JP4787540B2 - Method for producing dye-sensitized solar cell element - Google Patents

Description

  The present invention relates to a method for producing a dye-sensitized solar cell element.

  The dye-sensitized solar cell announced by Gretzell et al. In 1991 is a wet solar cell that uses a porous titanium oxide thin film spectrally sensitized with a ruthenium complex as a working electrode, and has the same performance as a silicon solar cell. Has been reported (see Non-Patent Document 1). Since this method can be used without purifying an inexpensive oxide semiconductor such as titanium oxide with high purity, an inexpensive dye-sensitized solar cell element can be provided, and the absorption of the dye is broad. There is an advantage that light in almost all wavelength regions of visible light can be converted into electricity. However, on the other hand, since it is a wet solar cell in which electrical connection with the counter electrode is performed by an electrolyte solution, there is a concern that when used for a long period of time, the photoelectric conversion efficiency is remarkably lowered due to depletion of the electrolyte and the device does not function.

Under such circumstances, various sealing materials and installation methods are being studied in order to prevent electrolyte depletion over time in dye-sensitized solar cell elements.
For example, an epoxy resin, a silicon resin, or the like is used as the sealing resin, and a method of fixing the sealing portion with a solid material for sealing such as glass, metal, or plastic has been reported (see Patent Document 1).
However, in this method, the sealing resin installation position uses the cell substrate cross section, and these sealing resins are eroded or swollen by the solvent in the electrolytic solution, and even if a sealing solid is used. The contact portion with the electrolyte has a problem in long-term sealing performance.

In addition, a method has been reported in which a polyisobutylene resin is used as a base material for the sealing resin, a thermosetting polyisobutylene resin is used for the cell peripheral seal portion, and an ultraviolet curable polyisobutylene resin is used for the electrolyte inlet. (See Patent Document 2).
However, although the polyisobutylene resin can suppress the erosion or swelling of the solvent and iodine in the electrolyte solution, the electrolyte is injected after the sealing material is pre-cured to prepare the cell, and then the injection port is made of an ultraviolet curable sealing material. In order to seal, the cell manufacturing process is complicated, and the seal at the inlet is in contact with the electrolyte before UV curing, which may cause problems in curing or adhesion to the substrate.

In addition, a method has been reported in which a gelled electrolyte or a solid electrolyte as an electrolyte is sandwiched between opposing substrates and then the cell is heated and pressed to fluidize and pressure-bond the electrolyte layer (see Patent Document 3).
However, although the electrolyte layer has sufficient adhesion to the opposing substrate, the seal around the cell is sealed by using an epoxy resin or the like on the periphery of the cell after the thermocompression bonding. Occasionally, components in the electrolyte may evaporate from the cell peripheral cross section, and the solar cell performance may be deteriorated. In addition, since the sealing material is not disposed in the cell surface, the seal part will cause problems such as peeling in the long term. There is a fear.

JP 2000-173680 A JP 2002-313443 A JP 2004-319197 A B. O'Regan, M. Gratzel, "Nature" (UK), 1991, 353, p. 737

  The present invention has been made in view of such a situation, and provides a method for producing a dye-sensitized solar cell element having excellent long-term stability without impairing solar cell performance.

  That is, in the present invention, an electrode substrate having a semiconductor layer modified with a dye on a light-transmitting conductive substrate and a counter electrode substrate having a catalyst layer on the conductive substrate are opposed to each other at a predetermined interval. And a method for producing a dye-sensitized solar cell element in which an electrolyte is disposed between these substrates, and a peripheral portion between the substrates is sealed with a sealing material, wherein a curable material is used as the sealing material. And forming a cell by providing a through-hole in a part of the seal part, sealing the through-hole by vacuum degassing the inside of the cell, and then curing the sealing material. The present invention relates to a method for producing a sensitive solar cell element.

