JP2005109031A - Photosensitive-type solar cell and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive-type solar cell capable of efficiently extracting a power and capable of increasing an area, and to provide a manufacturing method for the solar cell. <P>SOLUTION: The photosensitive-type solar cell has a transparent substrate, a current-collecting wiring layer formed on the substrate, a transparent insulator layer covering regions other than the wiring layer, and a transparent electrode layer formed on the wiring layer and the insulator layer. The solar cell further has a semiconductor layer formed on the electrode layer, a semiconductor electrode which is formed on the semiconductor layer and in which a pigment is carried on a surface, and counter substrates which are separated and facing, and arranged with respect to the semiconductor electrode and having conductive layers on surfaces. The solar cell further has an electrolyte layer, formed between the semiconductor electrode and the conductive layer and having iodine molecules and an electrolyte containing iodide. The solar cell is constituted so that the maximum thickness of the current-collecting wiring layer is made approximately the same as or larger than that of the transparent insulator layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a photosensitized solar cell and a method for manufacturing the same.

  As a general photosensitized solar cell, a transparent electrode that supports a semiconductor layer in which a pigment is supported on the surface of metal oxide fine particles, a counter electrode that faces the transparent electrode, and an electrode interposed between the two electrodes And an electrolyte layer.

  Such a photosensitized solar cell operates through the following process. That is, the light incident from the transparent electrode side reaches the dye carried on the surface of the semiconductor layer and excites this dye. The excited dye quickly passes electrons to the semiconductor layer. On the other hand, the positively charged dye by losing electrons is electrically neutralized by receiving electrons from ions diffused from the electrolyte layer. The ions that have passed the electrons diffuse to the counter electrode and receive the electrons. The photosensitized solar cell is operated by using a transparent electrode and a counter electrode facing the transparent electrode as a negative electrode and a positive electrode, respectively.

By the way, in a photosensitized solar cell, as a transparent electrode and a substrate provided with the transparent electrode, a glass with an ITO electrode used for a liquid crystal display or the like, a glass with a fluorinated SnO ₂ film, and the like are known. However, these transparent electrodes have a sheet resistance of 10 to 30Ω / □, and are higher in resistance than electrodes formed of metal. Therefore, when an attempt is made to produce a photosensitized solar cell having a large area, the resistance cannot be ignored, resulting in a problem that the efficiency is lowered.

  In order to solve this problem, it is preferable to insert wiring for collecting current with a metal such as aluminum on the substrate on which the transparent electrode is formed. However, since the electrolyte layer interposed between the two electrodes of the photosensitized solar cell contains iodine, this iodine reacts with the metal of the current collector wiring and is eluted into the electrolyte. Moreover, even if it is going to form current collection wiring between a glass substrate and a transparent electrode, a transparent electrode cannot be formed in the side surface of current collection wiring, and current collection wiring will also contact electrolyte solution.

In addition, the electrode substrate which has the conductive wiring which is used for a liquid crystal display element and is in conductive contact with the transparent electrode is known (see, for example, Patent Document 1).
JP 2000-148043 (page 5-24, FIG. 1)

  In view of this problem, the present invention provides a photosensitized solar cell that can efficiently extract electric power and can have a large area, and a method for manufacturing the same.

Accordingly, the present invention provides a transparent substrate, a first current collecting wiring layer provided on the transparent substrate, a first transparent insulator layer covering a region other than the first current collecting wiring layer on the transparent substrate, and a first current collecting layer. A transparent electrode layer provided on the electrical wiring layer and the first transparent insulator layer; a semiconductor layer provided on the transparent electrode layer; a semiconductor electrode provided on the semiconductor layer and having a dye supported on the surface; An electrolyte layer having a counter substrate disposed to be opposed to the semiconductor electrode, a conductive layer provided on the counter substrate, and an electrolyte containing iodine molecules and iodide provided between the semiconductor electrode and the conductive layer. The photosensitized solar cell is characterized in that the maximum thickness of the first current collecting wiring layer is substantially the same as or larger than the maximum thickness of the first transparent insulator layer.

  In the present invention, the first transparent insulator layer may be at least one selected from polysiloxane, polyacrylic acid, and polymethacrylic acid.

  In the present invention, the transparent substrate may be a plastic substrate.

  In the present invention, the second current-collecting wiring layer provided on the counter substrate between the counter substrate and the conductive layer and the second transparent insulation covering the region other than the second current collector wiring layer on the counter substrate. And the maximum thickness of the second current collecting wiring layer may be substantially the same as or larger than the maximum thickness of the second transparent insulator layer.

