JP2005108468A - Transparent conductive sheet, manufacturing method of the same, and photosensitive solar cell using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent conductive sheet having a specific structure, excellent in transparency, conductivity, and durability when used for an electrode of a solar cell, taking out current efficiently, capable of voltage control, and to provide a photosensitive solar cell using the same. <P>SOLUTION: The transparent conductive sheet, composed of a part having a transparent base body, the transparent conductive thin film layer, and a conductive mesh layer, and a part composed of a transparent base body, has a plurality of transparent conductive layers insulated from each other, and the transparent conductive layer has high transparency and high conductivity. (1) It is at least composed of a transparent conductive part (I) composed of the transparent base body (A), the transparent conductive thin film layer with a thickness of 1 to 100 nm (B), and the conductive mesh layer (C), having a structure that the transparent conductive thin film layer (B) is electrically connected to the conductive mesh layer (C); and a part (II) composed of the transparent base body (A). (2) Preferably, the transparent conductive part (I) has an island-shaped structure. (3) Preferably, the transparent base body (A) is a polymeric sheet (A1). (4) Preferably, the transparent base body (A) has a gas barrier film (D) at least on a main face at one side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a transparent conductive sheet that is excellent in light transmittance and conductivity, and also excellent in durability against chemical substances. Moreover, this invention relates to the solar cell using said transparent conductive sheet, especially a dye-sensitized solar cell.

  From the standpoint of preventing global warming and environmental pollution, power generation devices and solar cells that can convert solar light energy directly into electrical energy and supply clean energy are attracting attention. Silicon-based solar cells such as amorphous silicon solar cells, polysilicon solar cells, and single crystal silicon solar cells that have already applied semiconductor manufacturing processes and that are pn-connected or pin-connected have already been put to practical use. It is commercially available as a module for power generation. However, these solar cells are expensive to manufacture, which is an obstacle for the spread of solar cells to ordinary households.

On the other hand, as shown in Japanese Patent No. 2664194 (Patent Document 1) and Japanese Patent No. 2101079 (Patent Document 2), a wet sun using titanium oxide and a sensitizing dye devised in 1991 by Gretzel et al. High efficiency in dye-sensitized solar cells such as batteries has been advanced, and research has been actively conducted as a next-generation solar cell that is inexpensive, has low environmental impact, and has high performance.

  Furthermore, it is possible to produce by the roll-to-roll method, and further cost reduction is possible, and it is light and thin and difficult to break. There is also a great deal of investigation to replace the conventionally used glass with a plastic film. For example, there is a report such as ECN contributions 2nd World Conference and Exhibition on Photo-voltaic Solar Energy Conversion, Vienna 6-10 July 1998 (Non-Patent Document 1).

  As the transparent electrode, a thin film of transparent conductive ceramic that can transmit light and flow electricity is used. Transparent conductive ceramics include indium and tin oxides known as ITO (indium tin oxide), tin oxide with addition of fluorine or antimony oxide, zinc oxide with addition of fluorine or aluminum oxide (alumina), Etc. These transparent conductive ceramic thin films are usually formed by CVD (Chemical Vapor Deposition), PVD (Physical Vapor Deposition) such as sputtering, vapor deposition, and ion plating. It is formed on a transparent substrate such as glass or plastic by a dry method and used as a transparent electrode.

However, even though these transparent conductive ceramics have high conductivity, their conductivity is at most 10 ³ Scm ⁻¹ (resistivity is 10 ⁻⁴ Ωcm), and usually 10 ² Scm ⁻¹ ( Resistivity is 10 ⁻³ Ωcm), which is about two orders of magnitude lower than 10 ⁵ Scm ⁻¹ of a good conductor metal (10 ⁻⁶ Ωcm in resistivity), improving the conversion efficiency of solar cells Has become an obstacle to.

  For this reason, in order to achieve a required sheet resistance value of at least 10Ω / □ for a transparent electrode for a solar cell that is assumed to be used in the form of a large-area panel, a film thicker than 100 nm is required. Thickness is required.

  However, if the thickness of these transparent conductive ceramics is made larger than at least 100 nm, the transmittance of light in the visible light region converted into electric energy in the dye-sensitized solar cell is, for example, luminous average transmission There was a problem that the rate dropped to 75% or less. That is, the current value that can be taken out directly as electric energy is reduced, and the conversion efficiency of the solar cell is reduced. On the other hand, when the film thickness is reduced, if the sheet resistance is increased, the electric energy is lost while a current flows through the transparent conductive film, and the conversion efficiency is lowered.

  In a relatively large area solar cell, energy is not extracted with a low voltage and large current as a single large area solar cell, but a structure in which small solar cells are connected in series in a large area is created. In addition, a method is often used in which energy is extracted with a high voltage and a relatively low current by creating a structure connected in parallel as necessary. This is a preferable method because it has an effect of reducing electric energy loss when the resistance of the transparent conductive film is relatively high and avoiding a decrease in yield due to local structural defects. In order to realize such a solar cell, a transparent conductive sheet having a plurality of transparent conductive thin film layers insulated from each other is required.

  In order to form such a transparent conductive sheet, after forming a transparent conductive thin film layer on a transparent substrate, a method of patterning the transparent conductive thin film with a laser, dry etching using plasma, etc. There is a method of patterning by wet etching used.

However, when the transparent conductive thin film is formed of a plurality of types of films, or when the conductive layer is composed of a transparent conductive thin film and a metal mesh layer, these methods are effective for etching each layer. Since the processability is different, there are problems that the removal of the transparent conductive thin film may be insufficient or the transparent substrate may be damaged.
Japanese Patent No. 2664194 Japanese Patent No. 2101079 ECN contributions 2nd World Conference and Exhibition on Photo-voltaic Solar Energy Conversion, Vienna 6-10 July 1998

  Therefore, an object of the present invention is to be applied to dye-sensitized solar cells such as wet solar cells and solid electrolyte solar cells, and has high transparency, high conductivity, and chemically stable transparent conductivity. To provide a sheet. Moreover, it is providing the manufacturing method of the said transparent conductive sheet.

