JP2005268107A - Dye-sensitized solar cell and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye-sensitized solar cell capable of preventing deteriorate of photoelectric conversion efficiency by preventing liquid leakage of an electrolyte and improving the strength of a separator separating a working electrode and a counter electrode for preventing a short circuit between the electrodes. <P>SOLUTION: A spacer 12 is arranged between the working electrode 10 and the counter electrodes 8 facing the working electrode 10. The spacer 12 has inorganic fine particles 5, a porous adhesive resin film 14 comprising an adhesive resin 4 wherein the inorganic fine particles 5 are dispersed, and an electrolyte 3 held in pores of the porous adhesive resin 14. In the porous adhesive resin 14, between the inorganic fine particles 5, between the inorganic fine particles 5 and the working electrode 10 and between the inorganic fine particles 5 and the counter electrodes 8 are bonded with the adhesive resin 4 and between the working electrode 10 and the counter electrode 8A is bridged with a skeleton of the inorganic fine particles 5. Thereby, the strength as a spacer is maintained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a dye-sensitized solar cell and a method for producing the same.

  A dye-sensitized solar cell is mainly composed of a semiconductor electrode on which a dye is adsorbed, a counter electrode, and an electrolyte layer sandwiched between these electrodes. When an electrolytic solution is used as the electrolyte, the electrolytic solution may not be retained, and the electrolytic solution may leak or volatilize from the gap between the working electrode and the counter electrode, and the working electrode and the counter electrode may contact and short circuit. In order to prevent this, there is a photoelectric conversion element in which a separator holding an electrolytic solution in a porous polymer film is sandwiched between a working electrode and a counter electrode. (For example, refer to Patent Document 1).

JP-A-11-339866 (first page)

  In the photoelectric conversion element, the volatilization of the electrolytic solution can be suppressed by a capillary phenomenon by sandwiching the porous polymer film between the working electrode and the counter electrode. However, since the polymer porous film is only sandwiched between the electrodes, when gas or the like is generated in the element or when stress is applied, floating occurs, causing performance deterioration or increasing photoelectric conversion efficiency. For this reason, when the porosity of the polymer porous membrane is increased, the strength is lowered, and the role of the separator cannot be achieved, causing a short circuit between both electrodes.

  The present invention has been made to solve such a problem, and prevents leakage of the electrolytic solution, improves the strength of the separator separating the working electrode and the counter electrode, and prevents a short circuit between the electrodes. It aims at obtaining the dye-sensitized solar cell which can prevent the deterioration of photoelectric conversion efficiency by this, and this manufacturing method.

  A first dye-sensitized solar cell according to the present invention includes a working electrode having a porous semiconductor film coated with a dye, a counter electrode provided opposite to the working electrode, the working electrode, and the counter electrode. In the dye-sensitized solar cell provided with a spacer that is disposed between and holding the electrolytic solution, the spacer is made of inorganic fine particles and an adhesive resin in which the inorganic fine particles are dispersed, and adheres to the working electrode and the counter electrode. It has a porous adhesive resin film and an electrolytic solution held in the holes of the porous adhesive resin film.

