JP2014191869A - Method for manufacturing dye-sensitized solar cell and method for injecting and sealing electrolyte into dye-sensitized solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a dye-sensitized solar cell, capable of effectively suppressing leakage of an electrolyte, and to provide a method for injecting and sealing an electrolyte.SOLUTION: The method for manufacturing a dye-sensitized solar cell comprises the steps of: (1) forming, on a negative electrode substrate, a titanium oxide layer which is smaller than the negative electrode substrate in a plan view; (2) forming a sealing part at a portion where the titanium oxide layer is not formed, over the entire periphery of the end on the negative electrode substrate; (3) superposing a positive electrode on the sealing part; and (4) burning the positive electrode and the sealing part by irradiation with a laser having a wavelength of 200-400 nm to join them together.

Description

  The present invention relates to a method for producing a dye-sensitized solar cell and a method for injecting and sealing an electrolyte into the dye-sensitized solar cell.

  Solar cells are attracting attention as environmentally friendly power generation devices, and silicon-based semiconductors using pn junctions are widely known. However, silicon-based solar cells require a high vacuum and a high temperature during production, and it is difficult to reduce the cost, which has hindered their spread.

  While development of a lower cost solar cell is awaited, a dye-sensitized solar cell using a titanium dioxide modified with a dye as an active electrode has been reported by Gretzel et al. (See Patent Document 1). Dye-sensitized solar cells are attracting attention as solar cells that can be easily manufactured at low cost.

  In order to improve the durability of the dye-sensitized solar cell, improvements in the sealing material and sealing method for injecting and sealing the electrolytic solution have been actively made. In general, improvements are being made to the sealing material, and heat-free photo-curing properties against heating and leakage of electrolytes, which are the problems of conventional thermoplastic resins. Resins, highly durable thermosetting resins, glass frits, and the like have been newly developed. On the other hand, with regard to the sealing method, studies are being made on methods such as mechanically improving durability and using a laser.

Japanese Patent Publication No. 8-15097

  The wavelength of the laser employed in the improved sealing method is preferably about 800 to 1000 nm for the purpose of causing the glass to absorb the laser accurately. However, this method employs a laser having a long wavelength, and in this case, leakage of the electrolyte cannot be sufficiently suppressed.

  Then, an object of this invention is to provide the manufacturing method of the dye-sensitized solar cell which can suppress the leakage of electrolyte solution effectively, and the method of inject | pouring and sealing electrolyte solution.

In view of the above object, as a result of intensive studies, it has been found that leakage of the electrolyte can be more effectively suppressed by using a laser having a shorter wavelength than that generally used. This effect is more remarkable when a specific glass is used as the sealing material. The present invention has been completed by further research based on such knowledge. That is, the present invention includes the following configurations.
Item 1. A method for producing a dye-sensitized solar cell, comprising:
(1) forming a titanium oxide layer smaller than the negative electrode substrate in plan view on the negative electrode substrate;
(2) A step of forming a sealing portion at a portion where the titanium oxide layer is not formed over the entire circumference of the end portion on the negative electrode substrate;
(3) A step of superimposing a positive electrode on the sealing portion, and (4) a step of irradiating a laser having a wavelength of 200 to 400 nm to bond the positive electrode and the sealing portion by firing. A manufacturing method.
Item 2. Item 2. The manufacturing method according to Item 1, wherein the positive electrode is provided with an injection port for injecting and sealing the electrolytic solution.
Item 3. After the step (4),
(5) The manufacturing method of claim | item 2 provided with the process of inject | pouring electrolyte solution from the said inlet.
Item 4. The material constituting the sealing part is
Bi ₂ O ₃ 60 to 87 wt%
B ₂ O ₃ 3-12% by weight
ZnO 0-20% by weight
At least one selected from the group consisting of SiO ₂ , Al ₂ O ₃ and ZrO ₂ 0.5 to 10% by weight
The manufacturing method in any one of claim | item 1 -3 which consists of glass to contain.
Item 5. The manufacturing method of claim | item 4 whose softening point of the material which comprises the said sealing part is 550 degrees C or less.
Item 6. A method of injecting and sealing an electrolyte solution in a dye-sensitized solar cell,
(1) forming a titanium oxide layer smaller than the negative electrode substrate in plan view on the negative electrode substrate;
(2) A step of forming a sealing portion at a portion where the titanium oxide layer is not formed over the entire circumference of the end portion on the negative electrode substrate;
(3) a step of superposing a positive electrode on the sealing portion;
(4) A method comprising: irradiating a laser having a wavelength of 200 to 400 nm to bond the positive electrode and the sealing portion by baking; and (5) injecting an electrolyte from the injection port. .

