ or less, more preferably 20Ω / □ or less, further preferably 10Ω / □ or less, still more preferably 3Ω / □ or less, and particularly preferably 1Ω / □ or less. The light transmittance (measurement wavelength: 500 nm) of the photoelectrode substrate provided with a transparent conductive layer on a transparent substrate is preferably 60% or more, more preferably 75% or more, and most preferably 80% or more.

(Dye-sensitized semiconductor particle layer)
The dye-sensitized semiconductor particle layer is a so-called mesoporous semiconductor film in which nano-sized pores are formed in a network. It is preferable to use metal oxides and metal chalcogenides as multi-semiconductor materials, more preferably n-type inorganic semiconductors, TiO ₂ , TiSrO ₃ , ZnO, Nb ₂ O ₃ , SnO ₂ , WO ₃ , Si, CdS, CdSe. , V ₂ O ₅ , ZnS, ZnSe, SnSe, KTaO ₃ , FeS ₂ and PbS. TiO ₂ , ZnO, SnO ₂ , WO ₃ and Nb ₂ O ₃ are preferred, titanium oxide, zinc oxide, tin oxide and composites thereof are more preferred, and titanium dioxide is most preferred. The primary particle of the semiconductor preferably has an average particle size of 2 nm or more and 80 nm or less, and more preferably 10 nm or more and 60 nm or less.

(Sensitizing dye)
As the sensitizing dye used for sensitizing the dye-sensitized semiconductor particles, the same dyes as various organic and metal complex-based sensitizing materials can be used. Sensitizing dyes include organic dyes (eg, cyanine dyes, merocyanine dyes, oxonol dyes, xanthene dyes, squarylium dyes, polymethine dyes, coumarin dyes, riboflavin dyes, perylene dyes) and metal complex dyes (eg, phthalocyanine complexes, porphyrin complexes) including. Examples of the metal constituting the metal complex dye include ruthenium and magnesium. Organic dyes such as coumarin dyes are “functional materials”, 2003, June issue, P5-18, and “J. Phys. Chem.”, 2003, B 107. Volume, page 597. In particular, sensitizing dyes such as N-719 by Gretcher et al., MK-2 by AIST, or D-205 by Mitsubishi Plastics are well known.

(Electrolyte layer)
The electrolyte layer is composed of an aliphatic quaternary ammonium ion, imidazo in at least one solvent selected from a five-membered cyclic carbonate, γ-lactone, aliphatic nitrile, and aliphatic chain ether aliphatic cyclic ether as a solvent. A dye-sensitized photoelectric conversion element composed of an electrolytic solution in which a lithium ion and an iodide ion are dissolved is preferable. Still benzimidazole compounds and thiocyanate ions in the solvent of the electrolytic solution is also ^{preferably - - (= C = S N} ), the guanidinium ions are dissolved (S -C≡N) or isothiocyanate ion.

(Counter electrode layer)
The details of the counter electrode layer are the same as those of the conductive layer of the photoelectrode layer.
(Transparent substrate for counter electrode layer)
The transparent substrate for the counter electrode layer is the same as the substrate for the photoelectrode layer.

Furthermore, in the present invention, the substrate is designed to reduce its permeability to water vapor and gas, but output degradation may be observed due to severe environmental conditions, especially at high temperatures and high humidity. It is important to provide durability under environmental conditions. These improvement methods can be achieved by making the substrate a substrate having a barrier property against gas or water vapor, or enclosing the dye-sensitized photoelectric conversion element of the present invention in a package having a barrier property. Hereinafter, the barrier film preferably used in the present invention, particularly the water vapor barrier property will be described below.

As described above, the dye-sensitized photoelectric conversion element of the invention preferably has a layer having a barrier property against gas and water vapor outside the substrate. Furthermore, it is preferable that it is wrapped or wrapped with a packaging material having a water vapor barrier property. At that time, there may be a space between the dye-sensitized photoelectric conversion element of the present invention and the high barrier packaging material, or the dye-sensitized photoelectric conversion element may be bonded with an adhesive. Furthermore, the dye-sensitized photoelectric conversion element is packaged in a packaging material using a liquid or solid (eg, liquid or gel paraffin, silicon, phosphate ester, aliphatic ester, etc.) that is difficult to pass water vapor or gas. May be.

A preferable water vapor permeability of the substrate or packaging material having a barrier property preferably used in the present invention is a decrease of 0.1 g / m ² / day in an environment of 40 ° C. and a relative humidity of 90% (90% RH). preferably not more than 0.01 g / ^{m 2} / day, more preferably not more than 0.0005 g / ^{m 2} / day, particularly preferably not more than 0.00001 / ^{m 2} / day. Further, even when the environmental temperature is 60 ° C. and 90% RH, the water vapor permeability of the substrate or packaging material having a barrier property is more preferably 0.01 g / m ² / day or less, and still more preferably. Is 0.0005 g / m ² / day or less, particularly preferably 0.00001 g / m ² / day or less. The oxygen permeability 25 ° C. of the substrate or packaging materials with barrier property, in an environment of RH 0%, preferably not more than about 0.001 g / ^{m 2} / day, more preferably 0.00001 ^{/ m} 2 / Day is preferred.

