JP2014017165A - Method of manufacturing dye-sensitized solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of easily manufacturing a dye-sensitized solar cell having a high power generation efficiency.SOLUTION: A method of manufacturing a dye-sensitized solar cell includes: a first step of forming a porous semiconductor layer 20 on a transparent conductive substrate 10; a second step of mounting a mold having an unevenness shape on the porous semiconductor layer 20, pressing the mold to the porous semiconductor layer 20 to pattern the unevenness shape of the mold onto the porous semiconductor 20, peeling off the mold from the porous semiconductor layer 20, and then baking the porous semiconductor layer 20 to form a plurality of recessed parts α to the porous semiconductor layer 20; and a third step of making the plurality of the recessed parts α adsorb a sensitization dye.

Description

  The present invention relates to a dye-sensitized solar cell, and particularly to a method for producing a dye-sensitized solar cell excellent in design.

  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, dye-sensitized solar cells are attracting attention as solar cells that are inexpensive and can obtain high photoelectric conversion efficiency. As a general structure of this dye-sensitized solar cell, a porous film using oxide semiconductor nanoparticles such as titanium dioxide is formed on a transparent conductive substrate, and the sensitizing dye is supported thereon. A semiconductor electrode and a counter electrode such as platinum-sputtered conductive glass, and an organic electrolyte containing an oxidizing / reducing species such as iodine / iodide ions between both electrodes as a charge transport layer. it can.

  In addition, about the said dye-sensitized solar cell, what expressed a character, a symbol, a figure, a picture, etc. colorfully using several sensitizing dyes is known (for example, patent document 1, 2). However, in the method of Patent Document 1, when the porous semiconductor layer is patterned into a predetermined shape, the transparent conductive film formed under the porous semiconductor layer is also patterned because it is patterned with a laser. Therefore, the dye-sensitized solar cell produced by such a method has a problem that it does not function as a battery. In addition, since the glass frit is formed on the partition wall, it takes time to form the glass frit, and there is a problem that the production efficiency is lowered.

  Patent Document 2 discloses a method of forming a bank structure on a transparent conductive substrate in order to produce the dye-sensitized solar cell. However, since the bank structure is created by a photolithographic method, there are problems that the manufacturing process is multistage, and that the bank structure is burned out during the process of sintering the porous semiconductor layer. . Further, since the bank structure does not contribute to power generation, the dye-sensitized solar cell having the bank structure has a problem that the power generation area is reduced.

JP 2002-75472 A JP2007-149675

  Accordingly, an object of the present invention is to provide a method for easily producing a dye-sensitized solar cell having high power generation efficiency.

  In order to achieve the above object, the present invention is configured as follows.

  Below, it demonstrates in detail based on embodiment concerning this invention.

  According to a first aspect of the present invention, there is provided a method for producing a dye-sensitized solar cell in which a plurality of dyes are dyed on a porous semiconductor layer disposed on a transparent conductive substrate, the method comprising: A first step of forming a porous semiconductor layer, placing a mold on the porous semiconductor layer, pressing the mold into the porous semiconductor layer to form a plurality of recesses in the porous semiconductor; A dye-sensitized solar comprising a second step of firing the porous semiconductor layer after peeling the mold from the porous semiconductor layer and a third step of adsorbing a sensitizing dye to the plurality of recesses A method for manufacturing a battery is provided.

  According to the second aspect of the present invention, there is provided a method for producing a dye-sensitized solar cell in which sensitizing dyes of different colors are adsorbed in a plurality of adjacent concave portions.

  According to the 3rd aspect of this invention, the diameter of the said recessed part is 20-1000 micrometers, and the manufacturing method of the dye-sensitized solar cell whose depth is 1-4 micrometers is provided.

  According to the 4th aspect of this invention, the said sensitizing dye provides the manufacturing method of the dye-sensitized solar cell made to adsorb | suck by the inkjet method.

  According to the present invention, a dye-sensitized solar cell with high power generation efficiency can be easily produced.

It is sectional drawing which concerns on the manufacturing process of the dye-sensitized solar cell of this invention. It is sectional drawing of the dye-sensitized solar cell of this invention.

  Hereinafter, embodiments according to the present invention will be described in more detail with reference to the drawings. It should be noted that the dimensions, materials, shapes, relative positions, etc. of the parts and portions described in the embodiments of the present invention are not intended to limit the scope of the present invention only to those unless otherwise specified. This is just an illustrative example.