  ADVANTAGE OF THE INVENTION According to this invention, the positive electrode and the sealing material can be baked using a short wavelength laser, and the dye-sensitized solar cell which suppressed the leakage of electrolyte solution can be provided. This effect is more remarkable when a specific glass is used as the sealing material.

In this invention, it is the schematic explaining the photoelectric conversion element (dye sensitized solar cell) which joined the positive electrode 11 and the sealing part 15. FIG. In this invention, it is a schematic sectional drawing explaining the photoelectric conversion element (dye sensitized solar cell) which joined the positive electrode 11 and the sealing part 15. FIG. It is the schematic explaining each process (process (1)-(4)) of this invention.

  Hereinafter, the method for producing the dye-sensitized solar cell of the present invention and the method for injecting and sealing the electrolyte will be described with reference to the drawings. In the following description, the drawings are displayed for easy understanding, and the dimensional ratios of the constituent elements are not necessarily as described in the drawings. For convenience, only a part may be enlarged.

The method for producing the dye-sensitized solar cell of the present invention comprises:
(1) forming a titanium oxide layer smaller than the negative electrode substrate in plan view on the negative electrode substrate;
(2) A step of forming a sealing portion at a portion where the titanium oxide layer is not formed over the entire circumference of the end portion on the negative electrode substrate;
(3) A step of superimposing a positive electrode on the sealing portion, and (4) a step of irradiating a laser having a wavelength of 200 to 400 nm to bond the positive electrode and the sealing portion by firing. Prepare.

1. Process (1)
As shown in FIG. 3A, in step (1), a negative electrode in which a titanium oxide layer 13 is formed on a negative electrode substrate 12 is obtained.

  As the negative electrode substrate 12, a resin substrate or a glass substrate is preferable, and a transparent substrate made of a resin substrate or a glass substrate is more preferable. However, when heating to a temperature of 300 ° C. or higher, it is preferable to use a glass substrate.

  The resin substrate is not particularly limited. For example, polyester such as polyethylene naphthalate resin substrate (PEN resin substrate) and polyethylene terephthalate resin substrate (PET resin substrate); polyamide; polysulfone; polyether sulfone; polyether ether ketone; Polyphenylene sulfide; Polycarbonate; Polyimide; Polymethyl methacrylate; Polystyrene; Cellulose triacetate; Polymethylpentene.

  There is no restriction | limiting in particular also as a glass substrate, What is necessary is just to use a well-known or commercially available thing, and any of colorless or colored glass, meshed glass, a glass block etc. may be sufficient.

  As this resin substrate or glass substrate, the dimensions may be the same as those of the positive electrode, and those having a thickness of about 0.05 to 10 mm can be used.

  In the present invention, the titanium oxide layer 13 may be formed directly on the surface (one surface) of the negative electrode substrate 12, but may be formed through a transparent conductive film.

  Examples of the transparent conductive film include a tin-doped indium oxide film (ITO film), a fluorine-doped tin oxide film (FTO film), an antimony-doped tin oxide film (ATO film), an aluminum-doped zinc oxide film (AZO film), and a gallium-doped zinc oxide. Examples include a film (GZO film). In the case of a structure in which current is collected from the substrate side (front contact) through these transparent conductive films, the generated current can be easily taken out to the outside. The film thickness of these transparent conductive films is preferably about 0.02 to 10 μm.

When the titanium oxide layer 13 is formed on the negative electrode substrate 12, specifically,
(1-1) On the negative electrode substrate 12, it can form by the process of apply | coating the paste composition for titanium oxide layer formation.

  The negative electrode substrate 12 is as described above.

In the present invention, “titanium oxide” or “titania” does not mean only titanium dioxide (TiO ₂ ), but dititanium trioxide (Ti ₂ O ₃ ); titanium monoxide (TiO); Ti ₄ It is a concept including a composition having oxygen deficiency from titanium dioxide represented by O ₇ , Ti ₅ O _{9 and the} like. Further, as represented by the terminal OH group, a group other than Ti—O—Ti resulting from the synthesis of titanium oxide may be included.

  The paste composition for forming a titanium oxide layer preferably contains titanium oxide nanoparticles.

