JP4759984B2 - Electrode substrate for dye-sensitized solar cell, method for producing the same, and dye-sensitized solar cell - Google Patents

Description

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

  The use of solar power generation systems is increasing today because the load on the surrounding environment is small compared to power generation systems using fossil fuels and nuclear fuel, and it is easy to save resources.

  A solar cell used in a photovoltaic power generation system is a photoelectric conversion element that can directly convert light energy into electrical energy. Such solar cells include silicon solar cells, compound semiconductor solar cells (gallium arsenide solar cells, indium phosphide solar cells, CIS (copper indium selenium) solar cells, etc.), dye-sensitized solar cells, etc. Of these solar cells, silicon solar cells are already widely used as consumer solar cells. In recent years, attention has been focused on dye-sensitized solar cells that can be easily reduced in cost compared to silicon solar cells.

FIG. 5 is a schematic view showing a cross-sectional structure of a typical dye-sensitized solar cell (Gretzel cell). Dye-sensitized solar cell 150 shown, I ^- / I ₃ ^- is a wet solar cell having a structure which sandwiches an electrolyte layer 105 made of an electrolyte solution containing a redox couple at a pair of electrode substrates 120 and 130.

  The electrode substrate 120 includes a transparent substrate 111, a transparent conductive film (fluorine-doped tin oxide film) 113 formed on one surface thereof, and a porous semiconductor layer (porous titanium oxide thin film) 115 formed thereon. is doing. The porous semiconductor layer 115 is formed by a sol-gel method, and is a sintered body of a large number of anatase-type titanium oxide fine particles. On the surface of the porous semiconductor layer 115, a dye 117 made of one kind of ruthenium (Ru) complex is adsorbed. The absorption wavelength region of the dye 117 extends to a longer wavelength side than the absorption wavelength region of titanium oxide, and the energy level of electrons when the dye 117 is photoexcited is higher than the position of the conduction band edge of titanium oxide. . In FIG. 5, the dye 117 is drawn as one layer for convenience. On the other hand, the electrode substrate 130 includes a transparent substrate 121, a transparent conductive film (fluorine-doped tin oxide film) 123 formed on one surface thereof, and a platinum thin film 125 formed thereon. The transparent conductive film 113 in the electrode substrate 120 and the transparent conductive film 123 in the electrode substrate 130 are connected to the load 140 by lead wires 135a and 135b.

When the dye-sensitized solar cell 150 is irradiated with light within the absorption wavelength range of the dye 117, the dye 117 is excited, and photoexcited electrons (e ⁻ ) are injected into the porous semiconductor layer 115. Electronic (e ^-) dye 117 lost in, ^I in the electrolyte layer 105 - / _{I 3} ^- from redox pairs deprive electrons (I ^- reacts with _{I 3} ^- to occur), return to the original state . On the other hand, the electrons (e ⁻ ) injected into the porous semiconductor layer 115 move to the transparent conductive film 113 and further reach the electrode substrate 130 via the lead wire 135a, the load 140, and the lead wire 135b to reach I ₃ ^−. To give I ⁻ . Therefore, a closed circuit is formed in the dye-sensitized solar cell 150 by the light irradiation. When this closed circuit is formed, the dye-sensitized solar cell 150 generates power constantly. By using the dye 117 in this manner, it is possible to generate power using light having a longer wavelength than the light in the absorption wavelength region of the porous semiconductor layer 115, so that the photoelectric conversion efficiency can be increased. . Incidentally, the platinum thin film 125, the serving other to increase the conductivity of the electrode substrate _{^{130, I - / I 3 -}} I 3 of the redox pair ^- is I ^- also serves as a catalyst as it is reduced to.

  Research and development of dye-sensitized solar cells has mainly been focused on improving photoelectric conversion efficiency. By forming a porous semiconductor layer by a sol-gel method, supporting a specific dye on the porous semiconductor layer, and using a specific electrolyte, one having a relatively high photoelectric conversion efficiency is obtained.

Further, for example, in Patent Document 1, a transparent electrode serving as a base for a semiconductor electrode is formed by a metal film having a large number of holes, and directly or directly on the metal film, such as silicon nitride, aluminum nitride, nickel-chromium metal, etc. There is described a dye-sensitized solar cell in which conductivity is increased by forming a transparent conductive layer that is formed through a layer and covers the metal film, thereby improving photoelectric conversion efficiency. Patent Document 1 describes that the metal film having a large number of holes is formed by attaching a thin metal foil such as a copper foil to the substrate via an adhesive and etching it. Has been. FIG. 6 is a schematic view showing an example of a cross-sectional structure of such a dye-sensitized solar cell. In the dye-sensitized solar cell 160 shown in FIG. 6, a metal film 114 made of metal foil and having a hole is provided on the surface of the transparent substrate 111 with an adhesive 116, and covers the metal film 114. An electrode substrate 122 on which a transparent conductive film 113 and the like are formed is provided.
JP-A-2003-123858 (Claim 21, Stages 0021 to 0045 and Stage 0047)

  However, since the metal foil used for the metal film 114 as described above has a relatively thick film thickness of several μm, when the transparent conductive film 113 is formed so as to cover the metal film 114, the metal foil A concave-convex transparent conductive film 113 is formed reflecting the hole portion of the film 114. Therefore, the electrode substrate 122 in which the porous semiconductor layer 115 and the dye 117 are further provided thereon has an uneven surface.

  In the dye-sensitized solar cell, the thickness of the electrolyte layer is preferably as thin as possible unless a short circuit occurs from the viewpoint of reducing the internal resistance. However, when the dye-sensitized solar cell 160 is formed using the electrode substrate 122 having the uneven surface as described above, the thickness of the electrolyte layer 105 formed between the electrode substrates 122 and 130 is made uniform. Therefore, a thick portion of the electrolyte layer 105 has been formed. Accordingly, there is a problem that the internal resistance becomes high in such a thick part, and as a result, the photoelectric conversion efficiency of the dye-sensitized solar cell 160 is lowered.

  The present invention has been made in order to solve the above-mentioned problems, and its purpose is to provide a dye-sensitized solar cell electrode substrate capable of providing a dye-sensitized solar cell with low internal resistance and high photoelectric conversion efficiency, The manufacturing method and a dye-sensitized solar cell are provided.

  The electrode substrate for a dye-sensitized solar cell of the present invention for solving the above-mentioned problems is a transparent base material, a transparent electrode formed on one side of the transparent base material, and a plurality of semiconductor fine particles. An electrode substrate for a dye-sensitized solar cell, comprising: a porous semiconductor electrode formed on an electrode; and a dye supported on the surface of semiconductor fine particles forming the porous semiconductor electrode, wherein the transparent electrode The first conductive layer made of metal having a number of openings with a combination of a number of fine wires, and the first conductive layer is flattened or substantially flat by being embedded in the openings of the first conductive layer. And a second conductive layer made of a metal oxide formed on the first conductive layer and the flattened transparent layer.

  Here, “flattening or substantially flattening the first conductive layer” as used in this specification means that the above-described flattened transparent layer is embedded in the opening of the first conductive layer, and the upper surface of the flattened transparent layer. And the upper surface of the first conductive layer (excluding the opening) are at the same level or substantially the same level.

  According to this invention, since the first conductive layer is flattened by the flattening transparent layer, the second conductive layer, the porous semiconductor electrode, and the like provided on the first conductive layer are flat and have no irregularities on the surface. A dye-sensitized solar cell electrode substrate can be obtained. As a result, when producing a dye-sensitized solar cell using this electrode substrate, the thickness of the electrolyte layer provided between the electrode substrates can be reduced uniformly. Resistance becomes low and photoelectric conversion efficiency improves.

  In the dye-sensitized solar cell electrode substrate of the present invention, (1) the transparent electrode further includes an adhesive layer formed on one side of the transparent substrate, and the first conductive layer is a metal foil, Preferably, the first conductive layer is affixed to the transparent substrate by the adhesive layer, and (2) the flattened transparent layer is embedded in the opening of the first conductive layer without a gap. .

  In the dye-sensitized solar cell electrode substrate of the present invention, the transparent base material is a transparent resin film, and the outer surface of the first conductive layer is formed by electroplating, electroless plating, or chemical conversion treatment. It is preferable that the flattened transparent layer is covered with a prevention layer, and the first conductive layer whose outer surface is covered with the corrosion prevention layer is made flat or substantially flat. In this dye-sensitized solar cell electrode substrate, it is preferable that the outer surface of the corrosion-preventing layer includes a surface treatment layer formed by a chromate treatment to form a surface treatment layer.

  In the dye-sensitized solar cell electrode substrate of the present invention, the first conductive layer may be made of copper, nickel, or stainless steel.

  The method for producing an electrode substrate for a dye-sensitized solar cell according to the present invention that achieves the above-described object includes the transparent substrate, the transparent electrode formed on one side of the transparent substrate, and a large number of semiconductor fine particles. A method for producing a dye-sensitized solar cell electrode substrate, comprising: a porous semiconductor electrode formed on an electrode; and a dye supported on the surface of a semiconductor fine particle forming the porous semiconductor electrode, A preparation step of preparing a transparent base material having a metal first conductive layer formed on one side and having a shape in which a large number of openings are formed and a combination of a number of fine wires, and a resin in the openings of the first conductive layer A flattening transparent layer forming step of forming a flattening transparent layer to flatten or substantially flatten the first conductive layer, and metal oxide is formed on the first conductive layer and the flattening transparent layer. Second conductive layer forming process for forming a second conductive layer made of a product A porous semiconductor electrode forming step of forming a porous semiconductor electrode using a large number of semiconductor fine particles on the second conductive layer, and a dye is carried on the surface of the semiconductor fine particles forming the porous semiconductor electrode And a dye carrying step.

  According to this invention, the electrode substrate for dye-sensitized solar cells of the present invention that exhibits the technical effects described above can be manufactured.