(Embodiment 1)
FIG. 1 is a cross-sectional view relating to a manufacturing process of a dye-sensitized solar cell.

<Method for producing dye-sensitized solar cell>
The manufacturing method of the dye-sensitized solar cell of this invention is demonstrated. The method for obtaining a dye-sensitized solar cell includes the following steps.

  FIG. 1 is a cross-sectional view of a process for producing a dye-sensitized solar cell.

  As shown in FIG. 1A, the porous semiconductor layer 20 is formed on the transparent conductive substrate 10.

  The transparent conductive film is preferably indium tin oxide or fluorine-doped tin oxide. This is because it is inexpensive and inactive in the high-temperature sintering process.

  Note that the porous semiconductor layer is formed by printing and sintering a paste in which an oxide semiconductor is dispersed in a polymer and a solvent. For example, when the porous semiconductor layer is made of titanium oxide, it is formed as follows. First, acetic acid is added to a TiO 2 anatase powder, and then kneaded with deionized water and ethanol to prepare a titanium oxide paste stabilized with a solvent and a polymer. The prepared paste is applied on the transparent conductive film at a constant speed by a printing method such as a screen printing method or a doctor blade method, and is heated in the atmosphere at 400 to 600 ° C. for 10 to 60 minutes, preferably 20 to 40 minutes. By doing so, a porous semiconductor layer is obtained.

  Next, as shown in FIG. 1B, after placing a mold 30 having an uneven shape on the porous semiconductor layer 20, the mold is pushed into the porous semiconductor layer to form a recess in the porous semiconductor. Form.

  Moreover, it is preferable that the said recessed part is a hemispherical shape, the height is 1 micrometer-4 micrometers, and a radius is 20 micrometers-1000 micrometers. If the height of the recess is less than 1 μm, there is a problem that the dye solution cannot be held when supporting the sensitizing dye, and if it exceeds 4 μm, the volume of the porous semiconductor film layer becomes small, so that the power generation efficiency decreases. Occurs. Furthermore, if the radius of the recess is less than 20 μm, there is a problem that it is difficult to hold the dye solution, and if it exceeds 1000 μm, the volume of the porous semiconductor film layer becomes small, resulting in a problem that power generation efficiency decreases.

  In addition, in order to form a recessed part in a porous semiconductor layer, the metal mold | die which has uneven | corrugated shape is pressed against the paste-like porous semiconductor layer formed on the transparent conductive substrate, and it dries at the temperature of 100 to 200 degreeC. It is good to let them.

  Next, as shown in FIG.1 (c), after peeling a metal mold | die from a porous semiconductor layer, a porous semiconductor layer is baked.

  In addition, baking of a porous semiconductor layer is performed for 10 to 40 minutes at the temperature of 500 to 600 degreeC.

  Next, as shown in FIG. 1D, the sensitizing dye 41 is held in the concave portion α, and the sensitizing dye 42 having a color different from that of the sensitizing dye 41 is held in the concave portion β adjacent to the concave portion α.

  As the sensitizing dye, an organic dye or a metal complex dye can be used. Examples of the organic dye include an acridine dye, an azo dye, an indigo dye, a quinone dye, a coumarin dye, a merocyanine dye, and a phenylxanthene dye. As the metal complex dye, a ruthenium dye is preferable, and a ruthenium bipyridine dye and a ruthenium terpyridine dye, which are ruthenium complexes, are particularly preferable. For example, visible light (wavelength of about 400 to 800 nm) can hardly be absorbed with only an oxide semiconductor film, but by supporting a ruthenium complex, visible light can be significantly taken in and photoelectrically converted.

  For the adsorption of the sensitizing dye, an ink jet method is preferably used. This is because an appropriate amount of droplets can be supplied to the recesses, and fine colors can be dyed.

  In order to efficiently adsorb the sensitizing dye to the porous semiconductor layer, at least one carboxyl group, sulfonyl group, hydroxamic acid group, alkoxy group, aryl group, phosphoryl group, etc. are substituted on the sensitizing dye. It is effective to have it as a group. This is because these substituents can firmly chemisorb the first sensitizing dye itself to the porous semiconductor layer and can easily transfer charges from the excited sensitizing dye to the porous semiconductor layer.

