JP2011204464A - Dye-sensitized solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dye-sensitized solar cell with a high utilization rate of light and high power generation efficiency.SOLUTION: Light having entered from a transparent substrate 10 side is absorbed by dyes of an electron capture-dye layer 30 and excites the dyes. Electrons of the excited dyes are passed to an electron capturing agent of the electron capture-dye layer 30. The electrons received by the electron capturing agent move to the transparent conductive film 20. On the other hand, the dyes which have lost the electrons are supplied with electrons from an electron supply agent 80 which is in contact with a catalyst layer 60 on a conductive film 50. Thus, electric potential is generated between the transparent conductive film 20 and the conductive film 50. That means it functions as a battery. In this case, the light which is not absorbed by the dyes and has transmitted the electron capture-dye layer 30 and reached the catalyst layer 60 is diffused and reflected by a rough surface of the catalyst layer 60 and a part of the reflection light is absorbed by the dyes. That is to say, the light which has reached the catalyst layer 60 is reutilized. Since the catalyst layer 60 is a diffusion reflection surface, the reflected light is more scattered than the case of a mirror surface, and absorption rate by the dyes is high and power generation efficiency is good.

Description

  The present invention relates to a dye-sensitized solar cell.

  In recent years, solar power generation using natural energy that is in harmony with the environment and is inexpensive and clean has attracted attention. At present, solar cells using silicon crystals have been put into practical use, but the energy cost for production is high. In such a situation, compared with a solar cell using a silicon crystal, there is a feature that a large-area element can be manufactured at a low cost, and a flexible cell can be realized. The practical application of such dye-sensitized solar cells is expected. The power generation principle of such a dye-sensitized solar cell will be briefly described as follows. The dye molecules disposed on the light incident side of the dye-sensitized solar cell absorb the incident light and are excited. The excited dye molecule electrons are injected into, for example, titanium oxide, which is a semiconductor. On the other hand, the dye molecules are supplied with the lost amount of electrons from the electrolyte. Accordingly, a potential difference is generated between the titanium oxide and the electrolyte. This potential difference is used as a battery.

JP 2008-41258 A

  For example, when compared with a solar cell using silicon crystals, there is a problem that the power generation efficiency of the dye-sensitized solar cell as disclosed in Patent Document 1, for example, is low.

  An object of the present invention is to provide a dye-sensitized solar cell with high light utilization rate and high power generation efficiency.

  In order to achieve the above object, one aspect of the dye-sensitized solar cell of the present invention includes a first substrate, a second substrate disposed to face the first substrate, and the first substrate. A first electrode formed on a surface facing the second substrate; an electron scavenger disposed on the first electrode; and the first electrode and the second substrate. The electron supply agent disposed on the electron scavenger and an energy level higher than the energy level of the electron scavenger in the excited state and lower than the energy level of the electron supplier in the ground state. In the dye-sensitized solar cell comprising: a dye having a dye; and a catalyst layer disposed on a surface of the second substrate facing the first substrate, a surface of the catalyst layer facing the first substrate Is a diffuse reflection surface.

  According to the present invention, a dye-sensitized solar cell having a high light utilization rate and a high power generation efficiency can be provided.

Sectional drawing which shows the structural example of the dye-sensitized solar cell which concerns on one Embodiment of this invention. The energy diagram explaining the electric power generation principle of the dye-sensitized solar cell which concerns on one Embodiment of this invention. The figure which shows the example of the surface shape of the opposing board | substrate of the dye-sensitized solar cell which concerns on one Embodiment of this invention. The figure which shows the example of the outline of the structure formed on the opposing board | substrate of the dye-sensitized solar cell which concerns on one Embodiment of this invention. The figure which shows an example of the electric current-voltage curve in the Example and comparative example of a dye-sensitized solar cell which concern on this invention. The schematic diagram which shows the structural example of the part of the electrode of the dye-sensitized solar cell which concerns on the modification of one Embodiment of this invention, an electron scavenger, and a pigment | dye. The figure for demonstrating the effect | action of the dye-sensitized solar cell which concerns on the modification of one Embodiment of this invention.