  In the method for producing an electrode substrate for a dye-sensitized solar cell according to the present invention, (A) the preparation step includes a first sub-step of preparing a transparent base material having a metal foil attached to one side with an adhesive; A second sub-step of patterning a metal foil to obtain the first conductive layer, and (B) the flattening transparent layer forming step on the side of the transparent substrate on which the first conductive layer is formed. A first sub-step of applying a flattening transparent layer forming material on the surface; and applying the flattening transparent layer forming material so that the flattening transparent layer forming material does not remain on the upper surface of the first conductive layer. A second sub-step of pressing and sliding the formed surface, and (C) the flattening transparent layer forming step is flattened on the surface of the transparent substrate on which the first conductive layer is formed. Simultaneously or substantially simultaneously with the application of the transparent layer forming material, the upper surface of the first conductive layer is applied. Including a step of pressing and sliding the surface coated with the flattening transparent layer forming material so that the flattening transparent layer forming material does not remain, (D) a transparent resin film as the transparent base material Use the electrolyte for a dye-sensitized solar cell so as to cover the outer surface of the first conductive layer on the transparent resin film between the preparation step and the flattening transparent layer forming step. It is preferable that a corrosion prevention layer forming step of forming a corrosion prevention layer having corrosion resistance by electroplating, electroless plating, or chemical conversion treatment is included.

  In the invention described in (B), the flattening transparent layer forming step may include a third substep of pressing the surface on which the flattening transparent layer forming material is applied after the second substep. It is preferable to include. In the invention described in (C), the flattening transparent layer forming step may include a step of pressing the surface coated with the flattening transparent layer forming material after the pressurizing and sliding step. preferable. In the invention described in (D), it is preferable that the corrosion prevention layer forming step includes a surface treatment step of performing chromate treatment on the corrosion prevention layer.

  And in the manufacturing method of the electrode substrate for dye-sensitized solar cells of this invention, it can be set as (E) a said 1st conductive layer being formed with copper, nickel, or stainless steel.

  The dye-sensitized solar cell of the present invention for solving the above-mentioned problems is a first electrode substrate having a porous semiconductor electrode in which a dye is supported on the surface of semiconductor fine particles forming a porous semiconductor electrode; A dye-sensitized solar comprising a second electrode substrate disposed opposite to the first electrode substrate, and an electrolyte layer interposed between the first electrode substrate and the second electrode substrate A battery is characterized in that the first electrode substrate is the electrode substrate for a dye-sensitized solar cell described above.

  According to this invention, since the electrode substrate for a dye-sensitized solar cell of the present invention having no unevenness on the surface as described above is used as the first electrode substrate, the layer thickness of the electrolyte layer provided between the electrode substrates Can be thinned uniformly. As a result, a dye-sensitized solar cell with low internal resistance and high photoelectric conversion efficiency can be obtained.

  According to the dye-sensitized solar cell electrode substrate of the present invention, a dye-sensitized solar cell electrode substrate having high photoelectric conversion efficiency and capable of easily obtaining a practical dye-sensitized solar cell.

  According to the method for producing a dye-sensitized solar cell electrode substrate of the present invention, the above-described dye-sensitized solar cell electrode substrate of the present invention can be easily obtained.

  According to the dye-sensitized solar cell of the present invention, since the above-described electrode substrate for a dye-sensitized solar cell of the present invention is used as the first electrode substrate having a porous semiconductor electrode, the photoelectric conversion efficiency is high. Get higher.

  Hereinafter, the dye-sensitized solar cell electrode substrate of the present invention, the method for producing the same, and the form of the dye-sensitized solar cell will be sequentially described with reference to the drawings.

<Electrode substrate for dye-sensitized solar cell and method for producing the same>
FIG. 1 is a schematic view showing an example of a basic cross-sectional structure of an electrode substrate for a dye-sensitized solar cell of the present invention. In the illustrated dye-sensitized solar cell electrode substrate 20 (hereinafter referred to as “electrode substrate 20”), the adhesive layer 5, the first conductive layer 6, and the planarized transparent layer 7 are formed on one surface of the transparent substrate 1. And the second conductive layer 8 are formed, and a porous semiconductor electrode 15 is formed on the transparent electrode 10. A dye 17 is supported on the surface of the semiconductor fine particles 15 a forming the porous semiconductor electrode 15. In FIG. 1, the dye 17 is drawn as one layer for convenience. Hereinafter, the electrode substrate 20 and the manufacturing method thereof will be described in detail.

(1) Transparent substrate:
The transparent substrate 1 transmits light in a desired wavelength region in the wavelength region ranging from the ultraviolet region to the infrared region in an average value of approximately 85% or more, and has desired light resistance and weather resistance. Preferably, it can be formed by various methods using an inorganic material or an organic material, and optionally using various additives. The above-mentioned “desired wavelength range” can be appropriately selected in consideration of the absorption wavelength ranges of the porous semiconductor electrode 15 and the dye 17.

  As the transparent substrate 1, a transparent and inflexible rigid material (hard material) such as quartz glass, Pyrex (registered trademark), synthetic quartz plate, or the like can be used. From the viewpoint of obtaining a solar cell, it is preferable to use a transparent glass sheet or a transparent resin film, and it is particularly preferable to use a transparent resin film.

  Examples of the transparent resin film include biaxially stretched polyethylene terephthalate (PET) film, ethylene / tetrafluoroethylene copolymer film, polyethersulfone (PES) film, polyetheretherketone (PEEK) film, and polyether. An imide (PEI) film, a polyimide (PI) film, a polyester naphthalate (PEN) film, a polycarbonate (PC) film, a cyclic polyolefin film, or the like can be used. From the viewpoint of reducing the manufacturing cost of the electrode substrate 20, those formed of a relatively inexpensive resin material are preferable to those formed of a relatively expensive resin material such as engineering plastic.

  When a transparent resin film is used as the transparent substrate 1, the thickness can be appropriately selected within a range of approximately 15 to 500 μm depending on the use of a dye-sensitized solar cell produced using the electrode substrate 20. It is.

  In addition, since the transparent base material 1 is also heated when forming the porous semiconductor electrode 15, when selecting the material and thickness of the transparent base material 1, it is preferable to consider the heat resistance together.

(2) Transparent electrode:
The transparent electrode 10 receives a carrier (electron) from the porous semiconductor electrode 15 when a dye-sensitized solar cell manufactured using the electrode substrate 20 is irradiated with light in a desired wavelength range, or Carriers (holes) are transmitted to the porous semiconductor electrode 15, and the transparent electrode 10 preferably transmits 80% or more of the light in the “desired wavelength region”.

  The illustrated transparent electrode 10 includes an adhesive layer 5 formed on one side of the transparent substrate 1, a first conductive layer 6 having an opening attached to the transparent substrate 1 by the adhesive layer 5, and a first conductive layer. 6 includes a planarized transparent layer 7 embedded in the opening 6 and a second conductive layer 8 covering the first conductive layer 6 and the planarized transparent layer 7.

  The adhesive layer 5 is mainly used when the first conductive layer 6 is formed by patterning a metal foil (rolled metal foil, electrolytic metal foil or the like). For example, when a metal vapor deposition film is used for forming the first conductive layer, the adhesive layer 5 can be omitted.

  The adhesive layer 5 has (i) a light transmittance that allows the light transmittance of the transparent electrode 10 to be a desired value, and (ii) the above metal after the metal foil and the transparent substrate are bonded together. When the first conductive layer 6 is formed by patterning the foil into a desired shape by etching, it has etching resistance, and (iii) the porous semiconductor electrode 15 in the process of manufacturing the dye-sensitized solar cell. (Iv) Resistance to electrolytes used in dye-sensitized solar cells (electrolyte resistance) Preferably).

  Specific examples of the material of the adhesive layer 5 that satisfies such requirements include acrylic, ester, urethane, fluorine, polyimide, epoxy, polyurethane ester, and acrylic urethane adhesives. . These adhesives may be an ultraviolet curable type or a thermosetting type.

  The 1st conductive layer 6 is for improving the electroconductivity of the transparent electrode 10, and is a metal conductive layer which has the shape which combined many thin wires and has many opening parts. Here, the “metal conductive layer” in the present invention includes a conductive layer formed of an alloy in addition to a conductive layer formed of a single metal.

  The shape of the first conductive layer 6 in plan view is within a range in which the light transmittance of the transparent electrode 10 takes a desired value, for example, a lattice shape as shown in FIG. It can be selected as appropriate. Moreover, the layer thickness of the 1st conductive layer 6 can be suitably selected within the range from which the light transmittance of the electrode substrate 20 and sheet resistance become a desired value, and is about 5-50 micrometers in general.

  As a material of the first conductive layer 6, from the viewpoint of obtaining a transparent electrode 10 having high conductivity, copper (Cu), iron (Fe), nickel (Ni), chromium (Cr), aluminum (Al), gold ( It is preferable to use a metal or alloy such as Au), silver (Ag), stainless steel, titanium (Ti), etc. Among them, copper, nickel, aluminum, stainless steel, titanium, etc., which are highly conductive materials, are used. preferable. Further, from the viewpoint of suppressing the manufacturing cost of the electrode substrate 20, it is preferable to use copper, nickel, aluminum, and stainless steel, which are inexpensive metals.

  When a transparent resin film is used for the transparent substrate 1, it is preferable to use aluminum having a purity higher than 99.3% as the material of the first conductive layer 6. Since aluminum having a purity of more than 99.3% is difficult to be oxidized, when the first conductive layer 6 is formed of such high-purity aluminum, an electrode substrate using a transparent resin film as the transparent substrate 1 When the dye image-sensitive solar cell is manufactured using, the first conductive layer 6 is hardly corroded by the electrolyte.

  In general, when a transparent resin film having low heat resistance is used for the transparent substrate, it is difficult to form a dense second conductive layer because the formation temperature of the second conductive layer must be lower than the heat resistant temperature. In the dye-sensitized solar cell using such an electrode substrate, the electrolyte penetrates into the second conductive layer, reaches the first conductive layer, corrodes the metal of the first conductive layer, and the performance is deteriorated over time. May be reduced. At this time, since the first conductive layer 6 is formed of high-purity aluminum that is not easily corroded, such a problem is less likely to occur.

  When the first conductive layer is made of aluminum having a purity higher than 99.3%, the outer surface (upper surface and each side surface) of the first conductive layer is chromated to form a chromated layer. It is preferable. The first conductive layer having the chromate treatment layer formed on the outer surface further improves the corrosion resistance to the electrolyte when a dye-sensitized solar cell is produced using the electrode substrate 20. Moreover, the adhesiveness of a 1st conductive layer and a chromate treatment layer can be improved because the 1st conductive layer is formed with aluminum. The conditions for the chromate treatment are appropriately selected according to the heat resistance of the transparent substrate (transparent resin film) 1 and the like. When the first conductive layer 6 is chromated, a chromate layer (not shown) formed by the chromate treatment is interposed between the first conductive layer 6 and the planarized transparent layer 7.