As a result of studies by the present inventors to solve the above problems, a transparent conductive sheet comprising a portion having a transparent substrate, a transparent conductive thin film layer and a conductive mesh layer, and a portion comprising a transparent substrate, It has been found that a plurality of transparent conductive layers are insulated from each other, and the transparent conductive layer has high transparency and high conductivity. Moreover, it discovered that said transparent conductive sheet was easily obtained by the process of etching a transparent conductive thin film layer, and the process of etching a conductive mesh layer, and completed this invention. That is, the present invention
(1) At least the transparent substrate (A), the transparent conductive thin film layer (B) having a thickness of 1 to 100 nm, and the conductive mesh layer (C)
A transparent conductive portion (I) having a configuration in which at least the transparent conductive thin film layer (B) and the conductive mesh layer (C) are electrically connected to each other and a portion (II) consisting of the transparent substrate (A) (II) A transparent conductive sheet consisting of
(2) Preferably, the transparent conductive portion (I) is a transparent conductive sheet having an island-like configuration,
(3) Preferably, the transparent substrate (A) is a transparent conductive sheet that is a polymer sheet (A1),
(4) Preferably the transparent substrate (A) is a transparent conductive sheet which is a transparent substrate (A2) having a gas barrier film (D) on at least one principal surface,
(5) a conductive portion (III) comprising a transparent substrate (A) and a transparent conductive thin film layer (B) or a conductive mesh layer (C);
After producing a sheet comprising the transparent conductive portion (I),
The method for producing a transparent conductive sheet as described above, wherein the portion (II) comprising the transparent substrate (A) is formed by etching the conductive portion (III),
(6) A photosensitized solar cell using the above transparent conductive sheet.

  The transparent conductive sheet of the present invention has low sheet resistance, excellent electrical conductivity, high light transmittance, and excellent chemical stability required for wet solar cells. Moreover, since it has both an electroconductive site | part and an insulating site | part, when it uses for a wet solar cell, the said solar cell may be able to be produced with a high yield. Moreover, since the manufacturing method of the transparent conductive sheet of this invention can manufacture easily the transparent conductive sheet which has the above electroconductive site | parts and an insulating site | part, productivity of the said transparent electroconductive sheet | seat Can be increased.

  The transparent conductive sheet of the present invention comprises a transparent substrate (A), a transparent conductive thin film layer (B), a conductive mesh layer (C), and, if necessary, a gas barrier film (D). First, each layer which comprises the transparent conductive sheet of this invention is demonstrated.

(Transparent substrate (A))
The transparent substrate (A) in the present invention is not particularly limited as long as it is a substantially transparent substance having a high visible light transmittance. For example, it is sufficient that the light transmittance is high at a wavelength in the vicinity of the visible region, for example, 300 nm to 800 nm, which is a wavelength band used for photoelectric conversion in a photosensitized solar cell. More specifically, it is 80% or more, preferably 85% or more, more preferably 90% or more, and still more preferably 95% or more in terms of the luminous average transmittance defined in JIS-R3106.

  In the present invention, even if a polymer sheet is used as such a material, it is one feature that both high transparency and high conductivity can be achieved. Of course, glass can also be used. In addition, a combination of glass and a transparent polymer sheet may be used.

  A transparent plastic film or plate can be used as the polymer sheet (A1). For example, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherketone, polyetheretherketone (PEEK), polyolefin resin, cyclopolyolefin resin, polycarbonate resin (PC ), Polymethyl methacrylate resin (PMMA), cellulose acetate (TAC) resin, fluorinated resins such as tetrafluoroethylene resin, and the like. These may be used singly, laminated, or mixed and used as long as they are transparent. These may be modified as appropriate. In particular, PET, polymethyl methacrylate resin (PMMA) and polycarbonate resin are preferably used because they are highly transparent and inexpensive. In addition, moderately acetic esterified cellulose acetate, cyclopolyolefin resin, polyolefin resin, or fluorinated resin is used from the viewpoint of strong resistance to solvents such as acetonitrile, which is often used as a solvent for wet solar cells. It is preferable. Furthermore, polyether sulfone, polyethylene naphthalate, polyether ketone, polyether ether ketone, and polyimide resin are preferable resins to be used from the viewpoint of excellent heat resistance.

  The kind of glass that can be used in the present invention is not particularly limited, and examples thereof include quartz glass, borosilicate glass, and soda glass, which are readily available on the market.

  The thickness of the glass is not particularly limited as long as it can be used as a casing of a solar cell, or at least as a support for a transparent conductive thin film layer. For example, it can be appropriately selected and used within a range of 200 μm to 10 mm.

  The shape of the transparent substrate (A) may be flat or curved, but it is easy to handle in the process of a flat plate or a flexible sheet or film. The batch-type manufacturing process is preferably a flat plate, and the roll-to-roll manufacturing method is preferably a sheet or film.

  These thicknesses are not particularly limited, and can be selected by those skilled in the art with appropriate consideration of usage and processing steps. As a preferable range, for example, in the case of a flat material that can be suitably used for a batch process, the thickness is 200 μm to 10 mm. In the case of a sheet-like or film-like material suitable for a roll-to-roll process, the thickness is, for example, 10 μm to 500 μm, preferably 25 μm to 250 μm, and more preferably 50 μm to 200 μm.

  These polymer sheets (A1) are etched on the surface in advance by sputtering treatment, glow discharge treatment, corona discharge treatment or plasma or ion treatment using a plasma gun, flame treatment, ultraviolet irradiation, electron beam irradiation, or the like. You may perform a process, an undercoat process, etc. By performing the above-mentioned treatment, it may be possible to improve the adhesion of the transparent conductive thin film layer (B) and the conductive mesh layer (C) described later to the polymer sheet (A1). Moreover, before forming a transparent conductive thin film layer (B) and a conductive mesh layer (C), you may perform dust-proof processing, such as solvent cleaning and ultrasonic cleaning, as needed.

  The transparent substrate (A) in the present invention may be a transparent substrate (A2) having a gas barrier layer (D) described later.

(Transparent conductive thin film layer (B))
The transparent conductive thin film layer (B) in the present invention is not particularly limited as long as it is a transparent material having excellent conductivity.

  Desirable light transmittance is 80% or more, preferably 85% or more, more preferably 90% or more, and still more preferably 95% or more.

  The sheet resistance of the transparent conductive thin film layer (B) alone is preferably not more than a certain value. This is because the role of the transparent conductive thin film layer (B) is generated by the photosensitizing dye, and the electrons collected on the semiconductor electrode such as titanium oxide are made conductive through the transparent conductive thin film layer (B). This is because the electrical resistance of the transparent conductive thin film layer (B) can be reduced and the loss of electrical energy due to the resistance can be prevented because it leads to the mesh layer (C) and the highly conductive wiring. When the conductivity of the transparent conductive thin film layer (B) is low, the electric energy is lost before reaching the wiring, and it is difficult to improve the conversion efficiency of the solar cell.