  An embodiment of the present invention will be described with reference to the drawings. In the dye-sensitized solar cell according to the present embodiment, as shown in FIG. 1, an outline of the configuration is formed on, for example, indium tin oxide (ITO) or fluorine-doped tin oxide ( A transparent conductive film 20 as an electrode made of FTO) or the like is formed. The transparent conductive film 20 may be patterned, and a current collecting pattern such as silver may be provided on the upper layer or the lower layer of the transparent conductive film 20. On the transparent conductive film 20, an electron collection-dye layer 30 is formed.

The electron collection-dye layer 30 includes, for example, an electron collection agent made of anatase-type titanium oxide particles and the like, and a dye made of ruthenium dye (N719 dye or the like). The diameter of the electron scavenger is, for example, about 20 nm. The electron scavenger is not limited to titanium oxide, and for example, zinc oxide, tin oxide, tungsten oxide, niobium oxide, indium oxide, and a composite thereof can be used. In the present embodiment, it will be described that titanium oxide (TiO ₂ ), which is particularly excellent as a material for a dye-sensitized solar cell, is used. The dye is not limited to the N719 dye, and for example, N3 dye, BlackDye as the ruthenium-based dye, and D149, xanthene, PVK, merocyanine, oxazine, and the like as the pure organic dye can be used. The dye plays a role of absorbing light and emitting electrons.

  On the other hand, a conductive film 50 as an electrode is formed on a counter substrate 40 made of, for example, glass or a film that faces the transparent substrate 10. Further, a catalyst layer 60 made of platinum is formed on the conductive film 50. Even if the conductive film 50 is not formed, the catalyst layer 60 made of platinum formed on the counter substrate 40 can also function as the conductive film 50.

  Here, in the present embodiment, in order to increase the power generation efficiency by reusing the light incident on the dye-sensitized solar cell from the transparent substrate 10 side and transmitted through the electron collection-dye layer 30 by diffuse reflection, The surface of the catalyst layer 60 is a diffuse reflection surface. Therefore, fine irregularities are formed on the counter substrate 40. The unevenness may be formed by a chemical method such as etching with a solution, or may be formed by a physical method such as sand blasting. A diffuse reflection surface is formed by forming the conductive film 50 and the catalyst layer 60 made of platinum on the counter substrate 40 on which fine irregularities are formed.

  Even if the counter substrate 40 is not shaved to form irregularities, a diffuse reflection surface can be similarly formed even if irregularities are formed by forming an organic scattering film or the like on a flat glass surface.

  In the transparent substrate 10 and the counter substrate 40, the surface of the transparent substrate 10 on which the electron collection-dye layer 30 is formed and the surface of the counter substrate 40 on which the catalyst layer 60 is formed face each other and face each other. For example, the peripheral portions of the opposing surfaces are bonded together by the sealing material 70 so as to have a gap of, for example, about 10 to 50 μm. An electron supply agent 80 that is an electrolyte is sealed in the gap.

As a solvent for the electron supply agent 80, for example, acetonitrile, methoxyacetonitrile, ethylene carbonate, or the like can be used. Examples of the solute of the electron supply agent 80 include 1,2-dimethyl-3-n-propylimidazolium iodide (DMPImI), lithium iodide (LiI), iodine (I ₂ ), 4-tert-butylpyridine (TBP). ) Etc. can be used.

  In this way, for example, the transparent substrate 10 functions as a first substrate, for example, the counter substrate 40 functions as a second substrate, and for example, the transparent conductive film 20 faces the second substrate of the first substrate. For example, the electron collection agent in the electron collection-dye layer 30 functions as an electron collection agent disposed on the electrode. For example, the electron supply agent 80 is , Functioning as an electron supply agent arranged between the first substrate and the second substrate, for example, the dye in the electron collection-dye layer 30 is arranged on the electron collection agent in an excited state. It functions as a dye having an energy level higher than that of the electron scavenger and lower than that of the electron supply agent in the ground state. For example, the catalyst layer 60 is opposed to the first substrate of the second substrate. For example, the conductive film 50 is It serves as the second electrode.

  Next, the power generation principle of the dye-sensitized solar cell according to this embodiment will be described with reference to FIG. First, when light enters the dye-sensitized solar cell, the light is absorbed by the dye in the electron collection-dye layer 30. The light absorbed by the dye excites the dye (broken arrow in FIG. 2). Further, a part of the light that has not been absorbed by the dye and has passed through the electron collection-dye layer 30 is absorbed by the electron supply agent 80, but a part of the other light reaches the catalyst layer 60. The light reaching the catalyst layer 60 is diffusely reflected by the catalyst layer 60, and a part of the reflected light is absorbed by the dye of the electron collection-dye layer 30. Thus, the light reflected by the catalyst layer 60 and absorbed by the pigment also excites the pigment.