The present invention is described in detail below.
1 and 2 are schematic cross-sectional views of a dye-sensitized solar cell element produced by a conventional technique.
FIG. 1 shows a state in which a conductive substrate 2 having a catalyst layer 4 and a transparent conductive substrate 1 having a semiconductor layer 3 modified with a dye are superposed, an electrolyte 12 is soaked between the substrates, and then the periphery of the cell is epoxy-coated. In addition to the sealing material 10 such as resin, a cell is manufactured by sealing using a sealing solid material 11 such as plastic.
FIG. 2 shows that when a conductive substrate 2 having an electrolyte inlet 9 and a catalyst layer 4 and a transparent conductive substrate 1 having a semiconductor layer 3 modified with a dye are overlapped, a sealing material 10 is applied to the periphery of the cell. Then, after the cell is manufactured, the electrolyte 12 is injected from the injection port, and then the injection port is sealed to manufacture the cell.

FIG. 3 is an example of a schematic cross-sectional view of a dye-sensitized solar cell element produced by the method of the present invention.
As shown in FIG. 3, the dye-sensitized solar cell element according to the present invention includes an electrode substrate having a semiconductor layer 3 modified with a dye on a light-transmitting conductive substrate 1, and a conductive substrate 2. This is a configuration in which a counter electrode substrate having a catalyst layer 4 thereon is opposed to each other with a predetermined interval, an electrolyte 5 is disposed between these substrates, and a sealing material 6 is disposed at a peripheral portion between the substrates.

FIG. 4 is an example of a schematic diagram regarding the installation of the sealing material 6 in the present invention, and a through-hole 8 for vacuum deaeration inside the cell is provided. In this vacuum degassing step, the through-hole is sealed by bonding the sealing materials.
FIG. 5 shows an example of a method in which after a seal as shown in FIG. 4 is installed, an electrolyte is filled in a cell in which opposing substrates are stacked, and the cell is vacuum degassed.

  In the present invention, a curable material is used as the sealing material. The curable material used in the present invention is a component that seals the inside of the cell and isolates it from the outside, which may affect the performance of the element, such as active gas such as moisture, oxygen, carbon monoxide, etc. The material is not particularly limited as long as it can block transmission, and various curing materials such as thermosetting, photocuring, and electron beam curing types can be used for the curing method. is there.

  Specific examples of the curable material include polyisobutylene resin, phenol resin, urea resin, epoxy resin, polyvinyl acetate, polyvinyl acetal, polyvinyl alcohol, acrylic acid ester, methacrylic acid ester, and cyanoacrylic acid ester. And curable resins such as polyamide. These may be used alone or as a mixture of two or more. Further, various improvements may be added by modifying these or adding a filler. Among these, polyisobutylene resin, epoxy resin, and acrylic modified epoxy resin (in this case, those having an acrylic residue of 0.01 to 0.3 mol, more preferably epoxy, per 1 mol of the epoxy residue contained) Desirable is an epoxy resin that is acrylically modified so that an acrylic residue is contained in an amount of 0.05 to 0.2 mol per mol of the residue.

The method for sealing the cells using these curable resins is not particularly limited, and various known methods can be applied. For example,
(1) A method of forming the curable resin paste in a desired shape on a substrate surface using a known printing method,
(2) A method of applying the curable resin to the substrate surface as needed,
(3) A method of forming an arbitrary pattern on a substrate by sweeping while discharging the curable resin from a nozzle,
For example, a method of applying and sealing a sealing material can be used, and the method according to (3) is particularly preferable.
The sealing material may be applied to the substrate only on one of the pair of substrates or on both.

The curable resin may contain a spacer material for the purpose of adjusting the interval (cell interval) between the opposing substrates. The spacer material used for this purpose is at least a non-conductive material, and the shape thereof is not particularly limited, and any shape such as a sheet shape, a spherical shape, a fiber shape, and a rod shape can be used. Examples thereof include glass beads, plastic beads, glass fibers, and plastic fibers.
The diameter of the spacer material is not particularly limited, but is preferably 300 μm or less, more preferably 100 μm or less.