  Desirable sheet resistance is 500Ω / □ or less, preferably 300Ω / □ or less, more preferably 100Ω / □ or less, and still more preferably 50Ω / □ or less.

Desirable electric conductivity is 10 Scm ⁻¹ or more (10 ⁻¹ Ωcm or less), preferably 10 ² Scm ⁻¹ (10 ⁻² Ωcm or less), more preferably 10 ³ Scm or more (10 ⁻³ Ωcm or less), and further preferably. Is 10 ⁴ Scm or more (10 ⁻⁴ Ωcm or less). Further, a desirable film thickness for improving the transmittance is 100 nm or less, preferably 50 nm or less, and more preferably 30 nm or less.

  Such materials include ceramics such as transparent conductive oxides. For example, zinc oxide, tin oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), other composite oxides, or the like can be used. Furthermore, you may add the trace element for improving electrical conductivity to these. For example, by adding aluminum oxide, silicon oxide, fluorine, or gallium to zinc oxide, adding antimony oxide or fluorine to tin oxide, or adding cerium oxide to indium oxide, etc. It will be readily understood by those skilled in the art that the conductivity is improved. These addition amounts are usually about 1% by mass to 20% by mass.

These transparent conductive ceramics can easily form a thin film of 10 ³ Scm or more (10 ⁻³ Ωcm or less) or 10 ⁴ Scm or more (10 ⁻⁴ Ωcm or less), and has a sheet resistance of 500Ω / □ and a transmittance of 80 % Or more of the thin film can be obtained.

  In the present invention, these transparent conductive thin film layers (B) are desirably formed and used on a transparent substrate (A) such as glass or a polymer sheet (A1). As a method for forming the transparent conductive thin film (B), a sol-gel method or the like, a paste of a substance that is a precursor of these transparent conductive thin film layers (B), for example, a metal chloride or a solution thereof, a metal hydroxide And wet methods such as applying slurry of metal oxide fine particles, etc. and heat-treating (baking) at a temperature of several hundred degrees, CVD (Chemical Vapor Deposition), PECVD (Plasma Enhanced Chemical) Vapor Deposition (Plasma Enhanced Chemical Vapor Deposition) or film formation by dry methods such as sputtering, vapor deposition, ion plating, ion cluster beam, etc. PVD (Physical Vapor Deposition) Is possible. Among these, the PVD method can form these conductive thin films at a relatively low temperature. For example, when the polymer sheet (A) having many unstable materials at 200 ° C. or higher is used as a substrate, it is preferably used. This is a film forming technique that can be used. In particular, when zinc oxide, ITO, or the like is used, a transparent conductive thin film (B) having a relatively high conductivity can be formed at a low temperature, particularly by sputtering.

  The sputtering method is not particularly limited, and direct current (DC) sputtering method, RF sputtering method that is AC sputtering, direct current (DC) magnetron sputtering method, RF magnetron sputtering method that is AC sputtering, and other AC magnetrons. A sputtering method, an ECR sputtering method, a dual magnetron sputtering method, or the like can be appropriately selected. The DC magnetron sputtering method and the RF magnetron sputtering method are preferable because they can provide a sufficient film forming speed and controllability of the film quality. In particular, the DC magnetron sputtering method is particularly preferable because the apparatus configuration is simple. .

    As a target in the sputtering method, a target using a metal or an alloy, or a ceramic target having the same composition as the conductive ceramic to be formed can be used.

  For example, when an ITO film is formed, an indium / tin alloy or indium oxide / tin oxide, preferably an indium oxide / tin oxide sintered body can be used as a target.

  ITO can be obtained by adding tin oxide to indium oxide. Since tin acts as a dopant, the addition of tin facilitates the generation of electrons as carriers in the ITO, lowering the specific resistance and improving the conductivity. However, if the amount of tin added is too large, the specific resistance will increase, but excessive addition of tin is not preferable. When the addition amount of tin is expressed as the content of tin oxide in ITO, the specific resistance is usually a minimum value in the range of 5% by mass to 10% by mass. In addition, the addition of tin improves the durability of the ITO film both mechanically and chemically, but reduces the light transmittance. From the above conditions, the content of tin oxide in ITO is preferably 1 to 50% by mass, more preferably 3 to 30% by mass, and more preferably 3 to 30% by mass, in terms of the mass ratio of tin oxide to the total mass of ITO. Preferably it is 5-25 mass%. Even in the case of using an alloy target of indium-tin, the preferable range of the amount of tin added is 1 to 50% by mass, more preferably 3 to 30% by mass, when expressed in terms of the mass ratio of tin in the alloy. More preferably, it is 5-25 mass%. If it is this range, it can select suitably considering a desired characteristic and can be used as a target for sputtering.

  In addition, when forming a zinc oxide film, it is possible to use metallic zinc. However, since the metal is a metal having a relatively low melting point of 420 ° C., a zinc oxide or zinc oxide sintered body target is used. It is preferable to use it.

  The zinc oxide preferably contains a metal oxide serving as a dopant such as aluminum oxide. By containing aluminum oxide, electrons serving as carriers are easily generated in zinc oxide, the resistivity is lowered, and the conductivity is improved. However, when the amount of aluminum added is too large, the resistivity increases, and therefore excessive addition of aluminum oxide is not preferable. Therefore, the preferable addition amount of aluminum oxide is represented by the ratio of aluminum oxide to the total amount of zinc oxide and aluminum oxide, preferably 1 to 10% by mass, more preferably 1 to 5% by mass, and still more preferably, It is 1-3 mass%.

  Also, other transparent conductive ceramics can be formed by sputtering.

  Further, the purity of the material used for the sputtering target is 99% or more, preferably 99.9% or more, and more preferably 99.99% or more. It is easily understood by those skilled in the art to select a material by appropriately considering the above.

  The ratio of the metal element of the transparent conductive thin film (B) produced using these targets is substantially the same as the composition of the target. In addition, the quantitative determination of the composition of the transparent conductive thin film layer can be verified by a technique such as EPMA (EDX), ESCA (XPS), Auger electron spectroscopy, SIMS, or XRF.

  As the sputtering gas, an inert gas such as argon or neon can be used. In addition, it is preferable to add an appropriate amount of a reactive gas such as hydrogen or oxygen because the conductivity, transparency, chemical durability, and physical durability of the zinc oxide or ITO film to be formed may be improved. . The addition amount can be appropriately selected according to the purpose, but is usually 50 atom% or less, preferably 25 atom% or less.