  Solvents for dissolving the sensitizing dye when adsorbing the sensitizing dye to the porous semiconductor layer include alcohols such as ethanol, ketones such as acetone, ethers such as diethyl ether, nitrogen compounds such as acetonitrile, etc. May be one or a mixture of two or more. The concentration of the sensitizing dye in the solution is preferably about 5 × 10 −5 to 2 × 10 −3 mol / l (l (liter): 1000 cm 3).

  When adsorbing the sensitizing dye to the porous semiconductor layer, the temperature conditions of the solution and the atmosphere are not particularly limited, and examples thereof include conditions under atmospheric pressure or in vacuum, room temperature, or substrate heating. The time required for adsorption of the first sensitizing dye can be appropriately adjusted depending on the kind of the sensitizing dye and the solution, the concentration of the solution, the circulation amount of the solution of the sensitizing dye, and the like. Thereby, a sensitizing dye can be made to adsorb | suck to a porous semiconductor layer.

  Next, as shown in FIG. 1 (e), the first and second sensitizing dyes 41 and 42 are permeated and adsorbed on the porous semiconductor layer by leaving it alone.

  According to the above method, the recess is provided in the porous semiconductor layer by the mold having the uneven shape. Therefore, since a laser is not used to form sensitizing dyes having different colors on the porous semiconductor layer, the transparent conductive film layer is not patterned. Therefore, the function as a solar cell is not hindered. Furthermore, since no glass frit or bank structure is formed, a dye-sensitized solar cell with high power generation efficiency can be easily produced.

<Dye-sensitized solar cell>
Next, the dye-sensitized solar cell 1 created by the above manufacturing method will be described.

  FIG. 2 is a plan view of the dye-sensitized solar cell 1.

As shown in FIG. 2, the dye-sensitized solar cell 1 includes a transparent conductive substrate 10, a porous semiconductor layer 20, a charge transport layer 50, and a counter electrode 60 formed in this order. A sealing material 70 is formed on the peripheral portion so that the charge transport layer 50 does not come out of the system. The porous semiconductor layer 20 includes a first region 21 and a second region 22 each having a depression, and the first region 21 has a first sensitizing dye 41 and the second region 22 has a second sensitizing dye. 42 is adsorbed. Each of the recesses is hemispherical, and has a diameter of 20 μm to 1000 μm and a height of 1 μm to 4 μm. If comprised in this way, the dye-sensitized solar cell 1 equips each hollow with the sensitizing dye from which a color differs in a porous semiconductor layer. Therefore, the solar cell has a three-dimensional and colorful design.
<Transparent conductive substrate>
As shown in FIG. 2, the transparent conductive substrate 10 has a configuration in which a transparent conductive film 12 is formed on a substrate 11.

  The substrate is made of a transparent glass plate or plastic plate. The thickness of the substrate is about 0.1 to 5 mm.

  The transparent conductive film is made of an organic material or an inorganic material. As the organic material, a conductive polymer material can be used. Among the conductive polymer materials, it is preferable to use a water-dispersed polythiophene derivative (PEDOT: PSS) prepared using polystyrene sulfonic acid (PSS) and 3,4-ethylenedioxythiophene (EDOT). The water-dispersed polythiophene derivative (PEDOT: PSS) has high transparency and high conductivity. For this reason, by using a water-dispersed polythiophene derivative (PEDOT: PSS) as a transparent conductive film, it is possible to efficiently incorporate light from the outside into the dye-sensitized solar cell and to generate electrons generated from the dye sensitization. It can be efficiently transported to the electrode extraction part. As a result, a dye-sensitized solar cell with high energy efficiency is obtained. In addition to the above, since the water-dispersed polythiophene derivative (PEDOT: PSS) is water-soluble, it has an advantage that a transparent conductive film can be easily formed on the translucent substrate.

  As the inorganic material, an inorganic oxide such as fluorine-doped tin oxide, indium tin oxide, gallium-doped zinc oxide, aluminum-doped zinc oxide, or niobium-doped titanium oxide can be used. The thickness of the transparent conductive film is preferably about 0.3 to 2 μm. When the thickness is less than 0.3 μm, the sheet resistance increases, and the series resistance of the dye-sensitized solar cell increases, so that the fill factor characteristic tends to be deteriorated. In this case, the transparent conductive film is formed by a CVD method, a sputtering method, a spray method, or the like.