  The planarized transparent layer 7 is embedded in the opening of the first conductive layer 6. That is, the flattened transparent layer 7 is formed so as to be embedded in the opening of the first conductive layer 6 and plays a role of flattening the first conductive layer 6 and contributing to the production of an electrode substrate without an uneven surface. Have.

  The material of the flattened transparent layer 7 is not particularly limited as long as it is a resin that is transparent to visible light. For example, an acrylic resin, an ester resin, a polycarbonate resin, a urethane resin, a cyclic polyolefin resin, Examples thereof include polystyrene resin, fluorine resin, and polyimide resin resin. Examples of the fluororesin include polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA) made of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, copolymer of tetrafluoroethylene and hexafluoropropylene (FEP), tetra Copolymers of fluoroethylene, perfluoroalkyl vinyl ether and hexafluoropropylene (EPE), copolymers of tetrafluoroethylene and ethylene or propylene (ETFE), polychlorotrifluoroethylene resin (PCTFE), ethylene and chlorotrifluoroethylene (ECTFE), vinylidene fluoride resin (PVDF), vinyl fluoride resin (PVF), and the like can be used. In addition, examples of the polyimide resin include polyimide, polyamideimide, and polyetherimide. Among these resins, the resin that forms the flattened transparent layer 7 is preferably an acrylic resin, an ester resin, or a polycarbonate resin.

  The glass transition temperature of the resin forming the flattened transparent layer 7 is high from the viewpoint of ensuring the heat resistance required when the dye-sensitized solar cell using the electrode substrate 20 is actually used. Is preferred. As will be described later, from the viewpoint of forming the flattened transparent layer 7 in the opening of the first conductive layer 6 without any gap, the glass transition temperature is preferably low in order to ensure the flexibility of the resin. Specifically, the glass transition temperature of this resin is preferably 40 ° C. or higher and 150 ° C. or lower, and more preferably 50 ° C. or higher and 130 ° C. or lower. In addition, the glass transition temperature here is a value measured by the differential scanning calorimetry (DSC measurement method). The weight average molecular weight of the resin forming the flattened transparent layer 7 is preferably in the range of 500 to 600,000, preferably 10,000 to 400,000, from the same viewpoint as in the case of the glass transition temperature. Is more preferable.

  Further, like the adhesive layer 5, the flattened transparent layer 7 has (i) light transmittance with which the light transmittance of the transparent electrode 10 becomes a desired value, and (ii) a dye-sensitized type. (Iii) a dye-sensitized solar, having a solvent resistance to the dye solution used when the dye is supported on the surface of the semiconductor fine particles forming the porous semiconductor electrode 15 in the manufacturing process of the solar cell; It is preferable to have resistance (electrolyte resistance) to the electrolyte used in the battery.

  The layer thickness of the planarizing transparent layer 7 is the same as or substantially the same as the thickness of the first conductive layer. Since the planarizing transparent layer 7 has such a layer thickness, the first conductive layer can be planarized. Moreover, it is preferable that the planarizing transparent layer 7 is formed without a gap in the opening of the first conductive layer.

  The second conductive layer 8 receives carriers (electrons) from the porous semiconductor electrode 15 when the dye-sensitized solar cell is irradiated with light in a predetermined wavelength range, or the porous semiconductor electrode 15 receives carriers. (Hole) is supplied and can be formed using various conductive metal oxides. The second conductive layer 8 is formed so as to cover the first conductive layer 6 and the planarized transparent layer 7 in plan view.

  The second conductive layer 8 is made of indium tin oxide (ITO), fluorine-doped tin oxide, tin oxide, indium zinc oxide (IZO), zinc oxide (ZnO) or the like in consideration of light transmittance and conductivity. Among these, it is preferable to form by fluorine dope tin oxide or ITO which is a material excellent in both conductivity and light transmittance. The layer thickness of the second conductive layer 8 can be appropriately selected within a range of approximately 0.1 nm to 500 nm, and the sheet resistance is preferably as low as possible, approximately 15Ω / □ or less.

  The transparent electrode 10 includes a preparation step of preparing the transparent base material 1 having the first conductive layer 6 having a large number of openings formed on one side, and a flattened transparent layer formation for forming the flattened transparent layer 7 in the openings. And a second conductive layer forming step of forming the second conductive layer 8 on the first conductive layer 6 and the flattened transparent layer 7.

  The transparent substrate 1 provided with the first conductive layer 6 prepared in the preparation step may be manufactured by itself or may be purchased by others.

  When the first conductive layer 6 is formed by itself, there are a case where a metal foil is used as a metal thin film which is a source of the first conductive layer and a case where a metal vapor deposition film is used.

  When a metal foil is used for forming the first conductive layer 6, the adhesive layer 5 is formed on one side of the transparent substrate 1, the metal foil is applied to the adhesive layer 5, and the metal foil is patterned. The first conductive layer 6 can be formed. As the metal foil, a rolled metal foil, an electrolytic metal foil, or the like can be used. In particular, when an inexpensive rolled metal foil is used, the manufacturing cost can be easily suppressed. The metal foil can be stuck by a method such as a dry lamination method or a wet lamination method using the above-described adhesive.

  Examples of the patterning of the metal foil include a method of etching into a desired pattern shape using photolithography, for example. In forming the first conductive layer 6 using photolithography, for example, resist coating, pre-baking, exposure (contact exposure) processing, development processing, and post-baking are sequentially performed to form a resist pattern (etching mask). After this resist pattern (etching mask) is used for etching with an etchant such as iron oxide or ferric chloride solution, the resist pattern (mask) is stripped and rinsed in this order.

  When a metal vapor deposition film is used to form the first conductive layer 6, a desired metal may be a physical vapor deposition method (PVD method) such as a vacuum vapor deposition method, a sputtering method, or an ion plating method, or a plasma chemical vapor deposition method. The first conductive layer 6 can be formed by forming a film by a method (CVD method) or the like and patterning the film by the same method as in the case of a metal foil. Further, when forming a metal vapor deposition film, if a mask having an opening having a pattern corresponding to the shape of the first conductive layer 6 to be formed is used, the first conductive layer 6 is directly formed only by forming the metal vapor deposition film. can do.

  Moreover, when using copper as a material of the 1st conductive layer 6, as the transparent base material 1 in which the 1st conductive layer 6 was formed, the electroconductive film used for the material of an electromagnetic wave shielding film, ie, adhere | attaches on one side A transparent resin film to which a copper foil having a large number of openings is bonded by an agent can be diverted. Such diversion of the conductive film is advantageous in reducing the manufacturing cost of the electrode substrate 20. When this conductive film is diverted, the transparent resin film as the base material can be used as the transparent base material 1 of the electrode substrate 20 as it is.

  The flattening transparent layer 7 is an application step of applying a flattening transparent layer forming material to the surface of the transparent substrate 1 on which the first conductive layer 6 is formed, and pressurizing and sliding the application surface. Formed by a sliding process.

  As the material for forming the flattening transparent layer, a material for forming the flattening transparent layer 7 by dissolving or dispersing the resin for forming the flattening transparent layer 7 in a solvent or a dispersant can be used. Examples of the solvent or dispersant include ethyl acetate, toluene, methyl ethyl ketone (MEK), xylene, isopropyl alcohol (IPA), chloroform, tetrahydrofuran (THF), dimethylformamide (DMF), acetonitrile, trifluoropropyl alcohol, and the like. In addition, the flattening transparent layer forming material can contain various additives such as a photopolymerizer, a thickener, a plasticizer, or a dispersant as necessary.

  The viscosity of the flattening transparent layer forming material is appropriately selected depending on the application method, the type of resin used as the material, and the like, but is usually in the range of 0.01 Pa · s to 100 Pa · s. This viscosity is preferably within a range of 0.1 Pa · s to 10 Pa · s from the viewpoint of forming the flattened transparent layer 7 in the opening of the first conductive layer 6 without a gap.

  For the coating process, a conventionally known method can be used. For example, doctor blade method (blade coating method), die coating method, gravure coating method, gravure reverse coating method, roll coating method, reverse roll coating method, bar coating method , Knife coating method, air knife coating method, slot die coating method, slide die coating method, micro bar coating method, micro bar reverse coating method and the like can be used, among which the doctor blade method (blade coating method) should be used Is most preferred.

  In the pressure sliding step, the resin for forming the flattening transparent layer is formed on the upper surface of the first conductive layer by removing excess flattening transparent layer forming material, and the first conductive layer 6 and the second conductive layer are formed. This is done to prevent interfering with the conduction between the layers 8. In this step, the applied surface is pressurized using, for example, a squeegee (soft rubber blade or roll) before the applied flattening transparent layer forming material is hardened or solidified by evaporation of the solvent. While rubbed, the excess flattening transparent layer forming material is wiped off. By this step, the planarizing transparent layer forming material does not remain on the upper surface of the first conductive layer 6, and the opening of the first conductive layer 6 is covered with the planarizing transparent layer forming material without a gap.

  The flattened transparent layer 7 is slid by applying pressure to the flattened transparent layer forming material on the surface of the transparent substrate 1 on which the first conductive layer 6 is formed, or almost simultaneously with the applied surface. It is formed by doing. Specifically, for example, an appropriate amount of the flattening transparent layer forming material is placed on a part of the surface of the transparent substrate 1 on which the first conductive layer 6 is formed, and the flattening transparent layer forming material is used using a squeegee. Is applied to the entire surface of the transparent substrate 1 while being slid under pressure. When the planarized transparent layer 7 is formed in this way, excess planarized transparent layer forming material can be wiped off before curing or the like starts, and the planarized transparent layer forming material is formed on the upper surface of the first conductive layer 6. It can prevent effectively remaining.

  In the flattening transparent layer forming step, it is preferable to perform a pressing step of pressurizing the entire application surface of the flattening transparent layer forming material as necessary after the pressure sliding step. In the pressing step, a roll pressing method, a flat plate pressing method, or the like can be used. When the upper surface of the flattened transparent layer 7 has an uneven shape, the upper surface can be flattened by this step, so that the first conductive layer can be further flattened. In addition, the planarized transparent layer 7 can be embedded in the opening of the first conductive layer 6 without any gap by this process. Furthermore, when the haze increase of the electrode substrate 20 becomes a problem because the upper surface of the flattened transparent layer 7 has a fine uneven shape, the surface is flattened by pressing using a mirror-finished roll or flat plate. The fine uneven shape on the upper surface of the transparent layer 7 can be flattened. The pressure at the time of pressing can be suitably selected according to the viscosity of the flattening transparent layer forming material.