  The pressure during sputtering is 13.3 mPa to 2660 mPa, preferably 13.3 mPa to 1330 mPa, and more preferably 26.6 mPa to 266 mPa.

  For measurement and control of the flow rate of the sputtering gas or reactive gas, a mass flow controller, a float type flow meter, a bubble meter, or the like can be used. For pressure measurement, a Pirani vacuum gauge, a diaphragm vacuum gauge, a spinning rotor vacuum gauge, a heat conduction vacuum gauge, an ionization vacuum gauge, or the like can be used, but a diaphragm vacuum gauge is preferably used.

The power range at the time of sputtering is 1 kWm ^{−2 to} 1000 kWm ⁻² , preferably 10 kWm ^{−2 to} 1000 kWm ⁻² , more preferably 50 kWm ^{−2 to} 500 kWm ⁻² .

  In addition, it is preferable to heat-treat when forming these transparent conductive thin film layers (B), since the electrical conductivity of the conductive thin film may be improved. The effect of improving the conductivity by heating appears as the temperature rises at a temperature equal to or higher than normal temperature, and can be applied even when the polymer sheet (A1) having a relatively low heat resistance is used. In particular, heating at a temperature of 150 ° C. or higher promotes crystallization of ITO and zinc oxide and improves electrical conductivity and light transmittance in the visible light region. Therefore, when a heat-resistant substrate such as glass is used. Is preferred. Moreover, the same effect is often obtained by heat-treating the transparent conductive thin film after film formation.

  As a method of controlling the film thickness, the transmittance due to optical interference is determined from the use of a film thickness meter using a crystal resonator (quartz crystal method), or from the wavelength dispersion of the transmittance by the transparent conductive thin film layer (B). Examples include a method of controlling the conditions such as the power at the time of sputtering, the film forming time, and the film feed speed directly during film formation, such as a method (repetitive interferometer) for obtaining from the maximum value and minimum value periods. In addition, there may be mentioned a method in which the film forming speed under specific conditions is obtained in advance and the film forming time is managed or the film feeding speed is adjusted.

  As a method for obtaining the film thickness in advance, in addition to the method for obtaining the film thickness by the optical interference described above, a film is formed by previously providing a non-film forming portion with a masking tape or the like on a test substrate such as a slide glass, For example, a method of directly measuring the level difference between the non-film-formation part and the film-formation part by a stylus-type level difference meter (Dektak II, manufactured by Slaron, USA, Surfcoater SE3500, manufactured by Kosaka Laboratories, etc.) can be used.

  When the transparent substrate is a heat-resistant substrate such as glass, and fluorine-doped tin oxide is formed as the transparent conductive thin film layer, the CVD method, particularly atmospheric pressure thermal CVD method, can improve the deposition rate. In addition, a tin oxide thin film having good crystallinity and excellent conductivity is obtained, which is a suitable technique.

For example, by using tin chloride (SnCl ₄ ), HF, H ₂ O, oxygen, or the like as a source gas, the substrate temperature is 300 ° C. to 600 ° C., preferably 350 ° C. to 550 ° C., more preferably 400 ° C. to 550 ° C. Film formation is possible by setting it to ℃, more preferably from 500 ℃ to 550 ℃.

(Conductive mesh layer (C))
The material for forming the conductive mesh layer (C) in the present invention is not particularly limited as long as it has high conductivity. Although the electrical conductivity of the said conductive substance should just be higher than at least a transparent conductive thin film layer (B), the value is so preferable that it is high. The electrical conductivity at normal temperature is preferably 10 ³ Scm ⁻¹ or more (10 ⁻³ Ωcm or less), more preferably 10 ⁴ Scm ⁻¹ or more (10 ⁻⁴ Ωcm or less), and even more preferably 10 ⁵ Scm ⁻¹ ( 10 ⁻⁵ Ωcm or less). Examples of such substances include metals and alloys. For example, simple metals such as gold, silver, copper, aluminum, titanium, chromium, iron, cobalt, nickel, copper, zinc, tin, indium, tungsten, molybdenum, platinum, iridium, hafnium, niobium, tantalum, tungsten, magnesium Alternatively, an alloy mainly composed of at least one metal selected from these groups is excellent in conductivity and can be preferably used. Examples of the alloy include stainless steel, nichrome, inconel, bronze, phosphor bronze, brass, duralumin, white bronze, invar, and monel. In addition, a metal phosphorus compound such as a nickel phosphorus alloy, a metal boron compound such as nickel boron, and a nitride such as titanium nitride can be appropriately selected. In particular, copper and copper-based alloys, nickel and nickel-based alloys, cobalt and cobalt-based alloys, chromium and chromium-based metals, aluminum and aluminum-based alloys It is preferably used because of its excellent conductivity and good workability. These wirings may be a single layer of metal or alloy, or may be a multilayer structure made of at least two kinds of metals or alloys.

  In order to improve the adhesion between the conductive mesh layer (C) and the transparent substrate (A) in the present invention, an easy adhesion layer is formed between the conductive mesh layer (C) and the transparent substrate (A). Is preferred.

Examples of materials that can be used for such purposes include indium, tin, titanium, chromium, cobalt, zinc, molybdenum, hafnium, tungsten, niobium, tantalum, zirconium, magnesium, and the like. Moreover, you may use 1 or more alloys which consist of these groups, or these oxides. For example, examples of alloys are nichrome, inconel, monel and the like. Examples of oxides include zinc oxide, ITO, tin oxide, indium oxide, chromium oxide, zinc chromate (ZnCr ₂ O ₄ ), titanium oxide, molybdenum oxide and the like.

In the case where the conductive mesh layer (C) is affixed to the transparent substrate, it is preferable to form the easy adhesion layer on the conductive material side to be the wiring. When the conductive mesh layer is formed by plating, CVD, PECVD, PVD, or a combination thereof, it is preferable to form the easy adhesion layer on the transparent substrate.
The thickness of the easy adhesion layer is usually 0.1 nm to 10 μm, preferably 1 nm to 1 μm. When the thickness is small, these may not have a film shape but may have an island structure, but the effect is not impaired.

  In addition, it is preferable that the second conductive material is formed on the surface of the conductive material for the purpose of preventing corrosion or oxidation of the conductive material. Examples of the conductive material that can be used for such purposes include metals that can be used for the easy-adhesion layer, and also serves as a second conductive material layer that can prevent corrosion and oxidation. I can do it.

