JP2009277626A - Method of manufacturing acting electrode, acting electrode, and photoelectric conversion element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an acting electrode capable of manufacturing the acting electrode in which an increase in internal resistance due to the partial presence of an electrolyte when used for a photoelectric conversion element is prevented by a simple method, by eliminating nonuniformity of a surface irregularities of an oxide semiconductor porous layer. <P>SOLUTION: This manufacturing method of the acting electrode includes a process of forming the oxide semiconductor porous layer 21 on a transparent conductive substrate 10 by a lithographic printing method, a process of flattening its upper surface by uniformizing the thickness of the oxide semiconductor porous layer by pressing the upper surface of the oxide semiconductor porous layer by a plate by arranging the plate 60 having a die separable characteristic above the transparent conductive substrate via a spacer 61, a process of drying the oxide semiconductor porous layer in a state of pressing the upper surface of the oxide semiconductor porous layer by the plate, and a process of removing the plate after drying the oxide semiconductor porous layer and baking. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a working electrode having a porous oxide semiconductor layer, a working electrode, and a photoelectric conversion element.

  Against the backdrop of environmental issues and resource issues, solar cells as clean energy are attracting attention. However, conventional silicon-based solar cells still have problems such as high manufacturing costs and insufficient raw material supply, and have not yet been widely spread. In addition, although compound solar cells such as CIS have excellent characteristics such as extremely high photoelectric conversion efficiency, problems such as cost and environmental load are still an obstacle to widespread use.

  On the other hand, a dye-sensitized solar cell has attracted attention as a photoelectric conversion element that can be obtained at low cost and high photoelectric conversion efficiency (see, for example, Non-Patent Document 1). As a general structure of this photoelectric conversion element, a semiconductor electrode in which a porous film using oxide semiconductor nanoparticles such as titanium dioxide is formed on a transparent conductive substrate and a sensitizing dye is supported on the porous film. And a counter electrode such as a platinum-sputtered conductive glass, and an organic electrolyte containing an oxidizing / reducing species such as iodine / iodide ions between the two electrodes as a charge transfer layer.

In such a photoelectric conversion element, it has been reported that the semiconductor electrode has a porous structure having a large specific surface with a roughness factor> 1000, thereby increasing the light absorption rate and a photoelectric conversion efficiency of 10% or more. In terms of cost, it is expected to be about 1/2 to 1/6 that of current silicon-based solar cells, and does not necessarily require complicated and large-scale manufacturing facilities, and does not contain harmful substances. It can be said that it has high potential as an inexpensive and mass-produced solar cell that can be produced.
As the transparent substrate used here, a glass substrate is generally coated with a transparent conductive film such as tin-added indium oxide (ITO) or fluorine-added tin oxide (FTO) in advance by a technique such as vapor deposition or sputtering.

  In the above photoelectric conversion element, a technique using screen printing is used for forming the porous oxide semiconductor layer. This screen printing is a printing technique that uses a method in which a printing plate called a stencil is penetrated by small holes and the ink is rubbed from a hole in the plate itself. This screen printing has a feature that the printing pressure is low, a delicate material such as glass can be applied as a printing medium, and the manufacturing cost is low. Therefore, since it is possible to print a highly viscous substance on a material such as glass with a transparent conductive film, it is often used in a process for producing a dye-sensitized photoelectric conversion element (see, for example, Patent Document 1). ).

  However, since screen printing is performed by penetrating the ink from the mesh, if a substance having a high viscosity is used as the ink, the shape of the mesh is not formed on the coating film formed from the ink ejected from the mesh holes. Reflected irregularities may occur. In general, various additives are added to adjust the viscosity of the ink so that the surface after application becomes smooth (leveling), but that alone may not be sufficient. This tendency is particularly strong in ink composed of pigment particles such as titanium oxide.