  The first dye-sensitized solar cell of the present invention includes a working electrode having a porous semiconductor film coated with a dye, a counter electrode provided to face the working electrode, and a gap between the working electrode and the counter electrode. In the dye-sensitized solar cell provided with the spacer for holding the electrolytic solution, the spacer is made of an inorganic fine particle and an adhesive resin in which the inorganic fine particle is dispersed, and is porous to adhere to the working electrode and the counter electrode. Having a conductive adhesive resin film and an electrolytic solution held in the pores of the porous adhesive resin film, preventing leakage of the electrolytic solution, improving the strength of the separator separating the working electrode and the counter electrode, By preventing a short circuit between the electrodes, the photoelectric conversion efficiency can be prevented from deteriorating.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of the dye-sensitized solar cell according to the first embodiment of the present invention.
In other words, the working electrode 10 is configured by providing the light-transmissive conductive layer 6 provided on the surface of the working electrode base material 7 and the porous semiconductor film 11 coated with the dye 2 thereon, and the porous semiconductor described above. The film 11 is made of semiconductor fine particles 1. The counter electrode 8 facing the working electrode 10 is configured by providing a conductive layer 13 carrying an electrode material on the surface of the counter electrode base material 9, and a spacer 12 is disposed between the working electrode 10 and the counter electrode 8. Has been.
The spacer 12 is a porous adhesive resin film 14 composed of the inorganic fine particles 5 and the adhesive resin 4 in which the inorganic fine particles 5 are dispersed, and holds the electrolytic solution 3 in the holes of the porous adhesive resin film 14. In the present embodiment, since the porous adhesive resin film 14 is a dispersion of the inorganic fine particles 5, the strength of the separator separating the working electrode 10 and the counter electrode 8 is improved, and the working electrode and the counter electrode are bonded. Therefore, peeling due to stress applied to the dye-sensitized solar cell can be prevented.
In the dye-sensitized solar cell having the above configuration, when the dye 2 adsorbed on the porous semiconductor film 11 is irradiated with sunlight, the dye 2 absorbs light in the visible region and is excited. Electrons generated by this excitation move to the counter electrode 8 through the porous semiconductor film 11 and an external circuit (not shown), and the electrons moved to the counter electrode 8 reduce the redox system in the electrolytic solution 3. On the other hand, the dye 2 that has moved electrons to the porous semiconductor film 11 is in an oxidant state, and the dye 2 in the oxidized state is reduced by the redox system. Electrons flow as described above, and a dye-sensitized solar cell can be configured.

As shown in FIG. 1, the porous adhesive resin film 14 of the spacer 12 according to the embodiment of the present invention is composed of inorganic fine particles 5 and an adhesive resin 4 in which the inorganic fine particles 5 are dispersed. The adhesive resin 4 adheres between the electrode 5 and the working electrode 10 and between the inorganic fine particle 5 and the counter electrode 8, and the working electrode and the counter electrode are cross-linked by the skeleton of the inorganic fine particle 5 to further increase the strength as a spacer. Can be improved.
From the above, in the present embodiment, since the electrolytic solution 3 is used, the contact area between the working electrode and the electrolyte can be large, exhibit high conductivity, and pores can be used to improve the photoelectric conversion characteristics. Even if the rate is increased, the strength of the spacer can be maintained, and a short circuit between the positive and negative electrodes can be suppressed.

Further, the porous adhesive resin film 14 needs to have a strong property against light and is preferably resistant to heat. If it is weak against light and heat, long-term stability will deteriorate.
Further, the porous adhesive resin film 14 is insoluble in the electrolytic solution 3 and must not cause a chemical reaction with the electrolytic solution 3, and the porous adhesive resin film 14 dissolves or reacts in the electrolytic solution 3. The electrolyte solution 3 cannot be retained or the shape of the battery changes.

The average porosity in the dry state where the porous adhesive resin film 14 does not hold the electrolyte is preferably 30 to 80%, more preferably 35 to 80%, and most preferably 45 to 75%. is there. When the average porosity is less than 30%, the amount of the electrolyte supported becomes small, so that the electrical resistance of the spacer 12 is increased and the performance as a battery is deteriorated. When the average porosity exceeds 80%, the mechanical strength is reduced. To do.
The average pore diameter of the porous adhesive resin film 14 in a dry state is preferably 0.01 to 10 μm, more preferably 0.05 to 3 μm, and most preferably 0.1 to 1 μm. If the average pore diameter is less than 0.01 μm, the ion permeability decreases, the electric resistance increases, and the battery function is not sufficient. If the average pore diameter exceeds 10 μm, the pore size increases, so that the solution is retained by surface tension. Therefore, the ability to retain the electrolyte is reduced.
Further, the thickness of the porous adhesive resin film 14 is preferably 10 to 50 μm, and more preferably 15 to 25 μm. If it is less than 10 μm, it is easy to cause a short circuit due to mechanical deformation, and if it exceeds 50 μm, the volume ratio of the solid layer per battery increases, so the battery capacity decreases and the distance between the electrodes increases. The diffusion of.