  There is no restriction | limiting in particular as a titanium oxide nanoparticle, What is necessary is just to use a well-known or commercially available thing.

  The crystal structure of the titanium oxide nanoparticles is not particularly limited, but preferably contains at least one selected from the group consisting of anatase-type titanium oxide, rutile-type titanium oxide and brookite-type titanium oxide, and is active against light. From the point of being high, what contains anatase type titanium oxide is more preferable. Moreover, the crystal structure of the titanium oxide nanoparticles is not necessarily only one type, and two or more types of titanium oxide nanoparticles having different crystal structures may be mixed. When mixing two or more types of titanium oxide nanoparticles having different crystal structures, it is preferable to mix anatase-type titanium oxide and rutile-type titanium oxide and / or brookite-type titanium oxide. It is preferable to contain 70 to 95% by weight (particularly 90 to 95% by weight) of titanium oxide. The crystal structure of the titanium oxide nanoparticles can be measured by, for example, an X-ray diffraction method, Raman spectroscopic analysis, or the like.

  The average particle diameter of the titanium oxide nanoparticles is preferably 1 to 500 nm, more preferably 3 to 100 nm, from the viewpoint that more dye can be adsorbed and light can be absorbed. Moreover, as a titanium oxide nanoparticle, you may mix 2 or more types of metal oxide semiconductor nanoparticles from which an average particle diameter differs. In particular, from the viewpoint of the light confinement effect inside the battery, titanium oxide nanoparticles having a large average particle size (about 100 to 600 nm) and large light scattering are used together with titanium oxide nanoparticles having a small average particle size (about 3 to 100 nm). May be. The average particle diameter of the small titanium oxide nanoparticles that can be used here is preferably 3 to 100 nm, more preferably 3 to 50 nm, and still more preferably 3 to 30 nm. In addition, the average particle diameter of a titanium oxide nanoparticle can be measured by electron microscope (SEM) observation etc., for example.

  In the titanium oxide layer forming paste composition, the content of titanium oxide nanoparticles as a solid content balances the fluidity during coating and the thickness after coating, and the pore size of the titanium oxide coating film (titanium oxide layer 13). 5 to 40% by weight, particularly 8 to 20% by weight is preferable.

  Moreover, water, an organic solvent, etc. can be used as a solvent of the paste composition for titanium oxide layer formation, in order to form a dispersion liquid.

  The organic solvent is not particularly limited as long as it can disperse titanium oxide nanoparticles. For example, alcohols such as ethanol, methanol and terpineol (particularly α-terpineol); glycols such as ethylene glycol, polyethylene glycol, propylene glycol and polypropylene glycol can be used. These solvents may be used alone or in combination of two or more in consideration of dispersibility, volatility and viscosity. A preferred example is terpineol (particularly α-terpineol). As a ratio of the solvent in the paste composition for forming a titanium oxide layer, from the point of imparting fluidity at the time of coating, maintaining the thickness after coating, and forming a porous titanium oxide layer 13, 30 to 80% by weight, particularly 60 to 75% by weight, is preferred.

  A thickener or the like may be included as a component of the paste composition for forming a titanium oxide layer.

  Examples of the thickener include alkyl celluloses such as methyl cellulose and ethyl cellulose. Of these, ethyl cellulose can be preferably used.

  The proportion of the thickener in the paste composition for forming a titanium oxide layer is preferably 5 to 20% by weight, particularly 6 to 15% by weight, from the viewpoint of the balance between the fluidity during coating and the thickness after coating.

  The method for applying the titanium oxide layer forming paste composition on the negative electrode substrate 12 is not particularly limited, and conventional methods such as screen printing, doctor blade, dip coating, spray coating, spin coating, and squeegee method may be employed. It is preferable to employ screen printing from the viewpoints of realizing high-quality film formation without defects, film thickness control, and high throughput.

  The thickness of the titanium oxide layer 13 formed on the negative electrode substrate 12 in this way is preferably as thick as possible so that more incident light can be absorbed when used as an electrode for a dye-sensitized solar cell. Is preferably 2 to 30 μm, more preferably 10 to 20 μm, and even more preferably 10 to 15 μm from the viewpoint of ensuring that the film penetrates deep into the electrode film or ensuring uniform and good film formability. .

  It is preferable to adsorb the dye after forming the titanium oxide layer 13 on the negative electrode substrate 12.