  The conductive mesh layer (C) in the present invention may be all linear or mesh-like. Further, it may be curved or irregular. However, in order to suppress a decrease in electrical conductivity when the wiring is disconnected during processing or use of a wet solar cell, it is preferable that the electrical conductivity is less directional. Is preferably mesh-like. In addition, the shape of the mesh is not particularly limited, and the shape of the opening of the mesh may be a circle, an ellipse, or any other irregular shape. A combination of various sizes may be used.

  Hereinafter, for the sake of simplicity of description, unless otherwise specified, the wiring made of a conductive material is assumed to be formed in a square mesh shape, and the length of one side of the square mesh is defined as a repeating unit, a pitch, Express as

  Since the transparent conductive sheet according to the present invention is used as a light incident side electrode of a solar cell, in order to increase the amount of incident light as much as possible, the light is blocked by the conductive mesh layer (C) and the area is smaller. preferable. That is, the area of the transparent conductive sheet used as the light incident portion of the solar cell is defined as the effective area of the solar cell, and the ratio of the area not covered with the conductive mesh layer (C) is defined as the aperture ratio. The rate is 80% or more, preferably 85% or more, more preferably 90% or more, and still more preferably 95% or more. The wiring width and the wiring thickness are not particularly limited, and are determined by the wiring material to be used, the desired opening ratio of the wiring, the wiring pitch, and the desired surface resistance value, and are not particularly limited.

  Easiness of winding in roll-to-roll process, easy processing when forming wiring by subtractive method (etching method) described later, or forming wiring made of conductive thin film by additive method (pattern plating method) In consideration of the property, the thickness of the wiring is 100 μm or less, preferably 50 μm or less, more preferably 30 μm or less, and still more preferably 20 μm or less.

  Moreover, the lower the surface resistance value of the wiring by the conductive thin film, the more preferable, specifically 10Ω / □ or less, preferably 5Ω / □ or less, more preferably 1Ω / □ or less, and even more preferably 0.5Ω / □ or less. It is.

  If the pitch of the conductive mesh layer (C) is too large, the distance through which electrons flow in the transparent conductive thin film layer (B) having a lower conductivity than that of the conductive material is increased, resulting in a large loss of electrical energy. Sometimes. Also, if the wiring pitch is made too small, the width of the wiring processing has a lower limit that can be processed (usually about 5 to 10 μm), so the wiring cannot be made sufficiently thin and the aperture ratio cannot be increased, The amount of incident light may decrease, and the current that can be extracted by the solar cell may decrease.

  Therefore, the upper limit of the wiring pitch of the conductive mesh layer (C) of the present invention is 5 mm, preferably 1 mm, more preferably 500 μm, and the lower limit of the wiring pitch is 50 μm, preferably 100 μm, more preferably 200 μm, still more preferably. Is 300 μm or more.

  The formation method of a conductive mesh layer (C) is not specifically limited, A well-known method can be selected suitably and can be used. For example, after the conductive mesh layer (C) is prepared in advance, it can be pasted on the transparent substrate (A) or the transparent conductive thin film layer (B) using an adhesive or conductive paste, or a method such as thermocompression bonding. The transparent substrate (A) or the transparent conductive thin film layer (B) can be directly attached to the transparent substrate (A) or by a dry process such as CVD or PVD, or by a plating method that is a wet process. After the conductive material is formed on the thin film layer, the conductive material may be processed into a mesh shape by a dry or wet etching process. Alternatively, after the conductive material sheet is attached to the transparent substrate (A) with an adhesive or an adhesive, the conductive material may be processed into a mesh by a dry or wet etching process. Furthermore, the conductive mesh layer (C) is directly applied to the transparent substrate (A) or the transparent conductive thin film layer (by a dry process such as a CVD method or a PVD method or a plating method using a pattern resist or a pattern mask. B) It may be formed on top. Further, the conductive mesh layer (C) may be formed by appropriately combining these methods.

  As an example of the method for forming the conductive mesh layer (C) in the present invention, a method for obtaining the conductive mesh layer (C) by etching the metal foil will be described in more detail.

  A method in which a metal foil is attached to the transparent substrate (A), a circuit pattern is formed on the metal foil with a photosensitive resist, and the resist is then peeled off after etching with an etching solution, that is, printed wiring board processing. The metal wiring which is a conductive mesh layer (C) can be formed on a transparent base | substrate (A) by the method similar to the subtracting method. When a conductive material wiring or a metal foil as a material of the wiring is directly attached to the transparent substrate, an adhesive layer made of resin or the like may be inserted between the transparent substrate and the wiring or material. The preference is readily understood by those skilled in the art. Further, in the case where the transparent substrate is a thermoplastic resin, or in the case of a so-called B-stage resin having an ineffective component, it is possible to perform thermocompression bonding with a metal foil. Further, if the viscosity of the B-stage resin is low, it can be adhered by heating after applying it to the metal foil. As the metal foil material, copper, aluminum, nickel, titanium, stainless steel and the like are commercially available, and those having a thickness of 5 μm to 100 μm are readily available and available. Furthermore, it is also possible to obtain a metal film having a desired film thickness by rolling a commercially available metal foil.

  In addition, a method of directly forming a conductive mesh layer on the main surface of the transparent substrate (A) can be exemplified. In this case, a known plating method, a pattern plating method such as a semi-additive method or an additive method can be used.

  In the present invention, it is also possible to form a conductive mesh layer on the transparent conductive thin film layer (B) after the transparent conductive thin film layer (B) is previously formed on the entire surface of the transparent substrate. Further, when the transparent conductive thin film layer (B) is formed in advance on the entire surface of the transparent substrate, the conductive material is applied on the conductive thin film by a wet method such as electrolytic plating or electroless plating, or a dry method such as sputtering. Needless to say, after the formation, the conductive mesh layer can be processed by a subtracting method or the like.

  In the present invention, if the transparent conductive thin film layer (B) and the conductive mesh layer (C) ensure good electrical connection at the contact points between them, the production order, configuration, and production method are particularly problematic. is not. As a method for ensuring electrical connection, the transparent conductive thin film layer (B) and the conductive mesh layer (C) are preferably in contact with each other. Even if the transparent conductive thin film layer (B) and the conductive mesh layer (C) are not in direct contact, that is, installed in an insulating state, they are electrically connected by, for example, an electrolytic solution, a polymer electrolyte, a gel electrolyte, or the like. If it is, it can be suitably used. When used as a dye-sensitized solar cell, a structure in which electrical connection is ensured by a porous semiconductor film supporting a dye or a semiconductor film containing a dye can also be used.