Specifically, the adhesive resin 4 in the porous adhesive resin film 14 is a polymer having fluorine molecules such as vinylidene fluoride or 4-fluoroethylene in the molecular structure, or the polymer and polymethyl methacrylate. A mixture of polystyrene, polyethylene or polypropylene is used, and a polymer or copolymer having vinyl alcohol in the molecular skeleton, or the above polymer or copolymer and polymethyl methacrylate, polystyrene, polyethylene, polypropylene, polychlorinated A mixture with vinylidene, polyvinyl chloride, polyacrylonitrile, polyethylene oxide or the like is used.
In particular, polyvinylidene fluoride or polyvinyl alcohol is preferable because it has high chemical stability and can suppress deterioration over time.
However, the adhesive resin 4 may be swelled by the electrolytic solution 3, and the volume expansion due to the swelling makes the pore size smaller and the surface tension becomes smaller, so that the holding power of the solution is improved. Spattering of the liquid can be suppressed.

The inorganic fine particles 5 in the porous adhesive resin film 14 are desirably an insulator in order to suppress a short circuit between the working electrode 10 and the counter electrode 8. Specifically, fine particles such as oxide dielectrics such as silica, alumina and mica, and nitrides such as boron nitride and silicon nitride can be used.
The inorganic fine particles 5 preferably have a diameter of 1 μm or less, more preferably 100 nm or less in order to make the pores of the porous adhesive resin film 14 have the above average pore size. The fine particles may be aggregates of primary particles having a particle size of 100 nm or less, preferably 50 nm or less.

Embodiment 2. FIG.
A method for manufacturing the dye-sensitized solar cell according to the second embodiment of the present invention will be described.
First, an adhesive solution in which the adhesive resin 4 and the inorganic fine particles 5 in Embodiment 1 are mixed and dissolved or dispersed in a solvent is prepared. The solvent used here is not particularly limited as long as the dye 2 supported on the porous semiconductor film 11 is insoluble, but ether solvents such as dimethoxyethane, diethoxyethane, diethyl ether and dimethyl ether, propylene carbonate, carbonic acid A single solution of an ester solvent such as ethylene, diethyl carbonate, dimethyl carbonate, or γ-butyrolactone, a single solution of an amide solvent such as N-methylacetamide or N-methylpyrrolidone, or two types of the above solvents or different solvents Mixtures can be used.

When the porous adhesive resin film constituting the spacer according to the present embodiment has a structure in which the working electrode 10 and the counter electrode 8 are bridged by the skeleton of the inorganic particles 5, as shown in FIG. Can be improved.
In order to realize the cross-linked state, the mixing weight ratio of the inorganic fine particles 5 to the adhesive resin 4 and the concentration of the adhesive resin 4 and the inorganic fine particles 5 in the adhesive liquid according to the embodiment of the present invention are within the following predetermined ranges. It is necessary to.
That is, the mixing weight ratio of the inorganic fine particles 5 to the adhesive resin 4 is preferably in the range of 0.5 to 3, more preferably 0.8 to 2, and the concentration of the inorganic fine particles in the adhesive liquid is 5 to 40% by weight. The range is preferable, more preferably 5 to 20% by weight, and the concentration of the adhesive resin 4 is preferably 2 to 15% by weight, and more preferably 2 to 10% by weight.
If the mixing weight ratio of the inorganic fine particles 5 to the adhesive resin 4 is smaller than the above range, the pores of the porous adhesive resin film become small and it is difficult to permeate the electrolyte solution. If the mixing weight ratio is larger than the above range, the porous adhesive resin As the pores of the membrane become larger, it becomes difficult to retain the permeated electrolyte, and it tends to volatilize, resulting in a risk that the function of the battery will be reduced.
Further, if each concentration is lower than the above concentration range, the film thickness becomes thin, which is not practical. If each concentration is higher than the above concentration range, there is a risk that inorganic fine particles aggregate.
In addition, an additive such as a surfactant may be added in order to favor the dispersion of the inorganic fine particles 5 in the adhesive resin 4.

Next, the adhesive solution is applied to at least one of the working electrode 10 and the counter electrode 8, the working electrode 10 and the counter electrode 8 are aligned through the adhesive solution layer, and then the solvent in the adhesive solution layer is removed. The porous adhesive resin film 14 is used.
As a means for applying, a method using a bar coater or a spray gun, a dipping method, or a printing method such as screen printing or gravure printing can be adopted, so that high productivity can be expected.
After applying the adhesive liquid as described above, the working electrode 10 and the counter electrode 8 may be combined, and then the solvent may be removed and dried to form the porous adhesive resin film 14, or the working electrode 10 may be dried after the solvent is dried. And the counter electrode 8 may be bonded by thermocompression bonding or the like through the porous adhesive resin film 14.