  As the electrode of the dye-sensitized photoelectric conversion element, an electrode made of nano-sized titanium oxide particles or the like is applied onto conductive glass by screen printing and baked to form a porous oxide semiconductor layer. The electrode having a sensitizing dye adsorbed on this electrode serves as a photo-active electrode, and functions as a photoelectric conversion element by sandwiching an electrolyte solution containing an oxidation-reduction pair such as iodine between a counter electrode coated with platinum or the like.

At this time, if the coating film of the porous oxide semiconductor layer has irregularities, the distance between the two electrodes is determined by the film thickness of the convex part, and an excessive electrolyte solution enters the concave part. Since the electrolyte solution is the material having the highest electrical resistance value among the materials constituting the battery, using an excessive electrolyte solution causes an increase in the internal resistance of the battery.
Thus, due to the non-uniformity of the thickness of the porous oxide semiconductor layer, the electrolyte is unevenly distributed in the recesses on the surface of the porous oxide semiconductor layer, and the internal resistance increases in the photoelectric conversion element, and the photoelectric conversion efficiency It was a cause of lowering.
O 'Regan B, Gratzel M. A low cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films, Nature 1991; 353: 737-739 JP 2006-92854 A

The present invention has been devised in view of such conventional circumstances, and eliminates unevenness of the surface unevenness of the oxide semiconductor porous layer, and when used in a photoelectric conversion element, it is due to uneven distribution of the electrolyte. It is a first object of the present invention to provide a working electrode manufacturing method capable of manufacturing a working electrode in which an increase in internal resistance is prevented by a simple method.
In addition, the present invention provides a working electrode that eliminates unevenness of the surface unevenness of the oxide semiconductor porous layer and prevents an increase in internal resistance due to uneven distribution of the electrolyte when used in a photoelectric conversion element. Second purpose.
It is a third object of the present invention to provide a photoelectric conversion element that eliminates unevenness of the surface unevenness of the oxide semiconductor porous layer in the working electrode and prevents an increase in internal resistance due to uneven distribution of the electrolyte. And

The manufacturing method of the working electrode of Claim 1 of this invention is equipped with a transparent conductive substrate and the oxide semiconductor porous layer distribute | arranged on the said transparent conductive substrate, The said oxide semiconductor porous layer A method for producing a working electrode having a uniform thickness and a flat upper surface, wherein the oxide semiconductor porous layer is formed on the transparent conductive substrate by a stencil printing method; A flat plate having releasability is disposed above the transparent conductive substrate via a spacer, and the upper surface of the oxide semiconductor porous layer is pressed by the flat plate, whereby the oxide semiconductor porous layer A step of making the thickness uniform and flattening the upper surface, a step of drying the oxide semiconductor porous layer while pressing the upper surface of the porous oxide semiconductor layer with the flat plate, and the oxide After drying the semiconductor porous layer, the flat plate Removed by It, and comprising the a step of firing.
According to a second aspect of the present invention, there is provided a method for producing a working electrode according to the first aspect, wherein the oxide semiconductor porous layer is made of titanium oxide, zinc oxide, tin oxide, tungsten oxide, barium titanate, or strontium titanate. It is formed by any material.
The working electrode according to claim 3 of the present invention includes a transparent conductive substrate and an oxide semiconductor porous layer disposed on the transparent conductive substrate, and the oxide semiconductor porous layer has a thickness of It is uniform and its upper surface is made flat.
The photoelectric conversion element according to claim 4 of the present invention includes a working electrode, a counter electrode, and an electrolyte layer made of an electrolyte enclosed between the working electrode, the working electrode, the transparent conductive substrate, and the transparent electrode. An oxide semiconductor porous layer disposed on a conductive substrate, wherein the oxide semiconductor porous layer has a uniform thickness and a flat upper surface.