The electrons of the dye in the electron collecting-dye layer 30 excited here are transferred to the electron collecting agent in the electron collecting-dye layer 30 composed of, for example, titanium oxide which is a wide gap semiconductor. That is, the dye is oxidized. The electrons received by the electron scavenger move to the transparent conductive film 20. On the other hand, the dye that has lost electrons is supplied with electrons from, for example, I ⁻ of the electron supply agent 80 in contact with the conductive film 50 having the catalyst layer 60. That is, the dye is reduced by the electron supply agent 80. 3I ⁻ becomes I ₃ ⁻ when electrons are supplied to the dye. Therefore, for example, I ₃ ⁻ of the electron supply agent 80 tries to receive electrons from the conductive film 50. At this time, a potential difference is generated between the transparent conductive film 20 and the conductive film 50. If an external circuit is connected between the transparent conductive film 20 and the conductive film 50, the electrons that have moved to the transparent conductive film 20 move to the conductive film 50 through the external circuit. Then, the electrons move to, for example, I ₃ ⁻ of the electron supply agent 80, and I ₃ ⁻ becomes 3I ⁻ . The dye that has lost electrons is supplied with electrons from, for example, I ⁻ of the electron supply agent 80. In this way, by connecting an external circuit to the transparent conductive film 20 and the conductive film 50, the external circuit can extract current from the dye-sensitized solar cell according to the present embodiment that has absorbed light. That is, this dye-sensitized solar cell functions as a battery.

  Since the power generation principle of the dye-sensitized solar cell is as described above, the energy level of the excited state dye is higher than the energy level of the electron scavenger, and the energy level of the ground state dye is the electron supply agent 80. It requires a relationship that it is lower than the energy level of.

[Example]
Next, examples of the dye-sensitized solar cell according to the embodiment will be described. Here, the fine substrate is formed on the counter substrate 40, the surface of the catalyst layer 60 is a diffuse reflection surface, the dye-sensitized solar cell of this example, the counter substrate 40 is a plane, and the surface of the catalyst layer 60 is a mirror surface. The performance of the dye-sensitized solar cell of the comparative example was compared. The index used for the comparison is the conversion efficiency η, which is the ratio of the generated power energy to the incident light energy.

  Unevenness was formed on the counter substrate 40 by chemical polishing. FIG. 3 shows the surface shape of the counter substrate 40 on which the irregularities are formed. 3A shows a plan view, and FIG. 3B shows a perspective view. The uneven surface had a center line average roughness Ra of 0.137 μm and a ten-point average height Rz of 0.692 μm. Here, for the centerline average roughness Ra, the length of interest is extracted, the roughness curve is folded back from the centerline, and the area surrounded by the roughness curve and the centerline is divided by the length of interest. Value. Further, the ten-point average height Rz is a difference value between the average value of the heights of the five peaks from the highest and the average value of the depths of the five valleys from the lowest in the reference length of the cross-sectional curve. To express. Ra is preferably 0.14 μm ± 0.1 μm and Rz is preferably 0.7 μm ± 0.3 μm.

  As shown in FIG. 4, a conductive film 50 made of ITO was formed on the surface of the counter substrate 40 having unevenness, and titanium was deposited thereon to form a platinum underlayer 55. Then, a platinum film was formed on the platinum base layer 55 to form the catalyst layer 60. The platinum film constituting the catalyst layer 60 is a diffuse reflection surface due to the unevenness formed on the counter substrate 40. Here, the platinum underlayer 55 has an effect of increasing the surface area of platinum which is the catalyst layer 60.

  On the other hand, a transparent conductive film 20 made of ITO was formed on a transparent substrate 10 made of glass. On the transparent conductive film 20, an anatase-type titanium oxide paste having a particle size of 20 nm was screen-printed so as to have a 30 mm square and a film thickness of about 2 μm, and heat treatment was performed to form an electron scavenger. The D149 dye constituting the dye was adsorbed on the electron collector. In this way, an electron collection-dye layer 30 was formed.