In order to retain the electrolytic solution in the pores of the porous adhesive resin film 14 obtained as described above, the porous adhesive resin film 14 is impregnated with the electrolytic solution 3, but the method is not particularly limited, It is desirable to use an immersion method.
Alternatively, a part of the counter electrode may be cut out in a linear shape or a lattice shape so that the entire porous adhesive resin film can be quickly impregnated. In addition, it is desirable to remove bubbles by reducing the pressure during immersion.
Solvents preferable as the electrolytic solution 3 according to the embodiment of the present invention include, but are not limited to, water or alcohol and a mixture thereof, a non-volatile organic solvent such as propylene carbonate, ethylene carbonate, or methylpyrrolidone, or the above non-solvent. Dimethyl sulfoxide or dichloroethane, such as a mixture of a volatile organic solvent and a viscosity reducing agent such as acetonitrile, ethyl acetate or tetrahydrofuran can be used.
Any miscible solvent can be used as long as it is miscible, and ionic liquids such as pyridinium salts, imidazolium salts, or triazolium salts have low volatility, so that when used in the electrolytic solution 3, they can be used for a long time. It is preferable because stability can be expected.
The electrolyte solution 3 preferably contains a redox system, and the redox system present in the electrolyte solution 3 carries electric charge from one electrode to the other electrode, acts as a pure mediator, and is a battery. The redox system includes an iodine (I ₂ ) / iodine (I ₃ ⁻ ) solution, a bromine (Br ₂ ) / bromine (Br ₃ ⁻ ) solution, A transition metal complex solution such as a hydroxy solution or a quinone complex that transports unbonded electrons, a tetracyanoquinone dimethane (TCNQ) complex, or a dicyanoquinone diimine complex can be used.
The electrolytic solution 3 is preferably dissolved in an organic solvent in which the dye 2 coated on the porous semiconductor film 11 is insoluble, or the dye 2 is dissolved to a saturated concentration. As a result, dissolution of the dye 2 in the electrolytic solution can be suppressed, and thus long-term stability can be achieved.

The working electrode base material 7 or the counter electrode base material 9 according to the embodiment of the present invention is not limited at all as long as it is an insulating and transparent base material such as glass or plastic film. Methacrylate, polycarbonate, polystyrene, polyethylene sulfide, polyethersulfone, polyolefin, polyethylene terephthalate (PET), polyethylene naphthalate, or triacetyl cellulose can be used. A substrate with light resistance and heat resistance is preferred.
In order to effectively take in incident light, an antireflection layer may be provided on the surface of the working electrode substrate 7 on which the light-transmitting conductive layer 6 is not laminated, or an embossing process may be performed. Different materials may be selected for the base material 7 and the counter electrode base material 9.

Further, the porous semiconductor film 11 coated with the dye 2 according to the embodiment of the present invention is not particularly limited as long as it is generally used for a photoelectric conversion material. For example, titanium oxide, oxide Known, such as zinc, tungsten oxide, niobium oxide, tin oxide, vanadium oxide, indium oxide, tantalum oxide, zirconium oxide, molybdenum oxide, manganese oxide, barium titanate, strontium titanate, calcium titanate, magnesium titanate or strontium niobate One kind or two or more kinds of these semiconductors can be used, and titanium oxide is particularly preferred from the viewpoint of stability and safety.
Note that the titanium oxide used in the embodiment of the present invention is anatase-type titanium oxide, rutile-type titanium oxide, amorphous titanium oxide, titanium oxide such as meta-titanium oxide or ortho-titanium oxide, or titanium hydroxide, containing oxygen. Any of titanium and the like may be used.
Further, the surface of the porous semiconductor film 11 needs to secure the surface area of the porous film in order to increase the amount of the dye 2 carried thereon and increase the light absorption amount. The diameter of the semiconductor fine particles 1 constituting the conductive semiconductor film is preferably 5 nm to 200 nm. Furthermore, it is desirable that the particle size of the semiconductor fine particles 1 be about 20 nm or less. The range of the thickness of the porous semiconductor film is preferably 5 μm to 20 μm. If the thickness is less than 5 μm, the amount of light absorbed by the porous semiconductor film to which the dye has been adsorbed is reduced and the characteristics are lowered. If the thickness is more than 20 μm, the cell thickness is increased and the performance is deteriorated.

