JP2011165580A - Photoelectric conversion element, and photovoltaic generator device using the photoelectric conversion element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoelectric conversion element based on a dye-sensitization phenomenon in which a monolithic structure is employed. <P>SOLUTION: The photoelectric conversion element 1 is provided with a translucent substrate 2, a first translucent conductive layer 3 partially arranged on the translucent substrate 2, a second translucent conductive layer 4 arranged on the translucent substrate 2 with a wider interval than the first translucent conductive layer 3, a porous semiconductor layer 5 arranged on the first translucent conductive layer 3, a dye 6 adsorbed on the surface of the porous semiconductor layer 5, a porous insulation layer 7 arranged to cover the porous semiconductor layer 5 and each of the translucent conductive layers 3, 4, a porous carbon conductive layer 8 arranged continuously on the porous insulation layer 7 and the second translucent conductive layer 4, a sealing member 9 contacting each of the translucent conductive layers 3, 4 and surrounding the porous insulation layer 7 and the porous carbon conductive layer 8, and a charge transport layer 10 surrounded by the sealing member 9 arranged on the micropores of the porous semiconductor layer 5, the porous insulation layer 7 and the porous carbon conductive layer 8. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photoelectric conversion element that can obtain high photoelectric conversion efficiency, is suitable for mass production, and can be manufactured at low cost, and a photovoltaic device using the photoelectric conversion element.

  Our advanced cultural life is supported by resources, but the resources we have been using for a long time have been depleted. Not only that, the destruction of the earth's environment due to greenhouse gases generated by burning fossil fuels is advancing. Thus, there are problems that must be solved for the future of humanity.

  Thus, renewable natural energy resources such as sunlight, wind power, wave power, and geothermal heat have attracted attention. Compared to fossil fuels and the like, these energy resources have features such as no fear of depletion, a large amount of resources, and a small environmental load. In particular, among natural energies, sunlight attracts attention because the total amount of energy falling on the earth is several orders of magnitude larger than other renewable energies and can be used anywhere on the earth. However, conventional solar power generation systems are very expensive and cannot be used without government assistance. The development of low-cost next-generation solar cells is an urgent need for the existence of humankind.

  Incidentally, attention has been focused on dye-sensitized solar cells as low-cost solar cells. Dye-sensitized solar cells, also called Gretzell cells, were developed by Dr. Gretzell in Switzerland in 1988 and are expected to be the next generation of solar power generation to replace conventional silicone solar cells. The dye-sensitized solar cell is a new type of solar cell that is inexpensive and has high conversion efficiency to electricity, such as using a dye to convert sunlight into electricity. In addition, large-scale equipment is not required for production, and research and development are expected as a low-cost solar cell.

  However, the dye-sensitized solar cell is characterized in that its life is short because the charge transport agent is liquid. Since high durability is necessary for industrial use, development of a highly durable dye-sensitized solar cell is urgently needed for practical use.

  A high-efficiency dye-sensitized solar cell uses a liquid charge transport agent. However, due to the volatilization of the charge transport agent, the durability of a dye-sensitized solar cell using the same is hindered. Accordingly, there is an urgent need to develop a dye-sensitized solar cell that employs a structure that does not use a volatile charge transfer agent or that does not easily evaporate.

  A monolithic dye-sensitized solar cell that utilizes the capillary force of a porous electrode can be considered as an option for a structure in which the charge transfer agent is less likely to volatilize. As of January 2010, Sony Corporation has reported a monolithic dye-sensitized solar cell with a conversion efficiency of 8.2%.

  However, although the structure of monolithic dye-sensitized solar cells and simple preparation procedures have been reported, detailed preparation procedures and preparation procedures for the paste that forms the porous layer have not been reported. There is a need for a detailed process relating to the fabrication of solar cells and the paste that forms the porous layer.

  Accordingly, the present invention has been completed in view of the above-described conventional problems, and its object is a photoelectric conversion element based on a dye sensitization phenomenon employing a monolithic structure, which is inexpensive and highly durable. Is to provide.