  In the present invention, after the oxide semiconductor porous layer is formed by the stencil printing method, the thickness of the oxide semiconductor porous layer is pressed by pressing the upper surface of the oxide semiconductor porous layer with a release plate. Can be made uniform and the upper surface thereof can be flattened. Thereby, the unevenness | corrugation of the surface asperity of an oxide semiconductor porous layer can be eliminated. As a result, in the present invention, when used in a photoelectric conversion element, there is provided a method for producing a working electrode that can produce a working electrode that prevents uneven distribution of the electrolyte and an increase in internal resistance due to the electrolyte by a simple method. Can be provided.

  In the present invention, the thickness of the oxide semiconductor porous layer is uniform and the top surface thereof is flattened, so that the unevenness of the surface unevenness of the oxide semiconductor porous layer is eliminated. As a result, in the present invention, when used in a photoelectric conversion element, it is possible to provide a working electrode that prevents uneven distribution of the electrolytic solution and increase in internal resistance resulting therefrom.

  In the present invention, the oxide semiconductor porous layer has a uniform thickness and a flat top surface at the working electrode. Disappear. As a result, according to the present invention, it is possible to provide a photoelectric conversion element that prevents uneven distribution of the electrolytic solution and increase in internal resistance resulting therefrom.

  Hereinafter, an embodiment of a working electrode and a photoelectric conversion element according to the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing one embodiment of a working electrode of the present invention.
The working electrode 20 includes a transparent conductive substrate 10 and an oxide semiconductor porous layer 21 disposed on the transparent conductive substrate 10.

The working electrode 20 according to the present invention is characterized in that the oxide semiconductor porous layer 21 has a uniform thickness and the upper surface 21a is flat.
Here, in the present specification, the oxide semiconductor porous layer 21 “having a uniform thickness and its upper surface 21a is flat” means that when the surface of the upper surface 21a is observed in units of mm, it is localized. This means that the height difference is reduced and the distance from the lower surface of the working electrode 20 to the upper surface 21a is constant.

  In the present invention, since the thickness of the oxide semiconductor porous layer 21 is uniform and the upper surface 21a is flat, the unevenness of the surface unevenness of the oxide semiconductor porous layer 21 is eliminated. As a result, when the working electrode 20 of the present invention is used in a photoelectric conversion element, it is possible to prevent uneven distribution of the electrolytic solution and increase in internal resistance resulting therefrom.

The transparent conductive substrate 10 is roughly composed of a transparent base material 11 and a transparent conductive film 12 formed on one surface 11a thereof.
As the transparent base material 11, a substrate made of a light-transmitting material is used, and any glass, polyethylene terephthalate, polycarbonate, polyethersulfone, or the like that is usually used as a transparent base material for photoelectric conversion elements can be used. Can be used. The transparent substrate 11 is appropriately selected from these in consideration of resistance to the electrolytic solution. Moreover, as a transparent base material 11, the board | substrate which is excellent in the light transmittance as much as possible is preferable on a use, and the board | substrate whose transmittance | permeability is 90% or more is more preferable.

The transparent conductive film 12 is a thin film formed on one surface 11a in order to impart conductivity to the transparent substrate 11. In the present invention, the transparent conductive film 12 is preferably a thin film made of a conductive metal oxide so that the transparency of the transparent conductive substrate 10 is not significantly impaired.
Examples of the conductive metal oxide that forms the transparent conductive film 12 include tin-added indium oxide (ITO), fluorine-added tin oxide (FTO), and tin oxide (SnO ₂ ).

Among these, ITO and FTO are preferable from the viewpoint of easy film formation and low manufacturing costs. The transparent conductive film 12 is preferably a single layer film made of only ITO or a laminated film in which a film made of FTO is laminated on a film made of ITO.
By making the transparent conductive film 12 a single layer film made of only ITO or a laminated film made by laminating a film made of FTO on a film made of ITO, the amount of light absorption in the visible region is small, and the conductivity A transparent conductive substrate 10 having a high thickness can be formed.

