JP5007518B2 - Manufacturing method of oxide semiconductor electrode - Google Patents

Description

  The present invention relates to a method for producing an oxide semiconductor electrode used for a dye-sensitized solar cell or the like.

  In recent years, environmental problems such as global warming have progressed globally. In recent years, photovoltaic power generation has attracted attention as a clean energy with a low environmental load, and research and development are being actively promoted. As such solar cells, single crystal silicon solar cells, polycrystalline silicon solar cells, amorphous silicon solar cells, compound semiconductor solar cells and the like have already been put into practical use. However, these solar cells have problems such as high manufacturing costs and high energy consumption in the manufacturing stage. Under such circumstances, the dye-sensitized solar cell is attracting attention as a novel solar cell with high possibility of cost reduction, and research and development are being conducted energetically.

  In general dye-sensitized solar cells, an electrode layer made of a metal oxide and a porous layer having metal oxide semiconductor fine particles adsorbed with a dye sensitizer on the surface are laminated in this order on a substrate. The oxide semiconductor electrode is used, and the electrolyte layer, the counter electrode layer, and the counter substrate are stacked in this order on the porous layer.

The oxide semiconductor electrode used in such a dye-sensitized solar cell or the like is such that the porous layer is made of a porous body. Therefore, as a manufacturing method thereof, conventionally, an electrode layer is sputtered on a substrate. A method of obtaining a porous layer that is a porous body by applying a material constituting the porous layer on the electrode layer and firing the material is then used.
However, since such a method requires heating to about 600 ° C. when firing, there is a problem that a substrate having a low heat resistance such as a resin film cannot be used.

  With respect to such a problem, in Patent Document 1, a porous layer is obtained by applying a material or the like constituting the porous layer on a substrate having high heat resistance, and firing the material. A method for obtaining a semiconductor electrode by transferring a porous layer to a resin film or the like having low heat resistance has been disclosed (hereinafter, such a method is referred to as a transfer method). Since such a transfer method has an advantage that an oxide semiconductor electrode using a substrate having low heat resistance can be obtained, a flexible oxide semiconductor electrode is manufactured using a resin film substrate. Is attracting attention as a possible method.

  However, when producing a dye-sensitized solar cell substrate using the transfer method disclosed in Patent Document 1, at least a coating film made of a material constituting the porous layer is formed on the heat-resistant substrate. Many steps such as a step of baking, a step of baking the film, a step of bonding the porous layer onto a substrate to be transferred, and a step of peeling off the heat-resistant substrate. However, there is a problem that the manufacturing cost increases.

JP 2002-184475 A

  The present invention has been made in view of the above problems, and a main object of the present invention is to provide a method for manufacturing an oxide semiconductor electrode that can manufacture an oxide semiconductor electrode with high productivity by a transfer method. .

  In order to solve the above problems, the present invention provides an adhesive layer made of a resin material, an electrode layer made of a metal oxide, and a porous layer containing metal oxide semiconductor fine particles on a long base material. A method of manufacturing an oxide semiconductor electrode having a configuration in which layers are stacked in order, by continuously applying a coating liquid for forming a porous layer containing metal oxide semiconductor fine particles on a long heat-resistant substrate A porous layer forming layer forming step for forming a porous layer forming layer on the heat-resistant substrate, and by continuously firing the porous layer forming layer, the porous layer forming layer is made porous. By continuously applying an electrode layer forming coating solution containing a metal compound on the porous layer in a state where the porous layer is heated in the firing step to be a porous layer made of a porous material, An electrode layer forming step of forming an electrode layer on the porous layer; and the electrode layer In addition, a bonding process in which the adhesive layer and the base material are continuously bonded on the electrode layer so that the adhesive layer made of a resin material and the base material are laminated in this order, and the heat resistance A method for manufacturing an oxide semiconductor electrode, comprising: a heat-resistant substrate peeling step for continuously peeling a substrate.

  According to the present invention, in the porous layer forming layer forming step, by using a long heat-resistant substrate, the porous layer forming layer forming step, the firing step, the electrode layer forming step, and the bonding are performed. Since all of the steps and the heat-resistant substrate peeling step can be a roll-to-roll process, an oxide semiconductor electrode can be manufactured with high productivity.

  In the present invention, the layer forming step for forming a porous layer includes metal oxide semiconductor fine particles on the long heat-resistant substrate, and has a composition different from that of the coating solution for forming a porous layer. By applying the porous layer forming coating solution on the intermediate layer forming layer formed on the heat-resistant substrate by the intermediate layer forming layer forming step of continuously applying the coating solution, A step of forming a porous layer forming layer on the intervening layer forming layer is preferable. Thereby, the peelability of the heat resistant substrate in the heat resistant substrate peeling step can be improved.

  Moreover, in this invention, it is preferable to have the dye sensitizer carrying | support process which carries a dye sensitizer in the said porous layer after the said heat-resistant board | substrate peeling process. By having such a dye sensitizer carrying step, the oxide semiconductor electrode produced according to the present invention can be used as a substrate for a dye-sensitized solar cell used in a dye-sensitized solar cell. Because it becomes.

  Moreover, in this invention, it is preferable that the said baking process and the said electrode layer formation process are continuous processes. Since the firing step and the electrode layer forming step are continuous steps, it is possible to use the residual heat of the porous layer fired by the firing step in the electrode layer forming step. This is because the heat treatment for heating the porous layer in the forming step is not necessary, and thus the oxide semiconductor electrode can be more easily manufactured.

  Moreover, in this invention, it is preferable that the said baking process, the said electrode layer formation process, the said bonding process, and the said heat-resistant board | substrate peeling process are continuous processes. After the firing step, a laminate in which a porous layer made of a porous body is formed on a heat resistant substrate is formed. Since such a porous layer has low adhesion to the heat resistant substrate, for example, When the laminate is wound into a roll, the porous layer may be peeled off from the heat-resistant substrate. However, there is no such problem as long as the firing step, the electrode layer forming step, the bonding step, and the heat-resistant substrate peeling step are continuous steps.

  Further, in the present invention, it is preferable that all of the porous layer forming layer forming step, the firing step, the electrode layer forming step, the bonding step, and the heat resistant substrate peeling step are continuous steps. This is because when the present invention is such a continuous process, an oxide semiconductor electrode can be manufactured with the highest productivity.

  Still further, when the porous layer forming layer forming step, the firing step, the electrode layer forming step, the bonding step, and the heat resistant substrate peeling step are all continuous steps, the heat resistant substrate is endless. A belt shape is preferred. This is because when the heat-resistant substrate has an endless belt shape, the heat-resistant substrate can be circulated and used, so that an oxide semiconductor electrode can be manufactured at a lower cost.

  The present invention has an effect that an oxide semiconductor electrode can be manufactured with high productivity by a transfer method.

  Hereinafter, the manufacturing method of the oxide semiconductor electrode of this invention is demonstrated in detail.

  The method for producing an oxide semiconductor electrode according to the present invention includes an adhesive layer made of a resin material, an electrode layer made of a metal oxide, and a porous layer containing metal oxide semiconductor fine particles on a long base material. An oxide semiconductor electrode having a structure laminated in this order is manufactured, and a porous layer forming coating solution containing metal oxide semiconductor fine particles is continuously applied onto a long heat-resistant substrate. A porous layer forming layer forming step for forming a porous layer forming layer on the heat-resistant substrate, and the porous layer forming layer is continuously fired to form the porous layer forming layer. A baking step of forming a porous layer made of a porous body, and continuously applying a coating solution for forming an electrode layer containing a metal compound on the porous layer while the porous layer is heated. An electrode layer forming step of forming an electrode layer on the porous layer, and A bonding step of continuously bonding the adhesive layer and the base material on the electrode layer so that the adhesive layer made of a resin material and the base material are laminated in this order on the electrode layer; A heat-resistant substrate peeling step for continuously peeling the heat-resistant substrate.

Such a method for producing an oxide semiconductor electrode of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view illustrating an example of the method for producing an oxide semiconductor electrode of the present invention. As illustrated in FIG. 1, the oxide semiconductor electrode manufacturing method of the present invention includes a porous layer forming layer forming step (FIG. 1A), a firing step (FIG. 1B), and an electrode layer. It has a forming step (FIG. 1C), a bonding step (FIG. 1D), and a heat-resistant substrate peeling step (FIG. 1E).
Here, in the layer forming step for forming the porous layer (FIG. 1A), the long heat-resistant substrate 1 wound up in a roll shape is unwound, and the metal oxide semiconductor fine particles are placed on the heat-resistant substrate 1. The porous layer forming layer 2 ′ is formed on the heat resistant substrate by continuously applying the porous layer forming coating solution, and then the porous layer forming layer 2 is formed on the heat resistant substrate 1. This is a step of winding the laminated body 11 on which “is laminated.
Moreover, the said baking process (FIG.1 (b)) unwinds the said laminated body 11, and heats and bakes the said porous layer formation layer 2 'continuously, The said layer for porous layer formation This is a step of winding the laminate 12 in which the porous layer 2 is laminated on the heat-resistant substrate 1 after 2 ′ is made the porous layer 2 made of a porous body.
In the electrode layer forming step (FIG. 1 (c)), after unwinding the laminate 12, the porous layer 2 is heated, and in this state, an electrode containing a metal compound on the porous layer 2 After the electrode layer 3 is formed on the porous layer 2 by continuously spraying the layer forming coating solution 3 ′ with the spray device S, the porous layer 2 and the electrode layer are formed on the heat-resistant substrate 1. 3 is a step of winding the laminated body 13 laminated in this order.
Moreover, the said bonding process (FIG.1 (d)) is the said electrode of the said laminated body 13 which rolled the laminated body 6 which has the structure by which the contact bonding layer 4 which consists of resin materials on the base material 5 was laminated | stacked. After continuously laminating with a heat roll so that the layer 3 and the adhesive layer of the laminate 6 are adhered, the porous layer 2, the electrode layer 3, the adhesive layer 4, and the base material are formed on the heat resistant substrate 1. 5 is a step of winding the laminated body 14 laminated in this order.
Further, in the heat-resistant substrate peeling step (FIG. 1E), the laminate 14 is unwound, the heat-resistant substrate 1 is continuously peeled from the porous layer, and then the adhesive layer 4 is formed on the substrate 5. And a step of winding up the oxide semiconductor electrode 10 having a configuration in which the electrode layer 3 and the porous layer 2 are laminated in this order.
In such an example, the long oxide semiconductor electrode 10 in which the adhesive layer 4, the electrode layer 3, and the porous layer 2 are laminated in this order on the long base material 5 can be formed. .

  The method for producing an oxide semiconductor electrode by a transfer method has an advantage that a flexible oxide semiconductor electrode can be produced using a resin film base material, but has a large number of required steps. Therefore, there was a problem of lack of productivity. However, according to the present invention, in the porous layer forming layer forming step, by using a long heat-resistant substrate, the porous layer forming layer forming step, the firing step, the electrode layer forming step, the above Since all steps of the bonding step and the heat-resistant substrate peeling step can be a roll-to-roll process, an oxide semiconductor electrode can be manufactured with high productivity by a transfer method.