  The dye is not particularly limited as long as the dye has absorption characteristics in the visible region and the near infrared region and improves (sensitizes) the light absorption efficiency of the titanium oxide layer 13, but is not limited to metal dyes, organic dyes, natural dyes, A semiconductor or the like is preferable. Further, in order to impart adsorptivity to the titanium oxide layer 13, a carboxyl group, a hydroxyl group, a sulfonyl group, a phosphonyl group, a carboxylalkyl group, a hydroxyalkyl group, a sulfonylalkyl group, a phosphonylalkyl group, etc. in the dye molecule Those having a functional group of

  As the metal complex dye, for example, a ruthenium, osmium, iron, cobalt, zinc, mercury complex (for example, mellicle chromium), metal phthalocyanine, chlorophyll, or the like can be used. Examples of organic dyes include, but are not limited to, cyanine dyes, hemicyanine dyes, merocyanine dyes, xanthene dyes, triphenylmethane dyes, metal-free phthalocyanine dyes, and the like. As a semiconductor that can be used as a dye, an amorphous semiconductor having a large i-type light absorption coefficient, a direct transition semiconductor, a fine particle semiconductor that exhibits a quantum size effect and efficiently absorbs visible light, and the like are preferable. Usually, one of various semiconductors, metal complex dyes and organic dyes, or two or more kinds of dyes can be mixed in order to make the wavelength range of photoelectric conversion as wide as possible and increase the conversion efficiency. Moreover, the pigment | dye to mix and its ratio can be selected so that it may match with the wavelength range and intensity distribution of the target light source.

  As a method for adsorbing the dye on the titanium oxide layer 13, for example, a solution in which the dye is dissolved in a solvent is applied on the titanium oxide layer 13 by spray coating, spin coating, or the like, and then dried. it can. In this case, the negative electrode substrate 12 may be heated to an appropriate temperature. Further, a method in which the titanium oxide layer 13 is immersed in a solution and adsorbed can also be used. The immersion time is not particularly limited as long as the dye is sufficiently adsorbed, but is preferably 10 minutes to 30 hours, more preferably 1 to 20 hours. Moreover, you may heat a solvent and a board | substrate when immersing as needed. The concentration of the dye in the solution is preferably about 0.01 to 100 mmol / L, and more preferably about 0.1 to 10 mmol / L.

  The solvent to be used is not particularly limited, but water and an organic solvent are preferably used. Examples of the organic solvent include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and t-butanol; acetonitrile, propionitrile, methoxypropionitrile, glutaronitrile, and the like. Nitriles; aromatic hydrocarbons such as benzene, toluene, o-xylene, m-xylene, p-xylene; aliphatic hydrocarbons such as pentane, hexane, heptane; alicyclic hydrocarbons such as cyclohexane; acetone, methyl ethyl ketone Ketones such as diethyl ketone and 2-butanone; ethers such as diethyl ether and tetrahydrofuran; ethylene carbonate, propylene carbonate, nitromethane, dimethylformamide, dimethyl sulfoxide, hexamethylphosphoamide, dimethoxy Ethane, 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), Examples thereof include triphenyl polyethylene glycol phosphate and polyethylene glycol.

  In order to reduce the interaction such as aggregation between the dyes, a colorless compound having properties as a surfactant may be added to the dye adsorbing liquid and co-adsorbed on the titanium oxide layer 13. Examples of such colorless compounds include steroid compounds such as cholic acid having a carboxyl group or sulfo group, deoxycholic acid, chenodeoxycholic acid, taurodeoxycholic acid, sulfonates, and the like.

  It is preferable to remove the unadsorbed dye by washing immediately after the adsorption step. Washing is preferably performed using acetonitrile, an alcohol solvent or the like in a wet washing tank.

  After adsorbing the dye, oxidation with amines, quaternary ammonium salts, ureido compounds having at least one ureido group, silyl compounds having at least one silyl group, alkali metal salts, alkaline earth metal salts, etc. The surface of the titanium layer 13 may be treated. Examples of preferred amines include pyridine, 4-t-butylpyridine, polyvinylpyridine and the like. Examples of preferred quaternary ammonium salts include tetrabutylammonium iodide, tetrahexylammonium iodide and the like. These may be used by dissolving in an organic solvent, or may be used as they are in the case of a liquid.

  The titanium oxide layer 13 thus formed on the negative electrode substrate 12 is preferably smaller than the negative electrode substrate in plan view. Specifically, the titanium oxide layer 13 is preferably not formed 0.1 to 5 mm, particularly 0.3 to 2 mm from the outer peripheral edge of the negative electrode substrate.