(Gas barrier film (D))
When glass is used as the transparent substrate (A), it is not particularly necessary because the glass itself has a gas barrier property. However, when the polymer sheet (A1) is used as the transparent substrate (A), a transparent substrate ( It is preferable to provide a transparent substrate (A2) by providing a gas barrier film (D) on one main surface of A) or on both main surfaces. This is generally because the gas barrier property of the polymer sheet tends to be lower than that of glass.

The gas barrier property preferably has the following characteristics.
The water vapor transmission rate is 1 g / m ² day or less, preferably 0.1 g / m ² day or less, more preferably 10 ⁻² g / m ² day or less, and still more preferably 10 ⁻³ g / day. m2day or less.

The oxygen permeability ^is not more than 1cm ^{3 /} m 2 day, ^preferably, 0.1cm ^{3 /} m 2 day or less, more ^{preferably, 10 -2 cm 3 / m 2} day or less, more preferably 10 ^{- 3} cm ³ / m ² day or less.

  The lower the gas and oxygen and water vapor (water) transmittance, the more reliable the solar cell, that is, the photoelectric energy, such as degradation of the photosensitizing dye due to oxygen and water vapor (water) during solar cell operation. This is preferable because it has an effect of preventing a decrease in conversion efficiency.

  A material preferable for use as the gas barrier film is not particularly limited, and a transparent material having a known gas barrier property can be used, which may be an inorganic substance or an organic substance. For example, as an inorganic compound, the material etc. which form the above-mentioned transparent conductive thin film layer (B) are mentioned. Specifically, titanium oxide, tantalum oxide, iridium oxide, tin oxide, indium oxide, zirconium oxide, niobium oxide, ITO, zinc oxide, magnesium oxide, aluminum oxide, titanium oxide, silicon oxide and other metal oxides, oxynitriding Examples thereof include metal oxynitrides such as silicon and metal nitrides such as silicon nitride. Among these, silicon compounds such as silicon oxide, silicon oxynitride, and silicon nitride are particularly preferable materials for use because they have excellent transparency and gas barrier properties.

  As a method for forming the gas barrier layer (D) using the inorganic compound, a known method similar to the method for forming the transparent conductive thin film layer (B) such as a wet method, a dry method such as a PVD method, a PECVD method, or a CVD method is used. Can be adopted. The effects of the easy adhesion layer, the formation method, and the analysis method of the composition and thickness of the gas barrier layer (D) are all the same as described in the transparent conductive thin film layer (B).

The gas barrier film may be used as a single layer or may be used as a multilayer. Multi-layer stacking is more preferable because it has an effect of alternately closing pinholes that may be generated in each gas barrier film layer, and gas barrier properties are improved. In the case of stacking multiple layers, a single gas barrier film or different types of gas barrier films may be stacked. However, it is better to stack an inorganic gas barrier film and an organic barrier film. This is effective because the film prevents pinholes and cracks from expanding. In the present invention, the gas barrier layer (D) may be formed not only on the transparent substrate (A) but also on the conductive mesh layer (C). However, in order to facilitate the connection of the transparent conductive thin film layer (B) and the conductive mesh layer (C) and to ensure electrical conductivity with the electrolyte solution or solid electrolyte in contact with the transparent conductive sheet, the above In the case of the configuration, the gas barrier layer (D) preferably has conductivity. Specifically, it is preferably in the range of 10 ⁻⁵ to 10 ⁶ Ω / □, preferably 10 ⁻⁵ to 10 ³ Ω / □.

(Transparent conductive portion (I) having a transparent substrate (A), a transparent conductive thin film layer (B), and a conductive mesh layer (C))
The transparent conductive sheet of the present invention has a transparent conductive portion (I) having a transparent substrate (A), a transparent conductive thin film layer (B), and a conductive mesh layer (C). In the transparent conductive portion (I), the transparent conductive thin film layer (B) and the conductive mesh layer (C) need to be in contact with each other. It is particularly important that they are electrically connected. In particular, it is important that it can be electrically energized.

As long as the above conditions are satisfied, there is no particular limitation on the stacking order of the transparent substrate (A), the transparent conductive thin film layer (B), and the conductive mesh layer (C). The configuration may be A / B / C or A / C / B. Further, other layers may be provided in the AB layer, the AC layer, and the outermost layer within the scope of the object of the present invention. Specifically, in addition to the above-described easy adhesion layer, pressure-sensitive adhesive layer, and adhesive layer, a known antireflection layer can be used.

  The antireflection layer is preferably formed on one main surface or both main surfaces of the transparent substrate. The antireflection layer may improve photoelectric conversion efficiency by improving the light transmittance of the transparent conductive sheet according to the present invention and increasing the current value of the solar cell.

  The material used for the antireflection layer is not particularly limited and may be organic or inorganic, but is preferably a material having a refractive index lower than that of the transparent substrate. The antireflection layer may have a multilayer structure, but in this case, it is preferable to arrange the layer so that the layer closer to the light incident side has a lower refractive index. Moreover, you may have the laminated structure of low refractive index material and high refractive index material like low refractive index material / high refractive index material / low refractive index material.

  Since the transparent conductive part (I) of the present invention has a conductive mesh layer (C) and a transparent conductive thin film layer (B), it is excellent in transparency and conductivity and has chemical stability. Also, physical stability is excellent. In particular, even when the conductive mesh layer (C) is exposed, it is surprisingly excellent in chemical stability and physical stability.

  Since the transparent conductive sheet of the present invention has gas barrier properties, it is possible to protect the dye from gases that may cause deterioration of the dye, such as water and oxygen. Therefore, it has very excellent durability.

(Method for producing transparent conductive sheet of the present invention)
The transparent conductive sheet in the present invention has a portion (II) composed of the transparent conductive portion (I) and the transparent substrate (A). The transparent conductive sheet of the present invention is preferably arranged so as to have a sea-island configuration in which the portion (I) is an island and the portion (II) is the sea. That is, it is preferable that the part (II) is disposed at the peripheral portion of the part (I) and a plurality of insulated transparent conductive parts (I) are formed in the transparent conductive sheet.