  Hereinafter, the porous layer forming layer forming step, the firing step, the electrode layer forming step, the bonding step, and the heat resistant substrate peeling step in the present invention will be described in detail.

1. First, a porous layer forming layer forming step in the present invention will be described. In this step, a porous layer forming layer is formed on the heat resistant substrate by continuously applying a porous layer forming coating solution containing metal oxide semiconductor fine particles on a long heat resistant substrate. It is a process. The porous layer forming layer formed in this step is a porous layer made of a porous body by a firing step described later.

(1) Heat-resistant substrate The heat-resistant substrate used in this step is long. By using such a long heat-resistant substrate, the roll-to-roll process can be performed in this step and all steps of the baking step, electrode layer forming step, bonding step, and heat-resistant substrate peeling step described later. Therefore, an oxide semiconductor electrode can be manufactured with high productivity.

  The term “long” in this step means that the ratio of the length in the longitudinal direction to the width direction (length in the longitudinal direction / length in the width direction) is 5 or more. Usually, in this step, a heat-resistant substrate having the above ratio of 3000 or less is used.

  Further, in the present invention, in the case where the present process, the firing process described later, the electrode layer forming process, the bonding process, and the heat resistant substrate peeling process are “continuous processes” described later, an endless belt-shaped heat resistant substrate is formed. It is preferable to use it. This is because an oxide semiconductor electrode can be manufactured at lower cost by circulating and using an endless belt-shaped heat-resistant substrate.

  The heat-resistant substrate used in this step is not particularly limited as long as it has heat resistance against the heating temperature in the baking step described later. Here, the above-mentioned “heat resistance” refers to the heat resistance against the heating temperature in the firing step described later, and by using the heat-resistant substrate excellent in heat resistance as described above, the temperature is sufficiently high in the firing step described later. Since it becomes possible to heat, when the porous layer forming layer formed in this step is a porous layer made of a porous body in the firing step described later, the metal oxidation contained in the porous layer The binding property between the physical semiconductor fine particles can be increased. Especially in this process, it is preferable that melting | fusing point of the said heat-resistant board | substrate is in the range of 380 to 4000 degreeC, and it is especially preferable to exist in the range of 400 to 3800 degreeC.

  Moreover, it is preferable that the heat-resistant board | substrate used for this process is what has acid resistance further among what has the said heat resistance. Here, the above-mentioned “acid resistance” means that when the porous layer forming coating liquid described later is acidic, the acid resistance is such that it is not corroded by the porous layer forming coating liquid, or is somewhat corroded. Even so, it means acid resistance to such an extent that the acid decomposition product does not cause alteration or peeling of the porous layer.

  The heat-resistant substrate may be a single layer or a plurality of layers.

When the heat resistant substrate is a single layer, the material of the heat resistant substrate is not particularly limited as long as it has flexibility, heat resistance and acid resistance. Examples of such a material include metals such as simple metals, metal alloys, and metal oxides.
Examples of the metal simple substance include Ti, W, Mo, Nb, Cr, Ni, Ag, Zr, Pt, Ta, and Au. Among these, Ti, W, Pt, and Au are particularly used in this step. It is preferable to use it.
Examples of the metal alloy include SUS, Ti alloy, Fe alloy, Ni alloy, Al alloy, W alloy, Mg alloy, Co alloy, Cr alloy, etc. Among them, in this step, SUS, Ti Alloys and Al alloys are preferred.
Further, examples of the metal oxide include Si oxide, Al oxide, Ti oxide, Zr oxide, Sn oxide, Cr oxide, and W oxide. Among these, in this step, Si oxide, Al oxide, and Ti oxide are preferable.

  On the other hand, when the heat-resistant substrate has a plurality of layers, for example, the heat-resistant substrate may include a heat-resistant layer and an acid-resistant layer formed on the heat-resistant layer. Here, it is preferable that the acid-resistant layer is formed on the surface on which at least the porous layer forming layer is formed on the heat-resistant layer.

The heat-resistant layer is not particularly limited as long as it has sufficient heat resistance and flexibility with respect to the heating temperature in the baking step described later. In particular, it is preferable to use a metal in this step.
Specific examples of the metal include a single metal, a metal alloy, and a metal oxide. Since such metal simple substance, metal alloy, and metal oxide generally have sufficient heat resistance, the kind thereof is not particularly limited. In particular, in this step, it is preferable to use Ti, W, Pt, Au or the like as the metal simple substance, and it is preferable to use SUS, Ti alloy or Al alloy as the metal alloy, and further, the metal oxidation. As the material, it is preferable to use Si oxide, Al oxide, Ti oxide or the like.

The acid resistant layer is not particularly limited as long as it has acid resistance and heat resistance, and further has flexibility, but it is preferable to use a metal in this step. Examples of such metals include simple metals, metal alloys, and metal oxides.
Examples of the metal simple substance include Ti, W, Mo, Nb, Cr, Ni, Ag, Zr, Pt, Ta, and Au. Among these, Ti, W, Pt, and Au are particularly used in this step. It is preferable to use it.
Examples of the metal alloy include SUS, Ti alloy, Fe alloy, Ni alloy, Al alloy, W alloy, Mg alloy, Co alloy, and Cr alloy. Among these, SUS, It is preferable to use a Ti alloy or an Al alloy.
Further, examples of the metal oxide include Si oxide, Al oxide, Ti oxide, Zr oxide, Sn oxide, Cr oxide, and W oxide. Is preferably Si oxide, Al oxide, or Ti oxide.

  When the heat-resistant substrate used in this step has the heat-resistant layer and the acid-resistant layer, the combination of the heat-resistant layer and the acid-resistant layer is not particularly limited and can be arbitrarily selected. . Especially in this process, the combination whose material of the said heat resistant layer and the said acid resistant layer is a metal is preferable. This is because a heat-resistant substrate having excellent flexibility can be obtained according to such a combination, so that the oxide semiconductor electrode manufacturing method of the present invention can be easily implemented as a roll-to-roll process.

  As a combination in which the material of the heat resistant layer and the acid resistant layer is a metal, for example, the material of the heat resistant layer is a simple metal, a metal alloy, or a metal oxide, and the material of the acid resistant layer is the heat resistant layer. The combination which is a metal simple substance other than the metal used for (1), a metal alloy, or a metal oxide can be mentioned. Specifically, as a combination of the material of the heat resistant layer / the material of the acid resistant layer, Ti simple substance / Ti oxide, SUS / Cr simple substance, SUS / Si oxide, SUS / Ti oxide, SUS / Al oxide, Examples thereof include SUS / Cr oxide.

  Moreover, when the material of the said heat resistant layer and the said acid resistant layer is a metal, it is preferable that the metal element contained in the said heat resistant layer differs from the metal element contained in the said acid resistant layer. Here, “a metal element contained in the heat-resistant layer” means a metal element contained most in the heat-resistant layer. Therefore, for example, even when SUS contains Cr, Ni or the like, the “metal element contained in the heat-resistant layer” is Fe. The same applies to the “metal element contained in the acid-resistant layer”. As a combination of such a heat-resistant layer and an acid-resistant layer, as a combination of a material of a heat-resistant layer / a material of an acid-resistant layer, SUS / Cr simple substance, SUS / Si oxide, SUS / Ti oxide, SUS / Al Examples thereof include oxides and SUS / Cr oxides.

(2) Method for Forming Layer for Forming Porous Layer Next, a method for forming a layer for forming a porous layer on the heat-resistant substrate in this step will be described. In this step, as a method for forming a porous layer forming layer on the heat resistant substrate, a porous layer forming coating solution having metal oxide semiconductor fine particles is continuously applied on the heat resistant substrate. The method is used.

(Porous layer forming coating solution)
The coating solution for forming a porous layer used in this step is usually composed of metal oxide semiconductor fine particles, a resin, and a solvent, and may contain other compounds as necessary. Hereinafter, each structure of the coating liquid for porous layer formation used for this process is demonstrated.

First, the metal oxide semiconductor fine particles used in the porous layer forming coating solution will be described. Examples of the metal oxide semiconductor fine particles used in the porous layer forming coating liquid include TiO ₂ , ZnO, SnO ₂ , ITO, ZrO ₂ , MgO, Al ₂ O ₃ , CeO ₂ , Bi ₂ O ₃ , and Mn _3. O ₄ , Y ₂ O ₃ , WO ₃ , Ta ₂ O ₅ , Nb ₂ O ₅ , La ₂ O _{3 and the} like can be mentioned. Since these metal oxide semiconductor fine particles can improve energy conversion efficiency and reduce costs, they are preferably used in this step. Moreover, in this process, any 1 type may be used among the said metal oxide semiconductor fine particles, and 2 or more types may be mixed and used for it. Further, in this step, one of the metal oxide semiconductor fine particles described above may be a core fine particle, and a core shell structure in which the core fine particle is included to form a shell by other metal oxide semiconductor fine particles. Among these, in this step, it is most preferable to use TiO ₂ as the semiconductor oxide fine particles.

  The particle size of the metal oxide semiconductor fine particles used in the porous layer forming coating liquid is preferably a desired value in the porous layer obtained by firing the porous layer forming layer formed in this step. Although it will not specifically limit if it is in the range which can obtain a surface area, Usually, it is preferable to exist in the range of 1 nm-10 micrometers, and it is especially preferable to exist in the range of 10 nm-1000 nm. If the particle size is smaller than the above range, the respective metal oxide semiconductor fine particles may aggregate to form secondary particles. If the particle size is larger than the above range, the porous layer becomes thicker. In addition, the porosity of the porous layer, that is, the specific surface area is reduced. For example, when the oxide semiconductor electrode produced according to the present invention is used in a dye-sensitized solar cell, This is because a dye sensitizer sufficient for photoelectric conversion may not be supported.

In this step, a mixture of a plurality of metal oxide semiconductor particles having different particle diameters may be used as the metal oxide semiconductor particles. By using a mixture of metal oxide semiconductor fine particles having different particle sizes, the light scattering effect of the porous layer obtained by firing the porous layer forming layer formed by this step can be enhanced. This is because when the oxide semiconductor electrode produced according to the present invention is used in a dye-sensitized solar cell, light absorption by the dye-sensitizer can be efficiently performed.
The mixture of a plurality of metal oxide semiconductor fine particles having different particle diameters may be a mixture of the same type of metal oxide semiconductor fine particles, or a mixture of different types of metal oxide semiconductor fine particles. Good. Examples of combinations of different particle diameters include a mode in which metal oxide semiconductor fine particles in the range of 10 to 50 nm and metal oxide semiconductor fine particles in the range of 50 to 800 nm are mixed and used. .