  One or more through holes (exhaust ports) are provided in the seal portion manufactured by the above method. The through-hole can be easily made by, for example, intentionally not applying a sealing material, but may have any shape as long as the two spaces partitioned by the seal portion are simply connected.

The size of the through-hole of the seal part is not particularly limited, but it is sufficient that the through-hole part is deformed, closed and sealed under vacuum, preferably 0.1 mm to 5 mm width, more preferably 0.5 mm to 2 mm width. It is preferable to do this.
Further, the number of through-holes to be installed in the seal portion is not particularly limited as long as the inside of the element can be vacuum deaerated. However, considering the installation effort, it is preferably 20 or less, more preferably 10 or less. preferable.

  In addition, vacuum treatment is performed to remove gas such as oxygen contained in the electrolyte installed in the cell. In the present invention, a through-hole is provided in a part of the seal portion, and the inside of the cell at the time of vacuum processing is installed. By using a sealing material having a deaeration port and curable at the same time, the inside of the cell is evacuated and the sealing material is deformed at the same time, and the through port is closed, so that the sealing proceeds simultaneously. Therefore, the sealing work for device fabrication is eliminated and the work can be simplified.

The element can be vacuum-treated by inserting the element into a bag-like pack made of rubber sheets such as Viton rubber or neoprene rubber loaded with a jig that can be evacuated, or plastic films such as nylon or polyethylene. It is preferable to deaerate and seal under vacuum, but any method can be used as long as the device can be vacuum processed.
Further, there is no restriction on the number of elements inserted into the bag-shaped pack, and two or more elements may be inserted simultaneously. Needless to say, work efficiency is improved by simultaneous processing of a plurality of elements.

  Further, in the present invention, when the peripheral seal portion is crimped and sealed with a clip or the like without degassing under vacuum, the air dissolved in the electrolyte layer and the air remaining in the cell internal space are completely Since it is sealed without being removed, the cell spacing is expanded by the amount of residual air, resulting in poor adhesion between the substrate and the electrolyte layer, so that the solar cell performance is lowered and the long-term performance stability is also lowered. It is important to deaerate and seal under vacuum.

  The method for adjusting the cell interval is not particularly limited as long as the cell interval can be adjusted. For example, since the inside of the cell is a vacuum, it can be adjusted to a predetermined interval by exposing the cell to atmospheric pressure before the peripheral sealing material is cured. Further, the cell interval can be adjusted by curing the sealing material while setting the cell before curing of the sealing material in the pressure press and adjusting the thickness to a predetermined thickness. Further, as described above, a spacer material may be included in the sealing material.

As for the curing method of the sealing material, any method may be used as long as the cell interval can be maintained. For example, a method of curing in a state of being loaded in the bag-shaped pack and the inside of the bag-shaped pack. Either method of taking out the cell and curing it can be applied.
Needless to say, the curing method of the curable resin varies depending on the curable resin used.

In the case of thermosetting, those that can be cured at room temperature can be used. However, when heating is usually required, it is sufficient that curing can be performed between room temperature and 150 ° C, preferably between room temperature and 100 ° C. The time required for curing is not particularly limited as long as it does not impair the characteristics of the dye-sensitized solar cell, but is preferably within 24 hours, more preferably within 1 hour.
In the case of photocuring, any low-pressure, high-pressure, or ultrahigh-pressure mercury lamp, xenon lamp, incandescent lamp, laser light, or the like can be used as long as the lamp is adapted to the absorption wavelength of the initiator. During curing, the entire surface of the device may be uniformly exposed, so that the entire surface may be cured at the same time, or the focused spot light is scanned by moving a lamp or light source or using a light-guiding material such as an optical fiber. Then, it may be cured sequentially.
Moreover, you may make it harden | cure by repeating twice or more.