  The present invention also provides a step of selectively forming a first transparent insulator layer on a transparent substrate, and a first current collector wiring formed by plating on a region of the transparent substrate where the first transparent insulator layer is not formed. A step of forming a layer, a step of forming a transparent electrode layer so as to cover the first transparent insulator layer and the first current collecting wiring layer, a step of forming a semiconductor layer on the transparent electrode layer, and a semiconductor on the semiconductor layer A step of forming an electrode and supporting a dye on the semiconductor electrode, a step of forming a conductive layer on the surface of the counter substrate, and a transparent substrate on which the semiconductor electrode is formed and a counter substrate on which the conductive layer is formed are arranged to face each other. And a step of forming an electrolyte layer by injecting an electrolyte containing iodine molecules and iodide, and providing a method for producing a photosensitized solar cell.

  In the present invention, the first transparent insulator layer may be at least one selected from polysiloxane, polyacrylic acid, and polymethacrylic acid.

  In the present invention, the transparent substrate may be a plastic substrate.

  In the present invention, the step of forming the conductive layer on the surface of the counter substrate includes the step of selectively forming the second transparent insulator layer on the counter substrate, and the step of forming the second transparent insulator layer on the counter substrate. A step of forming the second current collecting wiring layer by a plating method in a region not formed and a step of forming a conductive layer so as to cover the second transparent insulator layer and the second current collecting wiring layer may be included.

  ADVANTAGE OF THE INVENTION According to this invention, electric power can be taken out efficiently and the photosensitized solar cell which can be enlarged, and its manufacturing method can be provided.

  Hereinafter, embodiments of the present invention will be described in detail.

  In the photosensitized solar cell according to the embodiment of the present invention, a transparent wiring layer and a transparent insulator layer that covers other regions are provided on a transparent substrate, and a transparent electrode layer, a semiconductor layer, and a semiconductor electrode are provided thereon. Are stacked. The maximum thickness of the current collecting wiring layer is substantially the same as or larger than the maximum thickness of the transparent insulator layer.

  Further, in the method of manufacturing a photosensitized solar cell in the embodiment of the present invention, a transparent insulator layer is formed on a transparent substrate and patterned, and a current collecting wiring layer is formed by plating on the unattached region. A transparent electrode layer, a semiconductor layer, and a semiconductor electrode are laminated on these.

  As described above, when the current collector wiring is provided in the photosensitized solar cell, it is necessary to prevent the metal of the current collector wiring from reacting with iodine in the electrolyte layer and eluting.

  Therefore, in the present embodiment, a transparent insulator layer is formed on a transparent substrate and patterned, and a current collecting wiring layer is formed on the unattached region by a plating method. As a result, the maximum thickness of the current collector wiring layer can be substantially the same as or larger than the maximum thickness of the transparent insulator layer, and the layer consisting of the current collector wiring layer and the transparent insulator layer is a layer with few steps. It is possible to prevent the transparent electrode layer formed thereon from being disconnected. In addition, the transparent electrode layer has no barrier property, and even if the transparent electrode layer covers the current collecting wiring layer without stepping, the elution of the current collecting wiring layer is still unavoidable due to the infiltration of the electrolyte. Since the semiconductor layer is formed on the layer, the infiltration of the electrolyte can be prevented by this semiconductor layer. The semiconductor layer is preferably a thin film so as not to increase the electrical resistance. Even when there is a small step, the semiconductor layer is likely to be cut off, but in this embodiment, the flatness of the layer on which the current collector wiring is formed is high. Further, it is possible to prevent the semiconductor layer from being disconnected for preventing a short circuit. The difference between the maximum thickness of the current collecting wiring layer and the maximum thickness of the transparent insulator layer is preferably 80 nm or less. If the thickness is larger than 80 nm, there is a high possibility that the semiconductor layer is disconnected. By controlling the plating conditions, the thickness can be made 80 nm or less.

  As a method other than the present invention, a transparent insulating layer is provided so as to cover the current collecting wiring layer after the current collecting wiring layer is formed, and the current collecting wiring layer is exposed so that the transparent insulating layer is the same layer as the current collecting wiring layer. However, this method cannot obtain the effect as in the present embodiment. The reason for this is that unevenness around the current collector wiring layer is unavoidable in this method, and the semiconductor layer consisting of a thin film is disconnected because the current collector wiring layer does not want to contact the electrolyte layer using iodine. This is because it is impossible to solve the problem unique to the photosensitized solar cell that it is necessary to prevent this.

  The photosensitized solar cell of this embodiment will be described using the cross-sectional views of FIGS. 1 and 2.

  As shown in FIG. 1, on a glass substrate 1, a transparent conductive layer 2 and a transparent semiconductor electrode 4 comprising a current collector wiring layer, a transparent insulator layer, a transparent electrode layer, a semiconductor layer (not shown in detail), and the like. Are sequentially formed. Since the semiconductor electrode 4 is formed from an aggregate of the fine particles 3, the surface area is extremely large. Further, a single molecule is adsorbed on the surface of the fine particles 3 of the semiconductor electrode 4. One counter substrate 6 includes a glass substrate 6 and a conductive layer 5 formed on the surface of the glass substrate 6 on the semiconductor electrode 4 side. The electrolyte composition 9 is held in the pores in the transparent semiconductor electrode 4 and is interposed between the semiconductor electrode 4 and the conductive layer 5. In such a photosensitized solar cell, after the dye adsorbed on the surface of the semiconductor electrode 4 absorbs the light 11 incident from the glass substrate 1 side, the dye passes electrons to the semiconductor electrode 4 and Photoelectric conversion is performed by the dye passing holes to the electrolyte layer 9.