  The content of the metal oxide semiconductor fine particles in the coating liquid for forming the porous layer can be arbitrarily determined according to the use of the oxide semiconductor electrode produced according to the present invention. Especially in this process, it is preferable that content of metal oxide semiconductor fine particle exists in the range of 50 mass%-100 mass% in solid content of the coating liquid for porous layer formation, Especially 65 mass%- It is preferably within the range of 90% by mass. When the content of the metal oxide semiconductor fine particles is less than the above range, for example, when the oxide semiconductor electrode produced according to the present invention is used in a dye-sensitized solar cell, the porous layer formed by this step is formed. This is because there is a possibility that a desired amount of the dye sensitizer cannot be contained in the porous layer obtained by firing the working layer. Moreover, it is because there exists a possibility that the resistance of the said porous layer may become large too much when it exceeds the said range.

  Further, the concentration of the metal oxide semiconductor fine particles with respect to the coating solution for forming a porous layer may be arbitrarily determined depending on the application method of the coating solution for forming a porous layer described later, but usually 5% by mass to It is preferably in the range of 50% by mass, and more preferably in the range of 10% by mass to 40% by mass.

  Next, the resin used for the porous layer forming coating solution will be described. The resin has a function of making the porous layer forming layer formed in this step into a porous body by being thermally decomposed in a baking step described later.

  Resin used for the said coating liquid for porous layer formation will not be specifically limited if it is decomposed | disassembled in the baking process mentioned later. Examples of such resins include cellulose resins, polyester resins, polyamide resins, polyacrylate resins, polyacryl resins, polycarbonate resins, polyurethane resins, polyolefin resins, polyvinyl acetal resins, and fluorine resins. In addition to resins and polyimide resins, polyhydric alcohols such as polyethylene glycol can be used.

  The content of the resin in the coating liquid for forming a porous layer is such that a desired porosity is obtained when the porous layer forming layer formed in this step is a porous layer made of a porous body. If it is in the range which can be obtained, it will not specifically limit. Especially in this process, it is preferable that it exists in the range of 0.1 mass%-30 mass% with respect to the coating liquid for porous layer formation, especially within the range of 0.5 mass%-20 mass%. It is preferable that it is in the range of 1% by mass to 10% by mass. When the resin content is less than the above range, for example, when the oxide semiconductor electrode produced according to the present invention is used in a dye-sensitized solar cell, the porous layer contains a desired amount of the dye-sensitizer. This is because the resistance of the porous layer may be excessively increased, or the mechanical strength of the porous layer may be reduced.

  Next, the solvent used for the porous layer forming coating solution will be described. The solvent used for the porous layer forming coating solution is not particularly limited as long as it can dissolve the resin in a desired amount. Examples of such a solvent include water and various solvents such as methanol, ethanol, isopropyl alcohol, propylene glycol monomethyl ether, terpineol, dichloromethane, acetone, acetonitrile, ethyl acetate, and tert-butyl alcohol. In particular, in this step, water or an alcohol solvent is preferable.

Various additives may be used in the porous layer forming coating solution. As such an additive, for example, a surfactant, a viscosity adjusting agent, a dispersion aid, a pH adjusting agent and the like can be used. Examples of the pH adjuster include nitric acid, hydrochloric acid, acetic acid, dimethylformamide, ammonia and the like.
Examples of the dispersion aid include polymers such as polyethylene glycol, hydroxyethyl cellulose, and carboxymethyl cellulose, surfactants, acids, and chelating agents.
In this step, it is particularly preferable to use polyethylene glycol as a dispersion aid, particularly as the additive. This is because by changing the molecular weight of polyethylene glycol, the viscosity of the dispersion can be adjusted, and it is possible to form a porous layer that does not easily peel off, adjust the porosity of the porous layer, and the like.

(Method for forming porous layer forming layer)
In this step, the porous layer forming layer is formed by continuously applying the porous layer forming coating solution on the long heat-resistant substrate. The application method for applying the liquid is not particularly limited as long as it is a method capable of continuously forming a coating film having a uniform film thickness and excellent flatness. Examples of such methods 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, dip coating, micro bar coating, Microbar reverse coating, offset coating, screen printing (rotary method) and the like can be mentioned. By using such a coating method, the porous layer forming layer can be adjusted to a desired film thickness by repeating coating and solidification one or more times. In particular, in this step, it is preferable to use die coating, blade coating, or screen printing (rotary method).

  The porous layer forming layer can be formed by applying the coating liquid for forming the porous layer on the heat-resistant substrate by such a method and then drying the coating film by a known method.

(Porous layer forming layer)
The porous layer forming layer formed in this step may be directly formed on the heat-resistant substrate, but in this step, the porous layer-forming layer contains metal oxide semiconductor fine particles on the long heat-resistant substrate, After forming the intervening layer forming layer on the heat-resistant substrate by continuously applying the intervening layer forming coating solution having a composition different from that of the layer forming coating liquid, Preferably, the porous layer forming layer is formed. This is because, by forming the porous layer forming layer on the heat resistant substrate through the intervening layer forming layer, the peelability of the heat resistant substrate in the heat resistant substrate peeling step described later can be improved. .
Hereinafter, a layer forming step for forming the intervening layer forming layer will be described.

  First, the intervening layer forming coating solution used in the intervening layer forming layer forming step will be described. The intervening layer-forming coating solution contains metal oxide semiconductor fine particles, an organic substance, and a solvent, and has a composition different from that of the porous layer-forming coating solution.

As an aspect in which the composition for forming the intervening layer is different from the composition for forming the porous layer, it is possible to improve the peelability of the porous layer formed by this step from the heat-resistant substrate. It is not particularly limited. Examples of such an embodiment include, for example, an embodiment in which the content of metal oxide semiconductor fine particles is less than that in the porous layer forming coating solution, and a metal oxide having a major particle size larger than that in the porous layer forming coating solution. The aspect etc. which contain a physical semiconductor fine particle can be mentioned. Here, the main particle diameter is a metal oxide having the largest weight ratio among the respective metal oxide semiconductor fine particles contained in the coating liquid for forming an intervening layer and the coating liquid for forming a porous layer. It shall mean the particle size of the semiconductor fine particles.
Hereinafter, such an intervening layer forming coating solution will be described in detail.

  Used as a coating liquid for forming an intervening layer when the one containing metal oxide semiconductor fine particles having a major particle size larger than that of the coating liquid for forming a porous layer is used as the coating liquid for forming a porous layer. The ratio of the main particle size of the metal oxide semiconductor fine particles to be obtained and the main particle size of the metal oxide semiconductor fine particles used in the coating liquid for forming the porous layer is within a range in which a desired peelability can be imparted to the porous layer. If it is in, it will not specifically limit. Among these, in this step, the main particle size of the metal oxide semiconductor fine particles used in the coating liquid for forming the intervening layer and the main particle size of the metal oxide semiconductor fine particles used in the coating solution for forming the porous layer The ratio is preferably in the range of 1.2: 1 to 300: 1, more preferably in the range of 3: 1 to 100: 1, especially in the range of 5: 1 to 30: 1. It is preferable to be within.

The main particle size of the metal oxide semiconductor fine particles used for the coating liquid for forming the intervening layer is usually within the range of 30 nm to 1 μm, more preferably within the range of 50 nm to 800 nm, and further preferably within the range of 100 nm to 600 nm. Is done.
In addition, since it is the same as that of what is used for the said coating liquid for porous layer formation as each particle size of the said metal oxide semiconductor fine particle, description here is abbreviate | omitted.

In addition, in the present step, when the intervening layer forming coating solution containing metal oxide semiconductor fine particles having a major particle size larger than that of the porous layer forming coating solution is used, The metal oxide semiconductor fine particles contained in the coating liquid preferably have a single distribution of particle sizes. In the case of using a metal oxide semiconductor fine particle having a major particle size larger than that of the porous layer forming coating solution as the intervening layer forming coating solution, This is because the intervening layer to be formed has a light scattering function, but the transparency of the porous layer can be improved by using metal oxide semiconductor fine particles having a single particle size. .
The specific particle size of the metal oxide semiconductor fine particles having a single particle size is preferably in the range of 5 nm to 50 nm, and more preferably in the range of 7 nm to 30 nm. It is preferably within the range of 10 nm to 25 nm.

  The metal oxide constituting the metal oxide semiconductor fine particles is the same as the metal oxide constituting the metal oxide semiconductor fine particles used in the porous layer forming coating solution, and therefore will be described here. Is omitted.

  The content of the metal oxide semiconductor fine particles in the solid content of the coating liquid for forming the intervening layer is a heat resistant substrate of the porous layer formed by this step according to the particle size of the metal oxide semiconductor fine particles. If it is in the range which can improve the peelability from, it will not specifically limit. Moreover, it may be the same as or different from the content in the porous layer forming coating solution. Especially in this process, it is preferable that content of a metal oxide semiconductor fine particle exists in the range of 20 mass%-80 mass% in solid content of the said coating liquid for intervening layer formation, Especially 30 mass%-70. It is preferable to be within the range of mass%. When the content of the metal oxide semiconductor fine particles is larger than the above range, the adhesion with the heat-resistant substrate becomes high, and the peelability of the heat-resistant substrate may be impaired in the heat-resistant substrate peeling step described later. If it is lower than the above range, it may be difficult to form a homogeneous porous layer forming layer on the formed intervening layer forming layer.

  Further, the concentration of the metal oxide semiconductor fine particles in the intervening layer forming coating solution may be arbitrarily determined according to the application method of the intervening layer forming coating solution described later, but is usually 0.01. It is preferable to be in the range of 30% by mass to 30% by mass, and it is particularly preferable to be in the range of 0.1% to 15% by mass.

  Next, the organic substance used for the intervening layer forming coating solution will be described. The organic substance has a function of making the intervening layer forming layer a porous body by being thermally decomposed in a baking step described later.

  The organic substance used in the intervening layer forming coating solution is not particularly limited as long as it is easily decomposed in the baking step described later. In particular, in the intervening layer forming layer forming step, it is preferable to use a synthetic resin as the organic substance. This is because the synthetic resin can obtain a compound having a desired thermal decomposability by arbitrarily selecting the molecular weight and material, and thus has advantages such as less restrictions on the processing conditions of the baking treatment described later.

  The synthetic resin is not particularly limited as long as it is difficult to dissolve in the solvent used in the above-described porous layer forming coating solution. In particular, in the layer forming step for forming the intervening layer, the weight average molecular weight of the synthetic resin is preferably in the range of 2000 to 600000, particularly preferably in the range of 5000 to 300000, and more preferably in the range of 10,000 to 200000. It is preferable to be within the range. When the molecular weight of the synthetic resin is larger than the above range, thermal decomposition in the baking step described later may be insufficient, and when the molecular weight is smaller than the above range, the viscosity of the coating liquid for forming the intervening layer is low. This is because the metal oxide semiconductor fine particles may be aggregated. The molecular weight of the synthetic resin can be measured by, for example, GPC.