  Furthermore, the transparent conductive film may be composed of a binder resin such as acrylic, polyester, polyurethane, and polyvinyl chloride, and conductive nanofibers. In this case, the transparent conductive film can be provided by a method such as painting or inkjet, and the thickness of the transparent conductive film can be appropriately set within a range of several tens of nm to several hundreds of nm. When the thickness is less than several tens of nm, the strength as a layer is insufficient, and when the thickness is greater than several hundred nm, the flexibility as the layer is lost and processing becomes difficult. In addition to carbon nanofibers, conductive nanofibers can be made continuously by applying an applied voltage or current from the tip of the probe to the surface of a precursor carrying metal ions such as gold, silver, platinum, copper, and palladium. Gold particles are added to metal nanowires produced by pulling them out, or nanofibers formed by self-organizing graphite nanofibers, peptides or their derivatives produced by introducing a source gas onto a light-transmitting substrate and using the CVD method And peptide nanofibers.

<Porous semiconductor layer>
The porous semiconductor layer adsorbs the sensitizing dye and holds the sensitizing dye on the transparent conductive substrate. Titanium oxide (TiO2) is optimal as the porous semiconductor layer, and other materials include titanium (Ti), zinc (Zn), tin (Sn), niobium (Nb), indium (In), yttrium ( Y), lanthanum (La), zirconium (Zr), tantalum (Ta), hafnium (Hf), strontium (Sr), barium (Ba), calcium (Ca), vanadium (V), tungsten (W), and other metals A metal oxide semiconductor of at least one kind of element is preferable, and is composed of, for example, at least one of TiO2, WO3, ZnO, Nb2O5, Ta2O5, or SrTiO3. Moreover, you may contain 1 or more types of nonmetallic elements, such as nitrogen (N), carbon (C), fluorine (F), sulfur (S), chlorine (Cl), phosphorus (P). Titanium oxide or the like is preferable because it has an electron energy band gap in the range of 2 to 5 eV, which is larger than the energy of visible light.

  The porous semiconductor layer is preferably a porous n-type oxide semiconductor layer made of the above material and having a large number of fine pores inside. Furthermore, the diameter of the holes is preferably 10 to 40 nm. When the diameter is less than 10 nm, the osmotic adsorption of the alternating copolymer is hindered, it is difficult to obtain a sufficient amount of adsorption for the alternating copolymer, and the diffusion resistance increases because the diffusion of the electrolyte is hindered. Therefore, the photoelectric conversion efficiency tends to decrease. If it exceeds 40 nm, the specific surface area of the porous semiconductor layer is reduced, so that the amount of adsorption of the alternating copolymer is reduced, and light is hardly transmitted, and the alternating copolymer cannot absorb light. In addition, since the transfer distance of the charge injected into the porous semiconductor layer becomes long, loss due to charge recombination increases, and further, the diffusion resistance increases because the diffusion distance of the electrolyte also increases. Efficiency tends to decrease.

  The porous semiconductor layer has a surface area that adsorbs a sensitizing dye by being a granular body, or a linear body such as a needle-shaped body, a tubular body, a columnar body, or a collection of these various linear bodies. And the photoelectric conversion efficiency can be increased. The porous semiconductor layer preferably has a porosity of 20 to 80%, and more preferably 40 to 60%. This is because the surface area as the light-working electrode layer can be increased by 1000 times or more by making the porous body more dense, and light absorption, photoelectric conversion, and electron conduction can be performed efficiently. .

  The porosity of the porous semiconductor layer is determined by obtaining an isothermal adsorption curve of the sample by a nitrogen gas adsorption method using a gas adsorption measuring device, and using a BJH (Barrett-Joyner-Halenda) method, a CI (Chemical Ionizati-on) method , DH (Dollimore-Heal) method or the like can be used to determine the pore volume and obtain it from the particle density of the sample.

  The shape of the porous semiconductor layer is preferably that having a large surface area and low electrical resistance, and is preferably composed of fine particles or fine linear bodies, for example. The average particle diameter or average wire diameter is preferably 5 to 500 nm, and more preferably 10 to 200 nm. If the average particle diameter or the average wire diameter is less than 5 nm, the material cannot be miniaturized, and if it exceeds 500 nm, the junction area becomes small and the photocurrent becomes remarkably small.

  By forming the porous semiconductor layer from a fine porous particle, the alternating copolymer is supported in the fine pores, and the surface becomes uneven, thereby providing a light confinement effect, so that the photoelectric conversion efficiency can be further increased.