The electrode substrate (photoelectrode) of the dye-sensitized solar cell element in the present invention is composed of a conductive substrate having optical transparency and a semiconductor layer containing a photosensitized dye.
A light-transmitting conductive substrate usually has a transparent electrode layer on a transparent substrate.
The transparent substrate is not particularly limited, and the material, thickness, dimensions, shape, and the like can be appropriately selected according to the purpose. For example, colorless or colored glass, meshed glass, glass block, etc. are used, and colorless. Alternatively, a colored transparent resin may be used. Examples of such resins include polyesters such as polyethylene terephthalate, polyamide, polysulfone, polyether sulfone, polyether ether ketone, polyphenylene sulfide, polycarbonate, polyimide, polymethyl methacrylate, polystyrene, cellulose triacetate, and polymethylpentene. The term “transparent” in the present invention means a transmittance of 10 to 100%, preferably a transmittance of 50% or more, and the substrate in the present invention has a smooth surface at room temperature. The surface may be a flat surface or a curved surface, or may be deformed by stress.

Further, the transparent electrode layer acting as an electrode is not particularly limited as long as it fulfills the object of the present invention. For example, a metal thin film such as gold, silver, chromium, copper, and tungsten, a conductive film made of metal oxide, etc. Is mentioned. Examples of the metal oxide include Indium Tin Oxide (ITO (In ₂ O ₃ : Sn)) obtained by doping a metal oxide such as tin and zinc with a small amount of other metal elements, Fluorine doped Tin Oxide (FTO (SnO ₂ )). : F)), Aluminum doped Zinc Oxide (AZO (ZnO: Al)) and the like are preferably used.
The thickness of the conductive film is usually 100 to 10,000 μm, preferably 500 to 3000 μm. The surface resistance (resistivity) is appropriately selected, but is usually 0.5 to 500 Ω / sq, preferably 1 to 50 Ω / sq.

  The method for forming the transparent electrode layer is not particularly limited, and a known method is appropriately selected and used depending on the type of the metal or metal oxide used as the electrode layer. Usually, the vacuum deposition method, the ion plating method are used. CVD method, sputtering method, or the like is used. In either case, it is desirable that the substrate temperature be formed within a range of 20 to 700 ° C.

  In addition, when it is necessary to further reduce the surface resistance of the substrate having a semiconductor layer, a thin metal wire such as silver or gold may be provided on the conductive substrate, and any method can be applied as long as the object can be achieved. is there.

The semiconductor layer used in the present invention is not particularly limited, for _{example, Bi 2 S 3, CdS,} CdSe, CdTe, CuInS 2, CuInSe 2, Fe 2 O 3, GaP, GaAs, InP, Nb 2 O 5, PbS, Si, SnO ₂ , TiO ₂ , WO ₃ , ZnO, ZnS and the like can be mentioned, preferably CdS, CdSe, CuInS ₂ , CuInSe ₂ , Fe ₂ O ₃ , GaAs, InP, Nb ₂ O ₅ , PbS, SnO ₂ , TiO ₂ , WO ₃ , ZnO, and may be a plurality of combinations. Particularly preferred are TiO ₂ , ZnO, SnO ₂ and Nb ₂ O ₅ , and most preferred are TiO ₂ and ZnO.

The semiconductor used in the present invention may be single crystal or polycrystalline. As the crystal system, anatase type, rutile type, brookite type and the like are mainly used, and anatase type is preferable. A known method can be used for forming the semiconductor layer.
As a method for forming the semiconductor layer, the semiconductor nanoparticle dispersion, the sol solution, or the like can be obtained by coating on a substrate by a known method. The coating method in this case is not particularly limited, and various printing methods including a screen printing method, in addition to a method obtained in a thin film state by a casting method, a spin coating method, a dip coating method, and a bar coating method. Can be mentioned.
Although the thickness of a semiconductor layer is arbitrary, it is 0.1 micrometer-300 micrometers normally, Preferably it is 1 micrometer-50 micrometers.