The oxide semiconductor porous layer 21 is one or more of titanium oxide (TiO ₂ ), tin oxide (SnO ₂ ), tungsten oxide (WO ₃ ), zinc oxide (ZnO), niobium oxide (Nb ₂ O ₅ ), and the like. It is a porous thin film which consists of oxide semiconductor fine particles in which seeds are combined, has countless fine pores inside, and has fine irregularities on the surface. The average particle diameter of the oxide semiconductor fine particles is preferably in the range of 1 to 1000 nm. The thickness of the oxide semiconductor porous film 21 is preferably about 0.5 to 50 μm.

  The oxide semiconductor porous layer 21 carries a photosensitizing dye. This photosensitizing dye includes ruthenium complexes containing ligands such as bipyridine structure and terpyridine structure, metal complexes such as porphyrin and phthalocyanine, and organic dyes such as eosin, rhodamine and merocyanine. It can be appropriately selected according to the type of semiconductor.

  In particular, in the working electrode 20 of the present invention, the thickness of the oxide semiconductor porous layer 21 is uniform and the upper surface 21a thereof is flat. The uniformity is lost. As a result, when the working electrode 20 of the present invention is used in a photoelectric conversion element, it is possible to prevent uneven distribution of the electrolytic solution and increase in internal resistance resulting therefrom.

Next, the manufacturing method of the working electrode 20 of this invention is demonstrated.
FIG. 2 is a cross-sectional view showing the method of manufacturing the working electrode 20 according to the present invention in the order of steps.
The method of manufacturing the working electrode 20 of the present invention includes a step of forming the oxide semiconductor porous layer 21 on the transparent conductive substrate 10 by a printing method, and a flat plate 60 having releasability. The upper surface 21a of the oxide semiconductor porous layer 21 is pressed uniformly by pressing the upper surface 21a of the oxide semiconductor porous layer 21 with the flat plate 60, and the oxide semiconductor porous A step of drying the oxide semiconductor porous layer 21 in a state where the upper surface 21a of the layer 21 is pressed, and a step of removing and baking the flat plate 60 after the oxide semiconductor porous layer 21 is dried. It is characterized by that.

In the present invention, after the oxide semiconductor porous layer 21 is formed by the stencil printing method, the upper surface 21a of the oxide semiconductor porous layer 21 is pressed by the flat plate 60 having releasability, whereby the oxide semiconductor porous layer 21 is pressed. The thickness of the quality layer 21 can be made uniform and the upper surface 21a can be made flat. Thereby, the unevenness | corrugation of the surface asperity of the oxide semiconductor porous layer 21 can be eliminated. As a result, in the method for producing a working electrode of the present invention, when used in a photoelectric conversion element, the working electrode 20 that prevents the uneven distribution of the electrolytic solution and the increase in internal resistance resulting therefrom can be produced by a simple method. it can.
Hereinafter, each step will be described in detail.

(1) First, as shown in FIG. 2A, an oxide semiconductor porous layer 21 is formed on a transparent conductive substrate 10 by a printing method.
First, a transparent conductive film 12 such as ITO or FTO is formed on a transparent substrate 11 made of glass or the like. As a method of forming the transparent conductive film 12, a known appropriate method corresponding to the material of the transparent conductive film 12 may be used. For example, sputtering, vapor deposition, SPD (spray pyrolysis), CVD Etc.

The method for forming the oxide semiconductor porous layer 21 is not particularly limited. For example, a dispersion obtained by dispersing oxide semiconductor fine particles such as TiO ₂ in a desired dispersion medium, or a sol-gel method. The colloidal solution that can be prepared by the above method is a method in which a desired additive is added as necessary and then applied by a known method such as a printing method.

  (2) Next, as shown in FIG. 2B, a flat plate 60 having releasability is disposed above the transparent conductive substrate 10 via a spacer 61, and the oxide semiconductor is formed by the flat plate 60. By pressing the upper surface 21 a of the porous layer 21, the thickness of the oxide semiconductor porous layer 21 can be made uniform and the upper surface 21 a can be made flat.