Although there is no particular limitation on imparting via properties to water vapor or gas to the substrate or packaging material having barrier properties for the dye-sensitized solar cell of the present invention, it is necessary not to interfere with the amount of light necessary for the solar cell. Therefore, it is a substrate or packaging material that is permeable and has a barrier property, and its transmittance is preferably 50% or more, more preferably 70% or more, still more preferably 85% or more, and particularly preferably. 90% or more. The board | substrate or packaging material which has the said characteristic with a barrier property is not specifically limited in the structure and material, If it has this characteristic, it will not specifically limit.

A substrate or packaging material having a preferable barrier film of the present invention is preferably a film in which a barrier layer having low water vapor and gas permeability is provided on a plastic support. Examples of the gas barrier film include those obtained by vapor-depositing silicon oxide and aluminum oxide (Japanese Patent Publication No. Sho 53-12953, Japanese Patent Laid-Open Publication No. 58-217344), and those having an organic-inorganic hybrid coating layer (Japanese Patent Laid-Open No. 2000-323273, Japanese Patent Laid-Open Publication No. 2004). 25732), those having an inorganic layered compound (Japanese Patent Laid-Open No. 2001-205743), those obtained by laminating inorganic materials (Japanese Patent Laid-Open No. 2003-206361, Japanese Patent Laid-Open No. 2006-263389), those obtained by alternately laminating organic layers and inorganic layers (special features) No. 2007-30387, U.S. Pat. No. 6,413,645, Affinito et al., Thin Solid Films 1996, pp. 290-291), and organic layers and inorganic layers (U.S. Pat. No. 2004-46497).

A method of forming an organic layer by polymerizing a monomer mixture containing a vinyl monomer having a sulfinyl group or a sulfonyl group when producing a barrier film substrate having a barrier layer containing an inorganic layer and an organic layer on a plastic film ( JP, 2009-28949), a transparent gas barrier film having a thin film containing silicon atoms and nitrogen atoms on one or both sides of a resin substrate, wherein the ratio of silicon atoms and nitrogen atoms contained in the thin film is SiNx (however, 0.5 ≦ x ≦ 1.4) and the thin film 2 has a thickness of 20 to 50 nm, a transparent gas barrier film (Japanese Patent Laid-Open No. 2008-240131), and at least one inorganic layer on the substrate film And at least one organic layer, wherein the organic layer has at least 1 A method of containing a polymer having a phosphoric acid ester group (Japanese Patent Laid-Open No. 2007-290369), a substrate film having at least one inorganic layer and at least one amorphous carbon layer mainly composed of amorphous carbon. And a gas barrier laminate film (Japanese Patent Application Laid-Open No. 2007-136800), wherein the ratio of (number of oxygen atoms / number of carbon atoms) on the surface of at least one amorphous carbon layer is 0.01 or more, thermoplasticity A barrier layer (A layer) made of a polyvinyl alcohol resin, a hydrolyzate of silicon alkoxide, and a layered silicate on at least one surface of a substrate layer made of a resin film via an anchor coat layer, and a polyvinyl alcohol resin And the barrier layer (B layer) made of layered silicate is the A layer / B layer from the base material layer side. Barrier film obtained by laminating in this order (JP 2005-225117), can be used a barrier film such as.

These are to provide a transparent substrate with a layer (barrier film) that suppresses permeation of water vapor and various gases to the base material. For example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a silicon carbide film, an aluminum oxide film, Inorganic thin films such as an aluminum oxynitride film, a titanium oxide film, a zirconium oxide film, and a diamond-like carbon film, and a gas barrier film in which an inorganic thin film having a high gas barrier property and a flexible organic thin film are laminated are also used.
The dye-sensitized solar cell of the present invention is provided with a lead wire capable of taking out electricity from a dye-sensitized solar cell packaged with a barrier film, and fixed with a filling resin such as EVA resin having a high barrier property. It is preferable to connect to various electric appliances.

Furthermore, in the present invention, it is also preferable that the outside of the substrate of the photoelectrode layer and the counter electrode layer has the above-described barrier layer, which can improve the storage stability at high temperature and high humidity. In that case, it is important to be careful when handling a substrate provided with a barrier layer so as not to damage the substrate. A preferable water vapor permeability of the substrate with an outer barrier preferably used in the present invention is a decrease of 0.1 g / m ² / day in an environment of 40 ° C. and a relative humidity of 90% (90% RH), and more preferably 0.8%. It is 01 g / m ² / day or less, more preferably 0.0005 g / m ² / day or less, and particularly preferably 0.00001 g / m ² / day or less. In particular, even when the ambient temperature is more severe at 60 ° C. and 90% RH, the water vapor permeability of the substrate is more preferably 0.01 g / m ² / day or less, and still more preferably 0.0005 g / m ^2. / Day or less, particularly preferably 0.00001 g / m ² / day or less. Further, the oxygen permeability is preferably about 0.001 cc / m ² / day or less, more preferably 0.00001 cc / m ² / day, in an environment of 25 ° C. and 90% RH.