In the dye-sensitized solar cell element of the present invention, a semiconductor layer modified with a dye (adsorption, inclusion, etc.) is used for the purpose of improving the light absorption efficiency of the semiconductor layer.
The dye that can be used in the present invention is not particularly limited as long as it is a dye that improves the light absorption efficiency of the semiconductor layer. Usually, one or more of various metal complex dyes and organic dyes are used. Can be used. In addition, in order to impart adsorptivity to the semiconductor layer, a functional group such as a carboxyl group, a hydroxyl group, a sulfonyl group, a phosphonyl group, a carboxylalkyl group, a hydroxyalkyl group, a sulfonylalkyl group, or a phosphonylalkyl group is included in the dye molecule. Those having a group are preferably used.
As the metal complex dye, a complex of ruthenium, osmium, iron, cobalt, zinc, metal phthalocyanine, chlorophyll, or the like can be used.

  As the organic dye, a cyanine dye, a hemicyanine dye, a merocyanine dye, a xanthene dye, a triphenylmethane dye, or a metal-free phthalocyanine dye can be used.

  As a method for adsorbing the dye to the semiconductor layer, a solution in which the dye is dissolved in a solvent is applied on the semiconductor layer by spray coating or spin coating and then dried. In this case, the substrate may be heated to an appropriate temperature. Alternatively, a method in which a semiconductor layer is immersed in a solution and adsorbed can be used. The immersion time is not particularly limited as long as the dye is sufficiently adsorbed, but is preferably 1 to 30 hours, particularly preferably 5 to 20 hours. Moreover, you may heat a solvent and a board | substrate when immersing as needed. Preferably, the concentration of the dye in the case of a solution is about 1 to 1000 mM / L, preferably about 10 to 500 mM / L.

  The solvent to be used is not particularly limited as long as it does not dissolve the dye and does not dissolve the semiconductor layer, such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and t-butanol. Nitrile solvents such as alcohol, acetonitrile, propionitrile, methoxypropionitrile, glutaronitrile, benzene, toluene, o-xylene, m-xylene, p-xylene, pentane, heptane, hexane, cyclohexane, heptane, acetone, Methyl ethyl ketone, diethyl ketone, 2-butanone, diethyl ether, tetrahydrofuran, ethylene carbonate, propylene carbonate, nitromethane, dimethylformamide, dimethyl sulfoxide, hexamethylphosphoamide, dimethoxy ester , Γ-butyrolactone, γ-valerolactone, sulfolane, dimethoxyethane, adiponitrile, methoxyacetonitrile, dimethylacetamide, methylpyrrolidinone, dimethylsulfoxide, dioxolane, sulfolane, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, ethyl phosphate Dimethyl, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, tris phosphate (trifluoromethyl), tris phosphate (pentafluoroethyl), Triphenyl polyethylene glycol phosphate, polyethylene glycol and the like can be used.

The counter electrode of the dye-sensitized solar cell element in the present invention is composed of a counter electrode substrate having a catalyst layer on a conductive substrate.
The conductive substrate only needs to be conductive or at least one surface of the conductive substrate, and may be a transparent conductive substrate or an opaque conductive substrate. Examples of the transparent conductive substrate include the transparent conductive substrate described above, and examples of the opaque conductive substrate include various metal electrodes and Au, Pt, Cr formed on a glass substrate. Can do.

The catalyst layer is for advancing the reduction reaction of the redox couple of the electrolyte, and any material having a catalytic function can be used. Examples of the material for forming such a catalyst layer include noble metals such as platinum, conductive organic compounds such as polydioxythiophene and polypyrrole, and carbon.
The formation method in particular of a catalyst layer is not restrict | limited, A well-known method is employable. For example, in the case of platinum or the like, it can be produced by a generally known vacuum deposition method, ion plating method, CVD method or sputtering method. In addition, the catalyst-forming material and the binder are mixed to form a paste, and screen printing, flat printing, gravure printing, intaglio printing, flexographic printing, letterpress printing, special printing on a conductive substrate surface, doctor blade method, etc. Can also be manufactured.

  The electrolyte used in the present invention is not particularly limited, and may be either a liquid system or a solid system, and preferably exhibits reversible electrochemical redox characteristics, but is not limited to a polymer solid electrolyte, gel electrolyte, normal temperature An electrolyte containing a molten salt is particularly preferred.