  Moreover, it is preferable that the thickness of a porous semiconductor layer is 1-15 micrometers. If the thickness is less than 1 μm, the photoelectric conversion effect is remarkably reduced and is not suitable for practical use. If the thickness exceeds 15 μm, the insulation between the porous semiconductor layer and the counter electrode becomes difficult.

  Further, the porous semiconductor layer is preferably composed of a sintered body of oxide semiconductor fine particles, and the average particle diameter of the oxide semiconductor fine particles is preferably gradually increased in the thickness direction from the translucent substrate side. The semiconductor layer is preferably composed of a two-layer laminate in which the average particle diameters of the oxide semiconductor fine particles are different. Specifically, the oxide semiconductor fine particles having a small average particle diameter are used on the transparent conductive film, and the oxide semiconductor fine particles having a large average particle diameter (scattering particles) are used on the formed semiconductor layer. The porous semiconductor layer having a large diameter produces a light confinement effect due to light scattering and light reflection, and can increase the photoelectric conversion efficiency.

  More specifically, as oxide semiconductor fine particles having a small average particle diameter, 100 wt% (wt%) having an average particle diameter of about 20 nm is used, and as the oxide semiconductor fine particles having a large average particle diameter, the average particle diameter is What is necessary is just to use 10 wt% of about 10 nm, and 90 wt% of those having an average particle diameter of about 400 nm. By changing the weight ratio, the average particle diameter, and the respective film thicknesses, an optimum light confinement effect can be obtained. In addition, by increasing the number of layers from two layers to three or more layers, or by coating and forming so that these boundaries do not occur, the average particle size gradually increases in the thickness direction from the transparent conductive film side. Can be formed.

<Sensitizing dye>
The sensitizing dye emits electrons to the porous semiconductor layer and imparts various colors to the surface of the dye-sensitized solar cell. Therefore, the first and second sensitizing dyes are
There is no particular limitation as long as it has a sensitizing action and the color is different.

  As such first and second sensitizing dyes, organic dyes or metal complex dyes can be used, and examples of organic dyes include acridine series, azo series, indigo series, quinone series, coumarin series, merocyanine series, Examples of the metal complex dye include a ruthenium dye, and particularly preferred are a ruthenium bipyridine dye and a ruthenium terpyridine dye, which are ruthenium complexes. For example, visible light (wavelength of about 400 to 800 nm) can hardly be absorbed with only an oxide semiconductor film, but by supporting a ruthenium complex, visible light can be significantly taken in and photoelectrically converted.

<Charge transport layer>
The charge transport layer is a layer that donates electrons supplied from the counter electrode (cathode side) to the sensitizing dye. As a material for the charge transport layer, a liquid electrolyte or a gel electrolyte is preferably used. Photoelectric conversion efficiency is improved by using a liquid electrolyte or a gel electrolyte excellent in charge transport characteristics. The charge transport layer is composed of a solid electrolyte such as a polymer electrolyte, a conductive polymer such as polythiophene / polypyrrole or polyphenylene vinylene, or an organic molecular electron transport agent such as a fullerene derivative, a pentacene derivative, a perylene derivative, or a triphenyldiamine derivative. There may be.

  The charge transport layer contains iodine / iodide salt, bromine / bromide salt, cobalt complex, potassium ferrocyanide and the like.

  The thickness of the charge transport layer is preferably 1 to 500 μm. If it exceeds 500 μm, the resistance increases during charge transport, and the efficiency of the dye-sensitized solar cell cannot be increased.

<Counter electrode>
The counter electrode constitutes a cathode electrode and passes electrons sent from the transparent conductive substrate to the charge transport layer. The counter electrode has a configuration in which a conductive layer and a catalyst layer are formed in this order on a substrate.

  A board | substrate consists of a glass plate, a plastic plate, etc., and thickness is about 0.5-20 mm.

  Examples of the material for the conductive layer include fluorine-doped tin oxide (FTO), tin-doped indium (ITO), aluminum-doped zinc (AZO), gallium-doped zinc (GZO), and niobium-doped titanium oxide (NTO). Among the above, it is preferable to use fluorine-doped tin oxide (FTO). By using fluorine-doped tin oxide (FTO), the conversion efficiency of the dye-sensitized solar cell is improved.