In the present invention, the use of the produced solar cell is not particularly limited. Preferably, it can be used as a power source for household power, a power source equivalent to a dry cell, or a power source equivalent to a button battery. For example, for unmanned equipment, maritime traffic (lighthouse, light buoy), land traffic (road sign, railway signal, intersection signal, emergency call), air traffic (obstacle indicator light, landing guide light), communication (wireless Relay station, weather observation telemeter, dam monitoring telemeter), electric corrosion prevention (oil and gas tanks and pipes, wharf, iron bridge), and other outdoor equipment (clocks, street lights, bus stops, telephone boxes, bulletin board lighting, evacuation areas) Mark lights), space (artificial satellites), etc.

For agriculture, forestry and fisheries, irrigation pumps, greenhouse fans, liquid fertilizer circulation pumps, grain drying fans, ranch electric fences, ranch drinking water pumps, aquaculture stirrers, storages, fish lamps, marine ranches, etc. I can do it. In addition, medical refrigerators for daily life and leisure use, refrigerators for medicines, clinic lighting, battery charging for motor boats, camping lighting, portable TV recorders, TVs, various AV devices (CD, DVD, Blu-ray, music, portable use) Mobile phone). In addition, alternative energy sources include solar power generation devices (for homes, factories, and power company equipment), solar power generation satellites, and solar cars. For indoor light use, such as calculators, remote controls for electrical products, and game consoles. Can also be applied.

According to the present invention, it is possible to provide a photoelectric conversion element having efficient power generation characteristics, and it is possible to improve deterioration of the photoelectric conversion element of the photoelectric conversion element due to storage aging. In addition, it is possible to provide an excellent dye-sensitized photoelectric conversion element even with an electrolytic solution having a small amount of iodine ions.

Although the specific example of this invention is given to the following, it is not limited to this.
[Example 1] (Invention)
(1-1) Preparation of electrolyte layer solution N-methylbenzimidazole 0.66 g, tetrabutylammonium iodide 7.38 g, 1,3-butylmethylimidazolium iodide 5.32 g, guanidine thiocyanate 0.58 g, Into a 5 mL volumetric flask, propylene carbonate was added to a total volume of 50 mL. After stirring for 1 hour by vibration with an ultrasonic cleaner, the solution was left in a dark place for 24 hours or more to prepare an electrolyte solution containing no iodine (electrolyte sample 11).

The absorption spectrum of an electrolytic solution containing no iodine and an electrolytic solution containing iodine was measured at an optical path length of 1 mm. It was confirmed that the preferable electrolytic solution (−) of the present invention containing no iodine has little absorption in the visible region and is almost transparent.

(1-2) Preparation of dye solution 7.2 mg of a ruthenium complex dye (N719, manufactured by Solaronics) was placed in a 20 mL volumetric flask. 10 mL of tert-butanol was mixed and stirred. Thereafter, 8 mL of acetonitrile was added, and the volumetric flask was stoppered, followed by stirring for 60 minutes by vibration with an ultrasonic cleaner. While keeping the solution at room temperature, acetonitrile was added to make the total volume 20 mL. The obtained sample solution (sample solution-12) was used.

(1-3) Production of Photoelectrode Layer 1-3-1) A polyethylene naphthalate film was used as a substrate for the photoelectrode layer and a production substrate for the conductive layer. Further, one surface thereof was coated with indium tin oxide (ITO) to obtain a polyethylene naphthalate film (ITO-PEN film, thickness 200 μm, sheet resistance 10Ω / □) (sample film-131).

1-3-2) Production of current collecting mesh with protective layer On sample film-131 produced in 1-3-1), a current collecting mesh having a protective layer was formed by the following method using a screen printing method. It carried out as follows.

(1-3-2-1) Preparation of current collecting mesh At the center of a screen (Asada mesh 3D mesh, # 200, emulsion thickness 15 μm) attached to a 32 cm × 32 cm aluminum frame, a width of 150 μm and a length of 10 cm Ten patterns were made at 5 mm intervals. This screen plate was set in a screen printing machine (MITANI, MEC-2400). The sample film-131 produced in 3-1) was fixed to a screen, and the clearance from the screen was set to 1 mm. A silver paste (Fujikura Kasei, Dotite D-550, silver filler) was applied on the sample film-131. The sample coated with the silver paste obtained after removing the screen was attached to a glass plate and dried at room temperature for 20 minutes, then dried at 150 ° C. for 30 minutes, and then a sample with a silver mesh (sample film) -1321). The thickness of the silver mesh portion of Sample Film-1321 was 6 μm.