As used herein, the “flat plate 60 having releasability” refers to flatness sufficient to uniformly flatten the upper surface 21a of the transparent conductive substrate 21 when the oxide semiconductor porous layer 21 is pressed, and transparent The conductive substrate 21 is not particularly limited as long as the conductive substrate 21 has a releasability that can be easily peeled off from the flat surface. For example, various flat plates whose surfaces are subjected to a release treatment, and Teflon (registered trademark) sheets. A polyimide film or the like can be used. Also, the thickness is not particularly limited as long as the object can be achieved.
At this time, the spacer 61 disposed between the transparent conductive substrate 10 and the flat plate 60 is not particularly limited, and for example, a spacer made of a metal such as aluminum can be used.

(3) Next, the oxide semiconductor porous layer 21 is dried in a state where the upper surface 21a of the oxide semiconductor porous layer 21 is pressed.
Although it does not specifically limit as drying conditions, For example, it carries out over 20 minutes-1 hour at the temperature of 130-160 degreeC.

(4) Next, as shown in FIG. 2C, the flat plate is removed after the oxide semiconductor porous layer 21 is dried. Then, the oxide semiconductor porous layer 21 is fired.
Although it does not specifically limit as conditions for baking, For example, it carries out at the temperature of 480-520 degreeC over 1-2 hours.

(5) Finally, dye support is performed on the oxide semiconductor porous layer 21.
As the dye solution for supporting the dye, for example, a solution prepared by adding an extremely small amount of N719 powder to a solvent of acetonitrile and t-butanol in a volume ratio of 1: 1 is prepared in advance.
A porous oxide semiconductor layer that has been heat-treated in a separate electric furnace at about 120 to 150 ° C. is immersed in a dye solvent placed in a petri dish-like container, and is immersed for a whole day and night (approximately 20 hours) in a dark place. . Thereafter, the oxide semiconductor porous layer 21 taken out from the dye solution is washed using a mixed solution of acetonitrile and t-butanol.
As described above, the working electrode 20 as shown in FIG. 1 is obtained.

Next, the photoelectric conversion element 50 of the present invention will be described.
FIG. 3 is a cross-sectional view schematically showing one embodiment of the photoelectric conversion element 50 according to the present invention.
This photoelectric conversion element 50 uses the working electrode 20 of the present invention as described above, and is roughly composed of the working electrode 20, the counter electrode 30, and the electrolyte layer 40 made of an electrolyte enclosed therebetween. Composed.
In the photoelectric conversion element 50, a laminated body in which the electrolyte layer 40 is sandwiched between the working electrode 20 and the counter electrode 30 is bonded and integrated by a sealing member 51 to function as a dye-sensitized photoelectric conversion element. .

The counter electrode 30 in this example is formed by depositing a conductive thin film 30a such as platinum or gold on one surface of a plastic film 30b such as polyimide or polyethylene terephthalate by vapor deposition or sputtering. Are arranged so as to be on the inner surface side of the element, thereby forming the photoelectric conversion element 50 of this example.
In addition, as the counter electrode 30, a metal foil body such as Ti may be used instead of the plastic film, and a conductive film such as platinum, gold, or carbon may be formed on one surface thereof. .

An electrolyte solution is filled between the counter electrode 30 and the working electrode 20 to form an electrolyte layer 40. The electrolytic solution is not particularly limited as long as it is a non-aqueous electrolytic solution containing a redox pair. As the solvent, for example, acetonitrile, methoxyacetonitrile, propionitrile, ethylene carbonate, propylene carbonate, γ-butyrolactone, methoxypropionitrile and the like are used.
As a redox pair, for example, a combination of iodine / iodine ion, bromine / bromine ion and the like can be selected. As a counter ion when this is added as a salt, lithium ion, tetraalkyl ion, imidazolium is added to the above redox pair. Ions can be used. Moreover, you may add an iodine etc. as needed. Moreover, you may use the solid thing which gelatinized such electrolyte solution with the appropriate polymer matrix.