  The photoelectric conversion element of the present invention includes a translucent substrate, a first translucent conductive layer partially disposed on the main surface of the translucent substrate, and a main surface of the translucent substrate. A second light-transmitting conductive layer provided at a distance from the first light-transmitting conductive layer, a porous semiconductor layer provided on the first light-transmitting conductive layer, and the porous Dye adsorbed as a monomolecular layer on the surface of the semiconductor layer, and porous insulation provided so as to cover the porous semiconductor layer, the first light-transmitting conductive layer, and the second light-transmitting conductive layer A porous carbon conductive layer continuously provided on the porous insulating layer and the second translucent conductive layer, the first translucent conductive layer, and the second translucent conductive layer. A sealing member provided in contact with the main surface of the translucent conductive layer and surrounding the porous insulating layer and the carbon conductive layer; and the porous semiconductor layer and the front It is formed in the porous insulating layer and the enclosed within the sealing member provided in the micropores of the carbon conductive layer charge transport layer.

In the photoelectric conversion element of the present invention, the carbon conductive layer is obtained by printing a paste in which amorphous carbon, graphite carbon (mass ratio 2: 3) and TiO ₂ are dispersed in a polymer and a solvent on the porous insulating layer. It is preferably formed by sintering.

In the photoelectric conversion element of the present invention, the porous insulating layer is formed by printing a paste in which insulating particles such as ZrO ₂ and Al ₂ O ₃ are dispersed in a polymer and a solvent on the porous semiconductor layer, and baking it. It is preferably formed by bonding.

  In the photoelectric conversion element of the present invention, the porous insulating layer is preferably pre-sintered at 500 ° C. before forming the carbon conductive layer.

In the photoelectric conversion element of the present invention, it is preferable that the porous semiconductor layer is made of at least one of TiO ₂ , WO ₃ , ZnO, Nb ₂ O ₅ , Ta ₂ O ₅ , or SrTiO ₃ .

  In the photoelectric conversion element of the present invention, the translucent conductive layer is at least one of fluorine-doped tin oxide, indium tin oxide, gallium-doped zinc oxide, aluminum-doped zinc oxide, or niobium-doped titanium oxide. Preferably it consists of.

  In the photoelectric conversion element of the present invention, it is preferable that the charge transport layer is made of at least one of iodide, cobalt complex, iron complex, CuI, CuSCN, or organic hole transport material.

  In the photoelectric conversion element of the present invention, the dye preferably comprises at least one of a metal complex dye such as a Ru complex dye, and an organic dye such as a porphyrin dye and an indoline dye.

  It is preferable that the photoelectric conversion element of the present invention uses the photoelectric conversion element according to any one of claims 1 to 8 as a power generation unit, and supplies the generated power of the power generation unit to a load.

  The photoelectric conversion element of the present invention includes a translucent substrate, a first translucent conductive layer partially disposed on the main surface of the translucent substrate, and a main surface of the translucent substrate. A second light-transmitting conductive layer provided at a distance from the first light-transmitting conductive layer, a porous semiconductor layer provided on the first light-transmitting conductive layer, and the porous Dye adsorbed as a monomolecular layer on the surface of the semiconductor layer, and porous insulation provided so as to cover the porous semiconductor layer, the first light-transmitting conductive layer, and the second light-transmitting conductive layer A porous carbon conductive layer continuously provided on the porous insulating layer and the second translucent conductive layer, the first translucent conductive layer, and the second translucent conductive layer. A sealing member provided in contact with the main surface of the translucent conductive layer and surrounding the porous insulating layer and the carbon conductive layer; and the porous semiconductor layer and the front Since it is formed of a porous insulating layer and a charge transport layer surrounded by the sealing member provided in the micropores of the carbon conductive layer, the light energy absorbed by the dye can be efficiently converted. Can do. In addition, since a porous carbon conductive layer is provided in place of the one obtained by thermally decomposing Pt on the translucent conductive layer, it is less expensive than Pt and is durable without melting like Pt. Will be better.

Further, in the photoelectric conversion element of the present invention, the carbon conductive layer includes a paste in which amorphous carbon, graphite carbon (mass ratio 2: 3), and TiO ₂ are dispersed in a polymer and a solvent on the porous insulating layer. A porous carbon electrode is obtained by printing and sintering.

In the photoelectric conversion element of the present invention, the porous insulating layer is obtained by printing a paste in which insulating particles such as ZrO ₂ and Al ₂ O ₃ are dispersed in a polymer and a solvent on the porous semiconductor layer. The spacer is formed by sintering and serves as a spacer for preventing contact between the porous semiconductor layer and the carbon conductive layer.