(1-3-2-2) Preparation of protective film for current collecting mesh At the center of a screen (Asada mesh 3D mesh, # 200, emulsion thickness 15 μm) attached to a 32 cm × 32 cm aluminum frame, width 300 μm, length Ten patterns of 10 cm lines were made at intervals of 5 mm. This screen plate was set in a screen printing machine (MITANI, MEC-2400). The sample film-1321 produced in (1-3-2-1) was fixed to the above-described screen. At this time, it was confirmed that the screen pattern matched the position of the silver mesh. The clearance between the sample film-1321 and the screen was set to 1 mm. An insulating coating paste (Asahi Chemical Laboratory, CR-20T, 10% by mass) was applied to the screen, and screen printing was performed on the silver wiring. The sample film was removed from the screen, the end was attached to a glass plate, dried at room temperature for 10 minutes, and then dried at 150 ° C. for 10 minutes to produce a current collecting mesh having a protective layer (sample film) -1322). At this time, the thickness of the protective layer on the silver mesh was 15 μm, and the width was 30 μm on average. Here, the properties of the insulating coating paste used (Asahi Chemical Laboratory, CR-20T, 10% by mass) were applied on PEN, dried at room temperature for 10 minutes, and then dried at 150 ° C. for 10 minutes. Then, when a 15 μm thick resin layer similar to the protective layer was produced, it was confirmed that the pencil hardness was 2H and the insulation resistance value was 10 ¹⁵ Ω or more (25 ° C., 60% RH).

1-3-3) Production of Porous Photoelectrode Layer Consisting of Dye-Sensitized Semiconductor Particles Titanium paste (10% by mass) in which titanium oxide having an average particle diameter of 20 nm is dispersed in a butanol solution is prepared using a Baker type applicator. Then, it was applied on the sample film 1322 prepared in (3) so that the coating thickness was 150 μm. The obtained titanium paste-coated film was bonded to a glass plate with an end and dried at room temperature for 10 minutes, and then further dried by heating in a dryer at 150 ° C. for 20 minutes to obtain a porous layer for dye sensitization. A sample film-133P having a semiconductor particle layer was produced.

Sample film-133P was cut into a size of 6 × 11.5 cm. Furthermore, the edge of 5 mm was scraped from the outer side of the short side (6 cm) of the cut sample film-133, and further, 5 mm on one side of the long side and 10 mm on the other side were cut and shaped. The size of the sample film-133P after shaping was 4.5 cm × 10 cm. This sample film-133P was again heat-dried at 110 ° C. for 10 minutes.
Thereafter, the sample film-133P after shaping was immersed in an N719 dye solution of Sample-12 prepared in advance in (1-2). While keeping the dye solution at 40 ° C., the dye was adsorbed while gently stirring. Two hours later, the dye-adsorbed titanium oxide film was taken out of the petri dish, washed with acetonitrile three times, dried, and a sample film having a porous photoelectrode layer made of dye-sensitized semiconductor particles (sample film- 133).

(1-4) Production of counter electrode layer A polyethylene naphthalate film (ITO-PEN film, thickness 200 μm, sheet resistance 10Ω / □) coated with indium tin oxide (ITO) was cut into 20 cm × 100 cm. A PEDOT-PSS aqueous dispersion (1.2% by weight, manufactured by Polyscience) diluted 50% with ethanol was applied by a bar coater. After drying at room temperature, it was dried at 150 ° C. for 10 minutes to produce a counter electrode film having a light transmittance of 70%. Thereafter, it was cut into a size of 4.5 cm × 10 cm. One hole for electrolyte injection having a diameter of 1 mm was formed in a portion 1 cm from the short side of the film (sample film for counter electrode-14).

(1-5) Preparation of dye-sensitized photoelectric conversion element A Surlyn film (thickness 25 μm, manufactured by DuPont) was cut into a size of 5.5 cm × 11 cm, and the center portion was cut out to 4.5 × 10 cm, and a spacer film (Sample film-F) was produced. The conductive properties of the sample film-133 and the sample film-14 are sandwiched between the dye-adsorbed titanium oxide electrode film (sample film-133), the counter electrode film (sample film-14), and the spacer film sample film-F). The layers were laminated so that the layer surfaces face each other and dried in an oven at 110 ° C. for 20 minutes.

And the sample solution-2 which is electrolyte solution was inject | poured from one hole for electrolyte solution injection. After that, a Surlyn film is installed in the hole for electrolyte injection, further covered with a 5 mm square cover glass, and heated by a soldering iron heated to 110 ° C. from the top of the cover glass to adhere the cover glass. And sealed the hole. In order to increase current collection efficiency, conductive aluminum tape (No. 5805, manufactured by Sliontec Co., Ltd.) was attached to the electrode terminals of the produced dye-sensitized solar cell. At this time, an aluminum tape was wound so that the electrodes could be taken out from both sides of the solar cell, and the dye-sensitized photoelectric conversion element (dye-sensitized photoelectric conversion element sample-15) of the present invention was produced.