Examples of the method for coating the porous semiconductor film 11 with the dye 2 include a method in which the porous semiconductor film 11 is immersed in a solution in which the dye 2 is dissolved. The porous semiconductor film 11 is immersed in the dye solution. At this time, it may be heated, the dye solution may be made acidic or basic, and the porous semiconductor film 11 may be immersed in the dye solution after being treated with an acid or a base.
The dye 2 that can be used here is preferably a dye that functions as a photosensitizer, and particularly has absorption in the visible light region or infrared light region, and has a carboxyl group, hydroxyalkyl group, hydroxyl group, Organic dyes having one or more linking groups such as sulfone group, carboxyalkyl group, amide group, amino group, carbonyl group, mercapto group, phosphino group or phosphonyl group are preferred. This is because visible light or infrared light of sunlight can be absorbed and excited to generate electrons, and can be firmly adsorbed to the semiconductor fine particles 1 by such bonding groups.
Specifically, metal-free phthalocyanine dyes, cyanine dyes {trade name: NK1194, manufactured by Nippon Photosensitizer Laboratories Co., Ltd.}, {product name: NK3422, manufactured by Nippon Photosensitizer Laboratories Co., Ltd.}, merocyanine system Dye {trade name: NK2426, manufactured by Nippon Photosensitive Dye Research Co., Ltd.}, {Product name: NK2501, manufactured by Nippon Photosensitive Dye Research Co., Ltd.}, xanthene dyes such as rose bengal and rhodamine B, malachite green or crystal Triphenylmethane dyes such as violet, metal phthalocyanines such as copper phthalocyanine or titanyl phthalocyanine, organic dyes such as chlorophyll, hemin, cyanidin dye, merocyanine dye or rhodamine dye, oxadiazole derivatives, benzothiazole derivatives, coumarin derivatives, stilbene derivatives Organic compounds having a body or aromatic ring, or ruthenium, osmium, and metal complex salt, such as complexes containing iron or zinc 1 more can be used.
The dye preferably has a large extinction coefficient and is stable against repeated redox. The dye 2 may be a low molecular compound or a polymer having a repeating unit. Of these, metal complexes are preferred because they are excellent in spectral sensitization and durability.

Further, the conductive film used as the light-transmissive conductive layer 6 is not particularly limited, but for example, a transparent conductive film such as ITO or SnO ₂ is preferable. A vacuum deposition process such as a reactive deposition method, an ion beam assisted deposition method, a sputtering method, an ion plating method, or a plasma CVD method can be used, but any deposition method may be used.
The electrode material constituting the conductive layer 13 of the counter electrode 8 is not particularly limited, and examples thereof include conductive carbon materials such as charcoal, carbon black and carbon nanotubes, or platinum nanoparticles. The counter electrode 8 may be prepared by forming the conductive layer on the counter electrode base material 9 and then carrying the electrode material. The conductive layer is not particularly limited, but may be a metal such as copper, aluminum or platinum. A thin film made of an oxide having conductivity such as ITO or SnO ₂ is preferable.

Embodiment 3 FIG.
FIG. 2 is a configuration diagram of the dye-sensitized solar cell according to the third embodiment of the present invention. That is, after impregnating the porous adhesive resin film 14 with the electrolytic solution 3, the working electrode lead wire 15 and the counter electrode lead wire 16 are attached, and the gap between the working electrode substrate 7 and the counter electrode 8 is sealed with the sealing member 17. The mechanical strength is further increased. Further, when there is a cut-out portion provided for impregnating the electrolytic solution in the counter electrode 8, the portion is also sealed with the sealant 17.
The sealant 17 is not particularly limited, but a material having light resistance, insulation, and moisture resistance is preferable. For example, epoxy resin, ultraviolet curable resin, acrylic adhesive, ethylene vinyl acetate (EVA), silicon rubber, ceramic A heat-sealing film or the like can be used.
Note that the working electrode lead wire 15 and the counter electrode lead wire 16 may be attached either inside or outside the sealant.