2. Step (2)
As shown in FIG. 3B, in the step (2), a sealing portion is formed in a portion where the titanium oxide layer 13 is not formed over the entire periphery of the end portion on the negative electrode substrate 12.

  The negative electrode substrate 12 and the titanium oxide layer 13 are as described above.

  It is preferable to provide a frame-shaped sealing portion 15 over the entire periphery of the end portion of the negative electrode 12 from the viewpoint of securing a space for injecting the electrolyte later and suppressing leakage. In particular, the frame-shaped sealing portion 15 preferably has the same size as the negative electrode 12 in plan view.

  The sealing part 15 is preferably made of glass, and the glass to be constituted is not particularly limited, and any known or commercially available glass may be used, such as colorless or colored glass, meshed glass, glass block, etc. Either is acceptable.

Among these, the sealing portion is preferably made of a glass material having a softening point of 550 ° C. or lower, particularly 250 to 500 ° C., from the viewpoint of preventing deterioration of members such as conductive glass due to high-temperature heating. In particular,
Bi ₂ O ₃ 60-87% by weight (especially 70-80% by weight)
B ₂ O ₃ 3 to 12 wt% (particularly 5 to 10 wt%)
ZnO 0-20% by weight (especially 5-16% by weight)
At least one selected from the group consisting of SiO ₂ , Al ₂ O ₃ and ZrO ₂ 0.5 to 10% by weight (particularly 0.7 to 0.9% by weight)
It is preferable that it consists of a glass material containing each.

  The planar shape (particularly the outer edge) of the sealing portion 15 is preferably the same as that of the negative electrode 12. The width of the portion in contact with the negative electrode 12 is not particularly limited, but is preferably 0.1 to 5 mm, and more preferably 1 to 3 mm. Furthermore, it is preferable to adjust the thickness of the sealing part 15 to be thicker than that of the titanium oxide layer 13. Specifically, the thickness is preferably 1 to 50 μm, and more preferably 10 to 30 μm.

  Specifically, the sealing portion 15 can be formed by applying and drying a glass paste composition containing the above components on the negative electrode substrate 12 where the titanium oxide layer 13 is not formed. it can.

  The method for applying the glass paste composition on the negative electrode substrate 12 is not particularly limited, and conventional methods such as screen printing, doctor blade, dip coating, spray coating, spin coating, and squeegee method may be employed, but there are no defects. Screen printing is preferably employed from the standpoint that good film formability, film thickness control, and high throughput can be realized.

3. Step (3)
As shown in FIG. 3C, in the step (3), the positive electrode is overlaid on the sealing portion 15.

  The sealing part 15 is as described above.

  The positive electrode 11 may have a single layer structure made of a conductive material, or may be composed of a conductive layer and a substrate. The substrate is not particularly limited, and the material, thickness, dimensions, shape, and the like can be appropriately selected according to the purpose (for example, the dimensions of the positive electrode 11 are 5 to 130 mm × 5 to 130 mm, and the thickness is 0.1 mm). For example, metal, colorless or colored glass, netted glass, glass block, etc. may be used, and 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. Alternatively, the positive electrode 11 may be formed by applying, plating, or vapor-depositing (PVD, CVD) a conductive material directly on the charge transport layer.

  As the conductive material, a metal having a small specific resistance, such as a metal such as platinum, gold, nickel, titanium, aluminum, copper, silver, or tungsten; a carbon material; or a conductive organic material is used.

  A metal lead may be used for the purpose of reducing the resistance of the positive electrode 11. The metal lead is preferably made of a metal such as platinum, gold, nickel, titanium, aluminum, copper, silver or tungsten, and particularly preferably made of aluminum or silver.

  The positive electrode 11 is preferably provided with an injection port from the viewpoint that the electrolytic solution can be injected and sealed more easily.

  From the viewpoint of improving the bonding strength, the inlet is preferably tapered so that its diameter is narrowed from the outer surface side of the positive electrode 11 toward the inner surface side (a portion in contact with the electrolytic solution) facing the positive electrode 11, The taper is preferably 45 ° or less with respect to the central axis of the inlet. The inlet is preferably adjusted to a diameter of about 1 to 5 mm.

  The method for providing the injection port in the positive electrode 11 is not particularly limited, and a known method can be adopted.