Further, instead of the electrolyte layer 40, a hole transport layer made of a p-type semiconductor may be used. For the p-type semiconductor, for example, a monovalent copper compound such as copper iodide or thiocyanic copper or a conductive polymer such as polypyrrole can be used, and copper iodide is particularly preferable. In the case of using a solid hole transport layer made of this p-type semiconductor or a gelled electrolyte, there is no fear of leakage of the electrolyte.
When a p-type semiconductor is used as a hole transport layer (for example, when a gelled electrolyte is used), a conductive thin film such as platinum is directly deposited on a glass substrate and sputtered because the p-type semiconductor is solid. For example, the counter electrode 30 can be formed.

  The sealing member 51 is not particularly limited as long as it has excellent adhesion to the transparent conductive substrate 10 and the counter electrode 30. For example, an adhesive made of a thermoplastic resin having a carboxylic acid group in the molecular chain is desirable. Specific examples include Hi Milan (made by Mitsui DuPont Chemical) and binel (made by Mitsui DuPont Chemical). In addition to these, as the sealing member 51, Aron Alpha (manufactured by Toagosei Co., Ltd.) may be used.

  In the photoelectric conversion element 50 of the present invention, the oxide semiconductor porous layer 21 has a uniform thickness in the working electrode 20, and the upper surface 21a thereof is flat. The unevenness of the surface irregularities is eliminated. As a result, in the photoelectric conversion element 50 of the present invention, the uneven distribution of the electrolytic solution and the variation in microscopic internal resistance resulting therefrom are made uniform, and as a result, the photoelectric conversion element 50 has excellent photoelectric conversion efficiency.

  As mentioned above, although the manufacturing method of the working electrode of this invention, the working electrode, and the photoelectric conversion element were demonstrated, this invention is not limited to said example, It can change suitably as needed.

A working electrode and a photoelectric conversion element were prepared as follows, and their characteristics were evaluated.
Example 1
First, an FTO glass substrate was prepared as a transparent conductive substrate, and a paste of titanium oxide nanoparticles was applied on the FTO glass substrate by a screen printing method to form an oxide semiconductor porous layer.
Next, a releasable flat plate was disposed on the oxide semiconductor porous layer through a spacer made of an aluminum plate having a thickness of 200 μm. As the releasable flat plate, a Teflon (registered trademark) sheet (thickness 3 mm) manufactured by Nippon Valqua Industries, Ltd. was used. It was made to dry at 150 degreeC in the state. Then, the said flat plate was removed and it baked at 500 degreeC.
N719 dye was supported on the porous oxide semiconductor layer. As a result, a working electrode having a porous oxide semiconductor layer having a uniform thickness and a flat upper surface as shown in FIG. 1 was obtained.

Moreover, the same FTO glass substrate as what was used for the working electrode was used, and on this transparent conductive film (FTO film), the thin film which consists of platinum was formed with sputtering method, and the counter electrode was obtained.
Next, an electrolyte was attached to the working electrode.
Next, the working electrode and the counter electrode were bonded together. Specifically, a sheet made of a thermoplastic resin having a width of 2 mm and a thickness of 50 μm as a sealing member (trade name High Milan, manufactured by Mitsui DuPont Polychemical Co., Ltd.) is fused to the mouth of the peripheral edge of the working electrode or the counter electrode. Were laminated and pressed to form a laminate.
Thus, a dye-sensitized photoelectric conversion element as shown in FIG. 3 was produced.

(Example 2 to Example 6)
A working electrode and a photoelectric conversion element were produced in the same manner as in Example 1 except that the thickness of the spacer and the type of the releasable substrate were as shown in Table 1 below.