  Next, the counter substrate 40 on which the catalyst layer 60 was formed and the transparent substrate 10 on which the electron collection-dye layer 30 was formed were bonded and sealed so as to provide a gap of 10 μm. Then, the iodine electrolyte solution which comprises the electron supply agent 80 was vacuum-injected and sealed, and the dye-sensitized solar cell was produced.

  In the dye-sensitized solar cell of the comparative example, no unevenness was formed on the counter substrate 40. Other configurations were the same as those in this example.

The value of the conversion efficiency η of the dye-sensitized solar cell according to this example and the dye-sensitized solar cell according to the comparative example was measured in accordance with JIS C 8914 “Crystalline solar cell module output measurement method” of JIS standard. . Briefly, in the measurement, light having a wavelength of 400 to 1100 nm and an illuminance of 1000 W / m ² was irradiated to obtain a current I-voltage V curve. And the value of conversion efficiency (eta) was calculated | required from the acquired IV curve. The larger the value of the conversion efficiency η, the higher the efficiency of converting light energy into electric energy and the higher the performance.

  The acquired IV curve is shown in FIG. In this figure, the solid line indicates the IV curve of the dye-sensitized solar cell according to this example, and the broken line indicates the IV curve of the dye-sensitized solar cell according to the comparative example. As shown in this figure, the IV curve of the dye-sensitized solar cell according to the present example is in the upper right direction in the graph than that according to the comparative example. This indicates that the conversion efficiency from light energy to electrical energy is good. The conversion efficiency η of the dye-sensitized solar cell according to this example was 0.117%, and that according to the comparative example was 0.096%. That is, the conversion efficiency η according to this example was 1.23 times that of the comparative example.

  The reason why the conversion efficiency η of this embodiment is higher than that of the comparative example can be considered as follows. Light that enters from the transparent substrate 10 side and reaches the catalyst layer 60 without being absorbed by the dye in the electron collection-dye layer 30 is reflected by the surface of the catalyst layer 60 and enters the electron collection-dye layer 30 again. To do. At this time, in the case of the comparative example, since the surface of the catalyst layer 60 is a mirror surface, the reflected light travels straight and the optical path passing through the electron collection-dye layer 30 is short. For this reason, a part of the light is absorbed by the pigment, but a lot of other light is transmitted without being absorbed. Compared to this, in the case of the present embodiment, since it is a diffuse reflection surface on the surface of the catalyst layer 60, the light path that is diffusely reflected and passes through the electron collection-dye layer 30 becomes long. For this reason, it is considered that the proportion of light is absorbed by the pigment and increased compared to the comparative example. For this reason, it is considered that the conversion efficiency η has increased.

  As described above, in the dye-sensitized solar cell according to this embodiment, since the surface of the catalyst layer 60 is a diffuse reflection surface, the proportion of the reflected light absorbed by the dye is when the surface of the catalyst layer 60 is a mirror surface. Higher than. For this reason, the conversion efficiency η increases. That is, according to this embodiment, the performance of the dye-sensitized solar cell is improved.

[Modification]
In order to improve the performance of the dye-sensitized solar cell, it is also meaningful to devise the configuration of the electron collection-dye layer 30. That is, as shown in FIG. 6, two types of titanium oxides having different particle diameters may be used for the anatase type titanium oxide constituting the electron scavenger 32. For example, the electron collecting agent 32 having a large particle diameter is called an electron collecting electron collecting particle 34, and the electron collecting agent 32 having a small particle diameter is called a dye adsorption electron collecting particle 36.

  As shown in FIG. 6, the electron collection particles 34 for electron transfer are in contact with each other, and some of them are in contact with the transparent conductive film 20. The dye-adsorbing electron-collecting particles 36 are in contact with the electron-transmitting electron-collecting particles 34. The dye 38 is adsorbed on the electron collecting electron collecting particles 34 and the dye adsorbing electron collecting particles 36. With such a configuration, the electron collection particle 34 for electron transmission plays a role of transmitting mainly electrons emitted from the pigment 38 to the transparent conductive film 20. Further, the dye-adsorbing electron collection particles 36 have a role of increasing the surface area of the electron collection agent 32 in order to adsorb more dye 38.