  Specific examples of the synthetic resin include ethyl cellulose, methyl cellulose, nitrocellulose, acetyl cellulose, acetyl ethyl cellulose, cellulose propionate, hydroxypropyl cellulose, butyl cellulose, benzyl cellulose, nitrocellulose and other cellulose resins, or methyl methacrylate, ethyl Acrylic resin made of a polymer or copolymer such as methacrylate, tertiary butyl methacrylate, normal butyl methacrylate, isobutyl methacrylate, isopropyl methacrylate, 2-ethyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, polyethylene glycol, etc. Examples thereof include polyhydric alcohols. In the intervening layer forming layer forming step, one kind of these synthetic resins may be used alone, or two or more kinds of synthetic resins may be mixed and used.

  The content of the organic substance in the intervening layer forming coating liquid is such that the intervening layer forming layer formed by the intervening layer forming layer forming step is porous in the heat resistant substrate peeling step described later in the baking step described later. There is no particular limitation as long as it is within a range in which the interstitial layer can be provided with a degree of porosity that allows adhesion between the heat-resistant substrate and the intervening layer to be within a desired range when the intervening layer is made of a material. In particular, in the intermediate layer forming layer forming step, the content is preferably in the range of 0.01% by mass to 30% by mass, particularly 0.1% by mass to 15% with respect to the intermediate layer forming coating solution. It is preferable to be within the range of mass%. If the content of the organic substance is less than the above range, the heat-resistant substrate peeling load in the heat-resistant substrate peeling step described later is increased, which may be disadvantageous in terms of productivity, and the content is more than the above range. This is because the intervening layer formed by the intervening layer forming layer forming step may self-peel from the heat-resistant substrate.

  Next, the solvent used for the intervening layer forming coating solution will be described. The solvent used in the intervening layer forming coating solution is not particularly limited as long as it can dissolve the organic substance in a desired amount. Examples of such solvents include ketones, hydrocarbons, esters, alcohols, halogenated hydrocarbons, glycol derivatives, ethers, ether esters, amides, acetates, ketone esters, glycol ethers. , Sulfones, sulfoxides and the like. These solvents may be used alone or as a mixed solvent in which two or more kinds are mixed. In particular, in the layer forming step for forming the intervening layer, organic substances such as acetone, methyl ethyl ketone, toluene, methanol, isopropyl alcohol, normal propyl alcohol, normal butanol, isobutanol, terpineol, ethyl cellosolve, butyl cellosolve, and butylcarbitol are used. It is preferable to use a solvent. This is because such an organic solvent has excellent wettability with respect to the heat-resistant substrate, and thus can improve the coating property of the coating liquid for forming an intervening layer on the heat-resistant substrate.

  Various additives may be used in the intervening layer forming coating solution. As such an additive, for example, a surfactant, a viscosity adjusting agent, a dispersion aid, a pH adjusting agent and the like can be used. Examples of the pH adjuster include nitric acid, hydrochloric acid, acetic acid, dimethylformamide, ammonia and the like. Examples of the dispersion aid include polymers such as polyethylene glycol, hydroxyethyl cellulose, and carboxymethyl cellulose, surfactants, acids, and chelating agents.

  The coating method for continuously coating the coating liquid for forming the intervening layer on the heat-resistant substrate is particularly limited as long as it is a method capable of continuously forming a coating film having a uniform film thickness and excellent flatness. Not. As an example of such a method, since it is the same as the application method of the coating liquid for porous layer formation mentioned above, description here is abbreviate | omitted.

  After the coating solution for forming the intervening layer is applied on the heat-resistant substrate by such a method, the coating layer is dried by a known method, whereby the intervening layer forming layer can be formed.

  The thickness of the intervening layer forming layer formed by the intervening layer forming layer forming step may be arbitrarily determined according to the heat-resistant substrate peeling method in the heat-resistant substrate peeling step described later. In particular, the thickness ratio between the porous layer forming layer and the intervening layer forming layer is preferably within the range of 10: 0.1 to 10: 5, and is preferably 10: 0.1 to 10: 3. More preferably within the range. If the thickness of the intervening layer forming layer is larger than the above range, cohesive failure of the intervening layer can easily occur when the intervening layer forming layer is made of an intervening layer made of a porous material by a firing process described later. Because there is sex. Further, if the thickness is smaller than the above range, the productivity of the oxide semiconductor electrode according to the present invention may be lowered.

2. Next, the firing process in the present invention will be described. In this step, the porous layer forming layer is formed by continuously firing the porous layer forming layer formed on the long heat-resistant substrate in the porous layer forming layer forming step. A step of forming a porous layer comprising:

  In this step, the porous layer forming layer is baked by heating. Such a heating temperature is within a range in which the organic matter and / or resin contained in the porous layer forming layer can be thermally decomposed. Although it will not specifically limit if it is inside, Usually, it is preferable to exist in the range of 300 degreeC-700 degreeC, and it is especially preferable to exist in the range of 350 degreeC-600 degreeC. This is because, by firing in a high temperature range within the above range, the porous layer formed by this step can be formed with good binding properties between the metal oxide semiconductor fine particles.

  In this step, the heating method for firing the porous layer forming layer is not particularly limited as long as it can be uniformly fired without heating unevenness, and a known heating method can be used. As such a method, for example, a method of continuously passing the porous layer forming layer formed on the long heat-resistant substrate through a baking furnace heated to a predetermined temperature can be exemplified.

  In this step, the porous layer forming layer is a porous layer made of a porous body, and the porosity of such a porous layer is in the range of 10% to 60%. In particular, it is preferably in the range of 20% to 50%. When the porosity of the porous layer is smaller than the above range, the specific surface area becomes small. For example, when the oxide semiconductor electrode produced according to the present invention is used in a dye-sensitized solar cell, the dye-sensitized agent. This is because the porous layer containing may not be able to absorb sunlight or the like effectively. Moreover, it is because it may become impossible to contain a desired amount of dye sensitizers in a porous layer when larger than the said range.

  Further, when the porous layer forming layer is formed on the above-described intervening layer forming layer, the porosity of the intervening layer of the porous body formed by this step is the adhesive strength to the heat resistant substrate. If it is in the range which can be in the desired range, it will not specifically limit. In particular, in this step, it is preferably in the range of 25% to 65%, and more preferably in the range of 30% to 60%. If the porosity of the intervening layer is smaller than the above range, the adhesive strength with the heat-resistant substrate is increased, so that productivity may be lost, and if it exceeds the above range, the mechanical strength of the intervening layer is reduced. This is because there is a case where it ends up.

3. Electrode Layer Forming Step Next, the electrode layer forming step in the present invention will be described. In the electrode layer forming step in the present invention, an electrode layer forming coating solution containing a metal compound is continuously applied on the porous layer formed on the heat-resistant substrate by the baking step, while the porous layer is heated. It is the process of forming an electrode layer on the said porous layer by giving automatically.

In this step, the method for providing the electrode layer on the porous layer is not particularly limited as long as the electrode layer can be continuously formed on the porous layer. Examples thereof include PVD methods such as vapor deposition, sputtering, and ion plating, dry deposition methods such as plasma CVD, thermal CVD, and CVD such as atmospheric pressure CVD, solution spraying, and spraying. Especially, since this process forms an electrode layer continuously on the porous layer formed on the said long heat-resistant board | substrate, it is preferable to use the method which can form an electrode layer under atmospheric pressure. In particular, it is preferable to use the solution spray method and the spray method. This is because such a method can form a dense electrode layer. Further, when such a solution spraying method and a spraying method are used, and the firing step described above and this step are “continuous steps” to be described later, the residual heat in the firing step can be used in this step. This is because the thermal energy required in this step can be suppressed.
Hereinafter, the solution spray method and spray method used in this step will be described in detail.

(1) Solution spray method First, the solution spray method used for this process is demonstrated. In the solution spray method used in this step, a base electrode layer-forming coating solution in which a metal compound having a metal element constituting the electrode layer is dissolved is brought into contact with the porous layer, whereby the inside of the porous layer or In this method, a solution treatment step of providing a base electrode layer on the surface and a spray treatment step of providing an upper electrode layer on the base electrode layer are performed to provide an electrode layer on the porous layer.

In the solution spray method, first, in the solution treatment step, the base electrode layer forming coating solution is used to the inside of the porous layer that is a porous body by using the base electrode layer forming coating solution. And a base electrode layer is provided inside the porous layer. Thereafter, in the spray treatment step, an electrode layer is formed by providing an upper electrode layer on the base electrode layer. According to such a method, a dense electrode layer can be obtained on the porous layer.
Hereinafter, the solution treatment process and the spray treatment process in the solution spray method will be described.

i. Solution treatment step The solution treatment step in the solution spray method involves contacting the porous layer with a coating solution for forming a base electrode layer in which a metal compound having a metal element constituting the electrode layer is dissolved. This is a step of providing a base electrode layer inside or on the surface of the layer.

a. Base Electrode Layer Forming Coating Solution First, the base electrode layer forming coating solution used in the solution treatment step will be described. The base electrode layer forming coating solution used in the solution treatment step is a solution in which a metal compound containing at least a metal element constituting the electrode layer is dissolved in a solvent. In this step, a metal salt or a metal complex (hereinafter sometimes referred to as “metal source”) can be used as such a metal compound. In this step, it is preferable that the base electrode layer forming coating solution contains at least one of an oxidizing agent and a reducing agent. This is because the base electrode layer can be formed at a lower temperature by the action of the oxidizing agent and / or the reducing agent.

(Metal source)
The metal source used for the base electrode layer forming coating solution will be described. The metal source may be a metal salt or a metal complex as long as it has a metal element and can form a base electrode layer. The “metal complex” in this step includes a metal ion coordinated with an inorganic substance or an organic substance, or a so-called organometallic compound having a metal-carbon bond in the molecule.

  The metal element constituting the metal source used in the base electrode layer forming coating solution is not particularly limited as long as it can obtain an electrode layer with excellent conductivity. For example, Mg, From the group consisting of Al, Si, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Ag, In, Sn, Ce, Sm, Pb, La, Hf, Sc, Gd, and Ta Mention may be made of at least one metal element selected. In particular, in this step, it is preferable to use at least one metal element selected from the group consisting of Zn, Zr, Al, Y, Fe, Ga, La, Sb, In, and Sn.

  Specific examples of the metal salt containing the metal element include chloride, nitrate, sulfate, perchlorate, acetate, phosphate, bromate and the like containing the metal element. it can. Of these, chloride, nitrate, and acetate are preferably used in this step. This is because these compounds are easily available as general-purpose products.