Embodiment 4 FIG.
FIG. 3 is a configuration diagram of the dye-sensitized solar cell according to the fourth embodiment of the present invention. That is, a cover 18 may be installed outside the counter electrode 8, and the cover 18 may be used to seal up to the working electrode substrate 7 of the working electrode 10.

Example 1.
After adjusting titanium oxide particles (anatase-type crystals, average coarse diameter 20 nm) {trade name: P-25, manufactured by Degasser Co., Ltd.} to 17% by weight with respect to diethylene glycol monomethyl ether, a small amount of dispersion aid Was added and dispersed with a paint shaker for 6 hours to obtain a titanium oxide suspension. This titanium oxide suspension was applied to a transparent conductive glass plate with a doctor blade with a film thickness of about 50 μm, pre-dried at 100 ° C. for 40 minutes, and then baked at 520 ° C. for 40 minutes to obtain a film thickness of 10 μm. A titanium oxide film of a degree was obtained.
On the other hand, the ruthenium dye [Ru (4,4′-dicarboxyl-2,2′-bipyridine) ₂ (NCS) ₂ ] is used in ethanol so that the dye concentration becomes 2.5 × 10 ⁻⁴ mol / l. The glass substrate which melt | dissolved and comprised the said titanium oxide film was immersed in the said pigment | dye solution at normal temperature for 12 hours, and the working electrode was obtained.
Moreover, what sputtered platinum on the transparent conductive glass plate was used as a counter electrode.
Further, fine powder alumina {trade name: Aerosil C, manufactured by Aerosil Co., Ltd.}, which is polyvinylidene fluoride and inorganic fine particles, is added to N-methylpyrrolidone (NMP) so that the polyvinylidene fluoride is 5% by weight. A viscous adhesive solution was prepared by sufficiently stirring so that powder alumina {trade name: Aerosil C, manufactured by Aerosil Co., Ltd.} was 5% by weight and dissolved to be a uniform solution.

After the adhesive liquid prepared as described above is uniformly applied on the counter electrode, the working electrode is brought into close contact with the adhesive surface of the counter electrode before the adhesive liquid dries. At this time, the width and length of the counter electrode are slightly smaller than the working electrode.
Next, the NMP in the adhesive liquid layer is evaporated in a hot air dryer at about 80 ° C. At this time, the NMP is removed from the adhesive liquid layer, so that the adhesive liquid layer becomes a porous adhesive resin. Become a film.
Next, after sufficiently drying and depressurizing to 50 Torr, after immersing in the electrolyte, the peripheral area of the working electrode is wiped and washed, and the gap between the working electrode and the counter electrode is sealed with an epoxy-based ultraviolet curable resin. Then, a working electrode lead wire and a counter electrode lead wire were attached to form a dye-sensitized solar cell of an example of the present invention.
In addition, the electrolyte solution contains tetrapropylammonium iodide and iodine in a mixed solvent of acetonitrile / ethylene carbonate having a volume ratio of 1: 4, with respective concentrations of 0.5 mol / l, 0.07 mol / What was melt | dissolved so that it might become 1 was used.

When the dye-sensitized solar cell of this example was irradiated with light having an intensity of 1000 W / m ^{2 with} a solar simulator, η (conversion efficiency) was 3.5%, which proved useful as a solar cell.
When the dye-sensitized solar cell was allowed to stand for 1 month at room temperature, in the air, in the dark, and then irradiated with light having an intensity of 1000 W / m ^{2 using} a solar simulator, η (conversion efficiency) was 3.2%. . Further, the same measurement was performed in a state where the gap between the working electrode and the counter electrode was strongly suppressed with a finger, but η (conversion efficiency) was not changed to 3.2%.

Comparative Example 1
Using a working electrode and a counter electrode obtained in the same manner as in Example 1, after attaching a lead wire to the working electrode, a tetrafluoroethylene resin film cut out from the periphery of the portion where the working electrode and the counter electrode overlap, A counter electrode to which a lead wire was attached was placed thereon, and the gap between the working electrode and the counter electrode was sealed with an epoxy-based ultraviolet curable resin except for the portion where the electrolyte solution was injected, to produce a cell.
After injecting the same electrolytic solution as in Example 1 into the cell, the injection site was sealed with an epoxy-based ultraviolet curable resin to obtain a dye-sensitized solar cell.
When the dye-sensitized solar cell was irradiated with light having an intensity of 1000 W / m ^{2 with} a solar simulator, η (conversion efficiency) was 3.7%, but this was for 1 month at room temperature, in the atmosphere, in the dark. Then, when irradiated with light having an intensity of 1000 W / m ² with a solar simulator, the electrolyte solution volatilized, and η (conversion efficiency) was 1.7%. Furthermore, when the same measurement was performed in a state where the gap between the working electrode and the counter electrode was strongly suppressed with a finger, it did not function as a battery due to a short circuit.