  Here, the diameter of the dye-adsorbing electron collection particles 36 is, for example, 5 nm or more and 25 nm or less, and the diameter of the electron transfer electron collection particles 34 is, for example, 100 nm or more and 400 nm or less. The ratio of the dye-adsorbing electron-collecting particles 36 and the electron-transmitting electron-collecting particles 34 is, for example, 20 to 25% of the dye-adsorbing electron-collecting particles 36 by weight, and the electron-transmitting electron-collecting particles 34. Is, for example, 75 to 80%. The thickness of the electron collection-dye layer 30 composed of the electron collection particles 34 for electron transfer, the electron collection particles 36 for dye adsorption and the dye 38 is, for example, about 10 μm.

  The electron collection-dye layer 30 is produced as follows, for example. After mixing titanium oxide particles having two kinds of particle sizes of anatase type as the electron collection particles 34 for electron transfer and the electron collection particles 36 for dye adsorption into a paste, the paste is applied to the transparent substrate 10. Printing or coating is performed, followed by baking to form a titanium oxide film. After the formation of the titanium oxide film, the titanium oxide film is immersed in a liquid of a dye 38 dissolved in an organic solvent, and the dye 38 is adsorbed on the titanium oxide.

  Next, examples of the dye-sensitized solar cell of this modification will be described. Here, the dye-sensitized solar cell of this example using titanium oxide as two types of electron-trapping agents 32 having different diameters as the electron-collecting particles 34 for electron transfer and the electron-trapping particles 36 for dye adsorption The performance was compared with that of a dye-sensitized solar cell of a comparative example using titanium oxide as the electron scavenger 32 having one diameter. What is compared is the value of the fill factor (FF), which is the ratio of the actual power to the apparent maximum power.

  In this example, the diameter of titanium oxide as the electron collection particle 34 for electron transfer was set to 100 nm, and the diameter of titanium oxide as the electron collection particle 36 for dye adsorption was set to 10 nm. The mixing ratio of the electron transfer electron collection particles 34 and the dye adsorption electron collection particles 36 is 75% by weight, the electron transfer electron collection particles 34 are 75%, and the dye adsorption electron collection particles 36 are 25%. It was. The average thickness of the electron collection-dye layer 30 containing the electron collection particles 34 for electron transfer, the electron collection particles 36 for dye adsorption and the dye 38 was 5 μm. On the other hand, in the dye-sensitized solar cell as a conventional example for reference, the diameter of titanium oxide constituting the electron scavenger 32 was all 10 nm, and other conditions were the same as in the case of the present example. In addition, when the diameter of the titanium oxide constituting the electron scavenger 32 is simply increased, the roughness factor (RF = actual surface area / projected area) is simply decreased, and the roughness factor is decreased. It is known that if the average of the thickness of the electron collection-dye layer 30 is increased by the amount, absorption of visible light increases, which is not practical.

  The FF values of the dye-sensitized solar cell according to the present example and the dye-sensitized solar cell according to the conventional example were obtained according to JIS standard JIS C 8914 “Crystalline solar cell module output measurement method” IV Obtained from the curve. The larger this value, the smaller the internal loss of the solar cell and the higher the performance.

  As a result of measuring three times for each of the present example and the conventional example, the FF value is 44.4 ± 1.3 (average ± standard deviation) in the dye-sensitized solar cell according to the present example, and the dye increase according to the conventional example. In the solar cell, it was 25.6 ± 0.3 (average ± standard deviation). That is, the FF value of this example increased by 74% compared to the conventional example.

Possible reasons for this difference are as follows. As shown in the schematic diagram of the electron collecting-dye layer 30 of the conventional example in FIG. 7A, in the conventional example, as indicated by the white arrowhead A in FIG. ⁻ Is transmitted to the transparent conductive film 20 through many particles having a small diameter constituting the electron scavenger 32. Therefore, it is necessary for the electron e ⁻ to greatly exceed the junction of the particles in the electron scavenger 32. For this reason, the resistance of the electrical connection path formed in the electron scavenger 32 becomes high and electrons are not easily transmitted. Further, as indicated by the white arrowhead B in FIG. 7A, the dyes 38 are associated with each other and enter between the particles constituting the electron scavenger 32, so that the particles constituting the electron scavenger 32 are There may be a part that does not touch. And in the part which the particles which comprise the electron scavenger 32 do not contact in this way, an electron e < ^- > will not be transmitted.