  Specific examples of the metal complex include magnesium diethoxide, aluminum acetylacetonate, calcium acetylacetonate dihydrate, calcium di (methoxyethoxide), calcium gluconate monohydrate, citric acid Calcium tetrahydrate, calcium salicylate dihydrate, titanium lactate, titanium acetylacetonate, tetraisopropyl titanate, tetranormal butyl titanate, tetra (2-ethylhexyl) titanate, butyl titanate dimer, titanium bis (ethylhexoxy) bis (2 -Ethyl-3-hydroxyhexoxide), diisopropoxytitanium bis (triethanolaminate), dihydroxybis (ammonium lactate) titanium, diisopropoxytitanium bis (ethylacetate) Toacetate), titanium peroxo ammonium citrate tetrahydrate, dicyclopentadienyl iron (II), iron lactate (II) trihydrate, iron (III) acetylacetonate, cobalt (II) acetylacetonate , Nickel (II) acetylacetonate dihydrate, copper (II) acetylacetonate, copper (II) dipivaloylmethanate, copper (II) ethylacetoacetate, zinc acetylacetonate, zinc lactate trihydrate , Zinc salicylate trihydrate, zinc stearate, strontium dipivaloylmethanate, yttrium dipivaloylmethanate, zirconium tetra-n-butoxide, zirconium (IV) ethoxide, zirconium normal propyrate, zirconium normal butyrate , Zirconium tetraacetylacetonate, zirconium monoacetylacetonate, zir Nitroacetylacetonate bisethylacetoacetate, zirconium acetate, zirconium monostearate, penta-n-butoxyniobium, pentaethoxyniobium, pentaisopropoxyniobium, tris (acetylacetonato) indium (III), indium 2-ethylhexanoate (III), tetraethyltin, dibutyltin oxide (IV), tricyclohexyltin (IV) hydroxide, lanthanum acetylacetonate dihydrate, tri (methoxyethoxy) lanthanum, pentaisopropoxytantalum, pentaethoxytantalum, tantalum ( V) Ethoxide, cerium (III) acetylacetonate n-hydrate, lead (II) citrate trihydrate, lead cyclohexanebutyrate and the like. Among these, in this step, magnesium diethoxide, aluminum acetylacetonate, calcium acetylacetonate dihydrate, titanium lactate, titanium acetylacetonate, tetraisopropyl titanate, tetranormal butyl titanate, tetra (2-ethylhexyl) titanate , Butyl titanate dimer, diisopropoxy titanium bis (ethylacetoacetate), iron (II) lactate trihydrate, iron (III) acetylacetonate, zinc acetylacetonate, zinc lactate trihydrate, strontium dipivaloyl Methanate, pentaethoxyniobium, tris (acetylacetonato) indium (III), indium (III) 2-ethylhexanoate, tetraethyltin, dibutyltin oxide (IV), lanthanum acetylacetonate dihydrate , It is preferable to use tri (methoxyethoxy) lanthanum, cerium (III) acetylacetonate n-hydrate.

  The concentration of such a metal source is not particularly limited as long as a desired base electrode layer can be obtained. However, when the metal source is a metal salt, it is usually within a range of 0.001 mol / L to 1 mol / L. It is preferable that it is in the range of 0.01 mol / L-0.1 mol / L especially. Moreover, when a metal source is a metal complex, it is preferable normally that it is 0.001 mol / L-1 mol / L, and it is preferable to exist in the range of 0.01 mol / L-0.1 mol / L especially.

(Oxidant)
The oxidizing agent used for the base electrode layer forming coating solution will be described. The oxidizing agent has a function of accelerating oxidation of metal ions and the like formed by dissolving the above-described metal source. By using such an oxidizing agent, the base electrode layer can be formed at a lower temperature.

  The concentration of the oxidizing agent is not particularly limited as long as a desired base electrode layer can be obtained, but it is usually preferably in the range of 0.001 mol / L to 1 mol / L, and in particular, the concentration is preferably 0.00. It is preferable to be within the range of 01 mol / L to 0.1 mol / L. If the concentration is below the above range, the oxidant may not exhibit the effect, and if the concentration is above the above range, there is a case where the obtained effect is not greatly different and may not be preferable in terms of cost. .

  Such an oxidizing agent is not particularly limited as long as it can be dissolved in a solvent described later and promote the oxidation of the above metal ions and the like. Examples of such an oxidizing agent include hydrogen peroxide, sodium nitrite, potassium nitrite, sodium bromate, potassium bromate, silver oxide, dichromic acid, and potassium permanganate. Of these, hydrogen peroxide and sodium nitrite are preferably used in this step.

(Reducing agent)
The reducing agent that can be used for the base electrode layer forming coating solution will be described. The reducing agent emits electrons by a decomposition reaction, generates hydroxide ions by electrolysis of water, and has a function of raising the pH of the coating solution for forming the base electrode layer. By using such a reducing agent, the pH of the coating solution for forming the base electrode layer is increased, so that the base electrode layer can be formed at a lower temperature.

The concentration of the reducing agent is not particularly limited as long as a desired base electrode layer can be obtained. However, when the metal source is a metal salt, it is usually in the range of 0.001 mol / L to 1 mol / L. In particular, it is preferably in the range of 0.01 mol / L to 0.1 mol / L.
On the other hand, when the metal source is a metal complex, it is usually preferably in the range of 0.001 mol / L to 1 mol / L, and in particular, in the range of 0.01 mol / L to 0.1 mol / L. preferable. This is because if the concentration is below the above range, the reducing agent may not exhibit an effect, and if the concentration is above the above range, there may be no significant difference in the obtained effect, which may be undesirable in terms of cost. .

  Such a reducing agent is not particularly limited as long as it can be dissolved in a solvent described later and can release electrons by a decomposition reaction. Examples of such reducing agents include borane-tert-butylamine complexes, borane-N, N diethylaniline complexes, borane-dimethylamine complexes, borane-trimethylamine complexes, and other borane complexes, sodium cyanoborohydride, sodium borohydride Etc. Among these, in this step, it is preferable to use a borane complex.

  Further, the base electrode layer forming coating solution may contain a reducing agent and an oxidizing agent. Such a combination of a reducing agent and an oxidizing agent is not particularly limited. For example, a combination of hydrogen peroxide or sodium nitrite and an arbitrary reducing agent, or an arbitrary oxidizing agent and a borane complex. A combination etc. can be mentioned. Of these, a combination of hydrogen peroxide and a borane complex is preferable in this step.

(solvent)
The solvent used for the base electrode layer forming coating solution will be described. The solvent is not particularly limited as long as it can dissolve the above-described metal compound and the like. As such a solvent, for example, when the metal source is a metal salt, water, methanol, ethanol, isopropyl alcohol, propanol, butanol, a lower alcohol having a total carbon number of 5 or less, toluene, and a mixed solvent thereof or the like Can be mentioned.
On the other hand, when the metal source is a metal complex, for example, the above-described lower alcohol, toluene, and a mixed solvent thereof can be exemplified.

(Additive)
In addition, the base electrode layer forming coating solution may contain additives such as an auxiliary ion source and a surfactant.

  The auxiliary ion source reacts with electrons to generate hydroxide ions and raises the pH of the base electrode layer forming coating solution. By using such an auxiliary ion source, It can be set as the environment where an electrode layer is easy to form. The amount of the auxiliary ion source used is preferably selected and used in accordance with the metal salt and reducing agent used.

  Examples of such auxiliary ion sources include chlorate ions, perchlorate ions, chlorite ions, hypochlorite ions, bromate ions, hypobromate ions, nitrate ions, and nitrite ions. be able to.

  The surfactant acts on the interface between the coating solution for forming the base electrode layer and the porous layer, and has a function of facilitating formation of a metal oxide film (base electrode layer) on the surface of the porous body. It is. The amount of the surfactant used is preferably appropriately selected according to the metal salt and reducing agent to be used.

  Such surfactants are specifically Surfinol 485, Surfinol SE, Surfinol SE-F, Surfinol 504, Surfinol GA, Surfinol 104A, Surfinol 104BC, Surfinol 104PPM, Surfinol 104E, Surfynol series such as Surfinol 104PA (all manufactured by Nissin Chemical Industry Co., Ltd.), NIKKOL AM301, NIKKOL AM313ON (all manufactured by Nikko Chemical Co., Ltd.) and the like can be mentioned.

b. Method of contacting the oxide semiconductor layer and the base electrode layer forming coating solution As a method of contacting the porous layer and the base electrode layer forming coating solution in this step, the base layer described above is applied to the porous layer described above. The method is not particularly limited as long as the electrode layer forming coating solution can be continuously contacted. In this step, as such a method, a method is generally used in which the coating solution for forming the base electrode layer is made into a mist using a spray device, and this is applied onto the porous material.

  Further, in this step, when the base electrode layer forming coating solution is brought into contact with the porous layer, the porous layer is heated, but the temperature of the porous layer at this time is These may be appropriately selected in accordance with the characteristics of the oxidizing agent, reducing agent, etc., but usually it is preferably in the range of 50 ° C. to 150 ° C., more preferably in the range of 70 to 100 ° C. preferable. Here, the method for heating the porous layer is not particularly limited as long as the porous layer formed on the long heat-resistant substrate can be continuously heated to a desired temperature, and is generally known. The method can be used.

ii. Spray Processing Step Next, the spray processing step in the solution spray method will be described. The spray treatment step is a step of providing an upper electrode layer by a spray method on the base electrode layer formed by the solution treatment step described above.

  In the spray method, the base electrode layer is heated to a temperature equal to or higher than the upper electrode layer formation temperature, and brought into contact with an upper electrode layer forming coating solution in which a metal compound having a metal element constituting the electrode layer is dissolved. In this method, the upper electrode layer is provided on the base electrode layer.

  In the spray method, the “upper electrode layer forming temperature” means that a metal element contained in an upper electrode layer forming coating liquid, which will be described later, is combined with oxygen to form a metal oxide film that is an upper electrode layer. The temperature at which the metal source is dissolved is greatly different depending on the type of metal ion or the like in which the metal source is dissolved, the composition of the coating solution for forming the upper electrode layer, and the like. In the spray method, such “upper electrode layer formation temperature” can be measured by the following method. That is, by preparing a coating solution for forming an upper electrode layer in which a desired metal source is actually dissolved and bringing it into contact with the heating temperature of the heat-resistant substrate having the base electrode layer changed, the metal that is the upper electrode layer The lowest substrate heating temperature at which an oxide film can be formed is measured. This lowest substrate heating temperature can be set as the “upper electrode layer forming temperature” in the spray method. At this time, whether or not the metal oxide film is formed is usually judged from the result obtained from an X-ray diffraction apparatus (Rigaku, RINT-1500). In the case of an amorphous film having no crystallinity, photoelectron spectroscopy is performed. It shall judge from the result obtained from the analyzer (the product made by VG Scientific, ESCALAB 200i-XL).

  In the spray method, the upper electrode layer is formed on the lower electrode layer by heating the lower electrode layer to a temperature equal to or higher than the upper electrode layer forming temperature and bringing it into contact with the upper electrode layer forming coating solution. As a result, a dense electrode layer can be obtained on the porous layer that is a porous body.

a. First, the upper electrode layer forming coating solution used in the spray method will be described. The upper electrode layer forming coating solution used in the spray method is a solution in which a metal compound having a metal element is dissolved in a solvent. As the metal compound, a metal salt or a metal complex can be used (hereinafter, the metal salt and the metal complex may be referred to as a metal source).