  After pressing or when the pressing process is not performed, the flattened transparent layer 7 is formed by curing or solidifying the resin that forms the applied flattened transparent layer after sliding under pressure.

  The formation of the second conductive layer 8 can be performed by a physical vapor deposition method such as a vacuum deposition method, a sputtering method, or an ion plating method. From the viewpoint of reducing the manufacturing cost, the ion plating method or the sputtering method is used. Preferably it is done.

(3) Porous semiconductor electrode:
The porous semiconductor electrode 15 is a porous semiconductor electrode that can receive carriers (electrons) from the photoexcited dye 17 or has a role of transmitting carriers (holes) to the photoexcited dye 17. .

  Examples of the material of the porous semiconductor electrode 15 include titanium oxide, zinc oxide, tin oxide, indium tin oxide, zirconium oxide, silicon oxide, magnesium oxide, aluminum oxide, cesium oxide, bismuth oxide, manganese oxide, yttrium oxide, and oxide. Metal oxide semiconductor fine particles such as tungsten, tantalum oxide, niobium oxide, and lanthanum oxide can be used. These metal oxide semiconductor fine particles are suitable for forming a porous semiconductor layer, and are preferable because they can improve the energy conversion efficiency of the dye-sensitized solar cell and reduce the cost. Considering the durability of the dye-sensitized solar cell using the electrode substrate 20 and the safety and economy when manufacturing the electrode substrate 20, titanium oxide is preferable as the material of the porous semiconductor electrode 15, and in particular. Anatase type titanium oxide is preferable. The “semiconductor fine particles” referred to in the present invention include not only fine-particle-shaped semiconductors but also amorphous micro-semiconductors and fine-powder semiconductors.

  The average particle diameter of the metal oxide semiconductor fine particles is preferably within a range of about 10 to 250 nm, and particularly preferably has a size that exhibits a quantum size effect. The film thickness of the porous semiconductor electrode 15 can be appropriately selected within a range of approximately 5 to 30 μm.

  The porous semiconductor electrode 15 may be a single component layer or a mixture layer. Further, it may be a stack of a plurality of semiconductor films. The conductivity type of the porous semiconductor electrode 15 is usually N-type.

  In manufacturing the electrode substrate 20, a porous semiconductor electrode forming step for forming the porous semiconductor electrode 15 on the second conductive layer 8 is performed following the second conductive layer forming step described above. From the viewpoint of increasing the photoelectric conversion efficiency of the dye-sensitized solar cell using the electrode substrate 20, the porous semiconductor electrode 15 formed in this step has the dye 17 on the surface of the semiconductor fine particles forming the porous semiconductor electrode 15. Is preferably supported on the surface of as many semiconductor fine particles as possible, and for that purpose, it is preferable to increase the specific surface area of the porous semiconductor electrode 15 as much as possible. From the same viewpoint, it is particularly preferable that the porous semiconductor electrode 15 is a mesoscopic porous material that exhibits a quantum size effect. In FIG. 1, the porous semiconductor electrode 15 is depicted as a porous body formed by a large number of semiconductor fine particles 15a.

  The porous semiconductor electrode 15 is prepared by preparing a desired dispersion of metal oxide semiconductor fine particles (hereinafter referred to as a “porous semiconductor electrode coating solution”), and using this porous semiconductor electrode coating solution as a second conductive material. The metal oxide semiconductor fine particles are formed by being applied on the layer 8 and then fired to sinter the metal oxide semiconductor fine particles. As such a forming method, a sol-gel method can be used. However, when using a base material with low heat resistance such as a transparent resin film for the transparent base material 1, it is necessary to form the porous semiconductor electrode 15 at a relatively low temperature. Therefore, in that case, it is preferable to form the porous semiconductor electrode coating liquid by applying it on the second conductive layer 8 and drying it without firing.

  If necessary, the coating liquid for a porous semiconductor electrode can contain fine particles that function as light scattering centers (not shown) in the porous semiconductor electrode 15. By incorporating these fine particles into the porous semiconductor electrode 15, the amount of light contributing to the photoexcitation of the dye 17 can be increased, and as a result, the photoelectric conversion efficiency of the dye-sensitized solar cell can be improved. Specific examples of the fine particles functioning as the light scattering center include titanium oxide fine particles having a particle diameter of approximately 50 to 200 nm.

  The coating liquid for a porous semiconductor electrode is, for example, (i) a method in which semiconductor fine particles are precipitated as crystallized fine particles in a predetermined solvent to form a sol liquid, or (ii) the semiconductor fine particles are ball milled, sand milled or roll milled. It is prepared by a method of mixing with an appropriate dispersion medium and dispersing in the dispersion medium using a known dispersing machine such as a kneader, a homogenizer or a planetary mixer. When preparing the coating liquid by the method (ii) above, if the semiconductor fine particles to be used are aggregated, it is preferable to loosen them before mixing with the above dispersion medium. The coating liquid can also be prepared by mixing the sol liquid (i) and the dispersion liquid (ii).

  As a dispersion medium for the coating liquid for the porous semiconductor electrode, for example, when the member on which the porous semiconductor electrode 15 is formed has relatively low heat resistance, (a) chlorine-based dispersion such as chloroform, methylene chloride, dichloroethane, etc. Medium, (b) ether dispersion medium such as tetrahydrofuran, (c) aromatic hydrocarbon dispersion medium such as toluene and xylene, (d) ketone dispersion medium such as acetone and methyl ethyl ketone, (e) ethyl acetate, butyl acetate Ester dispersion medium such as ethyl cellosolve acetate, (f) alcohol dispersion medium such as isopropyl alcohol (IPA), ethanol, methanol, butyl alcohol, etc. (g) other (N-methyl-2-pyrrolidone, pure water, etc. ), Can be used. When the binder described later is contained in the coating liquid for a porous semiconductor electrode, a dispersion medium capable of dissolving the binder is used.

  A binder made of a polymer material can be dissolved in the coating liquid for a porous semiconductor electrode. When a coating liquid for a porous semiconductor electrode containing a binder is used, the adhesion between the porous semiconductor electrode 15 and the transparent electrode 10 and the mechanical strength of the porous semiconductor electrode 15 itself can be improved. In particular, it is effective when a substrate having low heat resistance such as a transparent resin film is used as the transparent substrate 1 and the porous semiconductor electrode 15 cannot be formed by firing. Further, even when the transparent substrate 1 is made of a highly heat-resistant substrate such as a glass substrate and the porous semiconductor electrode 15 is formed by firing, a porous film can be formed more easily. Examples of such binders include cellulose resins, polyester resins, polyamide resins, polyacrylate resins, polycarbonate resins, polyurethane resins, polyolefin resins, polyvinyl acetal resins, fluorine resins, and polyimides. Resins such as resins and polyhydric alcohols such as polyethylene glycol can be used. The amount of the binder added to the coating solution for the porous semiconductor electrode is preferably as small as possible. Specifically, the ratio of the binder to the total solid content in the dispersion is preferably 0.5% by mass or less, and more preferably 0.2% by mass or less.

  In addition to the above-mentioned binder, the porous semiconductor electrode coating liquid may contain various additives in order to improve the coating suitability. Examples of the additive include a surfactant, a viscosity modifier, a dispersion aid, a pH adjuster, and the like. For example, nitric acid, hydrochloric acid, acetic acid, dimethylformamide, ammonia or the like can be used as a pH adjuster.

  The coating methods for the coating solution for porous semiconductor electrodes include die coating, gravure coating, gravure reverse coating, roll coating, reverse roll coating, bar coating, blade coating, knife coating, air knife coating, slot die coating, slide die coating, and dip. Various methods such as coating, microbar coating, microbar reverse coating, and screen printing (rotary method) can be applied. The porous semiconductor electrode 15 having a desired film thickness is formed by repeating application and drying of the coating liquid for porous semiconductor electrode one or more times by such a coating method. It is necessary to dry the coating film at a temperature lower than the heat resistant temperature of the transparent substrate 1. Specifically, when a substrate having low heat resistance such as a transparent resin film is used for the transparent substrate 1 at about 100 ° C. or higher, it is preferably heat-dried within a temperature range of the heat resistant temperature or less.

(4) Dye:
The dye 17 is carried on the surface of the semiconductor fine particles forming the porous semiconductor electrode 15, and is for sensitizing the porous semiconductor electrode 15.

  As the dye 17, (A) the absorption wavelength region extends to a longer wavelength side than the absorption wavelength region of the porous semiconductor electrode 15, and (B) the porous semiconductor electrode 15 is an N-type semiconductor. In the case where the energy level of electrons when photoexcited is higher than the position of the conduction band edge of the porous semiconductor electrode 15, (C) when the porous semiconductor electrode 15 is an N-type semiconductor, It is preferable that the time required to inject carriers into the semiconductor electrode 15 is shorter than the time required to recapture carriers from the porous semiconductor electrode 15.

  For example, when the porous semiconductor electrode 15 is formed of anatase-type titanium oxide, it is preferable to use a ruthenium complex represented by the following formula (I) as the dye 17.

  In order to obtain a dye-sensitized solar cell with high photoelectric conversion efficiency using the electrode substrate 20, among the ruthenium complexes represented by the formula (I), X is NCS (thiocyanate) (cis-di ( It is particularly preferred to use thiocyanate) -N, N′-bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II).

  Of course, metal complex dyes other than the ruthenium complex described above and organic dyes can also be used. Specific examples of the organic dye include acridine dyes, azo dyes, indigo dyes, quinone dyes, coumarin dyes, merocyanine dyes, and phenylxanthene dyes. Of these organic dyes, coumarin dyes are preferable.

  In manufacturing the electrode substrate 20, a dye carrying step for carrying a dye on the surface of the semiconductor fine particles 15 a forming the porous semiconductor electrode 15 is performed following the porous semiconductor electrode forming step described above.

  In supporting the dye 17 on the surface of the semiconductor fine particles 15a forming the porous semiconductor electrode 15, from the viewpoint of obtaining a dye image-sensitive solar cell with a high photoelectric conversion rate, the dye 17 is applied to as many semiconductor fine particles 15a as possible. In particular, it is preferable to support the dye 17 on the surface of each of the semiconductor fine particles 15 a forming the porous semiconductor electrode 15.