(1-6) Evaluation of dye-sensitized photoelectric conversion device 1-6-1) Pseudo solar light source (PEC-L11 type, Pexel The amount of light was adjusted to 1 sun (AM1.5G, 100 mWcm ⁻² (JIS-C-8912 class A)). Sample-15 which is the produced dye-sensitized photoelectric conversion element was connected to a source meter (2400 type source meter, manufactured by Keithley). For the current-voltage characteristics, the output current was measured while changing the bias voltage from 0 V to 0.8 V in units of 0.01 V under irradiation of 1 sun of light from the pseudo solar light source.

The output current was measured by integrating the values after 0.05 seconds and 0.15 seconds after changing the voltage in each voltage step. Measurement was also performed by stepping the bias voltage from 0.8 V to 0 V in the reverse direction, and the average value of the measurement in the forward direction and the reverse direction was used as photocurrent data. As a result, a current-voltage characteristic curve having a short-circuit current value of 200 mA, an open-circuit voltage value of 0.69 V, and a fill factor of 0.42 was obtained. In addition, the sample for comparison produced in exactly the same manner except that 1-3-2) the current collector mesh with a protective layer was not produced has a short-circuit current value of 10 mA at the maximum. It was extremely inferior to this.

1-6-2) Durability Evaluation 1-6-1) After the dye-sensitized solar cell element-15 used in the initial output characteristics was further left at 60 ° C. for 500 hours, its output characteristics were examined. It was confirmed that the output characteristics were almost equivalent. From the above, it was confirmed that the dye-sensitized solar cell element-15 of the present invention has excellent durability.

[Example 2] (Comparison)
In Example 1, (3-2-2) Dye sensitization for comparison consisting of current collecting mesh without protective layer exactly as in Example 1 except for the production of the current collecting mesh protective film. Solar cell element-25 was produced. The obtained dye-sensitized solar cell element-25 was evaluated according to 1-6-1) initial output characteristics and 1-6-2) durability evaluation of Example 1.

2-6-1) Initial output characteristics Similar to Example 1, excellent initial output characteristics were obtained.
2-6-2) Durability evaluation The characteristics were evaluated.
The dye-sensitized solar cell element-25 was left at 60 ° C. for 500 hours and then its output characteristics were examined. As a result, no output was obtained and no role as a dye-sensitized solar cell element was shown. . From the above, it was confirmed that the current collecting mesh provided with the protective layer of the present invention was very excellent in durability.

Example 3 (Invention)
In Example 1, (1-3-2-2) Dye-sensitized solar cell element of the present invention was made in exactly the same manner as in Example 1 except that the production of the protective film for the current collecting mesh was changed as follows. 35 was produced.

(3-3-2-2) Production of protective film for current collecting mesh At the center of a screen (Asadamesh 3D mesh, # 200, emulsion thickness 15 μm) attached to a 32 cm x 32 cm aluminum frame, width 300 μm, length Ten patterns of 10 cm lines were made at intervals of 5 mm. This screen plate was set in a screen printing machine (MITANI, MEC-2400). The sample film-131G produced in (1-1) was fixed to the aforementioned screen. At this time, it was confirmed that the screen pattern matched the position of the silver mesh. The clearance between the sample film-131G and the screen was set to 1 mm.

Insulating coating paste (polyurethane resin binder (Mitsui Chemicals Co., Ltd., Olester UD350, diluted to a solid content of 20% by mass)) was applied to the screen and screen-printed on the silver wiring. Remove the sample film from the screen, The edge part was affixed to the glass plate, dried at room temperature for 10 minutes, and then dried at 150 ° C. for 10 minutes to produce a current collecting mesh having a protective layer (sample film-331GH). The protective layer on the silver mesh had a thickness of 15 μm and an average width of 25 μm.

3-6-2) Durability Evaluation 3-6-1) The dye-sensitized solar cell element-35 used in the initial output characteristics was further allowed to stand at 60 ° C. for 500 hours. It was confirmed that the characteristics were almost equivalent to the characteristics. From the above, it was confirmed that the dye-sensitized solar cell element-35 of the present invention has excellent durability.

Example 4 (Invention)
In Example 1, the dye-sensitized solar cell element-45 of the present invention was produced in the same manner as in Example 1 except that the preparation of (1-2) dye solution was changed as follows.

(4-2) Preparation of dye solution 0.066 g of N-methylbenzimidazole (IV-1), 0.738 g of tetrabutylammonium iodide (II-4), 1,3-butylmethylimidazolium iodide (III- 1) 0.532 g and 0.058 g of guanidine thiocyanate were placed in a 5 mL volumetric flask, and γ-butyrolactone was added to a total volume of 5 mL. After stirring for 1 hour by vibration with an ultrasonic cleaner, the solution was left in a dark place for 24 hours or more to prepare an electrolytic solution containing no iodine.