  As shown in FIG. 2, the transparent conductive layer 2 includes a current collecting wiring layer 22 provided on the transparent substrate 1, a transparent insulator layer 21 covering a region other than the current collecting wiring layer 22 on the transparent substrate 1, The transparent electrode layer 23 is provided on the transparent insulator layer 21 and the current collecting wiring layer 22, and the semiconductor layer 24 is provided on the transparent electrode layer 23. The current collecting wiring layer 22 is provided to reduce the electric resistance, and the pattern may be a stripe shape, a lattice shape, or the like.

  Next, each structure used for the photosensitized solar cell of this embodiment will be described in detail.

  As the transparent substrate 1, it is desirable to use a substrate that absorbs light at a wavelength of 400 to 800 nm. As the substrate used for the transparent substrate 1, both inorganic and organic materials can be used. For example, glass is used as the inorganic material, and plastic substrates such as PET film, PEN film, polycarbonate substrate, and acrylic substrate are used as the organic material. Since the plastic substrate is difficult to flatten such as polishing, it can be said that this embodiment is more effective.

A current collecting wiring layer 22 is provided on the substrate. The material of the current collection wiring layer 22 is not specifically limited. For example, gold, silver, copper, aluminum or the like is used.

  On the transparent substrate 1 other than the current collecting wiring layer 22, a highly transparent transparent insulator layer 21 exists. As the material of the transparent insulator layer 21, either an organic material or an inorganic material can be used. For example, at least one selected from polysiloxane, polyacrylic acid, and polymethacrylic acid is preferable because of its high transparency.

  The transparent insulator layer 21 and the current collecting wiring layer 22 can be formed by the following method.

The transparent insulator layer 21 is produced using a photosensitive resin. The photosensitive resin composition is applied on the transparent substrate 1 so that the thickness is d ₁ . The photosensitive resin is not particularly limited. For example, a polymer having a moiety protected by a substituent that removes the carboxylic acid moiety of polyacrylic acid or methacrylic acid with an acid, such as -CH2COO-t-Bu, a pyranyl group, or a t-butyl group. Alternatively, a mixture of a polymer having a moiety in which -OH group of polyvinylphenol is protected with t-BOC, -CH2COO-t-Bu, pyranyl group, t-butyl group and a photoacid generator can be used. The photoacid generator is not particularly limited. For example, naphthoquinonediazide can be used. Further, polysilane having a Si—Si bond can also be used. As the polysilane, a functional group obtained by protecting a phenol group OH with t-butyl, pyranyl, or t-BOC, or a polysilane having a Si—H bond can be used. A composition in which the above-mentioned photoacid generator is mixed with a polysilane having a functional group in which phenolic OH is protected with t-butyl, pyranyl, or t-BOC, and a composition in which a radical generator is mixed with polysilane having a Si—H bond. Things can be used.

  In these resin compositions, the exposed portion is dissolved in an alkaline aqueous solution. Using a mask, selective exposure is performed by an exposure machine. Thereafter, heat may be applied to advance the reaction of the exposed portion. Thereafter, when exposed to an alkaline aqueous solution, the exposed portion dissolves. The unexposed portion becomes the transparent insulator layer 21, and the exposed portion becomes the current collecting wiring layer 22 later. Thereafter, the photoacid generator and the radical generator are removed by firing. In the case of polysilane, it is oxidized by this heat treatment to be stabilized as polysiloxane. Naphthoquinone diazide and the like can be photolyzed and decolored by front exposure.

  Commercially available photoresists can also be used. The photoresist can be either a positive type or a negative type.

  Next, the current collection wiring layer 22 is formed by a plating method. As a plating method, either electroless plating or electrolytic plating can be used.

In the case of electrolytic plating, a transparent electrode such as ITO is prepared on the entire surface of the transparent substrate 1 in advance, or ITO or metal wiring having a height of about 100 nm is prepared in advance in a place where wiring is required. it can. A photosensitive resin is applied on the transparent substrate 1 thus prepared so that the maximum thickness is d ₁ , exposed and developed, and the portion where the resin remains becomes the transparent insulator layer 21. Then, the portion of the resin on which the ITO or thin metal (about 100 nm) metal wiring is formed is exposed by etching, and the current collecting wiring layer 22 can be produced by a normal plating process so that the maximum thickness is d ₁ ^′. . Although a plating process is not particularly limited, gold, palladium, ruthenium, platinum, silver, nickel, copper, or the like can be used as a metal used for plating. The current collector wiring 22 can be produced by electrochemically reducing these metal ion compounds in a solution and precipitating them on the electrode surface.