  For this purpose, it is preferable to support the dye 17 on the porous semiconductor electrode 15 by a method capable of adsorbing the dye 17 to the inner surface of the pores of the porous semiconductor electrode 15. For example, a dye solution (hereinafter referred to as “dye-supporting coating liquid”) is prepared, and the electrode substrate formed up to the porous semiconductor electrode 15 is immersed in the dye-supporting coating liquid, and then dried. According to the method, or a method of applying a dye-supporting coating liquid to the porous semiconductor electrode 15, infiltrating it and then drying it, the dye 17 is adsorbed to the pore inner surface of the porous semiconductor electrode 15. It is also possible to support the dye 17 on the surface of each semiconductor fine particle 15a. The dye-supporting coating liquid is prepared by appropriately selecting either an aqueous solvent or an organic solvent according to the type of the dye used.

  From the viewpoint of obtaining a dye-sensitized solar cell with high photoelectric conversion efficiency, it is preferable to support the dye 17 on the porous semiconductor electrode 15 in the state of a monomolecular film. For this purpose, the dye 17 is supported on the porous semiconductor electrode 15. It is preferable that the excess dye is washed and removed with a solvent or the like that can be used for preparing the dye-supporting coating solution.

  By subjecting the porous semiconductor electrode 15 to surface treatment in advance, when the porous semiconductor electrode 15 is an N-type semiconductor, the moving speed of carriers from the dye 17 to the porous semiconductor electrode 15 can be increased. After the dye 17 is supported on the surface of the semiconductor fine particles forming the porous semiconductor electrode 15, the porous semiconductor electrode 15 and the dye 17 are subjected to a predetermined treatment, for example, the porous semiconductor electrode 15 is formed of titanium oxide, and the dye 17 is formed. In the case of the ruthenium complex described above, it is possible to improve the photoelectric conversion efficiency of the dye-sensitized solar cell using the electrode substrate 20 by performing a treatment with a base such as t-butylpyridine.

(5) Optional member:
A corrosion prevention layer, a gas barrier layer, a patterning layer, or the like can be formed on the electrode substrate 20 as necessary. Hereinafter, these optional members will be described.

(A) Corrosion prevention layer:
FIG. 3 is a cross-sectional view showing an example of an electrode substrate in which a corrosion prevention layer is further provided on the electrode substrate of the present invention described above.

  The corrosion prevention layer 9 prevents the electrolyte from penetrating into the first conductive layer 6 when a dye-sensitized solar cell is produced using an electrode substrate using a transparent resin film as the transparent base material 1. Of layers.

  In general, when a transparent resin film having low heat resistance is used for the transparent substrate, as described in the section of the transparent electrode, the formation temperature of the second conductive layer must be lower than the heat resistance temperature. It is difficult to form a second conductive layer. In the dye-sensitized solar cell using such an electrode substrate, the electrolyte penetrates into the second conductive layer, reaches the first conductive layer, corrodes the metal of the first conductive layer, and the performance is deteriorated over time. May be reduced. At this time, since the corrosion prevention layer 9 is provided on the outer surface of the first conductive layer 6, such a problem is less likely to occur.

  As shown in FIG. 3A, the corrosion prevention layer 9 only needs to cover at least the outer surface (upper surface and each side surface) of the first conductive layer 6. Further, as shown in FIG. 3B, the corrosion prevention layer 9 includes an outer surface of the first conductive layer 6 and a lower surface of the planarized transparent layer 7 (the surface of the underlying layer of the first conductive layer 6 in the opening. In the example, it is preferable that the surface of the adhesive layer 5 is continuously covered. By forming such a corrosion prevention layer 9, when a dye-sensitized solar cell is manufactured using the electrode substrate 20, the electrolyte penetrates into the interface between the first conductive layer 6 and its underlayer. It is possible to suppress the corrosion of the first conductive layer 6 and the corrosion of the first conductive layer 6 caused by the corrosion or dissolution of the underlayer. In the electrode substrate 20 on which the corrosion prevention layer 9 is formed, the planarizing transparent layer 7 is provided so as to planarize the first conductive layer whose outer surface is covered with the corrosion prevention layer, as shown in FIG. It has been.

  The corrosion prevention layer 9 is formed of a material having corrosion resistance with respect to the electrolyte for the dye-sensitized solar cell, and the material is appropriately selected according to the formation method of the corrosion prevention layer as described later. .

  The formation of the corrosion prevention layer 9 is performed by electroplating or non-plating after preparing the transparent base material (transparent resin film) 1 on which the first conductive layer 6 having an opening is formed and before forming the flattened transparent layer 7. It is performed by electrolytic plating or chemical conversion treatment. According to electroplating, electroless plating, or chemical conversion treatment, the relatively dense corrosion prevention layer 9 can be easily formed even if the heat resistance of the transparent substrate (transparent resin film) 1 is low. The plating conditions and chemical conversion treatment conditions at this time are appropriately selected according to the heat resistance of the transparent substrate (transparent resin film) 1 and the composition of the corrosion prevention layer 9 to be formed.

  For example, according to electroplating, nickel (Ni), zinc (Zn), gold (Au), platinum (Pt), chromium (Cr), aluminum (Al), cadmium (Cd), tungsten (W), tin (Sn ), Cobalt (Co), iron (Fe), or other metals, or alloys of the above metals, and forming a corrosion prevention layer 9 having corrosion resistance to the electrolyte for dye-sensitized solar cells. it can. Examples of plating baths used for electroplating include ordinary plating baths containing the above-described metal ions (cyanogen bath, borofluoride bath, pyrophosphate bath, zincate bath, hypophosphorous acid or boron hydride salt). A plating bath to which is added) can be used.

  According to the electroless plating treatment, nickel (Ni), zinc (Zn), gold (Au), platinum (Pt), chromium (Cr), aluminum (Al), cadmium (Cd), tungsten (W), tin ( Sn, Cobalt (Co), Iron (Fe), Titanium (Ti), Manganese (Mn), Zirconium (Zr) and other metals, or alloys of the above metals, for dye-sensitized solar cells The corrosion prevention layer 9 having corrosion resistance against the electrolyte can be formed. As a plating bath at the time of electroless plating, for example, a normal plating bath (alkali bath or the like) containing the above metal ions can be used. According to electroless plating, a corrosion prevention layer can be formed on the entire object by immersing the entire object in the plating solution.

  The formation of the corrosion prevention layer 9 by the chemical conversion treatment method is, for example, a transparent group in which a chemical conversion treatment agent containing a phosphate metal salt (hereinafter referred to as “phosphate metal chlorination treatment agent”) is formed up to the first conductive layer 6. The transparent base material (transparent resin film) 1 formed up to the first conductive layer 6 is immersed in the metal phosphate chlorination treatment agent by applying to the material (transparent resin film) 1 from the first conductive layer 6 side. Can be done. When applying the metal phosphate chlorination treatment agent, a known method can be used as the application method.

  Specific examples of the metal phosphate include, for example, chromium (III) phosphate, chromium (VI) phosphate, zirconium phosphate, titanium phosphate, lithium phosphate, manganese phosphate, phosphorus Examples include zinc oxide salts, cobalt phosphate salts, tin phosphate salts, nickel phosphate salts, tungsten phosphate salts, and molybdenum phosphate salts. These metal phosphates are used singly or in combination of two or more. The chemical conversion treatment agent may contain one or more water-soluble synthetic resins such as phenol resin, acrylic resin, and urethane resin. When the chemical conversion treatment agent contains a water-soluble synthetic resin, it is preferable to perform a heat treatment at about 80 to 200 ° C. after the chemical conversion treatment to promote a crosslinking reaction such as a covalent bond or a coordinate bond. By this heat treatment, a denser corrosion prevention layer 9 can be formed.

  In forming the corrosion prevention layer 9, it is preferable to perform a degreasing treatment in advance as a pretreatment. As a method of degreasing, known methods such as an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, and an acid activation method can be used. By performing a degreasing process in advance, a denser corrosion prevention layer 9 can be formed.

  If necessary, the surface of the corrosion prevention layer 9 can be chromated. This chromate treatment is particularly suitable when the main component of the corrosion prevention layer 9 is zinc. By performing the chromate treatment, it is possible to further suppress the penetration of the electrolyte into the first conductive layer 6 when a dye-sensitized solar cell is manufactured using the electrode substrate 20. The conditions for the chromate treatment are appropriately selected according to the heat resistance of the transparent substrate (transparent resin film) 1 and the composition of the corrosion prevention layer 9. When the corrosion prevention layer 9 is chromated, a surface treatment layer (not shown) formed by the chromate treatment is interposed between the corrosion prevention layer 9 and the second conductive layer 8.

  The surface treatment layer is, for example, a coating made of a chromium-containing metal, a chromium alloy made of a copper chromium alloy, or a chromium oxide layer. The chromate treatment is particularly preferably performed on the corrosion prevention layer 9 formed by galvanization or zinc alloy plating. When the object of chromate treatment is zinc plating or zinc alloy plating, the adhesion between the surface treatment layer (chromate treatment layer) and the plating layer (corrosion prevention layer 9) can be further enhanced.

  After performing the corrosion prevention layer forming step for forming the corrosion prevention layer as described above, the second conductive layer forming step for forming the metal oxide second conductive layer 8 covering the corrosion prevention layer 9 is performed. The transparent electrode 10 can be obtained.

(B) Gas barrier layer:
When a dye-sensitized solar cell is produced using the electrode substrate 20 using a transparent resin film as the transparent base material 1, the gas barrier layer allows oxygen and moisture to enter the dye-sensitized solar cell through the electrode substrate 20. In order to prevent the electrolyte used in the dye-sensitized solar cell from evaporating to the outside through the electrode substrate 20, the transparent base material (transparent resin film) 1, the transparent electrode 10, Or on the back surface of the transparent substrate (transparent resin film) 1 (meaning the surface opposite to the surface on which the transparent electrode 10 is formed).

The oxygen permeability of the gas barrier layer is preferably about 1 cc / m ² / day · atm (about 10 ml / m ² / day / MPa) or less, and the water vapor permeability is about 1 g / m ² / day or less. It is preferable. Such a gas barrier layer is a vapor-deposited film of a desired organic material (meaning a film formed by physical vapor deposition or chemical vapor deposition, hereinafter the same shall apply) or film, or of a desired inorganic material. It can be formed by a deposited film.

  By preventing oxygen from entering the dye-sensitized solar cell, deterioration of the dye 17 and the electrolyte is suppressed, so that a decrease in the performance of the dye-sensitized solar cell with time can be suppressed. In addition, by suppressing the intrusion of moisture, for example, even when the second conductive layer 8 is formed of a material that is relatively easily deteriorated by moisture, such as ITO, the deterioration of its performance over time is suppressed. A decrease in the performance of the solar cell over time can be suppressed.