The liquid electrolyte is not particularly limited. Usually, a solvent, a substance exhibiting reversible electrochemical redox characteristics (soluble in a solvent), and, if necessary, a supporting electrolyte as a basic component Composed.
Any solvent can be used as long as it is generally used in electrochemical cells and batteries. Specifically, acetic anhydride, methanol, ethanol, tetrahydrofuran, propylene carbonate, nitromethane, acetonitrile, dimethylformamide, dimethyl sulfoxide, hexamethylphosphoamide, ethylene carbonate, dimethoxyethane, γ-butyrolactone, γ-valerolactone, sulfolane, dimethoxy Ethane, propiononitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, dimethylacetamide, methylpyrrolidinone, dimethyl sulfoxide, dioxolane, sulfolane, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, ethyldimethyl phosphate, tributyl phosphate, phosphorus Tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, phosphoric acid Tridecyl, tris phosphate (trifluoromethyl), tris phosphate (pentafluoroethyl), triphenyl polyethylene glycol phosphate, polyethylene glycol, and the like can be used. In particular, propylene carbonate, ethylene carbonate, dimethyl sulfoxide, dimethoxyethane, acetonitrile, γ-butyrolactone, sulfolane, dioxolane, dimethylformamide, dimethoxyethane, tetrahydrofuran, adiponitrile, methoxyacetonitrile, methoxypropionitrile, dimethylacetamide, methylpyrrolidinone, dimethylsulfoxide , Dioxolane, sulfolane, trimethyl phosphate and triethyl phosphate are preferred.

  Moreover, room temperature molten salts can also be used as a solvent. Here, the room temperature molten salt is a salt composed of an ion pair that is melted at room temperature (that is, in a liquid state) and usually has a melting point of 20 ° C. or lower and is a liquid at a temperature exceeding 20 ° C. Is a salt.

In addition, examples of substances that exhibit reversible electrochemical oxidation-reduction characteristics include what are commonly referred to as so-called redox materials, but the type is not particularly limited. Examples of such substances include ferrocene, p-benzoquinone, 7,7,8,8-tetracyanoquinodimethane, N, N, N ′, N′-tetramethyl-p-phenylenediamine, tetrathiafulvalene, thi Anthracene, p-toluylamine, etc. can be mentioned. Further, LiI, NaI, KI, CsI , CaI 2, 4 quaternary imidazolium iodide salt, iodine tetraalkylammonium Motoshio, Br ₂ and LiBr, NaBr, KBr, CsBr, and metal bromides, such as CaBr ₂ and the like, In addition, Br ₂ and tetraalkylammonium bromide, bipyridinium bromide, bromine salts, complex salts such as ferrocyanic acid-ferricyanate, sodium polysulfide, alkylthiol-alkyldisulfides, hydroquinone-quinones, viologen dyes and the like can be mentioned. .

As the redox material, only one of an oxidant and a reductant may be used, or the oxidant and the reductant may be mixed and added at an appropriate molar ratio. Further, these redox pairs may be added so as to show electrochemical responsiveness. Materials exhibiting such properties include halogen ions, SCN ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N _{^{-, PF 6 -, AsF 6}} -, CH 3 COO -, CH 3 (C 6 H 4) SO 3 -, and _{(C 2 F 5 SO 2)} 3 C - , such as ferrocenium having a counter anion selected from metallocenium of In addition to salts, halogens such as iodine, bromine and chlorine can also be used.

In addition, redox room temperature molten salts can also be used as substances exhibiting reversible electrochemical redox properties. Here, the redox room temperature molten salt is a salt composed of an ion pair melted at room temperature (that is, in a liquid state), and usually has a melting point of 20 ° C. or lower and is a liquid at a temperature exceeding 20 ° C. A salt consisting of a pair is shown, and a reversible electrochemical redox reaction can be performed.
The redox room temperature molten salt can be used alone or in combination of two or more.