4-6-2) Durability Evaluation 4-6-1) The dye-sensitized solar cell element-45 used in the initial output characteristics was further allowed to stand at 60 ° C. for 500 hours. It was confirmed that the characteristics were almost equivalent to the characteristics. From the above, it was confirmed that the dye-sensitized solar cell element-45 of the present invention has excellent durability.

Example 5 (Invention)
The dye-sensitized solar cell element-15 produced in Example 1 was sealed in a barrier package having a moisture permeability of 10 ⁻⁴ g / day · cm ² and filled with a packaging material. Was made.
(Production of packaging materials)
A deposited thin film layer of silicon oxide having a thickness of 30 nm is laminated on one surface of a base material made of a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm, and the coating amount is 3 g / m ² (dry state) on the deposited thin film layer. A biaxially stretched nylon film having a thickness of 15 μm is laminated via a polyurethane adhesive, and the thickness of the biaxially stretched nylon film is 30 μm via a polyurethane adhesive having a coating amount of 3 g / m ² (dry state). unstretched polypropylene film was laminated, _C 3 _F 7 on the other side _- from _{(OC 3 F 6) 24 -O-} (CF 2) 2 -C 2 H 4 -O-CH 2 Si (OCH 3) 3 Laminate having an antifouling layer with a thickness of 3 μm was applied by applying a coating solution obtained by diluting a perfluoropolyether group-containing silane coupling agent to 0.5 wt% with perfluorohexane To obtain a fee.

(Preparation of dye-sensitized solar cell element-55 encapsulating packaging material)
The non-stretched polypropylene film surfaces of the two laminated materials slit into the predetermined dimensions of the laminated material are overlapped, three sides are heat-sealed, and a three-side sealed bag (packaging bag) having one side as an opening is created. The dye-sensitized photoelectric conversion element-15 with a cable is inserted from the opening of the three-way seal bag, one end of the cable is taken out of the bag, the air in the bag is sucked in vacuum, and then heat-sealed and sealed. A prepackaged dye-sensitized photoelectric conversion element-55 was obtained.

5-6-2) Durability Evaluation When the output characteristics of the packaged dye-sensitized photoelectric conversion element-55 of the present invention were allowed to stand for 3000 hours at 40 ° C. and 90% relative humidity, the initial output characteristics were obtained. On the other hand, it was confirmed that almost the same characteristics were exhibited. From the above, it was confirmed that the packaged dye-sensitized photoelectric conversion element-55 of the present invention has excellent durability.

[Example 6]
The dye-sensitized solar cell element-15 produced in Example 1 was encapsulated in a high-barrier packaging body having the following moisture permeability of 10 ⁻⁶ g / day · cm ² or less, and encapsulated in the packaging material. A solar cell element-65 was produced.

(Production of packaging materials)
(6H-1) Base material of packaging material: 50 μm thick polyethylene terephthalate on one side, the following anchor coat layer, inorganic thin film layer (MH layer), polyvinyl alcohol / ethylene / unsaturated carboxylic acid copolymer / inorganic particles / An organic layer (YA layer) composed of a crosslinking agent (5/80/30/5 weight ratio), MH layer, YA layer, MH layer, YA layer, MH layer, and YA layer are laminated in this order, and a barrier layer is formed. A packaging material was prepared.

(6H-2) Preparation method of each liquid 6H-2-1) Anchor coat isocyanate compound (“Coronate L” manufactured by Nippon Polyurethane Industry) and saturated polyester (“Byron 300” manufactured by Toyobo Co., Ltd.) at a weight ratio of 1: 1. Used in combination.

6H-2-2) Preparation of aqueous solution of polyvinyl alcohol (PVA) Ion exchange of polyvinyl alcohol (PVA, "GOHSENOL NM-14" manufactured by Nippon Synthetic Chemical Industry Co., Ltd., saponification degree 99 mol% or more, polymerization degree 1400) The mixture was stirred in water and dissolved at 95 ° C. for 60 minutes to obtain a PVA aqueous solution (a-1) having a solid content concentration of 10%.

6H-2-3) Preparation of ethylene / unsaturated carboxylic acid copolymer aqueous liquid Ethylene / acrylic acid copolymer (EAA) (acrylic acid 20 wt%, MFR: 300 g / 10 min), ammonia and ion-exchanged water The mixture was stirred and mixed at 95 ° C. for 2 hours to prepare an aqueous liquid (b-1) having a neutralization degree of 50% and a solid content of 20%.

6H-2-4) Preparation of aqueous solution of inorganic particles According to the information from silicic acid aqueous solution, colloidal silica sol is prepared and passed through hydrogen type cation exchange resin column, hydroxyl type anion exchange resin column, hydrogen type cation exchange resin column in this order, and ammonia. An aqueous silica sol having a pH of 9, an average particle diameter of 4 nm, and various metal oxide concentrations of less than 500 ppm was prepared with water.