As the method of providing the part (II), after forming the transparent conductive thin film layer (B) and the conductive mesh layer (C) on the transparent substrate (A), it is transparent by etching using a pattern resist or the like. Although the method of removing the conductive thin film layer (B) and the conductive mesh layer (C) at a time is efficient, the etching rate of the transparent conductive thin film layer (B) and the conductive mesh layer (C) is usually high. As described above, various problems occur due to differences.
In the method for producing a transparent conductive sheet according to the present invention, first, a step of forming either the transparent conductive thin film layer (B) or the conductive mesh layer (C) by the above-described method, and the other layer as a pattern resist or the like. The conductive part (III) comprising the transparent substrate (A) and the transparent conductive thin film layer (B) or the conductive mesh layer (C) and the transparent conductive part (I ). A publicly known method can be applied to the method of partially forming the transparent conductive thin film layer (B) or the conductive mesh layer (C). Examples thereof include a transfer method, an additive method, a subtractive method, and a printing method. As a specific example, when the conductive mesh layer (C) is formed by a transfer method, a gap is formed between the wiring patterns made of a conductive material for each transfer, or the wiring pattern to be transferred is previously transferred. It can be easily realized by providing a non-wiring portion made of a conductive material, that is, by forming a cell pattern in advance.

  Even when the conductive mesh layer (C) is formed by an additive method or a subtractive method, it can be easily realized. In the case where the conductive mesh layer (C) is provided by the subtractive method, a portion where no etching resist is formed around the mesh pattern may be provided in advance. In the case where the resist is scanned with focused spot-like light such as laser light to directly expose and form the wiring pattern, it is possible to provide an etching resist non-formation portion in the same manner.

  In addition to the subtractive method, plating resist is used in the additive method, so the part where the conductive mesh layer (C) does not exist is formed in the resist formation part, so the resist formation method similar to the subtractive method is used. On the other hand, a frame-like strip-shaped resist forming portion may be provided around the cell pattern. In addition, when a conductive paste or the like is formed by a printing method, providing a non-formation portion of a conductive substance means forming a non-printing portion of the conductive paste in a frame shape in advance on a printing plate. It can be easily realized.

Providing a non-formed part in the transparent conductive thin film (B) means that the non-formed part of the transparent conductive thin film (B) is formed in a chemical vapor deposition method or a physical vapor deposition method, which is a method for forming the thin film. By using a mask made of metal or the like on which a pattern has been drawn, or by previously forming a resist on a transparent substrate, forming a transparent conductive thin film (B), and then developing and removing it. Is possible.
By the above method, it consists of a conductive part (III) composed of a transparent substrate (A) and a transparent conductive thin film layer (B) or a conductive mesh layer (C), and a transparent conductive part (I). After producing the sheet, it is a preferred method for producing the transparent conductive sheet of the present invention to obtain the sheet of the present invention by removing the conductive part (III) by etching. The etching is generally performed using a pattern resist.

As described above, the transparent conductive sheet of the present invention has a structure in which the transparent conductive portion (I) forms an island shape such as a cell shape, and the portion (II) made of the transparent substrate (A) becomes the sea. It is preferable to have. The width of the part (II) and the size of the transparent conductive part (I) are not particularly limited, and may be processed so as to obtain a desired current value and voltage value. However, if the width of the part (II) is too wide, the area that can be effectively used for power generation of the solar cell is reduced. Therefore, it is preferably 5 mm or less, more preferably 1 mm or less, and even more preferably 500 μm or less. It is. Furthermore, when too large an area of the transparent conductive sites (I), the output of the solar cell is reduced by the resistance of the transparent conductive sheet, preferably 1000 cm ² or less, more preferably 500 cm ² or less, more preferably 100 cm ² or less It is.

  For the etching of the transparent conductive thin film (B) and the conductive mesh layer (C), a liquid or dry film-like etching resist or etching solution can be used and can be easily obtained in the market. It is. Hydrochloric acid ferric chloride solution, cupric chloride solution, ammonium sulfate-hydrogen peroxide mixture solution, ammonia, etc. can etch metal materials that are suitably used as conductive substances. Etching of transparent conductive ceramics such as zinc oxide that can be suitably used as a transparent conductive thin film is also possible. In addition, an etching solution for transparent conductive ceramics that can be suitably used as a transparent conductive thin film, such as ITO, tin oxide, and zinc oxide, is readily available in the market.

  The photosensitized solar cell of the present invention uses the transparent conductive sheet as an electrode. Therefore, sunlight can be guided to the photosensitizing dye with high efficiency, and the resulting current can be efficiently extracted. In addition, since the electrode and the photosensitizing dye are little deteriorated with time, they have high durability as a solar cell. Further, by controlling the shape of the conductive portion (I), the current can be taken out efficiently, and the voltage can also be controlled.

Hereinafter, the present invention will be described in detail by way of examples and comparative examples. In addition, this invention is not limited at all by a present Example and a comparative example.
Example 1
After applying a photocurable resin adhesive to a thickness of 2 μm on a PET film (thickness of 188 μm), a 9 μm thick copper foil was applied. Next, the mesh pattern was exposed and developed on the surface of the copper foil by a known method to form an etching resist. Further, an etching process was performed with a ferric chloride-based etchant to remove the pattern resist, and a conductive mesh layer having a width of 10 μm, a thickness of 9 μm, and a wiring pitch of 300 μm was formed on the PET film. At this time, an etching resist having a width of 500 μm was formed in a frame shape of 5 cm □ to provide a portion where the conductive mesh layer was not formed.

Next, an ITO sintered body (composition ratio In ₂ O ₃ : SnO ₂ = 95: 5 mass%) is used as the sputtering target, and an argon / oxygen mixed gas (total pressure 270 mPa: oxygen partial pressure 8 mPa) is used as the sputtering gas. A 26 nm thick ITO film was formed by DC magnetron sputtering, and the copper wiring and the exposed resin surface were covered with the ITO film.

In the transparent conductive sheet produced in this way, there is a portion where only a frame-like ITO film having a width of 500 μm and a 5 cm □ exists, and further, a photosensitive region is formed in a portion where only the ITO film is formed. After forming an opening of the frame-like etching resist with a width of 100 μm and a width of 100 μm using the etching resist (the portion where the resist is not formed), the ITO film is etched with a ferric chloride solution, and the copper wiring A 5 cm square cell pattern on which the pattern and the ITO film were formed was formed.
The average line width of the etched ITO film was 100 μm, and the unevenness of the wiring width was within 10 μm, so that it could be etched into a straight line uniformly. In addition, when the electrical resistance of a transparent conductor made of a copper wiring pattern and an ITO film with a 5 cm square cell pattern and the copper wiring and ITO film around the cell pattern was measured with a tester, a value of 1 MΩ or more was obtained. It showed good insulation.