  The amount of the substance exhibiting reversible electrochemical redox properties is not particularly limited as long as it dissolves in the solvent, but is usually 1% by mass to 50% by mass, preferably 3% by mass with respect to the solvent. % To 30% by mass is desirable.

Further, as the supporting electrolyte added as necessary, salts, acids, alkalis, and room temperature molten salts that are usually used in the field of electrochemistry or the field of batteries can be used.
The salt is not particularly limited, and examples thereof include inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, cyclic quaternary ammonium salts, and quaternary phosphonium salts. preferable.
The acids are not particularly limited, and inorganic acids and organic acids can be used. Specifically, sulfuric acid, hydrochloric acid, phosphoric acids, sulfonic acids, carboxylic acids and the like can be used.
The alkalis are not particularly limited, and any of sodium hydroxide, potassium hydroxide, lithium hydroxide and the like can be used.

  The electrolyte may be a liquid as described above, but a polymer solid electrolyte (ion conductive film) may be used. Particularly preferable examples of the polymer solid electrolyte include a polymer matrix containing a substance exhibiting at least reversible electrochemical redox characteristics in a polymer matrix, and further containing a plasticizer if desired. In addition to these, other optional components such as the above-mentioned supporting electrolyte and room temperature molten salt may be further contained as desired.

  The material that can be used as the polymer matrix is not particularly limited as long as a solid state or a gel state is formed by the polymer matrix alone, or by the addition of a plasticizer, the addition of a supporting electrolyte, or the addition of a plasticizer and a supporting electrolyte. In general, so-called polymer compounds that are generally used can be used.

  Examples of the polymer compound exhibiting characteristics as the polymer matrix include hexafluoropropylene, tetrafluoroethylene, trifluoroethylene, ethylene, propylene, acrylonitrile, vinylidene chloride, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, and methyl methacrylate. And polymer compounds obtained by polymerizing or copolymerizing monomers such as styrene and vinylidene fluoride. These polymer compounds may be used alone or in combination. Among these, a polyvinylidene fluoride polymer compound is particularly preferable.

  The thickness of the electrolyte layer is not particularly limited, but is preferably 1 μm or more, more preferably 10 μm or more, and preferably 3 mm or less, more preferably 1 mm or less, and still more preferably 0.5 mm or less.

  According to the present invention, the sealing step is completed simultaneously with the vacuum degassing by installing the curable sealing material provided with the through-hole in the in-plane peripheral edge of the dye-sensitized solar cell element, and then the sealing material Is cured, a dye-sensitized solar cell element with good durability can be produced by a simplified method.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Example 1]
On a 10 cm square ITOF glass having a surface resistance of 2Ω / sq, a titania paste Ti-Nanoxide T / SP manufactured by SOLARONIXS was applied by a screen printing method and dried at 100 ° C. The coated substrate was baked at 450 ° C. for 30 minutes. When the film thickness of the titania semiconductor layer after firing was measured with a stylus type film thickness meter, it was found to be 12 μm. This substrate was immersed in a ruthenium dye / ethanol solution (3.0 × 10 ⁻⁴ mol / L) represented by the following formula (1) for 15 hours to adsorb the dye.

Next, a gel electrolyte film was produced as follows.
6 g of a poly (vinylidene fluoride-hexafluoropropylene) block copolymer (hexafluoropropylene content: 5% by weight) was dissolved in a mixed solvent of 14 g of γ-butyrolactone and 15 g of acetone.
To this solution, 230 mg of iodine, 1.2 g of lithium iodide and 6.0 g of 4-t-butylpyridine were added and dissolved by heating. Then, the solution was cooled to room temperature, then applied onto a glass substrate, and acetone was vaporized. This was removed to obtain a film having a thickness of 52 μm.
After the obtained gel electrolyte film is mounted on the substrate, a predetermined amount of a mixture of thermosetting polyisobutylene-based sealing material mixed with 50 μm glass beads at the peripheral edges of the four sides is applied using a dispenser method. did. The through holes were 2 mm wide and provided at the four corners of the substrate.