6H-2-5) Preparation of Crosslinking Agent Liquid 130 parts by mass of hexamethylene diisocyanate, 170 parts by mass of polyethylene glycol monomethyl ether (average molecular weight 400), 20 parts by mass of 4,4′-dicyclohexylmethane diisocyanate and 3-methyl-1- 3 parts by mass of phenyl-2-phospholene-1-oxide was added and reacted at 185 ° C. under a nitrogen stream to prepare a carbodiimide group-containing crosslinker solution.

(6H-3) Production of packaging material film provided with barrier layer An anchor coat layer having a thickness of 0.1 μm is formed by applying and drying an anchor coat liquid on one surface of the biaxially stretched PET film (hereinafter referred to as OPET). Formed. Next, SiO was evaporated by a high-frequency heating method under a vacuum of 1 × 10 ⁻⁵ Torr using a vacuum deposition apparatus, and an inorganic thin film layer having a thin film thickness of about 20 nm was formed on the anchor coat layer. Furthermore, the organic layer solution is applied onto the surface of the inorganic thin film layer by a gravure roll coating method with a wet thickness of 2.9 g / m ² , a film running speed of 200 m / min, and dried with hot air at 90 ° C. for 5 seconds. A coating layer (organic layer) having a thickness of 0.4 μm was prepared. Furthermore, the inorganic layer and the organic layer were laminated | stacked 2 layers each in order, and the barrier film (barrier film-6H3) which has the barrier property with the outstanding water vapor | steam and gas was obtained.

(Preparation of dye-sensitized solar cell element-65 encapsulating packaging material)
A three-sided sealing bag (packaging) in which the unstretched polypropylene film surfaces of two laminated materials slit into a predetermined dimension are laminated on the laminated material (barrier film-6H3), the three sides are heat-sealed, and one side is an opening. Bag), insert a dye-sensitized photoelectric conversion element-15 with a cable from the opening of the three-side seal bag, take out one end of the cable outside the bag, and suck the air in the bag in a vacuum, Heat-sealed and sealed to obtain a prepackaged dye-sensitized photoelectric conversion element-65 of the present invention.

6-6-2) Durability Evaluation When the packaged dye-sensitized photoelectric conversion element-65 of the present invention was allowed to stand for 1000 hours at 60 ° C. and 90% relative humidity, its output characteristics were examined. On the other hand, it was confirmed that almost the same characteristics were exhibited. From the above, it was confirmed that the packaged dye-sensitized photoelectric conversion element-65 of the present invention has excellent durability.

[Example 7]
In Example 1, the dye-sensitized photoelectric conversion element (dye sensitization) of the present invention was exactly the same as Example 1 except that the substrate for the photoelectrode layer and the substrate for the counter electrode layer and the conductive layer were changed as follows. Type photoelectric conversion element sample-75) was produced.
7-3-1) Preparation of photoelectrode layer substrate and conductive layer The above barrier film-6H3 having a barrier layer on one side is used as the substrate, and indium tin oxide (ITO) is coated on the opposite side as the conductive film. Polyethylene telenaphthalate film (ITO-PET film, thickness 200 μm, sheet resistance 15Ω / □) was used to obtain a PET film having an ITO conductive layer.
(7-4) Production of counter electrode layer 7-3-1) The counter electrode layer of the present invention was produced in the same manner as the production of the substrate of the photoelectrode layer and the conductive layer.

7-6-2) Durability Evaluation The dye-sensitized photoelectric conversion element-75 comprising the substrate provided with the gas barrier layer of the present invention was allowed to stand for 3000 hours at 60 ° C. and 90% relative humidity, and then its output characteristics were examined. As a result, it was confirmed that the characteristics were almost equivalent to the initial output characteristics. From the above, it was confirmed that the packaged dye-sensitized photoelectric conversion element-75 of the present invention has excellent durability.

Example 8 (Invention)
In the production of (1-3-2-1) current collecting mesh of Example 1, silver paste (Fujikura Kasei, Dotite D-550, silver filler) was replaced with nickel paste (Fujikura Kasei, Dotite FN-101, nickel filler). Except for changing to paste, the dye-sensitized photoelectric conversion element-85 of the present invention was produced in the same manner as in Example 1. The result of measurement of the output current showed excellent characteristics similar to those of Example 1. Further, when the output characteristics were examined after being allowed to stand at 60 ° C. for 500 hours, it was confirmed that the characteristics were substantially equivalent to the initial output characteristics. From the above, it was confirmed that the dye-sensitized solar cell element-85 of the present invention has excellent durability.

[Example 9] (Invention)
In preparation of (1-3-2-1) current collecting mesh of Example 1, silver paste (Fujikura Kasei, Dotite D-550, silver filler) was changed to silver / copper paste (Fujikura Kasei, Dotite FE-107, silver / Except for changing to a copper filler paste, a dye-sensitized photoelectric conversion element-95 of the present invention was produced in the same manner as in Example 1. The result of measurement of the output current showed excellent characteristics similar to those of Example 1. Further, when the output characteristics were examined after being allowed to stand at 60 ° C. for 500 hours, it was confirmed that the characteristics were substantially equivalent to the initial output characteristics. From the above, it was confirmed that the dye-sensitized solar cell element-95 of the present invention has excellent durability.