(C) Patterning layer:
The “patterning layer” in the present specification means a layer capable of changing the wettability of the surface by light irradiation. Specific examples of this patterning layer include: (i) a photocatalyst-containing layer having a structure in which a photocatalyst (fine particles of photo semiconductor) is dispersed in a hydrophobic binder, and (ii) hydrolysis and polycondensation of chlorosilane, alkoxysilane, or the like. The resulting organopolysiloxane layer, (iii) a reactive silicone-crosslinked organopolysiloxane layer with excellent water repellency and oil repellency, and (iv) a self-assembled film exhibiting water repellency using fluoroalkylsilane, etc. , Etc.

  The photocatalyst-containing layer (i) above changes the wettability of the exposed region by selectively exposing the surface with light in a wavelength region including the absorption wavelength of the photocatalyst contained in the photocatalyst-containing layer. This can be made hydrophilic. Such a photocatalyst-containing layer is prepared by, for example, preparing a coating liquid in which a photocatalyst is dispersed in a hydrophobic binder, applying the coating liquid to a desired location to form a coating film, and then drying the coating film. Can be formed.

  Moreover, each layer of said (ii)-(iv) can change the wettability of the exposed area | region by selectively exposing the surface, for example by ultraviolet light, and can hydrophilize here. In selectively exposing the surface of each layer of (ii) to (iv) above, a photocatalyst-containing layer can be provided on the surface of the photomask (ultraviolet mask) on the exposed object side, if necessary. By providing this photocatalyst-containing layer on the photomask, it is possible to perform a desired hydrophilization treatment with longer wavelength ultraviolet light.

  The patterning layer is provided on the transparent electrode 10 and is used as an underlayer for the porous semiconductor electrode 15. Of the surface of the patterning layer, the region where the porous semiconductor electrode 15 is to be formed is hydrophilized as described above. When the above-mentioned coating liquid that is the material of the porous semiconductor electrode 15 is applied on the patterning layer in this state, a coating film, and thus the porous semiconductor electrode 15 is formed substantially only on the hydrophilic region. can do.

  For example, in order to obtain a dye-sensitized solar cell having a large operating voltage or current, a plurality of relatively small cells are electrically connected in series or in parallel to the structure of this dye-sensitized solar cell. A structure is preferred. In this case, one transparent electrode 10 is formed on one electrode substrate 20 and a plurality of porous semiconductor electrodes 15 are formed thereon, or a plurality of transparent electrodes 10 are formed to form individual transparent electrodes 10. One porous semiconductor electrode 15 is formed on each electrode 10. The patterning layer is useful for forming a plurality of porous semiconductor electrodes 15 at desired locations.

<Dye-sensitized solar cell>
FIG. 4 is a schematic view showing an example of a basic cross-sectional structure of the dye-sensitized solar cell of the present invention. In the illustrated dye-sensitized solar cell 50, the electrode substrate 20 described above is used as a photoelectrode, and the first conductive film 24 and the second conductive film 26 are laminated in this order on one side of the transparent base material 22. A dye-sensitized solar cell electrode substrate 30 (hereinafter referred to as “electrode substrate 30”) is used as a counter electrode. The electrode substrate 20 of the present invention used here is flat with no unevenness on the surface facing the electrode substrate 30 serving as a counter electrode. In place of the electrode substrate 30, an electrode substrate in which the transparent electrode 10 described above is formed on one surface of a transparent base material and a conductive film corresponding to the second conductive film 26 is formed on the transparent electrode 10. It may be used.

  Since the configuration of the electrode substrate 20 has already been described, the description thereof is omitted here. Moreover, as the transparent base material 22 and the 1st electrically conductive film 24 in the electrode substrate 30 used as a counter electrode, the thing similar to the transparent base material 1 or the 2nd conductive layer 8 in the electrode substrate 20 mentioned above, respectively is used. Therefore, the description of the transparent base material 22 and the first conductive film 24 is also omitted here.

  The second conductive film 26 is for improving the conductivity of the electrode substrate 20. The second conductive film 26 may be formed by appropriately selecting a conductive material having corrosion resistance to the electrolyte according to the type of electrolyte used in the dye-sensitized solar cell using the electrode substrate 30. preferable. The material of the second conductive film 26 is most preferably platinum (Pt), but the second conductive film 26 can also be formed of carbon, a conductive polymer, or the like. From the viewpoint of obtaining a dye-sensitized solar cell with high photoelectric conversion efficiency using the electrode substrate 30, when one ionic species constituting the redox pair reacts with a carrier during light irradiation to generate the other ionic species. The second conductive film 26 is preferably formed of a metal that can function as a catalyst (for example, platinum (Pt)).

  The second conductive film 26 can be formed by, for example, a vapor deposition method, a sputtering method, a CVD method, or the like, and the film thickness can be appropriately selected within a range of approximately 1 to 500 nm. From the viewpoint of reducing the manufacturing cost of the electrode substrate 30, it is preferable to form the second conductive film 26 by sputtering.

  The electrode substrate 20 that is a photoelectrode and the electrode substrate 30 that is a counter electrode are arranged such that the porous semiconductor electrode 15 in the electrode substrate 20 and the second conductive film 26 in the electrode substrate 30 face each other. The electrolyte layer 35 is interposed between the electrode substrates 20 and 30. The transparent electrode 10 in the electrode substrate 20 is connected to a load 45 by a lead wire 40a, and this load 45 is connected to the first conductive film 24 in the electrode substrate 30 by a lead wire 40b. Although not shown in the drawing, in the dye-sensitized solar cell 50, in order to prevent the electrolyte forming the electrolyte layer 35 from leaking, the periphery of the electrode substrates 20, 30 and the electrolyte layer 35 is disposed. Sealed with a sealant.

  Spacers such as glass spacers, resin spacers, and olefinic porous membranes are disposed between the electrode substrate 20 and the electrode substrate 30 in order to keep the distance between the electrode substrates 20 and 30 accurately at a desired interval and prevent short circuit. May be. The spacer can be formed in advance on one of the electrode substrates 20 and 30, or can be used by being fixed to at least one of the electrode substrates 20 and 30 when assembling the dye-sensitized solar cell. . The spacer can also serve as a sealant.

  The electrolyte layer 35 is located between the electrode substrate 20 and the electrode substrate 30 and is reduced by the photoexcited dye 17, while being oxidized by carriers (electrons) supplied through the electrode substrate 30. A closed circuit including the substrate 20, the lead wire 40a, the load 45, the lead wire 40b, and the electrode substrate 30 can be formed.

  As the material of the electrolyte layer 35, various electrolytes used for dye-sensitized solar cells containing at least a redox pair contributing to carrier transport can be used, and the form thereof is liquid, solid, and It may be any gel. From the viewpoint of improving the durability and stability of the dye-sensitized solar cell 50, it is preferable to use a room temperature molten salt electrolyte or a gel electrolyte.

The redox couple is not particularly limited as long as it is used for an electrolyte. As a combination of raw materials of such a redox pair, a combination of iodine and iodide, or a combination of bromine and bromide is preferably exemplified. For example, specific examples of combinations of iodine and iodide include metal iodides such as lithium iodide (LiI), sodium iodide (NaI), potassium iodide (KI), calcium iodide (CaI ₂ ), and iodine. A combination with (I ₂ ) can be mentioned. Specific examples of the combination of bromine and bromide include lithium bromide (LiBr), sodium bromide (NaBr), potassium bromide (KBr), calcium bromide (CaBr ₂ ), and the like, and bromide (Br). ₂ ) and a combination thereof.

  When a gel electrolyte is used as the material of the electrolyte layer 35, the electrolyte may be a physical gel or a chemical gel. A physical gel is gelled near room temperature due to physical interaction, and a chemical gel is a gel formed by a chemical bond such as a crosslinking reaction. The physical gel can be prepared by using a gelling agent such as polyacrylonitrile or polymethacrylate, and as the chemical gel, an acrylic ester-based or methacrylic ester-based one can be used.

  When a solid electrolyte is used as the material of the electrolyte layer 35, it is preferable to use a conductive polymer having a high hole transporting property such as copper iodide (CuI), polypyrrole, or polythiophene as the electrolyte.

  The thickness of the electrolyte layer 35 can be selected as appropriate, but the thickness of the electrolyte layer is such that the total of the thickness of the porous semiconductor electrode 15 is in the range of 2 μm to 100 μm, and in particular, in the range of 2 μm to 50 μm. It is preferable to select the thickness. If the thickness of the electrolyte layer 35 is thinner than the above range, the porous semiconductor electrode 15 and the second conductive film 26 are likely to come into contact with each other, causing a short circuit. Moreover, when the thickness of the electrolyte layer 35 is thicker than the above range, the internal resistance of the dye-sensitized solar cell 50 is increased, and the photoelectric conversion efficiency is lowered.

  In the dye-sensitized solar cell 50 of the present invention, since the electrode substrate 20 having no uneven surface is used, the thickness of the electrolyte layer 35 does not increase locally. Therefore, in this dye-sensitized solar cell 50, the electrolyte layer 35 can be uniformly thin as long as no short circuit occurs, and the photoelectric conversion efficiency can be improved.

  The electrolyte layer 35 described above can be formed by various methods depending on the material. For example, a method of forming an electrolyte layer forming coating solution used for forming the electrolyte layer 35 by applying it on the porous semiconductor electrode 15 and drying it (hereinafter sometimes referred to as “coating method”), Alternatively, the electrode substrates 20 and 30 are arranged so that the porous semiconductor electrode 15 and the second conductive layer 26 have a predetermined interval, and an electrolyte layer forming coating solution is placed in the gap between the electrode substrate 20 and the electrode substrate 30. Examples thereof include a method of forming the electrolyte layer 35 by injection (hereinafter sometimes referred to as “injection method”). Hereinafter, these “coating method” and “injection method” will be described.

(I) Application method:
The coating method is a method mainly used for forming a solid electrolyte layer. As the coating solution for forming an electrolyte layer used in this coating method, at least a redox pair and a polymer holding the redox pair are used. The one containing is used. In addition, it is preferable to add a crosslinking agent, a photopolymerization initiator, and the like.

  The coating solution for forming the electrolyte layer can be applied by die coating, gravure coating, gravure reverse coating, roll coating, reverse roll coating, bar coating, blade coating, knife coating, air knife coating, slot die coating, slide die coating, dip coating, and micro bar. It can be performed by various methods such as coating, microbar reverse coating, and screen printing (rotary method).