Comparative Example 2
Using a working electrode and a counter electrode obtained in the same manner as in Example 1, after attaching a lead wire to the working electrode, a tetrafluoroethylene resin film cut out from the periphery of the portion where the working electrode and the counter electrode overlap, A counter electrode with a lead wire placed thereon is placed, a 15 μm thick polyethylene porous film is sandwiched between the working electrode and the counter electrode, an electrolytic solution is put in, and an epoxy-based UV curable resin is removed except for the injection portion of the electrolytic solution. Sealed.
After injecting the same electrolytic solution as in Example 1 into the polyethylene porous film, the injection site was sealed with an epoxy-based ultraviolet curable resin to obtain a dye-sensitized solar cell.
When the above dye-sensitized solar cell was irradiated with light having an intensity of 1000 W / m ^{2 with} a solar simulator, η (conversion efficiency) was 3.7%, but this was left for one month at room temperature in the atmosphere and in the dark. Later, when irradiated with light having an intensity of 1000 W / m ² with a solar simulator, η (conversion efficiency) was 3.1 because the electrolyte solution volatilized. Furthermore, when the same measurement was performed with the finger held tightly between the working electrode and the counter electrode, η (conversion efficiency) decreased to 1.8% due to a short circuit between the working electrode and the counter electrode. .

Example 2
Titanium oxide paste (25% by weight titanium oxide content) {trade name: SP-200, manufactured by Showa Titanium Co., Ltd.} is applied onto a transparent conductive film (substrate PET) by a spray method, and 20 at 120 ° C. Partial firing was performed to obtain a titanium oxide film having a thickness of about 10 μm.
On the other hand, ruthenium dye [Ru (4,4′-dicarboxyl-2,2′-bipyridine) ₂ (NCS) ₂ ] is used in ethanol so that the concentration of the dye is 2.4 × 10 ⁻⁴ mol / l. The dissolved PET film having the titanium oxide film was immersed in the dye solution at room temperature for 12 hours to obtain a working electrode.
Further, a transparent conductive film (base material PET) obtained by sputtering platinum was used as a counter electrode.
Also, polyvinylidene fluoride and fumed silica {manufactured by Nippon Aerosil Co., Ltd.] as N-methylpyrrolidone, and fumed silica {manufactured by Nippon Aerosil Co., Ltd.} are 5% by weight so that the polyvinylidene fluoride is 5% by weight. Thus, a viscous adhesive solution was prepared by sufficiently stirring so as to dissolve and form a uniform solution.

Using the adhesive solution prepared as described above, the working electrode and the counter electrode were bonded together with a porous adhesive resin film in the same manner as in Example 1. Then, acetonitrile was used as the electrolytic solution, tetrabutylammonium iodide, iodine, and 4 -T-butylpyridine and lithium iodide dissolved so that their respective concentrations are 0.4 mol / l, 0.04 mol / l, 0.3 mol / l, and 0.4 mol / l In the same manner as in Example 1, a dye-sensitized solar cell of the example of the present invention was manufactured.
When the dye-sensitized solar cell of the example of the present invention was irradiated with light having an intensity of 1000 W / m ^{2 with} a solar simulator, η (conversion efficiency) was 3.0%, which is useful as a solar cell. all right. When this was bent with a curvature radius of 1 cm and irradiated with light having an intensity of 1000 W / m ² with a solar simulator, η (conversion efficiency) was 2.5%.