  The method for superimposing the positive electrode 11 on the sealing portion 15 is not particularly limited. For example, the positive electrode 11 may be bonded to the sealing portion 15 via a spacer as necessary.

4). Step (4)
As shown in FIG.3 (c), in a process (4), it joins by irradiating the laser with a wavelength of 200-400 nm, and baking the positive electrode 11 and the sealing part 15. FIG. In the step (3), the negative electrode 12 and the sealing portion 15 can be bonded, but the positive electrode 11 and the sealing portion 15 cannot be bonded. For this reason, it joins by irradiating a laser.

  The positive electrode 11 and the sealing portion 15 are as described above.

  The laser to irradiate is about 200 to 400 nm, preferably about 250 to 350 nm from the viewpoint that the leakage of the electrolyte cannot be effectively suppressed unless the wavelength is within an appropriate range.

5. Process (5)
After the step (4), it is preferable to inject an electrolytic solution from the injection port when an injection port is provided in the positive electrode.

  The electrolyte solution as a charge transport material involving ions is preferably composed of an electrolyte, a solvent, and an additive.

Examples of the electrolyte used in the electrolytic solution, iodine and iodide (LiI, NaI, KI, CsI, metal iodide such as CaI _2, tetraalkylammonium iodide, pyridinium iodide, iodine, such as dialkyl imidazolium iodide Motoshio Etc.), combinations of bromine and bromides (metal bromides such as LiBr, NaBr, KBr, CsBr, CaBr, CaBr ₂ , bromine salts such as tetraalkylammonium bromide, pyridinium bromide, dialkylimidazolium bromide, etc.), ferrocyanic acid Examples thereof include metal complexes such as salt-ferricyanate and ferrocene-ferricinium ions, sulfur compounds such as sodium polysulfide and alkylthiol-alkyldisulfides, viologen dyes, and hydroquinone-quinone. Among them, an electrolyte obtained by combining I ₂ and iodine salt such as LiI, pyridinium iodide, dialkylimidazolium iodide is preferable. The electrolyte may be used as a mixture.

  Any solvent can be used as long as it is generally used in electrochemical cells and batteries. In particular, not only low-viscosity solvents such as organic solvents, but also high-viscosity solvents such as ionic liquids that are likely to cause performance degradation can be employed in the same manner, and in any case, performance degradation is substantially suppressed. A photoelectric conversion efficiency close to the maximum performance can be obtained, but it is preferable to employ an organic solvent.

  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, triethyl phosphate and the like are preferable.

  An ionic liquid can also be used. Since the ionic liquid has characteristics such as a vapor pressure of almost zero, high chemical stability, high thermal stability, etc., it can be expected to improve the durability of the photoelectric conversion element at high temperatures, preferable.

  Usable ionic liquids are 1,3-dimethylimidazolium iodide, 1-ethyl-3-methylimidazolium iodide, 1-methyl-3-propylimidazolium iodide, 1-butyl-3-methylimidazolium iodide. And 1-pentyl-3-methylimidazolium iodide, 1-hexyl-3-methylimidazolium iodide, and the like.

  As additives, 4-t-butylpyridine, N-butylbenzimidazole, guanidine dithiocyanate, 2-picoline, 2,6-lutidine and the like are preferably added to the above electrolyte. A preferable concentration range when these are added to the electrolytic solution is about 0.05 to 2 mol / L.

  In addition, as electrolyte solution, a thing with a high dielectric constant is preferable so that more electrolytes, such as the above-mentioned iodine ion, can be melt | dissolved, and a thing with a low viscosity is preferable so that the dissolved ion may move easily.

  The method for injecting the electrolytic solution is not particularly limited, and a conventionally known method can be employed. For example, the method etc. which inject | pour through a thin tube are mentioned.

  Thereafter, the inlet can be sealed with a plug member.

  The plug member that seals the inlet is preferably formed mainly of a member in which the inlet is formed, that is, a glass material having a small difference in linear expansion coefficient with respect to the glass material forming the positive electrode 11.

  The gap between the peripheral surface of the stopper member and the peripheral surface of the injection port is preferably kept at 0.1 mm or less from the viewpoint of reliably preventing leakage and evaporation of the electrolyte.

  By such a method, the dye-sensitized solar cell which suppressed the leakage of electrolyte solution can be provided (FIGS. 1-2). Specifically, the photoelectric conversion element of the present invention can be obtained by the above steps (1) to (4) (and step (5) as necessary). Then, while making said photoelectric conversion element into a module, the dye-sensitized solar cell of this invention can be manufactured by providing predetermined | prescribed electric wiring.