  When the above-mentioned photopolymerization initiator is contained in the electrolyte layer forming coating solution, the electrolyte layer 35 is formed by applying the electrolyte layer forming coating solution and then exposing the photopolymerization initiator to light. Can do.

(II) Injection method:
The injection method is a method used to form a liquid, gel, or solid electrolyte layer. When the electrolyte layer 35 is formed by this method, the above-described spacer is used to form the electrode substrate 20. It is preferable to previously form a cell in which the electrode substrate 30 is held at a desired interval. Injection | pouring of the coating liquid for electrolyte layer formation can be performed using a capillary phenomenon, for example. In the case of forming the gel-like or solid electrolyte layer 35, the two-dimensional or three-dimensional crosslinking reaction is performed by, for example, performing temperature adjustment, ultraviolet irradiation, electron beam irradiation, etc. after injecting the electrolyte layer forming coating solution. Give rise to

<Example 1>
(Preparation process)
First, an A4 size (JIS standard) 100 μm thick polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., product number: E5100) is used as a transparent substrate, and a 9 μm thick copper is used as a material for the first conductive layer. Using the foil, the transparent substrate and the copper foil were bonded together by dry lamination using a urethane-based adhesive (glass transition temperature (Tg): 20 ° C., weight average molecular weight: 30,000).

  Next, a resist is applied on the copper foil to form a resist layer, and the resist layer is subjected to an exposure process using a mask having a predetermined shape and a development process in order to form an etching mask having a predetermined shape. After that, the copper foil was etched, and then the resist was removed (peeling of the etching mask). Thereby, the said copper foil was patterned in the grid | lattice form, and the 1st conductive layer was obtained. The size of the opening in the first conductive layer (the part corresponding to the grid eyes) is 300 μm □, and the line width of each part is 10 μm. The aperture ratio of the first conductive layer is 90%, and the light transmittance of the transparent base material formed up to the first conductive layer is 83.1%. From each opening part of the 1st conductive layer, the adhesive bond layer used in order to bond said transparent base material and copper foil is exposed.

(Corrosion prevention layer forming process)
First, Ni-Sn alloy plating bath was prepared by dissolving nickel chloride in water at a rate of 300 g / l, tin chloride at 15 g / l, acidic ammonium fluoride at 56 g / l, and boric acid at a rate of 30 g / l. .

  Next, the transparent substrate on which the first conductive layer was formed was immersed in the plating bath described above and electroplated for 3 minutes. Thereby, the corrosion prevention layer which consists of a Ni-Sn alloy was formed in the outer surface of the 1st conductive layer. In the opening of the first conductive layer, the adhesive layer remained exposed. The composition of the corrosion prevention layer was identified by X-ray diffraction.

(Planarization transparent layer formation process)
First, a flattening transparent layer forming coating solution (viscosity: 480 mPa · s) in which an acrylic resin (Tg: 100 ° C., weight average molecular weight: 240,000) was diluted to 40 wt% with methyl ethyl ketone was prepared.

  Next, 10 g of a flattening transparent layer-forming coating solution is placed on a part of the surface of the transparent substrate on which the first conductive layer and the corrosion prevention layer are formed, and squeegee (manufactured by Mino Corporation, trade name: Mino Fine). The above flattening transparent layer forming coating solution was applied to the entire surface of the transparent substrate while scraping off the excess coating solution using a squeegee, hardness: 60). Then, this transparent base material was heated, and the planarizing transparent layer was formed by drying the apply | coated coating liquid for planarization transparent layer formation. When the cross section of the transparent substrate formed up to the flattened transparent layer was observed with a scanning electron microscope, a flattened transparent layer having a thickness of 9 μm was formed in the opening of the first conductive layer. It was confirmed that there was no resin coating on the top surface. The glass transition temperature here is a value measured by a differential scanning calorimetry (DSC measurement method).

(Second conductive layer forming step)
The transparent substrate formed up to the flattened transparent layer is placed in the chamber of the ion plating apparatus, and the film forming pressure is 1.5 × 10 ⁻ on the surface of the transparent substrate on which the first conductive layer is formed. Indium tin oxide (ITO) as a sublimation material is deposited under the conditions of ¹ Pa, argon gas flow rate 18 sccm, oxygen gas flow rate 28 sccm, and film formation current value 60 A, and a second conductive layer made of ITO having a thickness of 150 nm is deposited. Formed. The second conductive layer covers the corrosion prevention layer and the flattening transparent layer.

  By forming up to the second conductive layer, a transparent electrode was obtained in which the adhesive layer, the first conductive layer, the planarizing transparent layer, the corrosion prevention layer, and the second conductive layer were formed on one side of the transparent substrate. The surface resistance value of this transparent electrode was 0.08Ω / □.

(Porous semiconductor electrode formation process)
First, titanium oxide (TiO ₂ ) fine particles having a primary particle diameter of 15 nm (F-5 manufactured by Showa Denko KK) and a polyester resin as a binder were mixed with water and polypropylene glycol monomethyl ether in a homogenizer. After dissolution and dispersion, the slurry is stirred using a self-revolving stirrer and contains 20.5% by mass of the TiO ₂ fine particles and 0.3% by mass of the binder (viscosity: 86 mPa · s) was prepared. This slurry corresponds to a coating solution for a porous semiconductor electrode.

  Next, the slurry was applied onto the transparent electrode by the doctor blade method, and then dried at 150 ° C. for 30 minutes to form a porous semiconductor electrode having a thickness of 12 μm.

(Dye support process)
A dye-supporting coating solution prepared by dissolving a ruthenium complex (manufactured by Kojima Chemical Co., Ltd.) as a sensitizing dye in ethanol so that its concentration is 3 × 10 ⁻⁴ mol / l is prepared. The transparent electrode on which the electrode is formed is immersed in this dye-supporting coating solution and left for 1 hour under the condition of a liquid temperature of 40 ° C. Then, this is pulled up from the dye-supporting coating solution, and each porous The dye-supporting coating solution adhering to the semiconductor electrode was air-dried. Thereby, said pigment | dye was carry | supported by each porous porous semiconductor electrode.

  Thereafter, the above-described porous semiconductor electrode is trimmed so as to be a 1 cm × 1 cm square when viewed in plan, and has the same configuration as that of the electrode substrate 20 shown in FIG. A substrate (hereinafter referred to as “electrode substrate A”) was obtained.

  Next, under the same conditions as the formation of the second conductive layer, an ITO film (thickness 150 nm) as a first conductive film is formed on one side of a 100 μm-thick PET film (manufactured by Toyobo Co., Ltd., product number: A4300). And a platinum thin film (film thickness: 50 nm) as a second conductive film is formed thereon by a sputtering method, and the dye-sensitized solar cell having the same configuration as that of the electrode substrate 30 shown in FIG. Electrode substrate (hereinafter referred to as “electrode substrate P”).

  The electrode substrate P and the electrode substrate A are bonded together using a 20 μm thick heat-sealing film (DuPont Co., Ltd., trade name: Surlyn), and an electrolyte layer is formed in the gap between the electrode substrate P and the electrode substrate A. The coating liquid was filled to obtain a dye-sensitized solar cell of Example 1 having the same configuration as that of the dye-sensitized solar cell 50 shown in FIG.

  At this time, the above-mentioned heat-sealing film was used by previously shaping the shape into a rectangular frame so as to be fused only to the inner edge portions of the electrode substrate P and the electrode substrate A, respectively. As the electrolyte layer forming coating solution, methoxyacetonitrile is used as a solvent, and in this solvent, lithium iodide is 0.1 mol / l, iodine is 0.05 mol / l, and dimethylpropylimidazolium iodide is 0.3 mol / l. 1 and tertiary butylpyridine dissolved in a ratio of 0.5 mol / l were used.

The battery characteristics of the dye-sensitized solar cell of Example 1 thus obtained were evaluated. Specifically, the current-voltage characteristics of the dye-sensitized solar cell of Example 1 were measured using a source measure unit (Caseley 2400 type) as a measuring device and pseudo-sunlight (AM1.5, irradiation intensity 100 mW / cm) as a light source. ² ). As a result, the battery characteristics of the dye-sensitized solar cell of Example 1 were as follows: the short-circuit current was 12.1 mA / cm ² , the open-circuit voltage was 0.71 V, the fill factor was 0.65, and the photoelectric conversion efficiency was 5.8%. Met.

<Example 2>
In the production of the dye-sensitized solar cell of Example 1, except that the flattened transparent layer was formed by the flattened transparent layer forming step shown below instead of the flattened transparent layer forming step in the production of the electrode substrate A. In the same manner as in Example 1, a dye-sensitized solar cell of Example 2 having the same configuration as that of the dye-sensitized solar cell 50 shown in FIG. 4 was obtained.

The battery characteristics of the dye-sensitized solar cell of Example 2 obtained in this way were evaluated in the same manner as in Example 1. As a result, the battery characteristics of the dye-sensitized solar cell of Example 2 were as follows: the short-circuit current was 11.8 mA / cm ² , the open-circuit voltage was 0.71 V, the fill factor was 0.67, and the photoelectric conversion efficiency was 5.6%. Met.

(Planarization transparent layer formation process)
The transparent base material on which the first conductive layer and the corrosion prevention layer are formed contains a UV curable epoxy resin (Tg: 50 ° C., weight average molecular weight: 30,000) and various additives such as a photopolymerization initiator. A material for forming a flattened transparent layer (viscosity: 620 mPa · s) was prepared.

  Next, 10 g of a flattened transparent layer forming material is placed on a part of the surface of the transparent substrate on which the first conductive layer and the corrosion prevention layer are formed, and squeegee (manufactured by Mino Corporation, trade name: Mino Fine Squeegee, hardness) : 60) was applied to the entire surface of the transparent substrate while scraping off the excess coating material. Thereafter, the transparent base material was irradiated with UV to cure the applied flattening transparent layer forming material to form a flattening transparent layer. When the cross section of the transparent substrate formed up to the flattened transparent layer was observed with a scanning electron microscope, a flattened transparent layer having a thickness of 9 μm was formed in the opening of the first conductive layer. It was confirmed that there was no resin coating on the top surface. The glass transition temperature (Tg) described above is a value measured by the differential scanning calorimetry (DSC measurement method) as in the case of Example 1.