As another method, electroless plating can be used. The wiring patterning method is not particularly limited. For example, a catalyst for electroless plating is applied to the transparent substrate 1 in advance, and then the resin portion is patterned in the same manner as described above to form the transparent insulator layer 21. The transparent substrate 1 to which the catalyst is added by patterning is exposed. The current collecting wiring layer 22 can be selectively formed on the exposed portion.

  As another method of electroless plating, after a photosensitive resin is applied to the entire surface of the transparent substrate 1, a thin film is formed using, for example, a water-repellent fluororesin, Teflon dispersion liquid (R), or the like. Thereafter, the photosensitive resin is patterned by the above-described method to form the transparent insulator layer 21, and then the electroless plating catalyst is brought into contact with the whole. The contact method is not limited, and for example, dip coating, spin coating, spraying, or the like can be used. The contacted catalyst does not adhere to the water repellent portion, but adheres to the exposed transparent substrate 1 portion, and the current collecting wiring layer 22 can be formed.

  Electroless plating can be selectively performed by these methods. The electroless plating catalyst is not particularly limited, and for example, Pd colloid, Sn—Pd colloid, or the like can be used. Although the metal to plate is not specifically limited, Nickel, copper, cobalt, gold | metal | money, silver, palladium etc. can be used. An electrode is formed by reducing the electroless plating solution containing these metal ions. In order to stabilize these ions, chelating agents such as EDTA, 2-MBT and 2,2′-bipyridine can be used. Other stabilizers include, but are not limited to, 1,10-phenanthronium chloride, neocuproine, 2,2'-biquinoline, bankproin disulfonic acid-DNS, benzoquinoline, azo dyes dithizone, diphencarbazide, methyl As a 5-membered ring such as orange, pyrrole, pyrazole, imidazole, 1,2,4-triazole, 1,2,4-benzotriazole, etc. As a 6-membered ring, pyridine, triazine, nicotinic acid, etc. as thioureas Examples include thiourea, rubeanic acid, tetramethylthiourea, and other thiophenes, 2-mercaptobenzothiazole (2-MBT), thiazole, thionalid, sodium cyanide, Rainecke salt, cupron, and cupron. As the reducing agent, NaH2PO2, DMAB (dimethylamine borane), KBH4, N2H4, Na2HPO3, HCHO, and the like can be used. Further, a pH adjusting agent or a surfactant for removing bubbles when oxygen is generated can be used.

  Further, after forming a thin film by electroless plating, a denser current collecting wiring layer 22 can be produced by electrolytic plating.

By these methods, the maximum thickness of the current collector wiring layer 22 can be made substantially the same or larger than the maximum thickness of the transparent insulator layer 21. When the current collecting wiring layer 22 is produced by plating, it is possible to obtain a wiring having the highest central portion in the width direction of the wiring and the lower peripheral portion in the width direction of the wiring. When the central portion is located on the upper surface, the subsequent transparent electrode layer and the semiconductor layer can be formed seamlessly, and the barrier property from the electrolyte layer is enhanced. That is, in FIG. 2, _'when compared with the, d ₁ ≦ d _1' height d ₁ of the central portion of the height d ₁ and the width direction of the collector wiring layer 22 of the transparent insulator layer 21 and. In FIG. 2, the height is larger than that of the transparent insulating layer 21 except in the central portion in the width direction of the current collecting wiring layer 22, but as shown in FIG. The end height d _{2 ″} may be lower than the height d ₂ of the transparent insulator layer 21. Even in this case, if the height d _{2 ′} of the central portion of the current collecting wiring layer 22 is the same as or slightly higher than the height d ₂ of the transparent insulator layer 21, d ₂ and d _{2 ″} are different from each other. This is because the difference is not so great that cutting occurs. The method for determining the height of the central portion of the wiring is performed by controlling the plating time. The current collector wiring layer 22 and the transparent insulator layer 21 can be aligned by measuring the growth rate by plating in advance and controlling it by time.

  For the transparent electrode layer 23, ITO, SnO2, fluorine-doped SnO2, or the like can be used. The transparent electrode layer 23 is produced so as to cover the current collecting wiring layer 22 and the transparent insulator layer 21 by CVD, sputtering, or the like.

The semiconductor layer 24 includes oxides of transition metals such as titanium, tin, zinc, zirconium, hafnium, strontium, indium, yttrium, lanthanum, vanadium, niobium, tantalum, chromium, molybdenum, or tungsten, SrTiO ₃ , CaTiO ₃ , BaTiO ₃ . ₃ , perovskites such as MgTiO ₃ and SrNb ₂ O ₆ , or complex oxides or oxide mixtures thereof, and GaN can be used. The semiconductor layer 24 preferably has a thickness of about 0.7 to 20 nm. The semiconductor layer 24 prevents a reverse current from the transparent electrode layer 23 to the electrolyte layer 9 and at the same time prevents the electrolyte in the electrolyte layer 9 from passing through the transparent electrode layer 23 and contacting the current collecting wiring layer 22. When the thickness of the semiconductor layer 24 is less than 0.7 nm, the barrier property of the electrolytic solution is lowered, and when it is 20 nm or more, the resistance is increased and the energy conversion efficiency as a solar cell is lowered.