A counter electrode substrate having a film thickness of 30 nm formed on a titanium plate was combined with the obtained substrate, and then inserted into a nylon bag with a vacuuming jig as shown in FIG. The through hole was closed. Furthermore, in this state, it processed for 30 minutes at 100 degreeC using the heating oven, and hardened the sealing material. The distance between the cells thus obtained was 50 μm.
A lead wire was connected to the conductive layer portion of the transparent conductive substrate and the counter electrode.
When the device thus obtained was irradiated with AM1.5G artificial sunlight and the current-voltage characteristics were measured, good photoelectric conversion characteristics (conversion efficiency 4.1%) were obtained.
Further, as a result of evaluating this element after being left at room temperature for 1000 hours, the photoelectric conversion characteristics (conversion efficiency: 4.0%) hardly changed, and no breakage of the seal part such as liquid leakage was observed.

[Example 2]
As a result of evaluating the device produced in Example 1 after being allowed to stand for 200 hours in an environment at 80 ° C., the photoelectric conversion characteristics (conversion efficiency 3.4%) were lowered, but the sealing part was not damaged such as liquid leakage.

[Example 3]
A device was fabricated in the same manner as in Example 1 except that five cells were simultaneously loaded in a nylon bag as shown in FIG.
The five elements thus obtained were each irradiated with AM1.5G pseudo-sunlight and the current-voltage characteristics were measured. As a result, all the five elements had good photoelectric conversion characteristics (conversion efficiency 4.1 to 4.3). %)was gotten.

[Comparative Example 1]
In Example 1, the cell peripheral portion was closed with a clip without being inserted into the nylon bag as shown in FIG. 5, and then treated with a heating oven at 100 ° C. for 30 minutes to obtain a sealing material. A cell was produced in the same manner as in Example 1 except that was cured.
The obtained cell spacing was 100 μm, voids were formed in the peripheral portion, and partial peeling was observed at the interface between the substrate and the electrolyte layer.
Next, lead wires were connected to the conductive layer portion of the transparent conductive substrate and the counter electrode.
When the device thus obtained was irradiated with AM1.5G pseudo-sunlight and the current-voltage characteristics were measured, photoelectric conversion characteristics (conversion efficiency 1.2%) were obtained.
By sealing without vacuum degassing as described above, air remains inside the cell, and at the same time, the cell interval is widened and the substrate and the electrolyte layer are not uniformly adhered. Compared to a significant drop.
Moreover, as a result of evaluating this element after being allowed to stand at room temperature for 1000 hours, the photoelectric conversion characteristics (conversion efficiency 0.5%) were lowered.

It is sectional drawing which shows the dye-sensitized solar cell element of a prior art example. It is sectional drawing which shows the dye-sensitized solar cell element of a prior art example. It is an example of the cross-sectional schematic which shows the dye-sensitized solar cell element of this invention. It is the schematic which shows an example of sealing material installation. It is the schematic which shows an example of the vacuum deaeration method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent conductive substrate 2 Conductive substrate 3 Semiconductor layer modified with photosensitizing dye 4 Catalyst layer 5 Electrolyte 6 Curing type sealing material 8 Through port 9 Inlet 10 Sealing material 11 Solid material for sealing 12 Electrolyte 13 Sealing Non-stop solar cell 14 Vacuum bag 15 Vacuum drawing jig

Claims (1)

An electrode substrate having a semiconductor layer modified with a dye on a light-transmitting conductive substrate and a counter electrode substrate having a catalyst layer on the conductive substrate are opposed to each other at a predetermined interval. A method for producing a dye-sensitized solar cell element in which an electrolyte is disposed on a substrate and a peripheral portion between the substrates is sealed with a sealing material, wherein a curable material is used as the sealing material, and After forming a cell by providing a through-hole in the part, the inside of the cell is vacuum degassed , the sealant is deformed with vacuum degassing, and the through-hole is blocked by bonding the sealant, A method for producing a dye-sensitized solar cell element, wherein the sealing material is cured.

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