Example 2
A PET film (188 μm), an ITO sintered body (composition ratio In ₂ O ₃ : SnO ₂ = 95: 5% by mass) as a sputtering target, and an argon / oxygen mixed gas (total pressure 270 mPa: oxygen partial pressure 8 mPa) as a sputtering gas An ITO film having a thickness of 26 nm was formed by a DC magnetron sputtering method. At this time, a stainless steel mask on which a pattern of 200 μm width and 5 cm □ was formed was attached to the surface of the PET film so that a 5 cm □ cell pattern could be formed, and an ITO film was formed. A non-formed portion of the frame-like ITO film was provided. Further, a copper thin film having a thickness of 280 nm was formed on the PET film and the ITO film by a DC magnetron sputtering method using copper as a target and argon (pressure 270 mPa) as a sputtering gas. Note that the mask used during the ITO film formation was not used during copper sputtering.

  Next, a photosensitive resist was applied to the surface of the copper thin film, and the wiring pattern was exposed and developed to form a plating resist. Furthermore, using ITO and a copper sputtered film as the power feeding layer, a copper wiring pattern is formed by an electrolytic plating method using a copper sulfate-based copper plating solution, the plating resist is peeled off, and the sheet is further subjected to sulfuric acid-peroxidation. By dipping in an etching solution made of hydrogen water for a short time, the sputtered copper thin film remaining between the copper wirings was removed, and the ITO was exposed. In this manner, copper wiring having a wiring width of 10 μm, a wiring thickness of 10 μm, and a wiring pitch of 300 μm was formed on the ITO film. At this time, the exposure pattern of the copper wiring was designed so that the plated copper was not formed on the 5 cm □ frame-shaped ITO film non-formed part.

    The average line width of the non-formed portion of the 5 cm □ ITO film exposed from under the sputtered copper film is 180 μm, and the unevenness of the wiring width is within 10 μm. The formation part could be produced. In addition, when the electrical resistance of a transparent conductor made of a copper wiring pattern and an ITO film with a 5 cm square cell pattern and the copper wiring and ITO film around the cell pattern was measured with a tester, a value of 1 MΩ or more was obtained. It showed good insulation.

Comparative Example 1
A copper wiring having a thickness of 9 μm, a wiring width of 10 μm, and a wiring pitch of 300 μm was formed on a PET film having a thickness of 188 μm by a subtractive method, and an ITO sintered body target (composition ratio In ₂ O ₃ : SnO ₂ = 95: A transparent conductive sheet composed of a PET film, a copper wiring, and an ITO film was formed by forming an ITO film to a thickness of 26 nm by a sputtering method using 5 mass%). Furthermore, in order to form a cell pattern of 5 cm □ using a photosensitive etching resist (dry film resist) on the conductive sheet, an etching resist provided with a 5 cm □ frame-like opening having a width of 100 μm is provided. Then, an etching process was performed using a ferric chloride etching solution so that an etching portion having a width of 100 μm could be formed at a portion where the copper wiring portion and the ITO thin film were formed. However, since the copper etching rate is high, the copper wiring portion is further etched by 100 μm or more from the etching end of the ITO film, and it is impossible to etch into a uniform linear shape.

Comparative Example 2
A copper wiring having a thickness of 9 μm, a wiring width of 10 μm, and a wiring pitch of 300 μm was formed on a PET film having a thickness of 188 μm by a subtractive method. At this time, the cell pattern had a 5 cm pitch and a size of 5 cm □ and a width of 500 μm. A frame-shaped copper foil was formed. Furthermore, an ITO film is formed to a thickness of 26 nm by sputtering using an ITO sintered body target (composition ratio In ₂ O ₃ : SnO ₂ = 95: 5% by mass), and the surface of the resin film and the surface of the copper wiring are made ITO. A transparent conductive sheet coated with was obtained. Using a photosensitive etching resist (dry film resist) at the center of the 500 μm wide copper / ITO laminated portion formed in the frame shape of the transparent conductive sheet, an etching resist having a width of 5 cm □ and a width of 100 μm is used. An opening was provided, and an attempt was made to form an etched portion having a width of 100 μm using a ferric chloride etchant. However, because the etching rates of copper and ITO differ, the etching of the copper foil begins from the location where the holes in the ITO film partially opened, and the copper below the ITO film is etched quickly (undercut), and is uniform However, the maximum wiring width unevenness reached 100 μm or more, and uniform linear etching treatment was impossible.

Comparative Example 3
An ITO film was formed on the entire surface of the PET without using a mask when forming the ITO film, and a copper frame having a width of 500 μm and 5 cm □ that became a cell pattern when forming a copper wiring pattern by the additive method A transparent conductive sheet was produced in the same manner as in Example 2 except that the forming portion was provided. A laminated structure of ITO / copper was formed in the frame-shaped copper forming portion. At this location, a photosensitive etching resist (dry film resist) is used to provide an opening with a size of 5 cm □ and a width of 100 μm, and an attempt is made to form an etched portion with a width of 100 μm using a ferric chloride-based etchant. It was.
However, since the copper etching rate is high, the copper directly under the resist is etched, so that a portion where the ITO film comes into contact with the etching solution with a width wider than the opening width of the etching resist is generated, or The etching resist peeled off, and the unevenness of the maximum etching width reached 100 μm or more, and uniform linear etching was impossible.

Claims (6)

At least a transparent substrate (A), a transparent conductive thin film layer (B) having a thickness of 1 to 100 nm, and a conductive mesh layer (C)
A transparent conductive portion (I) having a configuration in which at least the transparent conductive thin film layer (B) and the conductive mesh layer (C) are electrically connected to each other and a portion (II) consisting of the transparent substrate (A) (II) A transparent conductive sheet comprising: The transparent conductive sheet according to claim 1, wherein the transparent conductive portion (I) has an island-like configuration. The transparent conductive sheet according to claim 1, wherein the transparent substrate (A) is a polymer sheet (A1). The transparent conductive sheet according to claim 1, wherein the transparent substrate (A) is a transparent substrate (A2) having a gas barrier film (D) on at least one principal surface. A conductive portion (III) comprising a transparent substrate (A) and a transparent conductive thin film layer (B) or a conductive mesh layer (C);
After producing a sheet comprising the transparent conductive portion (I),
The method for producing a transparent conductive sheet according to claim 1, wherein the portion (II) comprising the transparent substrate (A) is formed by etching the conductive portion (III). A photosensitized solar cell using the transparent conductive sheet according to claim 1.