  The upper electrode layer forming coating solution preferably contains at least one of an oxidizing agent and a reducing agent. It is because an upper electrode layer can be obtained at a lower upper electrode layer formation temperature by containing at least one of an oxidizing agent and a reducing agent.

(Metal source)
The metal source used in the upper electrode layer forming coating solution may be a metal salt or a metal complex as long as it can form the upper electrode layer. The same metal source as the metal salt of the base electrode layer forming coating solution described in the solution treatment step described above can be used, but the upper electrode layer acts as a collecting electrode. Therefore, a metal source that can obtain an upper electrode layer having light transmittance and conductivity is particularly preferable.
The metal oxide constituting such an upper electrode layer is not particularly limited as long as it can constitute an upper electrode layer having transparency and conductivity. For example, ITO, ZnO, FTO (fluorine-doped tin oxide), ATO (antimony-doped tin oxide), SnO ₂ (TO) and the like can be mentioned. Therefore, as a metal source constituting such a metal oxide, in the case of ITO, for example, tris (acetylacetonato) indium (III), indium (III) 2-ethylhexanoate, tetraethyltin, dibutyltin oxide ( IV), tricyclohexyl tin (IV) hydroxide and the like can be used.
In the case of ZnO, zinc acetylacetonate, zinc lactate trihydrate, zinc salicylate trihydrate, zinc stearate and the like can be used.
In the case of the FTO, for example, tetraethyltin, dibutyltin oxide (IV), tricyclohexyltin (IV) hydroxide, or the like can be used, and ammonium fluoride or the like can be used as the fluorine doping agent.
In the case of the above ATO, for example, antimony (III) butoxide, antimony (III) ethoxide, tetraethyltin, dibutyltin oxide (IV), tricyclohexyltin (IV) hydroxide and the like can be used.
In the case of SnO ₂ (TO), tetraethyltin, dibutyltin oxide (IV), tricyclohexyltin (IV) hydroxide, or the like can be used.

  Further, the metal source used in the upper electrode layer forming coating solution may be the same as or different from the metal source used in the base electrode layer coating solution described above. The combination of the upper electrode layer and the base electrode layer will be described in the section “c.

In addition, the concentration of the metal source in the upper electrode layer forming coating solution is not particularly limited as long as it is within a range in which a desired upper electrode layer can be obtained, but is usually 0 when the metal source is a metal salt. It is preferably in the range of 0.001 mol / L to 1 mol / L, and more preferably in the range of 0.01 mol / L to 0.5 mol / L.
On the other hand, when the metal source is a metal complex, it is usually preferably in the range of 0.001 mol / L to 1 mol / L, and in particular, in the range of 0.01 mol / L to 0.5 mol / L. preferable. If the concentration is below the above range, it may take too much time to form the upper electrode layer, and if the concentration is above the above range, an upper electrode layer with a uniform thickness may not be obtained. Because.

(Other)
Further, the oxidizing agent, reducing agent, solvent, additive, and the like used in the upper electrode layer forming coating solution are the same as those described in the above-described solution processing step, and thus the description thereof is omitted here.

b. Next, a method for contacting the upper electrode layer-forming coating liquid and the base electrode layer in the spray method will be described. Such a contact method is not particularly limited as long as the above-described upper electrode layer forming coating solution can be continuously brought into contact with a base electrode layer formed in a long heat-resistant substrate shape. It is not something. In particular, in this step, it is preferable to use a method that does not lower the temperature of the heated base electrode layer when the upper electrode layer forming coating solution and the base electrode layer are continuously brought into contact with each other. This is because if the temperature of the base electrode layer is lowered, a desired upper electrode layer may not be obtained.

  The method for not lowering the temperature is not particularly limited. For example, the upper electrode layer is formed on the base electrode layer by spraying the upper electrode layer forming coating liquid as droplets. A method of continuously contacting the coating liquid for coating, a method of continuously passing the long heat-resistant substrate on which the base electrode layer is formed in a space in which the coating solution for forming the upper electrode layer is mist-shaped, etc. Can be mentioned.

  In the case of spraying using the above spray device, the diameter of the droplets is preferably preferably in the range of 0.1 μm to 1000 μm, and more preferably in the range of 0.5 μm to 300 μm. If the droplet diameter is within the above range, temperature drop can be suppressed, and a continuously uniform upper electrode layer is obtained on the base electrode layer formed on the long heat-resistant substrate. Because you can. Moreover, as spray gas of the said spray apparatus, air, nitrogen, argon, helium, oxygen etc. can be mentioned, for example. Further, the injection amount of the injection gas is preferably in the range of 0.1 L / min to 50 L / min, and more preferably in the range of 1 L / min to 20 L / min.

  On the other hand, in the case where the long heat-resistant substrate on which the base electrode layer is formed is continuously passed through the space in which the above-described upper electrode layer forming coating solution is made into a mist, the upper electrode layer forming coating is used. The diameter of the liquid droplets is usually 0.1 μm to 300 μm, preferably 1 μm to 100 μm. This is because if the diameter of the droplet is within the above range, the temperature drop of the base electrode layer can be suppressed, and a continuous and uniform upper electrode layer can be obtained on the base electrode layer.

In the spray method, when the upper electrode layer forming coating solution and the heated base electrode layer are brought into contact with each other, the base electrode layer is heated to a temperature equal to or higher than the “upper electrode layer forming temperature”. . Such “upper electrode layer forming temperature” varies greatly depending on the type of metal ions and the like formed by dissolving the metal source, the composition of the upper electrode layer forming coating solution, and the like. When an oxidizing agent and / or a reducing agent is not added to the working liquid, it is usually preferably in the range of 400 ° C to 600 ° C, and more preferably in the range of 450 ° C to 550 ° C.
On the other hand, when an oxidizing agent and / or a reducing agent is added to the upper electrode layer forming coating solution, it can usually be in the range of 150 ° C. to 600 ° C., and in particular, in the range of 250 ° C. to 400 ° C. Is preferred. In particular, when the electrode layer of the ITO film is formed using the spray method, the temperature is preferably in the range of 300 ° C. to 500 ° C., and more preferably in the range of 350 ° C. to 450 ° C. More preferred.

Such a heating method is not particularly limited as long as it is a method capable of continuously heating the base electrode layer. Examples of such a method include heating methods such as an infrared lamp and a hot air blower.
Moreover, when this process is a continuous process with the said baking process, the residual heat of baking in the said baking process can be utilized.

c. Others The combination of the metal oxide constituting the base electrode layer and the metal oxide constituting the upper electrode layer is not particularly limited as long as an electrode layer having a desired density can be obtained. Among them, a combination in which the metal oxide crystal system is close is preferable, and a combination in which the metal elements are common is particularly preferable.

For example, when the upper electrode layer is an ITO film, the base electrode layer is not particularly limited as long as a dense ITO film can be formed as the upper electrode layer. For example, ZnO, ZrO ₂ , Al ₂ O ₃ , Y ₂ O ₃ , Fe ₂ O ₃ , Ga ₂ O ₃ , La ₂ O ₃ , Sb ₂ O ₃ , ITO, In ₂ O ₃ , SnO _2, etc. From the viewpoint that the ITO film is close to the crystal system, Al ₂ O ₃ , Y ₂ O ₃ , Fe ₂ O ₃ , Ga ₂ O ₃ , La ₂ O ₃ , Sb ₂ O ₃ , ITO, In ₂ O ₃ , SnO ₂ In particular, from the viewpoint that the metal elements (In, Sn) constituting the metal oxide film (ITO film) are common, ITO, In ₂ O ₃ , and SnO ₂ are more preferable.

  The film thickness of the electrode layer formed in this step is not particularly limited as long as it is a film thickness that can exhibit excellent conductivity, and specifically, within the range of 5 nm to 2000 nm, among them. It is preferably within the range of 10 nm to 1000 nm.

(2) Spray Method Next, the spray method in this step will be described. In the spray method in this step, the porous layer is heated to a temperature equal to or higher than the electrode layer forming temperature, and is brought into contact with the electrode layer forming coating solution in which the metal compound having the metal element constituting the electrode layer is dissolved. This is a method of providing an electrode layer on the porous layer.

  The spray method is a method in which an electrode layer is directly provided on a porous layer without performing a solution treatment step in the solution spray method described above. Since the solution treatment step is not performed, an electrode layer can be obtained by a simple method on the porous layer that is a porous body. In addition, since the spray method in this process is the same as the spray method used for the spray processing process of the solution spray method mentioned above, description here is abbreviate | omitted. The electrode layer formation temperature in the spray method in this step can be determined in the same manner as the upper electrode layer formation temperature in the spray method used in the solution spray method described above.

  The film thickness of the electrode layer formed in this step is not particularly limited as long as it is a film thickness that can exhibit excellent conductivity, and specifically, within the range of 5 nm to 2000 nm, among them. It is preferably within the range of 10 nm to 1000 nm.

4). Next, the bonding process in the present invention will be described. In the bonding step, in the electrode layer forming step, the electrode is formed such that an adhesive layer made of a resin material and a base material are laminated in this order on the electrode layer formed on the porous layer. In this step, the adhesive layer and the substrate are continuously bonded onto the layer.

(1) Adhesive layer The adhesive layer bonded on the said electrode layer in this process is demonstrated. The adhesive layer used in the present invention is made of a resin material.

  The resin material in this step is not particularly limited as long as it can bond the electrode layer and the base material with desired strength. Examples of such resin materials include thermoplastic resins, thermosetting resins, ultraviolet curable resins, electron beam curable resins, and two-component curable resins. In particular, in this step, it is preferable to use a thermoplastic resin, a thermosetting resin, and an ultraviolet curable resin from the viewpoint of simplifying the process.

  The thermoplastic resin preferably has a melting point in the range of 50 ° C to 200 ° C, particularly preferably in the range of 60 ° C to 180 ° C, and in particular, in the range of 65 ° C to 150 ° C. Those are preferred. The heating temperature at the time of heat-sealing the adhesive layer and the electrode layer whose melting point of the thermoplastic resin is higher than the above range may become high, and the base material described later may be thermally damaged. Because. If the melting point is lower than the above range, for example, when a dye-sensitized solar cell produced using the oxide semiconductor electrode produced according to the present invention is used outdoors, the adhesive layer may be melted depending on the use environment. Because it will do.

  Specific examples of such thermoplastic resins include polyethylene, polypropylene, polyisobutylene, polystyrene, polyolefins such as ethylene-propylene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethyl cellulose, cellulose triacetate. Cellulose derivatives such as poly (meth) acrylic acid and its esters, polyvinyl acetal such as polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyacetal, polyamide, polyimide, nylon, polyester resin, urethane resin, epoxy resin , Silicone resin, fluorine resin and the like. Of these, polyolefins, ethylene-vinyl acetate copolymers, urethane resins, epoxy resins, silane-modified resins, and acid-modified resins are preferred from the viewpoints of adhesiveness, resistance to electrolytic solutions, light transmittance, and transferability. It is preferable to use a modified resin.