  The present invention will be specifically described based on examples, but the present invention is not limited to these examples.

<Example 1>
(Process 1)
A titania paste (PST30NRD manufactured by JGC Catalysts & Chemicals Co., Ltd.) is applied on a glass (20 mm × 100 mm) with an FTO film by screen printing, and then dried at 500 ° C., whereby a titanium oxide layer (6 mm × 85 mm, thickness 10 μm). ) Was formed.

(Process 2)
A glass paste (manufactured by Asahi Glass Co., Ltd., 5094D1) was applied to the outer peripheral end of the titania negative electrode on the FTO glass by screen printing so as to have a width of 1 mm and a thickness of 30 μm.

  Then, the glass sealing part after sintering was produced by drying at 125 degreeC and baking at 500 degreeC for 1 hour.

(Process 3)
An ITO conductive glass (manufactured by Geomat Co., Ltd., resistance: 2Ω / sq, 20 mm × 100 mm) is irradiated with a Nd-YAG laser (manufactured by LTS Co., Ltd., wavelength: 355 nm), and an electrolyte injection port having a diameter of 1 to 2 mm is provided. Created.

  On the sealing part, the ITO conductive glass in which the said injection hole was created was piled up as a positive electrode.

(Process 4)
The glass sealing portion was irradiated with an Nd-YAG laser (manufactured by LTS, wavelength: 355 nm), and the sealing portion and the positive electrode were joined.

(Process 5)
An electrolyte (Iodolyte AN-50 manufactured by Solaronix) was sealed from the positive electrode inlet. This electrolyte leakage was not observed.

<Comparative Example 1>
In Step 4, when the semiconductor laser (wavelength: 808 nm) was used instead of the Nd-YAG laser (LTS, wavelength: 355 nm), the sealing portion and the positive electrode were joined. It was not possible to suppress the leakage of the electrolyte.

<Comparative example 2>
In Step 4, when a semiconductor laser (wavelength: 1100 nm, manufactured by Tamari Kogyo Co., Ltd.) was used instead of the Nd-YAG laser (manufactured by LTS, wavelength: 355 nm), the sealing portion and the positive electrode were joined. It was not possible to suppress the leakage of the electrolyte.

DESCRIPTION OF SYMBOLS 10 Dye-sensitized solar cell 11 Positive electrode 12 Negative electrode 13 Titanium oxide layer 14 Space for electrolyte solution 15 Sealing part

Claims (6)

A method for producing a dye-sensitized solar cell, comprising:
(1) forming a titanium oxide layer smaller than the negative electrode substrate in plan view on the negative electrode substrate;
(2) A step of forming a sealing portion at a portion where the titanium oxide layer is not formed over the entire circumference of the end portion on the negative electrode substrate;
(3) A step of superimposing a positive electrode on the sealing portion, and (4) a step of irradiating a laser having a wavelength of 200 to 400 nm to bond the positive electrode and the sealing portion by firing. A manufacturing method. The manufacturing method of Claim 1 with which the injection hole for inject | pouring and sealing electrolyte solution is provided in the said positive electrode. After the step (4),
(5) The manufacturing method of Claim 2 provided with the process of inject | pouring electrolyte solution from the said inlet. The material constituting the sealing part is
Bi ₂ O ₃ 60 to 87 wt%
B ₂ O ₃ 3-12% by weight
ZnO 0-20% by weight
At least one selected from the group consisting of SiO ₂ , Al ₂ O ₃ and ZrO ₂ 0.5 to 10% by weight
The manufacturing method in any one of Claims 1-3 consisting of the glass to contain. The manufacturing method of Claim 4 whose softening point of the material which comprises the said sealing part is 550 degrees C or less. A method of injecting and sealing an electrolyte solution in a dye-sensitized solar cell,
(1) forming a titanium oxide layer smaller than the negative electrode substrate in plan view on the negative electrode substrate;
(2) A step of forming a sealing portion at a portion where the titanium oxide layer is not formed over the entire circumference of the end portion on the negative electrode substrate;
(3) a step of superposing a positive electrode on the sealing portion;
(4) A method comprising: irradiating a laser having a wavelength of 200 to 400 nm to bond the positive electrode and the sealing portion by baking; and (5) injecting an electrolyte from the injection port. .

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