The semiconductor electrode 4 is preferably made of a transparent semiconductor that has little absorption in the visible light region. The semiconductor electrode 4 is an aggregate of fine particles or a porous body formed by collecting a large number of fine particles 3 having a size of about 5 to 20 nm. As such a semiconductor, a metal oxide semiconductor is preferable. Specifically, oxides of transition metals such as titanium, tin, zirconium, hafnium, strontium, zinc, indium, yttrium, lanthanum, vanadium, niobium, tantalum, chromium, molybdenum or tungsten, SrTiO ₃ , CaTiO ₃ , BaTiO ₃ Perovskites such as MgTiO ₃ and SrNb ₂ O ₆ , or complex oxides or oxide mixtures thereof, and GaN can be used. The semiconductor layer 24 and the semiconductor electrode 4 are preferably made of the same material.

  Examples of the dye adsorbed on the surface of the semiconductor electrode 4 include a ruthenium-tris transition metal complex, a ruthenium-bis transition metal complex, an osmium-tris transition metal complex, and an osmium-bis transition metal complex. , Ruthenium-cis-diaqua-bipyridyl complexes, phthalocyanines, and porphyrins.

  For example, the dye is adsorbed on the titania surface by an ester bond by immersing the semiconductor electrode 4 in a dye solution dissolved in a medium such as ethanol.

  The counter substrate 6 preferably has little absorption in the visible light region.

  The conductive layer 5 provided on the surface of the counter substrate 6 may be formed of, for example, a tin oxide film, a tin oxide film doped with fluorine, a zinc oxide film, a metal such as platinum, gold, and silver, or carbon. it can. In view of durability against the electrolyte, platinum is particularly preferable. Platinum can be attached to the counter substrate 6 by electrochemical or sputtering.

  In the present embodiment, a current collector wiring layer provided on the counter substrate and a transparent insulator layer covering other regions may be provided between the counter substrate 6 and the conductive layer 5. The material and manufacturing method of the current collecting wiring layer and the transparent insulator layer can be the same as those described above. In this case, the conductive layer 5 can be efficiently collected using a metal having a low resistance as described above by using a material that becomes a barrier layer that prevents the infiltration of the electrolyte.

The electrolyte composition contained in the electrolyte layer 9 preferably includes a reversible redox pair consisting of I ⁻ and I ₃ ⁻ . The reversible redox _couple can be supplied from a mixture of iodine (I ₂ ) and iodide.

The redox couple as described above desirably exhibits a redox potential that is 0.1 to 0.6 V smaller than the oxidation potential of the dye described later. In a redox pair showing a redox potential 0.1 to 0.6 V lower than the oxidation potential of the dye, for example, a reducing species such as I ⁻ can receive holes from the oxidized dye. By containing such a redox pair in the electrolyte layer 9, the speed of charge transport between the semiconductor electrode 4 and the conductive layer 5 can be increased, and the open-circuit voltage can be increased.

  The electrolyte composition contains iodide. Examples of iodides include alkali metal iodides, iodides of organic compounds, and molten salts of iodides.

  Examples of the molten salt of iodide include iodides of heterocyclic nitrogen-containing compounds such as imidazolium salts, pyridinium salts, quaternary ammonium salts, pyrrolidinium salts, pyrazolidium salts, isothiazolidinium salts, and isoxazolidinium salts. Can be used.

  Examples of the molten salt of iodide include 1,3-dimethylimidazolium iodide, 1-ethyl-3-methylimidazolium iodide, 1-methyl-3-propylimidazolium iodide, 1-methyl-3-pentyl. Imidazolium iodide, 1-methyl-3-isopentylimidazolium iodide, 1-methyl-3-hexylimidazolium iodide, 1-methyl-3-isohexyl (branched) imidazolium iodide, 1-methyl-3 Ethyl imidazolium iodide, 1,2-dimethyl-3-propylimidazole iodide, 1-ethyl-3-isopropylimidazolium iodide, 1-propyl-3-propylimidazolium iodide, and pyrrolidinium iodide Etc. Kill. Such a molten salt of iodide can be used alone or in combination of two or more. The content thereof is preferably about 0.005 mol / l to 7 mol / l in the electrolyte layer 9. If it is less than 0.005 mol / l, it is difficult to obtain sufficient effects. On the other hand, if it exceeds 7 mol / l, the viscosity is high and the ionic conductivity may be remarkably lowered.

  Further, the electrolyte composition contains iodine, and the content is preferably 0.01 mol / L or more and 3 mol / L or less. Iodine is mixed with iodide in the electrolyte layer 9 and acts as a reversible redox pair. Therefore, when the iodine content is less than 0.01 mol / L, the oxidized form of the redox couple is insufficient and it becomes difficult to transport charges. On the other hand, if it exceeds 3 mol / L, the light absorption of the solution increases, and there is a possibility that light cannot be efficiently applied to the semiconductor electrode 4. The iodine content is more preferably 0.03 mol / L or more and 1.0 mol / L or less.