  In this step, it is preferable to use a copolymer of a polyolefin compound and an ethylenically unsaturated silane compound among the silane-modified resins. This is because by using such a copolymer, it is easy to adjust various physical properties of the silane-modified resin within a suitable range.

  The thermosetting resin preferably has a curing temperature in the range of 20 ° C. to 200 ° C., particularly preferably in the range of 40 ° C. to 150 ° C., and more preferably in the range of 60 ° C. to 120 ° C. Are preferred.

  Examples of such thermosetting resins include epoxy resins, diallyl phthalate resins, silicone resins, phenol resins, unsaturated polyester resins, polyimide resins, polyurethane resins, melamine resins, urea resins, and fluorine resins. . Among these, in this step, it is preferable to use a silicone resin, a fluororesin, or an epoxy resin.

  The ultraviolet curable resin is not particularly limited as long as it can be cured without damaging the substrate when irradiated with ultraviolet rays from the substrate side and cured. Examples of such ultraviolet curable resins include acrylate monomers, methacrylate monomers, cationic polymerization monomers, acrylate oligomers, polyester oligomers, epoxy acrylate oligomers, urethane acrylate oligomers, and the like. In particular, it is preferable to use an acrylate monomer or an acrylate oligomer in this step.

  The thickness of the adhesive layer used in this step is not particularly limited as long as it is within a range in which a necessary adhesive force can be expressed, depending on the type of resin material constituting the adhesive layer, but is usually within a range of 5 μm to 300 μm. In particular, the range of 10 μm to 200 μm is preferable. If the thickness of the adhesive layer is thinner than the above range, a desired adhesive force may not be obtained, and if the thickness is thicker than the above range, excessive heating is required to sufficiently express the interlayer adhesive strength by the adhesive layer. This is because the thermal damage to the base material and the like may increase.

(2) Base material The base material used for this process is demonstrated. The base material used in this step has a long shape. Here, the “long” is the same as the content related to the “long” of the heat-resistant substrate described in the section “1. Porous layer forming layer forming step”.

  For example, when the oxide semiconductor electrode produced according to the present invention is used in a dye-sensitized solar cell, the base material used in this step is disposed on the forefront for receiving sunlight. Therefore, it is preferable to use a material that has high transparency to sunlight. More specifically, the transmittance for light with a wavelength of 400 nm to 1000 nm is preferably 78% or more, and more preferably 80% or more. When the transmittance of the substrate is lower than the above range, for example, when a dye-sensitized solar cell is prepared using the oxide semiconductor electrode manufactured according to the present invention, the power generation efficiency of the dye-sensitized solar cell is This is because it may be damaged.

Moreover, it is preferable that the base material used for this process is the thing excellent in heat resistance, a weather resistance, water vapor | steam, and other gas-barrier property among what has the said transparency. When the base material has gas barrier properties, for example, when a dye-sensitized solar cell is prepared using the oxide semiconductor electrode produced according to the present invention, the temporal stability of the dye-sensitized solar cell can be improved. Because. More specifically, it is 1 cc / m ² / day · atm or less under the conditions of an oxygen permeability of 23 ° C. and a humidity of 90%, and 1 g / m ² under a condition of a water vapor permeability of 37.8 ° C. and a humidity of 100%. It is preferable to use a base material having a gas barrier property of m ² / day or less. In order to achieve such a gas barrier property, a substrate provided with a gas barrier layer on an arbitrary substrate may be used as the substrate used in the present invention.

Specific examples of the substrate used in this step include quartz glass, Pyrex (registered trademark), a transparent rigid material such as a synthetic quartz plate, an ethylene / tetrafluoroethylene copolymer film, and biaxial stretching. Polyethylene terephthalate film, polyethersulfone (PES) film, polyetheretherketone (PEEK) film, polyetherimide (PEI) film, polyimide (PI) film, polyester naphthalate (PEN), polycarbonate (PC) and other resins Mention may be made of a film substrate.
Especially in this invention, it is preferable to use the said resin-made film base materials. This is because by using a resin film base material, all the steps in the present invention can be made into a roll-to-roll process, so that an oxide semiconductor electrode can be manufactured with higher productivity.

  Furthermore, it is preferable to use a biaxially stretched polyethylene terephthalate film (PET), polyester naphthalate (PEN), or polycarbonate (PC) among the resin film base materials in this step.

  In addition, the base material in this process may be used individually by 1 type, and 2 or more types may be laminated | stacked and used for it.

  The thickness of the base material used in this step is usually preferably in the range of 50 μm to 2000 μm, more preferably in the range of 75 μm to 1800 μm, and particularly preferably in the range of 100 μm to 1500 μm. preferable. When the thickness of the substrate is thinner than the above range, for example, when a dye-sensitized solar cell is produced using the oxide semiconductor electrode produced according to the present invention, the self-supporting property necessary for the dye-sensitized solar cell is obtained. This is because it may not be ensured, and if the thickness is larger than the above range, the workability may be impaired.

(3) Others As an aspect in which the adhesive layer and the base material are bonded on the electrode layer in this step, the electrode layer and the base material can be continuously bonded via the adhesive layer. If it is an aspect, it will not specifically limit. As such an embodiment, for example, when an adhesive layer made of a thermoplastic resin is used as the adhesive layer, an adhesive layer made of a thermoplastic resin is formed on the electrode layer, and then the base layer is formed on the adhesive layer. A mode in which materials are thermally fused, a mode in which a laminated body in which the adhesive layer is laminated on the substrate is prepared in advance, and the laminated body is thermally fused so that the adhesive layer and the electrode layer are in contact with each other. And a method of preparing a dry film made of a thermoplastic resin in advance and thermally fusing the electrode layer and the substrate through the dry film. As a specific heat fusion method, a method of laminating between heat rolls is most preferable, but the shape of the press surface at the time of heat laminating is not limited to the roll shape, for example, one side is on the surface. A method of supporting and pressing the other surface with a roll can also be used. Further, the heat source may be single-sided or double-sided.

  In the case where an adhesive layer made of a thermosetting resin is used as the adhesive layer described later, for example, an adhesive layer made of a thermosetting resin is formed on the electrode layer, and then the base material is pasted on the adhesive layer. After that, a mode in which thermosetting is performed by applying a predetermined temperature, or a laminate in which the adhesive layer made of a thermosetting resin is previously laminated on a base material is bonded to the electrode layer, and the predetermined temperature is set. A mode in which the adhesive layer is cured by applying a film and a dry film made of a thermosetting resin are prepared in advance, the electrode layer and the base material are bonded to each other through the dry film, and then a predetermined temperature is applied. The aspect etc. which harden the said contact bonding layer by this can be mentioned. Further, as a specific thermosetting method, for example, a method of holding the adhesive layer and the transparent electrode in a predetermined thermosetting temperature atmosphere for a predetermined curing time can be exemplified.

  Further, when an adhesive layer made of an ultraviolet curable resin is used as the adhesive layer described later, for example, an adhesive layer made of an ultraviolet curable resin is formed on the electrode layer, and then the substrate is pasted on the adhesive layer. Then, an aspect of curing by irradiating with ultraviolet rays of a predetermined wavelength, or a laminate in which the adhesive layer made of an ultraviolet curable resin is previously laminated on a base material is bonded to the electrode layer, A mode of curing by irradiating with ultraviolet rays having a wavelength of, and a dry film made of an ultraviolet curable resin is prepared in advance, and the electrode layer and the base material are bonded to each other through the dry film, and then a predetermined wavelength. The mode etc. which harden | cure by irradiating an ultraviolet-ray etc. can be mentioned. In addition, as a specific curing method, there may be mentioned a method of irradiating a light source having a predetermined wavelength from the base material side until a predetermined irradiation light amount is reached in a state where the adhesive layer and the electrode layer are bonded together. it can.

5. Next, the heat-resistant substrate peeling process in this invention is demonstrated. This step is a step of continuously peeling the long heat-resistant substrate adhered to the porous layer.

  The method for peeling the long heat-resistant substrate in this step is not particularly limited as long as it is a method capable of continuously peeling the long heat-resistant substrate, and a general peeling method is used. Can do. Examples of such a method include a method of winding the long heat-resistant substrate and the long oxide semiconductor electrode formed by peeling the long heat-resistant substrate on separate rolls. be able to.

  Moreover, as an aspect which peels a heat-resistant board | substrate in this process, you may peel between layers from the boundary of a heat-resistant board | substrate and a porous layer, and may peel with the cohesive failure of a porous layer. Further, when the porous layer is composed of two layers of the oxide semiconductor layer and the intervening layer, the heat resistant substrate is peeled off from the intervening layer. In this case as well, the heat resistant substrate is similarly formed between the heat resistant substrate and the intervening layer. Delamination may occur from the boundary, or may occur with cohesive failure of the intervening layer.

6). Other Steps The present invention has other steps other than the layer forming step for forming the porous layer, the firing step, the electrode layer forming step, the bonding step, and the heat-resistant substrate peeling step. Also good. Examples of such other steps include a dye sensitizer carrying step.

  The dye sensitizer carrying step will be described. The dye sensitizer carrying step is a step that is arranged after the heat-resistant substrate peeling step and carries the dye sensitizer on the porous layer. Since the present invention has such a dye sensitizer carrying step, the oxide semiconductor electrode produced according to the present invention can be used as a substrate for a dye-sensitized solar cell used in a dye-sensitized solar cell. become.

  In this step, as a method of supporting the dye sensitizer on the porous layer, a method capable of continuously adsorbing the dye sensitizer on the surface of the metal oxide semiconductor fine particles contained in the porous layer. If it is, it will not specifically limit. Examples of such a method include a method in which a solution of a dye sensitizer is continuously applied to a porous layer and allowed to permeate and then dried.

  The dye sensitizer used in this step is not particularly limited as long as a charge is generated by light irradiation. As such a dye sensitizer, for example, an organic dye or a metal complex dye can be used. Examples of the organic dye include acridine dyes, azo dyes, indigo dyes, quinone dyes, coumarin dyes, merocyanine dyes, and phenylxanthene dyes. Of these, a coumarin type is preferable in this step.

  The metal complex dye is preferably a ruthenium dye, and particularly preferably a ruthenium bipyridine dye and a ruthenium terpyridine dye, which are ruthenium complexes. The oxide semiconductor layer can hardly absorb visible light (light having a wavelength of about 400 to 800 nm). For example, by supporting a ruthenium complex on the oxide semiconductor layer, the visible light can be greatly absorbed. This is because conversion can be caused and the wavelength range of light that can be photoelectrically converted can be greatly expanded.

7). Method for Producing Oxide Semiconductor Electrode The method for producing an oxide semiconductor electrode of the present invention comprises the above-mentioned porous layer forming layer forming step, the firing step, the electrode layer forming step, the bonding step, and the heat-resistant substrate peeling. It has a process. In FIG. 1 described above, an example in which these steps are all separate steps has been described. However, in the present invention, a plurality of steps may be continuous steps. Here, the “continuous process” means that two consecutive processes are performed continuously without a winding process between the two processes.