(Comparative Example 1)
First, an FTO glass substrate was prepared as a transparent conductive substrate, and a paste of titanium oxide nanoparticles was applied on the FTO glass substrate by a screen printing method to form an oxide semiconductor porous layer.
Next, the oxide semiconductor porous layer was leveled for 20 minutes and dried at 150 ° C. Then, it baked at 500 degreeC for 2 hours. As a result, a working electrode was obtained.
Using this working electrode, a dye-sensitized photoelectric conversion element was produced in the same manner as in Example 1.

(Comparative Example 2 to Comparative Example 4)
A working electrode and a photoelectric conversion element were produced in the same manner as in Comparative Example 1 except that the leveling time was as shown in Table 1 below.

Below, the result of having evaluated "photoelectric conversion efficiency" and "corrosion of metal grid wiring" with respect to the photoelectric conversion element produced by each Example and comparative example mentioned above is described.
(Evaluation) Photoelectric conversion efficiency About the photoelectric conversion element of each Example and the comparative example, the photoelectric conversion efficiency was measured and evaluated using the artificial sunlight whose air mass is 1.5. However, the photoelectric conversion efficiency of the comparative example was set to 1.
The evaluation results are shown in Table 1 below.

As can be seen from Table 1, all of the devices of the examples had higher photoelectric conversion efficiency than the comparative example.
From the above results, it was confirmed that the working electrode and the photoelectric conversion element of the present invention have high photoelectric conversion efficiency. By making the thickness of the oxide semiconductor porous layer uniform and flattening its upper surface at the working electrode, the increase in internal resistance due to the uneven distribution of the electrolyte is prevented, and the decrease in photoelectric conversion efficiency is prevented. it is conceivable that.

  The present invention is widely applicable to a method for producing a working electrode having an oxide semiconductor porous layer, a working electrode, and a photoelectric conversion element.

Sectional drawing which shows typically an example of the working electrode which concerns on this invention. Typical sectional drawing which shows an example of the manufacturing method of the working electrode shown in FIG. 1 in order of a process. Sectional drawing which shows typically an example of the photoelectric conversion element which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Transparent conductive substrate, 11 Transparent base material, 12 Transparent electrically conductive film, 20 Working electrode, 21 Oxide semiconductor porous layer, 21a Upper surface, 30 Counter electrode, 40 Electrolyte layer, 50 Photoelectric conversion element, 60 Flat plate, 61 Spacer.

Claims (4)

A transparent conductive substrate; and an oxide semiconductor porous layer disposed on the transparent conductive substrate, wherein the oxide semiconductor porous layer has a uniform thickness and a flat upper surface. A working electrode manufacturing method comprising:
Forming the oxide semiconductor porous layer on the transparent conductive substrate by a stencil printing method;
A thickness of the oxide semiconductor porous layer is obtained by disposing a flat plate having releasability via a spacer above the transparent conductive substrate and pressing the upper surface of the oxide semiconductor porous layer with the flat plate. Uniformly and flattening the upper surface;
Drying the oxide semiconductor porous layer while pressing the upper surface of the oxide semiconductor porous layer with the flat plate;
And a step of removing the flat plate and firing after drying the porous oxide semiconductor layer.   2. The working electrode according to claim 1, wherein the oxide semiconductor porous layer is formed of any one of titanium oxide, zinc oxide, tin oxide, tungsten oxide, barium titanate, and strontium titanate. Production method. A transparent conductive substrate;
An oxide semiconductor porous layer disposed on the transparent conductive substrate,
A working electrode characterized in that the oxide semiconductor porous layer has a uniform thickness and a flat upper surface. It is composed of a working electrode, a counter electrode, and an electrolyte layer composed of an electrolyte enclosed between them,
The working electrode includes a transparent conductive substrate,
An oxide semiconductor porous layer disposed on the transparent conductive substrate,
A photoelectric conversion element characterized in that the porous oxide semiconductor layer has a uniform thickness and a flat upper surface.

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