<Example 3>
Adhering to one side of a PET film in the same manner as in Example 1 except that an aluminum foil having a thickness of 12 μm (Toyo Aluminum Co., Ltd., purity: 99.7%) was used as the material for the first conductive layer, and no corrosion prevention layer was formed. A transparent electrode composed of an agent layer, a first conductive layer, a planarized transparent layer, and a second conductive layer was formed. The surface resistance value of this transparent electrode was 0.006Ω / □.

(Durability check)
In order to confirm the resistance to the iodine electrolyte of the PET film on which the transparent electrode thus obtained was formed, first, an iodine electrolyte solution using methoxyacetonitrile as a solvent was prepared. This iodine electrolyte solution was lithium iodide at a rate of 0.1 mol / l, iodine at 0.05 mol / l, dimethylpropylimidazolium iodide at 0.3 mol / l, and tertiary butylpyridine at a rate of 0.5 mol / l. Contains each.

  Next, the PET film on which the transparent electrode was formed was immersed in the iodine electrolyte solution for a whole day and night, and then the surface resistance value was measured. As a result, the surface resistance value after immersion in the iodine electrolyte solution was 0.006Ω / □, and the surface resistance value before immersion was maintained.

<Comparative Example 1>
In the production of the dye-sensitized solar cell of Example 1, a dye-sensitized solar cell of Comparative Example 1 was obtained in the same manner as in Example 1 except that no flattened transparent layer was formed.

The battery characteristics of the obtained dye-sensitized solar cell of Comparative Example 1 were evaluated in the same manner as in Example 1. As a result, the battery characteristics of the dye-sensitized solar cell of Comparative Example 1 are as follows: the short-circuit current is 7.4 mA / cm ² , the open-circuit voltage is 0.68 V, the fill factor is 0.61, and the photoelectric conversion efficiency is 3.1%. It was inferior to the dye-sensitized solar cell of Example 1 or 2. The reason is that in the dye-sensitized solar cell of Comparative Example 1, the distance between the electrode substrates is wide in the vicinity of the opening of the first conductive layer, and the thickness of the electrolyte layer is thick at that portion. Is done.

<Comparative example 2>
In the production of the dye-sensitized solar cell of Example 1, a dye-sensitized solar cell of Comparative Example 2 was obtained in the same manner as Example 1 except that no corrosion prevention layer was formed.

  When the battery characteristics of the obtained dye-sensitized solar cell of Comparative Example 1 were evaluated in the same manner as in Example 1, a decrease in characteristics over time was observed during the characteristic evaluation. The reason is presumed to be that the electrolyte penetrated into the second conductive layer and reached the first conductive layer, and the first conductive layer was corroded.

<Comparative Example 3>
In the production of the dye-sensitized solar cell of Example 1, except that the flattened transparent layer was formed by the flattened transparent layer forming step shown below instead of the flattened transparent layer forming step in the production of the electrode substrate A. Produced the transparent base material formed to the planarization transparent layer like Example 1. FIG.

When the surface resistance value of the obtained transparent substrate was measured by a four-end needle method using Loresta EP manufactured by Dia Instruments Co., Ltd. as a measuring device, it was a measurement limit value (10 ⁶ Ω / □) or more. . Therefore, the dye-sensitized solar cell of Comparative Example 3 produced using such a transparent substrate does not function as a dye-sensitized solar cell. Moreover, when the cross section of this transparent base material was observed with the scanning electron microscope, what hardened | cured the flattening transparent layer forming material was laminated | stacked on the 1st conductive layer.

(Planarization transparent layer formation process)
An acrylic resin was applied as a planarizing transparent layer forming material to the transparent base material on which the first conductive layer and the corrosion prevention layer were formed by a doctor blade method. Next, this transparent base material was heated in an oven at 100 ° C. for 5 minutes and dried to solidify the applied flattening transparent layer forming material to form a flattening transparent layer.

It is the schematic which shows an example of the basic cross-section of the electrode substrate for dye-sensitized solar cells of this invention. It is a top view which shows roughly an example of the 1st conductive layer which comprises the electrode substrate for dye-sensitized solar cells of this invention. It is the schematic which shows another example of the basic cross-section of the electrode substrate for dye-sensitized solar cells of this invention. It is the schematic which shows an example of the basic cross-section of the dye-sensitized solar cell of this invention. It is the schematic which shows an example of the cross-sectional structure of the conventional dye-sensitized solar cell. It is the schematic which shows another example of the cross-section of the conventional dye-sensitized solar cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent base material 5 Adhesive layer 6 1st conductive layer 7 Flattening transparent layer 8 2nd conductive layer 9 Corrosion prevention layer 10 Transparent electrode 15 Porous semiconductor electrode 17 Dye 20 Dye-sensitized solar cell electrode substrate 22 Transparent group Material 24 First conductive film 26 Second conductive film 30 Electrode substrate for dye-sensitized solar cell 35 Electrolyte layer 50 Dye-sensitized solar cell

Claims (16)

A transparent base material, a transparent electrode formed on one side of the transparent base material, a porous semiconductor electrode formed on the transparent electrode using a large number of semiconductor fine particles, and the porous semiconductor electrode are formed A dye-sensitized solar cell electrode substrate having a dye supported on the surface of semiconductor fine particles,
The transparent electrode includes a first conductive layer made of a metal having a large number of openings a shape that combines a large number of fine lines, a is embedded in the opening portion of the first conductive layer first conductive layer Tan Taira and planarizing transparent layer made of a resin that the dye-sensitized, characterized in that it comprises a metal oxide of the second conductive layer formed over said flattening transparent layer and the first conductive layer Solar cell electrode substrate.   The transparent electrode further includes an adhesive layer formed on one side of the transparent substrate, the first conductive layer is a metal foil, and the first conductive layer is attached to the transparent substrate by the adhesive layer. The electrode substrate for a dye-sensitized solar cell according to claim 1, wherein the electrode substrate is a dye-sensitized solar cell.   3. The dye-sensitized solar cell electrode substrate according to claim 1, wherein the flattened transparent layer is embedded in the opening of the first conductive layer without any gap. The transparent substrate is a transparent resin film, and the outer surface of the first conductive layer is covered with a corrosion prevention layer formed by electroplating, electroless plating or chemical conversion treatment, and the planarized transparent layer is dye-sensitized solar cell electrode substrate according to any one of claims 1 to 3, characterized in that it is the first conductive layer of the outer surface is covered with the corrosion preventing layer on the Tan Taira .   The electrode substrate for a dye-sensitized solar cell according to claim 4, wherein an outer surface of the corrosion prevention layer is a chromate treatment to form a surface treatment layer.   The dye-sensitized solar cell electrode substrate according to any one of claims 1 to 5, wherein the first conductive layer is formed of copper, nickel, or stainless steel. A transparent base material, a transparent electrode formed on one side of the transparent base material, a porous semiconductor electrode formed on the transparent electrode using a large number of semiconductor fine particles, and the porous semiconductor electrode are formed A method for producing a dye-sensitized solar cell electrode substrate having a dye supported on the surface of semiconductor fine particles,
A preparation step of preparing a transparent base material in which a first conductive layer made of metal that has a shape in which a large number of openings are formed and a combination of a large number of fine wires is formed on one side;
By burying the resin in the opening of the first conductive layer, and planarizing transparent layer forming step of forming a planarizing transparent layer to said first conductive layer on a Tan Taira,
A second conductive layer forming step of forming a second conductive layer made of metal oxide on the first conductive layer and the planarized transparent layer;
Forming a porous semiconductor electrode using a plurality of semiconductor fine particles on the second conductive layer; and
A method for producing a dye-sensitized solar cell electrode substrate, comprising: a dye carrying step of carrying a dye on the surface of semiconductor fine particles forming the porous semiconductor electrode.   The preparatory step includes a first sub-step of preparing a transparent substrate having a metal foil attached to one side by an adhesive, and a second sub-step of patterning the metal foil to obtain the first conductive layer. The manufacturing method of the electrode substrate for dye-sensitized solar cells of Claim 7 characterized by these.   The flattening transparent layer forming step includes a first sub-step of applying a flattening transparent layer forming material to a surface of the transparent substrate on which the first conductive layer is formed, and an upper surface of the first conductive layer. Or a second sub-step of pressing and sliding the surface coated with the flattening transparent layer forming material so that the flattening transparent layer forming material does not remain. The manufacturing method of the electrode substrate for dye-sensitized solar cells of Claim 8.   The said flattening transparent layer formation process includes the 3rd sub process of pressing the surface where the said flattening transparent layer formation material was apply | coated after the said 2nd sub process. A method for producing an electrode substrate for a dye-sensitized solar cell.   At the same time or substantially simultaneously with the step of forming the flattening transparent layer forming step, the flattening transparent layer forming material is applied to the surface of the transparent base on which the first conductive layer is formed. 9. The method according to claim 7, comprising a step of pressing and sliding the surface coated with the flattening transparent layer forming material so that the flattening transparent layer forming material does not remain on the upper surface. Of producing a dye-sensitized solar cell electrode substrate.   The dye according to claim 11, wherein the flattening transparent layer forming step includes a step of pressing the surface coated with the flattening transparent layer forming material after the pressurizing and sliding step. A method for producing an electrode substrate for a sensitized solar cell.   An electrolyte for a dye-sensitized solar cell, using a transparent resin film as the transparent substrate and covering the outer surface of the first conductive layer between the preparation step and the flattening transparent layer forming step The dye according to any one of claims 7 to 12, further comprising a corrosion prevention layer forming step of forming a corrosion prevention layer having corrosion resistance against electrolysis by electroplating, electroless plating, or chemical conversion treatment. A method for producing an electrode substrate for a sensitized solar cell.   The method for producing an electrode substrate for a dye-sensitized solar cell according to claim 13, wherein the corrosion prevention layer forming step includes a surface treatment step of performing chromate treatment on the corrosion prevention layer.   The method for producing a dye-sensitized solar cell electrode substrate according to any one of claims 7 to 14, wherein the first conductive layer is formed of copper, nickel, or stainless steel. A first electrode substrate having a porous semiconductor electrode in which a dye is supported on the surface of semiconductor fine particles forming a porous semiconductor electrode, and a second electrode substrate disposed opposite to the first electrode substrate And a dye-sensitized solar cell comprising an electrolyte layer interposed between the first electrode substrate and the second electrode substrate,
The dye-sensitized solar cell, wherein the first electrode substrate is the electrode substrate for a dye-sensitized solar cell according to any one of claims 1 to 6.

Images