  Such “continuous process” will be described with reference to the drawings. FIG. 2 is a schematic diagram for explaining an example of the “continuous process” in the present invention. In FIG. 2, an example of the “continuous process” will be described using the firing process (FIG. 1B) and the electrode layer forming process (FIG. 1C). In the present invention, the case where the firing step (FIG. 1 (b)) and the electrode layer forming step (FIG. 1 (c)) are “continuous steps”, as illustrated in FIG. After unwinding the body 11, the porous layer forming layer 2 ′ is heated and fired to form a porous layer 2 made of a porous body, and then the porous layer 2 is heated continuously without being wound. In this state, the electrode layer 3 is formed by applying the electrode layer forming coating solution 3 ′ to the porous layer 2, and then the porous layer 2 and the electrode layer 3 are laminated on the heat-resistant substrate 1. This is a mode in which the laminated body 13 is wound up into a roll.

  In the present invention, the oxide semiconductor electrodes may be manufactured with higher productivity because each of the above processes is a continuous process in a predetermined combination. The combination of the steps constituting the continuous step in the present invention is not particularly limited, and any combination can be made according to a specific embodiment of each step. Especially in this invention, as illustrated in FIG. 2, it is preferable that the said baking process and the said electrode layer formation process are a continuous process. Since the firing step and the electrode ancestor formation step are continuous steps, it becomes possible to utilize the residual heat of the porous layer fired by the firing step in the electrode layer formation step. This is because the heat treatment for heating the porous layer in the forming step is not necessary, and thus the oxide semiconductor electrode can be more easily manufactured.

  Moreover, in this invention, it is preferable that the said baking process, the said electrode layer formation process, the said bonding process, and the said heat-resistant board | substrate peeling process are continuous processes. For example, when an intervening layer is formed between the substrate and the porous layer, after passing through the firing step, the porous body passes through the intervening layer having low adhesion to the heat resistant base substrate on the heat resistant substrate. Since the laminated body in which the porous layer which becomes is formed is formed, when the said laminated body is wound up in roll shape, there exists a possibility that an intervening layer may peel from the said heat-resistant board | substrate. However, since the firing step, the electrode layer forming step, the bonding step, and the heat-resistant substrate peeling step are continuous steps, the laminate in which the heat-resistant substrate and the intervening layer are bonded is wound into a roll. This is because there is no such a problem because there is no process of taking.

  Furthermore, in this invention, it is preferable that the said layer forming process for porous layer formation, the said baking process, the said electrode layer forming process, the said bonding process, and the said heat-resistant board | substrate peeling process are continuous processes. This is because when the present invention is such a continuous process, an oxide semiconductor electrode can be manufactured with the highest productivity. Further, in such a continuous process, an endless belt-like heat-resistant substrate can be circulated and used as the long heat-resistant substrate, whereby an oxide semiconductor electrode can be manufactured at a lower cost.

  The above-described porous layer forming layer forming step, the firing step, the electrode layer forming step, the bonding step, and the heat resistant substrate peeling step are continuous steps, and the long heat resistant substrate. An example of using an endless belt-like heat-resistant substrate will be described with reference to the drawings. As illustrated in FIG. 3, when the porous layer forming layer forming step, the firing step, the electrode layer forming step, the bonding step, and the heat resistant substrate peeling step are continuous steps, Since the endless belt-shaped heat-resistant substrate 1 ′ can be used as the long heat-resistant substrate, and the heat-resistant substrate 1 ′ can be circulated and used, an oxide semiconductor electrode can be manufactured at a lower cost. be able to. Also, as shown in the example of FIG. 3, when the endless belt-shaped heat-resistant substrate 1 ′ is circulated and used, the heat-resistant substrate 1 ′ is placed between the heat-resistant substrate peeling step and the porous layer forming layer forming step. You may have the washing process which wash | cleans the surface.

  Furthermore, in this invention, when the said bonding process and the said heat-resistant board | substrate peeling process are continuous processes, both processes may be united. This is because the manufacturing apparatus for carrying out the method for manufacturing an oxide semiconductor electrode of the present invention can be further simplified. In addition, as an example in case the said bonding process and the said heat-resistant board | substrate peeling process are united, for example, the said bonding process and the said heat-resistant board | substrate peeling using the same roll so that it may illustrate in FIG. An example of performing the process can be given.

8). Oxide Semiconductor Electrode An oxide semiconductor electrode produced according to the present invention is a porous material comprising an adhesive layer made of a resin material, an electrode layer made of a metal oxide, and metal oxide semiconductor fine particles on a long base material. The layers are stacked in this order.
Therefore, the oxide semiconductor electrode manufactured according to the present invention can be used for various applications by cutting into a predetermined size. Examples of such applications include, for example, a dye-sensitized photocharging capacitor substrate used for a dye-sensitized photocharging capacitor, an electrochromic display substrate used for an electrochromic display, and a photocatalytic reaction in the atmosphere. It can be used as a pollutant-decomposing substrate capable of decomposing these pollutants, and a dye-sensitized solar cell substrate used for a dye-sensitized solar cell. Especially, it uses suitably for the base material for dye-sensitized solar cells used for a dye-sensitized solar cell.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the technical idea described in the claims of the present invention has substantially the same configuration and exhibits the same function and effect regardless of the case. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be described more specifically with reference to examples.

1% by mass of TiO ₂ fine particles having a primary particle size of 20 nm (Nippon Aerosil P25), 10% by mass of acrylic resin (molecular weight 25000, glass transition temperature 105 ° C.) whose main component is polymethyl methacrylate (BR87 manufactured by Mitsubishi Rayon Co., Ltd.) In this way, an acrylic resin was dissolved in methyl ethyl ketone and toluene using a homogenizer, and then a coating solution for forming an intervening layer was prepared by dispersing TiO 2 fine particles. This coating solution was coated on a titanium substrate (thickness 120 μm, width 300 mm), which was a long substrate prepared as a heat-resistant substrate, by a roll-to-roll gravure printing machine and dried at 100 ° C. for 5 minutes.

  Next, Solar Nanox Ti Nanoxide D is prepared as a coating liquid for forming an oxide semiconductor layer, and coated on the titanium substrate on which the intervening layer forming layer is formed by a roll-to-roll die coater. C. for 30 minutes.

  Thereafter, firing was performed at 500 ° C. for 30 minutes in an air atmosphere in an open-type firing furnace of a roll-to-roll method, and organic components were decomposed and removed. As a result, a porous layer formed on the titanium substrate as a porous body and having a configuration in which the intervening layer and the oxide semiconductor layer were laminated was obtained.

  Subsequently, in order to form an electrode layer by spray pyrolysis, an electrode layer forming coating solution was prepared by dissolving 0.1 mol / L of indium chloride and 0.005 mol / L of tin chloride in ethanol. Then, the titanium substrate that has been baked is heated to 400 ° C. with an infrared heater with the porous layer facing upward, and the coating liquid is sprayed onto the heated porous layer with an ultrasonic sprayer. An ITO film as an electrode layer was formed with a thickness of 500 nm.

  A heat sealant (Toyobo MD1985) was applied as an adhesive layer on a PET film (Toyobo E5100, thickness 125 μm) as a long substrate and allowed to air dry. A long substrate coated with an adhesive layer is supplied from the second paper feed roll, and the electrode layer on the heat-resistant substrate supplied from the first paper feed roll is heated to 120 ° C. so that the adhesive layer adheres. Bonded with a roll.

  Further, after bonding, the long heat-resistant substrate was peeled off to transfer the electrode layer and the porous layer from the heat-resistant substrate side to the base material side, thereby obtaining a long oxide semiconductor layer electrode. At this time, the heat resistant substrate was wound into a roll shape by a winding mechanism, and the quality oxide semiconductor electrode was wound into a roll shape by another winding mechanism. With such a method, an oxide semiconductor could be manufactured with high productivity.

It is the schematic which shows an example of the manufacturing method of the oxide semiconductor electrode of this invention. It is the schematic explaining the continuous process in this invention. It is the schematic which shows the other example of the manufacturing method of the oxide semiconductor electrode of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 '... Heat-resistant board | substrate 2' ... Porous layer formation layer 2 ... Porous layer 3 ... Electrode layer 3 '... Electrode layer formation coating liquid 4 ... Adhesive layer 5 ... Base material 10 ... Oxide semiconductor electrode 11 -14 ... Laminated body

Claims (7)

An oxide semiconductor having a configuration in which an adhesive layer made of a resin material, an electrode layer made of a metal oxide, and a porous layer containing metal oxide semiconductor fine particles are laminated in this order on a long base material An electrode manufacturing method comprising:
Porous layer formation for forming a porous layer forming layer on the heat resistant substrate by continuously applying a porous layer forming coating liquid containing metal oxide semiconductor fine particles on a long heat resistant substrate Layer forming step,
A firing step of continuously firing the porous layer forming layer to make the porous layer forming layer a porous layer made of a porous body;
An electrode layer that forms an electrode layer on the porous layer by continuously applying a coating solution for forming an electrode layer containing a metal compound on the porous layer in a state where the porous layer is heated. Forming process;
A bonding step of continuously bonding the adhesive layer and the base material on the electrode layer so that the adhesive layer made of a resin material and the base material are laminated in this order on the electrode layer. When,
A heat-resistant substrate peeling step for continuously peeling the heat-resistant substrate;
A method for producing an oxide semiconductor electrode, comprising:   The porous layer forming layer forming step includes a metal oxide semiconductor fine particle on the long heat-resistant substrate, and a continuous intervening layer forming coating solution having a composition different from that of the porous layer forming coating solution is continuously formed. The intermediate layer forming layer is formed by applying the porous layer forming coating liquid on the intermediate layer forming layer formed on the heat-resistant substrate by the intermediate layer forming layer forming step. The method for producing an oxide semiconductor electrode according to claim 1, wherein the method is a step of forming a porous layer forming layer thereon.   3. The production of an oxide semiconductor electrode according to claim 1, further comprising a dye sensitizer carrying step of carrying a dye sensitizer on the porous layer after the heat-resistant substrate peeling step. Method.   The method for producing an oxide semiconductor electrode according to any one of claims 1 to 3, wherein the firing step and the electrode layer forming step are continuous steps.   The said baking process, the said electrode layer formation process, the said bonding process, and the said heat-resistant board | substrate peeling process are continuous processes, The claim in any one of Claim 1 to 3 characterized by the above-mentioned. Manufacturing method of oxide semiconductor electrode.   The said layer formation process for porous layer formation, the said baking process, the said electrode layer formation process, the said bonding process, and the said heat-resistant board | substrate peeling process are continuous processes, The Claims 1-3 characterized by the above-mentioned. The method for producing an oxide semiconductor electrode according to any one of the preceding claims.   The method for manufacturing an oxide semiconductor electrode according to claim 6, wherein the heat-resistant substrate has an endless belt shape.

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