Comparative Example 3
Using the working electrode and counter electrode obtained in the same manner as in Example 2, after attaching a lead wire to the working electrode, a tetrafluoroethylene resin film cut out of the portion where the working electrode and the counter electrode overlap was placed around the lead wire, A counter electrode to which a lead wire was attached was placed thereon, a polyethylene porous film having a thickness of 15 μm was sandwiched between the working electrode and the counter electrode, and sealing was performed with an epoxy-based ultraviolet curable resin except for the electrolyte injection portion.
After injecting the same electrolytic solution as in Example 1 into the polyethylene porous film, the injection site was sealed with an epoxy-based ultraviolet curable resin to obtain a dye-sensitized solar cell.
When the above dye-sensitized solar cell was irradiated with light having an intensity of 1000 W / m ^{2 with} a solar simulator, η (conversion efficiency) was 3.3%, but this sample was bent at a radius of curvature of 1 cm. When irradiated with light having an intensity of 1000 W / m ² with a solar simulator, a short circuit between the working electrode and the counter electrode occurred in part, and η (conversion efficiency) was 1.0%.

  In addition, Table 1 collectively shows η (conversion efficiency) in each state of the dye-sensitized solar cells of the above Examples and Comparative Examples.

As shown in Table 1, there is no difference in the conversion efficiency of the initial product in any of the examples. However, in Example 1, the electrolyte solution holding ability of the porous adhesive resin film is superior to that of Comparative Example 1. Even after long-term storage, there is almost no decrease in conversion efficiency. Moreover, since the mechanical strength of the porous adhesive resin film is superior to that of Comparative Example 2, a short circuit does not occur even when pressure is applied between the working electrode and the counter electrode, so that the conversion efficiency does not decrease.
Similarly, in Example 2, since the mechanical strength of the porous adhesive resin film is superior to that in Comparative Example 3, short-circuiting between the working electrode and the counter electrode is suppressed even when bent. The decline is suppressed.

It is a block diagram of the dye-sensitized solar cell of Embodiment 1 of this invention. It is a block diagram of the dye-sensitized solar cell of Embodiment 3 of this invention. It is a block diagram of the dye-sensitized solar cell of Embodiment 4 of this invention.

Explanation of symbols

2 dye, 3 electrolyte, 4 adhesive resin, 5 inorganic fine particles, 8 counter electrode, 10 working electrode, 11 porous semiconductor film, 12 spacer, 14 porous adhesive resin film.

Claims (5)

A working electrode having a porous semiconductor film coated with a dye, a counter electrode provided opposite to the working electrode, and a dye provided between the working electrode and the counter electrode and having a spacer for holding an electrolytic solution In the sensitized solar cell, the spacer is made of an inorganic fine particle and an adhesive resin in which the inorganic fine particle is dispersed, a porous adhesive resin film that adheres to the working electrode and the counter electrode, and a hole in the porous adhesive resin film A dye-sensitized solar cell, comprising: The adhesive resin adheres between the inorganic fine particles and the working electrode, between the inorganic fine particles and the counter electrode, and between the inorganic fine particles, and the working electrode and the counter electrode are cross-linked by a skeleton of the inorganic fine particles. 2. A dye-sensitized solar cell according to 1. Applying an adhesive liquid containing inorganic fine particles and an adhesive resin in a solvent to at least one of a working electrode having a porous semiconductor film coated with a dye and a counter electrode facing the porous semiconductor film; A step of disposing the working electrode and the counter electrode through the layer of the adhesive liquid, and removing the solvent of the layer of the adhesive liquid to form a porous adhesive resin film. A method for producing a dye-sensitized solar cell, comprising: a step of bonding an electrode and the counter electrode; and a step of impregnating the porous adhesive resin film with an electrolyte. Applying an adhesive solution containing inorganic fine particles and an adhesive resin in a solvent to at least one of a working electrode having a porous semiconductor film coated with a dye and a counter electrode facing the porous semiconductor film; Removing the solvent of the adhesive liquid layer to form a porous adhesive resin film; adhering the working electrode and the counter electrode through the porous adhesive resin film; and the porous adhesive resin film A method for producing a dye-sensitized solar cell, comprising: impregnating an electrolyte solution with an electrolyte solution. The mixing weight ratio of the inorganic fine particles to the adhesive resin in the adhesive liquid is 0.5 to 3, the concentration of the inorganic fine particles is 5 to 40% by weight, and the concentration of the adhesive resin is 5 to 15% by weight. The method for producing a dye-sensitized solar cell according to claim 3 or 4, wherein:

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