  The electrolyte composition may be liquid or gel, and may contain an organic solvent. By containing the organic solvent, the viscosity of the electrolyte composition can be further reduced, so that the electrolyte composition can easily penetrate into the semiconductor electrode 4.

  Examples of the organic solvent that can be used include cyclic carbonates such as ethylene carbonate (EC) and propylene carbonate (PC); chain carbonates such as dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate; γ-butyrolactone, acetonitrile, propionic acid Examples include methyl and ethyl propionate. Furthermore, cyclic ethers such as tetrahydrofuran and 2-methyltetrahydrofuran; chain ethers such as dimethoxyethane and diethoxyethane; nitrile solvents such as acetonitrile, propionitrile, glutaronitrile, and methoxypropionitrile It is done. These organic solvents can be used alone or as a mixture of two or more.

  The content of the organic solvent is not particularly limited, but is preferably 30% by weight or less in the electrolyte composition. If the content of the organic solvent exceeds 30% by weight, performance may be deteriorated due to volatilization. The content of the organic solvent is more preferably 0% by weight or more and 30% by weight or less.

  You may manufacture the photosensitized solar cell of embodiment of this invention by the method demonstrated below, for example.

  First, a substrate having a light receiving surface is prepared, and a transparent conductive layer and a semiconductor electrode are sequentially formed on one surface thereof. Then, the dye is adsorbed on the surface of the semiconductor electrode. On the other hand, a counter substrate having a conductive layer provided on the surface is prepared, and the battery unit is assembled by disposing the conductive layer and the above-described semiconductor electrode so as to face each other.

  Next, an electrolyte is injected into the gap between the semiconductor electrode and the conductive layer to form an electrolyte layer. When the gel electrolyte layer is used, the electrolyte precursor is gelled. Subsequently, the photosensitized solar cell of the embodiment of the present invention is obtained by sealing the battery unit.

Hereinafter, specific examples will be described in more detail with reference to the drawings.
(Example 1)
A Pd colloid was applied on a PET film having a thickness of about 200 μm to form an electroless plating catalyst. 7 parts by weight of a photoacid generator 4NT (4) 300 was prepared in a 20 wt% ethyl lactate solution based on 100 parts by weight of a resin obtained by replacing the carboxylic acid of polyacrylic acid with 50% t-butyl group.

  As shown in FIG. 4A, this solution was spin-coated on a PET film 1 (transparent substrate 1) to which a catalyst was attached, baked at 80 ° C. for 1 minute, and dried to form a transparent insulator layer 21. . The transparent substrate 1 was exposed for 1 minute using an exposure machine PLA manufactured by Canon Inc. using a photomask 31 on which a pattern of the current collecting wiring layer was written.

  As shown in FIG. 4B, the exposed portion 32 was etched when developed with AD10 (TMAH 2.38% alkaline aqueous solution) for 1 minute after exposure.

  As shown in FIG.4 (c), the current collection wiring layer 22 which consists of copper was produced using PB-503A by the commercially available electroless-plating liquid Sugawara Eugelite company. When the maximum heights of the transparent insulator layer 21 and the current collecting wiring layer 22 were measured, they were 1.8 μm and 1.85 μm, respectively.

  As shown in FIG. 4D, an ITO film 23 (transparent electrode layer 23) was formed by sputtering. The thickness of the ITO film 23 was about 0.1 μm. On the ITO film 23, a coating type peroxotitanic acid solution was applied to form a dense titania film 24 (semiconductor layer 24) having a thickness of 7 nm.

  1 g of Teflon (R) particles were added to 100 g of P25 manufactured by Nippon Aerosil Co., and dispersed uniformly on a mortar. The paste was formed into a 50 μm sheet with a roll.

As shown in FIG. 5A, this sheet was placed on the titania film 24 of the transparent substrate 1 and passed through a roll, whereby an n-type semiconductor electrode 4 (semiconductor electrode 4) was produced. On the other hand, cis-bis (thiocyanato) -N, N-bis (2,2′-dipyridyl-4,4′-dicarboxylic acid) -ruthenium (II) dihydrate) is dissolved in dry ethanol to give 3 × A 10 ⁻⁴ M dry ethanol solution was prepared. The n-type semiconductor electrode 4 described above was immersed in this solution for 12 hours and then pulled up in an argon stream. As a result, a ruthenium complex as a dye was supported on the surface of the n-type semiconductor electrode 4.

  A fluorine-doped tin oxide electrode 5 (conductive layer 5) was formed on the counter substrate 6 having platinum attached to the surface. On the transparent substrate 1 on which the n-type semiconductor electrode 4 was produced, this counter substrate 6 was placed via a spacer having a diameter of 15 μm. Further, the periphery of the electrolyte composition was left, and the periphery was fixed with epoxy resin 7 and fixed.