Example 10 (Invention)
In the production of (1-3-2-1) current collecting mesh of Example 1, the silver paste (Fujikura Kasei, Dotite D-550, silver filler) was replaced with the carbon paste (Fujikura Kasei, Dotite XC-12, carbon filler). Except for changing to a paste, the dye-sensitized photoelectric conversion element-105 of the present invention was produced in the same manner as in Example 1. The result of measurement of the output current showed excellent characteristics similar to those of Example 1. Further, when the output characteristics were examined after being allowed to stand at 60 ° C. for 500 hours, it was confirmed that the characteristics were substantially equivalent to the initial output characteristics. From the above, it was confirmed that the dye-sensitized solar cell element-105 of the present invention has excellent durability.

Example 11 (Invention)
In the production of (1-3-2-1) current collecting mesh of Example 1, the silver paste (Fujikura Kasei, Dotite D-550, silver filler) was replaced with the carbon paste (Fujikura Kasei, Dotite FA-401C, silver filler). A dye-sensitized photoelectric conversion element-115 of the present invention was produced in the same manner as in Example 1 except that the paste was changed. The result of measurement of the output current showed excellent characteristics similar to those of Example 1. Further, when the output characteristics were examined after being allowed to stand at 60 ° C. for 500 hours, it was confirmed that the characteristics were substantially equivalent to the initial output characteristics. From the above, it was confirmed that the dye-sensitized solar cell element-115 of the present invention has excellent durability.

[Example 12] (the present invention)
In the preparation of the dye solution of (1-2) in Example 1, a ruthenium complex dye (N719, manufactured by Solaronics)
Ruthenium complex dyes with 2-cyano-3- [5 '''-(9-ethyl-9H-carbazol-3-yl)-3', 3 '', 3 ''', 4-tetra-n-hexyl -[2,2 ', 5', 2 '', 5 '', 2 ''']-quarter thiophenyl-5-yl] acrylic acid, except that it is changed to acrylic acid. The dye-sensitized photoelectric conversion element-125 was prepared. The result of measurement of the output current showed excellent characteristics similar to those of Example 1. Further, when the output characteristics were examined after being allowed to stand at 60 ° C. for 500 hours, it was confirmed that the characteristics were substantially equivalent to the initial output characteristics. From the above, it was confirmed that the dye-sensitized solar cell element -125 of the present invention has excellent durability.

Claims (9)

In a dye-sensitized photoelectric conversion element having a photoelectrode layer made of dye-sensitized semiconductor particles, an electrolyte layer, and a counter electrode layer in this order, the photoelectrode layer is a collection with a substrate, a conductive layer, and a protective layer. A dye-sensitized photoelectric conversion element comprising an electrode layer in which an electric mesh and a dye-sensitized semiconductor particle layer are sequentially laminated. The protective layer of the current collecting mesh with the protective layer is a crosslinked resin composition comprising at least one resin selected from an epoxy resin, a urethane resin, an acrylic resin or a methacrylate resin, and an ester resin and a crosslinking agent. The dye-sensitized photoelectric conversion element according to claim 1, which is characterized by: The dye-sensitized photoelectric conversion element according to claim 1 or 2, wherein the current-collecting mesh of the current-collecting mesh with a protective layer and / or its protective layer is formed by screen printing. The protective layer of the current collecting mesh with the protective layer is a resin composition having a pencil hardness of 2H or more and a resistance value of 10 ¹² Ω / □ or more (25 ° C, 60% RH). The dye-sensitized photoelectric conversion element according to 1 to 3. In the aprotic solvent, the electrolyte layer has 0.05 to 5 M of aliphatic quaternary ammonium ions having 4 to 80 total carbon atoms and imidazolium ions having 4 to 43 total carbon atoms. 5. The dye-sensitized photoelectric conversion element according to claim 1, comprising 0.05 to 5 M and an electrolytic solution in which iodide ions are dissolved in an amount of 0.1 to 10 M. 6. The dye-sensitized photoelectric conversion element according to claim 1, wherein a ratio of triiodide ions to iodide ions in the electrolytic solution is less than 1 mol%. In the solvent of the electrolytic solution, a benzimidazole compound having 7 to 47 total carbon atoms is dissolved in an amount of 0.01 to 1M, and a thiocyanate ion or an isothiocyanate ion is dissolved in an amount of 0.01 to 1M. The dye-sensitized photoelectric conversion element according to claim 1, further comprising 0.01 to 1 M of guanidinium ion having 1 to 61 total carbon atoms dissolved therein. The dye-sensitized photoelectric conversion element according to claim 1, wherein the dye-sensitized photoelectric conversion element is a substrate having a gas barrier property. The dye-sensitized photoelectric conversion element according to claim 1, wherein the dye-sensitized photoelectric conversion element is housed in a gas barrier packaging bag made of a transparent plastic film substrate.