On the other hand, as shown in the schematic diagram of the electron collection-dye layer 30 of this example in FIG. 7B, in this example, the electrons e ⁻ emitted from the dye 38 have a small number of large diameters. It is transmitted to the transparent conductive film 20 through the electron collecting particles 34 for electron transmission. Therefore, there are few junction parts of the electron collection particle | grains 34 for electron transmission which the electron e < ^- > needs to exceed. In addition, since the electron-collecting particles 34 for electron transfer have a large diameter and a large surface area per one, the bonding between the electron-collecting particles 34 for electron transfer is excellent. For this reason, the resistance of the electrical connection path formed in the electron scavenger 32 is lower than in the case of FIG. 7B, and electrons are easily transmitted. Further, since there are many dye-adsorbing electron-collecting particles 36, the surface area is large, and the roughness factor is 1000 or more, which is more than the value that is said to be necessary in a dye-sensitized solar cell. For this reason, a sufficient number of dyes 38 are adsorbed by the electron scavenger 32.

From the above, in this embodiment, electrons e ⁻ emitted from a sufficient number of dyes 38 are smoothly transmitted to the transparent conductive film 20. As a result, in this example, it is considered that the FF value increased compared to the conventional example.

  As described above, in the dye-sensitized solar cell according to this modification, the electron collection particles 34 and the dye adsorption electron collection particles 36 having different particle diameters are used as the electron collection agent 32. As a result, obstacles related to the electron transfer from the dye 38 to the transparent conductive film 20 are reduced, the electron transfer is performed smoothly and has a sufficient surface area. 32 can be adsorbed. As a result, the FF value can be increased. That is, the internal loss of the dye-sensitized solar cell can be reduced and the performance can be improved.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the problem described in the column of problems to be solved by the invention can be solved and the effect of the invention can be obtained. The configuration in which this component is deleted can also be extracted as an invention.

  DESCRIPTION OF SYMBOLS 10 ... Transparent substrate, 20 ... Transparent electrically conductive film, 30 ... Electron collection-dye layer, 32 ... Electron collection agent, 34 ... Electron collection particle | grains for electron transfer, 36 ... Electron collection particle | grains for dye adsorption, 38 ... Dye 40 ... Counter substrate, 50 ... Conductive film, 55 ... Platinum underlayer, 60 ... Catalyst layer, 70 ... Sealing material, 80 ... Electron supply agent.

Claims (11)

A first substrate;
A second substrate disposed opposite the first substrate;
A first electrode formed on a surface of the first substrate facing the second substrate;
An electron scavenger disposed on the first electrode;
An electron supply agent disposed between the first substrate and the second substrate;
A dye disposed on the electron scavenger, having an energy level higher than the energy level of the electron scavenger in the excited state and lower than the energy level of the electron supplier in the ground state;
A catalyst layer disposed on a surface of the second substrate facing the first substrate;
In a dye-sensitized solar cell comprising:
The surface of the catalyst layer facing the first substrate is a diffuse reflection surface.
The dye-sensitized solar cell characterized by the above-mentioned.   The diffuse reflection surface is formed by roughening a surface of the second substrate facing the first substrate, forming a second electrode on the rough surface, and forming the catalyst layer on the second electrode. It forms, The dye-sensitized solar cell of Claim 1 characterized by the above-mentioned.   The dye-sensitized solar cell according to claim 2, wherein the rough surface is formed by frost processing, chemical etching, and / or sand blasting.   4. The dye-sensitized solar cell according to claim 3, wherein a center line average roughness Ra of the rough surface is 0.14 μm and a ten-point average height Rz is 0.7 μm.   The dye-sensitized solar cell according to claim 2, wherein the rough surface is formed by forming an organic scattering film on the second substrate.   The dye-sensitized solar cell according to claim 2, wherein an underlayer is formed between the second electrode and the catalyst layer.   The dye-sensitized solar cell according to claim 6, wherein the underlayer is made of titanium.   The dye-sensitized solar cell according to claim 1, wherein the catalyst layer is a platinum film.   The dye-sensitized solar cell according to claim 1, wherein the first electrode is patterned.   The dye-sensitized solar cell according to claim 1, wherein a current collecting pattern is provided on an upper layer or a lower layer of the first electrode.   The dye-sensitized solar cell according to claim 10, wherein the current collection pattern is made of silver.

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