  The electrolyte composition was prepared as follows. First, in 100 ml of acetonitrile, 0.5 mol / L of lithium iodide, 0.3 mol / L of methylhexylimidazolium iodide, 0.5 mol / L of t-butylpyridine, and 0.05 mol / L of iodine were dissolved. It was.

  As shown in FIG. 5B, the electrolyte composition 9 was injected from the injection port 8 into the opening of the photoelectric conversion unit.

  As shown in FIG. 5 (c), the electrolyte composition 9 penetrated into the n-type semiconductor electrode 4 and was also injected between the n-type semiconductor electrode 4 and the conductive layer 5 to form the electrolyte layer 9.

  As shown in FIG.1 (d), after sealing the opening part of a photoelectric conversion unit with the epoxy resin 10, by heating on a hotplate for 30 minutes at 60 degreeC, a photoelectric conversion element, ie, a photosensitized solar, is shown. A battery was manufactured.

When the energy conversion efficiency of the obtained photosensitized solar cell was measured using 100 mW / cm ² pseudo-sunlight, the energy conversion efficiency of this solar cell was 2.0%. This cell was left for 1 month to check the stability of the cell. The current collecting wiring layer 22 was protected by the transparent electrode layer 23 and the semiconductor layer 24 that were sputtered on the surface having no irregularities, so that it did not come into contact with the electrolytic solution and the performance was not deteriorated.
(Example 2)
A solution prepared by preparing 7 parts by weight of a photoacid generator 4NT (4) 300 in a 20 wt% ethyl lactate solution with respect to 100 parts by weight of a resin obtained by replacing the carboxylic acid of polyacrylic acid of Example 1 with 50% t-butyl group. , Except that 100 parts by weight of the resin obtained by replacing 30% of the OH group of polyvinyltoluene with CH2COOt-Bu group was changed to a solution prepared by adding 7 parts by weight of photoacid generator 4NT (4) 300 to a 20 wt% ethyl lactate solution. Similarly, a photosensitized solar cell was produced. The energy conversion efficiency was measured and found to be 2.1%. The condition after one month was also good without deterioration.
(Example 3)
A solution prepared by preparing 7 parts by weight of a photoacid generator 4NT (4) 300 in a 20 wt% ethyl lactate solution with respect to 100 parts by weight of a resin obtained by replacing the carboxylic acid of polyacrylic acid of Example 1 with 50% t-butyl group. , 95 parts by weight of polyphenylsilane and 5 parts of 2,4-bis (trichloromethyl) -6-methyl-s-triazine were changed to a solution prepared in a 20 wt% toluene solution and baked at 150 degrees for 30 minutes after patterning Then, a photosensitized solar cell was formed in the same manner except that polysilane was oxidized. The energy conversion efficiency was measured and found to be 2.2%. Similarly, the condition at 1 month was good without deterioration.
Example 4
A sensitized solar cell was prepared in the same manner except that the photosensitive resin of Example 1 was changed to a commercially available acrylic photoresist JSR Co., Ltd. HRC. The energy conversion efficiency was measured and found to be 2.0%. Similarly, the condition at 1 month was good without deterioration.
(Example 5)
As shown in Fig. 4 (a), a commercially available acrylic photoresist JSR Co., Ltd. HRC was applied onto a PET film with ITO (transparent substrate 1) with a thickness of about 200μm, baked at 80 ° C for 1 minute, and dried. Thus, a transparent insulator layer 21 was obtained. The transparent substrate 1 was exposed for 1 minute using an exposure machine PLA manufactured by Canon Inc. using a photomask 31 on which a pattern of the current collecting wiring layer was written.

  As shown in FIG. 4B, the exposed portion 32 was etched when developed with AD10 (TMAH 2.38% alkaline aqueous solution) for 1 minute after exposure.

As shown in FIG.4 (c), the patterned transparent substrate 1 was attached to the electrode, and 2V voltage was applied in the copper sulfate aqueous solution, and the current collection wiring layer 22 was created. Transparent insulator layer 21 and current collecting wiring layer 2
When the maximum height of 2 was measured, they were 1.8 μm and 1.85 μm, respectively.

  As shown in FIG. 4D, an ITO film 23 (transparent electrode layer 23) was formed by sputtering. The thickness of the ITO film 23 was about 0.10 μm. On the ITO film 23, a coating type peroxotitanic acid solution was applied to form a dense titania film 24 (semiconductor layer 24) having a thickness of 10 nm.

As shown in FIG. 5 (a), a commercially available titania paste nanoxide manufactured by Swiss Solaronics SA
DL was applied and dried at 100 degrees to produce a 10 μm titania film 4 (semiconductor electrode 4).

Subsequent steps were performed using the same materials and methods as in Example 1 to produce a photosensitized solar cell. The energy conversion efficiency was measured and found to be 2.3%. The condition after one month was also good without deterioration.
(Comparative Example 1)
A Pd-colloid was selectively applied in the form of wiring on a PET film having a thickness of about 200 μm, and a current collecting wiring layer was prepared using PB-503A made by commercially available electroless plating solution Sugawara Eugene.