  The thickness of the conductive layer is preferably 0.1 to 10 μm. If it is less than 0.1 μm, high conductivity cannot be obtained. If it exceeds 10 μm, the dye-sensitized solar cell cannot transmit light. The conductive layer is formed on the substrate by a method such as chemical vapor deposition (CVD), spray pyrolysis (SPD), or sputtering.

  Examples of the material for the catalyst layer include platinum, carbon, and polythiophene derivatives. Among the above, it is preferable to use platinum. By using platinum, conversion efficiency and transparency are improved. The thickness of the catalyst layer is preferably 0.1 to 100 nm. If the thickness is less than 0.1 μm, the material constituting the charge transport layer cannot be reduced. If it exceeds 100 μm, the cost is too high. Furthermore, a dye-sensitized solar cell that transmits light cannot be produced. The catalyst layer is formed on the conductive layer by a method such as doctor blade, screen printing, spray coating, or ink jet.

<Encapsulant>
The encapsulant is a member that encapsulates the charge transport layer in the dye-sensitized solar cell. Since the sealing material seals the charge transport layer, the durability and reliability of the photoelectric conversion element against light irradiation and high-temperature heating can be effectively maintained. That is, leakage of the charge transport layer from the dye-sensitized solar cell due to light irradiation and high-temperature heating can be effectively suppressed.

  Examples of the material for the sealing material include resin adhesives such as polyethylene, polypropylene, epoxy resin, fluororesin or silicone resin, acrylic UV resins, or inorganic adhesives such as glass frit and ceramics.

  The thickness (height) of the sealing material is preferably 0.5 to 500 μm. If the thickness is less than 0.5 μm, the thickness of the porous semiconductor layer becomes 0.5 μm or less, and the dye cannot sufficiently absorb light. When the thickness exceeds 500 μm, the charge transport layer becomes close to 500 μm and the internal resistance increases. The sealing member is formed by a method such as hot pressing or UV curing.

1: Dye-sensitized solar cell 10: Transparent conductive substrate 11: Substrate 12: Transparent conductive film 20: Porous semiconductor layer 21: First region 22: Second region 30: Mold having irregularities 41: First increase Dye Sensitive 42: Second Sensitizing Dye 50: Charge Transport Layer 60: Counter Electrode 61: Substrate 62: Catalyst Layer 70: Sealing Material

Claims (5)

A method for producing a dye-sensitized solar cell in which a plurality of dyes are dyed on a porous semiconductor layer disposed on a transparent conductive substrate,
A first step of forming a porous semiconductor layer on the transparent conductive substrate;
A mold is placed on the porous semiconductor layer, the mold is pushed into the porous semiconductor layer to form a plurality of recesses in the porous semiconductor, and the mold is peeled from the porous semiconductor layer. Then, a second step of firing the porous semiconductor layer,
A third step of adsorbing a sensitizing dye to the plurality of recesses;
The manufacturing method of the dye-sensitized solar cell containing this.   The method for producing a dye-sensitized solar cell according to claim 1, wherein sensitizing dyes of different colors are adsorbed in a plurality of adjacent concave portions.   The diameter of the said recessed part is 20-1000 micrometers, and the depth is 1-4 micrometers, The manufacturing method of the dye-sensitized solar cell of Claims 1-2.   The method for producing a dye-sensitized solar cell according to claim 1, wherein the sensitizing dye is adsorbed by an ink jet method. A dye-sensitized solar cell in which a plurality of dyes are dyed separately on a porous semiconductor layer disposed on a transparent conductive substrate, and a design pattern is drawn on the transparent conductive substrate,
The transparent conductive substrate;
A first porous semiconductor layer formed on the transparent conductive substrate and adsorbed with a first sensitizing dye;
A second porous semiconductor layer formed on the transparent conductive substrate and adsorbed with a second sensitizing dye having a color different from that of the first sensitizing dye;
A counter electrode formed on the porous semiconductor layer so as to face the transparent conductive substrate and spaced from the porous semiconductor layer;
A charge transport layer formed between the porous semiconductor layer and the counter electrode;
A sealing material for sealing the transparent conductive substrate and the counter electrode so that the charge transport layer does not go out of the system;
The first porous semiconductor layer and the second porous semiconductor layer are dye-sensitized solar cells each having a recess having a diameter of 20 to 1000 μm and a depth of 1 to 4 μm.

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