  An ITO film (transparent electrode layer) was formed by sputtering on the PET film on which the current collecting wiring layer was formed. The thickness of the ITO film was about 0.10 μm. On the ITO film, a coating type peroxotitanic acid solution was applied to form a dense titania film (semiconductor layer) having a thickness of 10 nm.

  Thereafter, a commercially available titania paste nanoxide D-L manufactured by Swiss Solaronics SA was applied and dried at 100 degrees to form a 10 μm titania film (semiconductor electrode). Otherwise, a photosensitized solar cell was produced in the same manner as in Example 1. In the obtained solar cell, the electrolyte and the current collector wiring were in contact with each other, and the current collector wiring was eluted. This is because the transparent electrode layer and the semiconductor layer were laminated on the uneven substrate by forming the current collector wiring, so that the semiconductor layer did not function as a barrier and the electrolyte was in contact with the current collector wiring. Conceivable. The energy conversion efficiency was measured and found to be 0.1%.

It is sectional drawing which shows the photosensitized solar cell which concerns on embodiment of this invention. It is sectional drawing which shows the electrode part of the photosensitized solar cell which concerns on embodiment of this invention. It is sectional drawing which shows the modification of the electrode part of the photosensitized solar cell which concerns on embodiment of this invention. It is sectional drawing which shows the manufacturing method of the photosensitized solar cell which concerns on embodiment of this invention. It is sectional drawing which shows the manufacturing method of the photosensitized solar cell which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2 ... Transparent conductive layer 3 ... Fine particle 4 ... Semiconductor electrode 5 ... Conductive layer 6 ... Opposite substrate 7,10 ... Epoxy resin 8 ... Injection port 9 ... Electrolyte layer 11 ... Incident light 21 ... Transparent insulator layer 22 ... current collection wiring layer 23 ... transparent electrode layer 24 ... semiconductor layer 31 ... photomask 32 ... exposure part

Claims (8)

A transparent substrate;
A first current collecting wiring layer provided on the transparent substrate;
A first transparent insulator layer covering a region other than the first current collecting wiring layer on the transparent substrate;
A transparent electrode layer provided on the first current collector wiring layer and the first transparent insulator layer;
A semiconductor layer provided on the transparent electrode layer;
A semiconductor electrode provided on the semiconductor layer and having a dye supported on the surface;
A counter substrate disposed to face and separate from the semiconductor electrode;
A conductive layer provided on the counter substrate;
An electrolyte layer provided between the semiconductor electrode and the conductive layer and having an electrolyte containing iodine molecules and iodide;
The photosensitized solar cell, wherein the maximum thickness of the first current collecting wiring layer is substantially the same as or greater than the maximum thickness of the first transparent insulator layer. 2. The photosensitized solar cell according to claim 1, wherein the first transparent insulator layer is at least one selected from polysiloxane, polyacrylic acid, and polymethacrylic acid. The photosensitized solar cell according to claim 1, wherein the transparent substrate is a plastic substrate. Between the counter substrate and the conductive layer,
A second current collecting wiring layer provided on the counter substrate;
A second transparent insulator layer covering a region other than the second current collecting wiring layer on the counter substrate;
2. The photosensitized solar cell according to claim 1, wherein a maximum thickness of the second current collecting wiring layer is substantially the same as or greater than a maximum thickness of the second transparent insulator layer. Selectively forming a first transparent insulator layer on a transparent substrate;
Forming a first current collector wiring layer by a plating method in a region where the first transparent insulator layer is not formed on the transparent substrate;
Forming a transparent electrode layer to cover the first transparent insulator layer and the first current collector wiring layer;
Forming a semiconductor layer on the transparent electrode layer;
Forming a semiconductor electrode on the semiconductor layer, and supporting a dye on the semiconductor electrode;
Forming a conductive layer on the surface of the counter substrate;
Disposing the transparent substrate on which the semiconductor electrode is formed and the counter substrate on which the conductive layer is formed facing each other, injecting an electrolyte containing iodine molecules and iodide, and then sealing to form an electrolyte layer A method for producing a photosensitized solar cell, comprising: 6. The method for producing a photosensitized solar cell according to claim 5, wherein the first transparent insulator layer is at least one selected from polysiloxane, polyacrylic acid, and polymethacrylic acid. 6. The method for producing a photosensitized solar cell according to claim 5, wherein the transparent substrate is a plastic substrate. Forming the conductive layer on the surface of the counter substrate,
Selectively forming a second transparent insulator layer on the counter substrate;
Forming a second current collector wiring layer by a plating method in a region where the second transparent insulator layer on the counter substrate is not formed;
The method for producing a photosensitized solar cell according to claim 5, further comprising: forming the conductive layer so as to cover the second transparent insulator layer and the second current collecting wiring layer.

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