  In addition, the photoelectric conversion element of the present invention prints the carbon conductive layer by preliminarily sintering the porous insulating layer at 500 ° C. before the carbon conductive layer is formed. When dried, the porous insulating layer does not condense and therefore does not crack or peel off.

Moreover, the photoelectric conversion element of the present invention comprises a layer composed of at least one of TiO ₂ , WO ₃ , ZnO, Nb ₂ O ₅ , Ta ₂ O ₅ or SrTiO ₃ as a porous layer, whereby It becomes an electrode that efficiently adsorbs and supports the surface of the porous semiconductor layer and efficiently receives electrons from the dye.

  In the photoelectric conversion device of the present invention, the light-transmitting conductive layer is at least one of fluorine-doped tin oxide, indium-doped tin oxide, gallium-doped zinc oxide, aluminum-doped zinc oxide, or niobium-doped titanium oxide. By being constituted, it becomes a window layer for introducing light into the dye, and the electric power obtained from the dye can be efficiently taken out.

  In the photoelectric conversion element of the present invention, the charge transport layer is composed of at least one of iodide, a cobalt complex, an iron complex, CuI, CuSCN, or an organic hole transport material, so that excited electrons are contained in the porous layer. The charge transport layer can efficiently supply electrons to the dye that has moved to the oxidized semiconductor layer and oxidized.

  In the photoelectric conversion element of the present invention, the dye is a metal complex dye such as a Ru complex dye, or an organic dye such as a porphyrin dye or an indoline dye. Light incident from the translucent conductive layer can be efficiently converted into electrons.

  In addition, the photovoltaic device of the present invention uses the photoelectric conversion element of the present invention as a power generation means and supplies the generated power of the power generation means to a load, so that the photoelectric conversion characteristics are improved.

Sectional drawing which shows an example of embodiment about the photoelectric conversion element of this invention Photoelectric characteristics of monolithic dye-sensitized solar cells using porous carbon conductive layer and Pt-processed fluorine-doped tin oxide glass substrate

  Embodiments according to the present invention will be described below in detail with reference to the drawings.

  As shown in FIG. 1, 1 is a photoelectric conversion element, 2 is a translucent substrate, 3 is a first translucent conductive layer made of an ITO (indium doped tin oxide) layer, FTO (fluorine doped tin oxide) or the like. 4 is a second light-transmitting conductive layer made of ITO (indium-doped tin oxide) or FTO (fluorine-doped tin oxide), 5 is a porous semiconductor electrode, 6 is a dye, and 7 is porous insulation. A body spacer, 8 is a porous carbon electrode, 9 is a sealing member, and 10 is a charge transport layer.

  In the photoelectric conversion element 1, electrons move from the dye 6 to the external circuit through the porous semiconductor layer and the translucent conductive layer 3, and the electrons moved from the external circuit are in the porous carbon conductive layer 8 and the charge transport layer 10. Power is generated by being supplied to the oxidized pigment through

  The translucent board | substrate 2 consists of a transparent glass plate, a plastic board, etc., and thickness is about 0.1-5 mm.

  The translucent conductive layer 3 (4) is made of at least one of fluorine-doped tin oxide, indium tin oxide, gallium-doped zinc oxide, aluminum-doped zinc oxide, or niobium-doped titanium oxide, and has a thickness of About 0.3-2 micrometers is preferable. When the thickness is less than 0.3 μm, the sheet resistance increases and the series resistance of the photoelectric conversion element 1 increases, so that the fill factor characteristic tends to deteriorate. The translucent conductive layer 3 (4) is formed by a CVD method, a sputtering method, a spray method, or the like.

  The porous semiconductor layer 5 is formed on the translucent conductive layer 3 and sensitized with the dye 6.

The material and composition of the porous semiconductor layer 5 is optimally titanium oxide (TiO ₂ ), and other materials are 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 A metal oxide semiconductor of at least one metal element such as (W) is preferable, and is composed of at least one of TiO ₂ , WO ₃ , ZnO, Nb ₂ O ₅ , Ta ₂ O ₅ , or SrTiO ₃ , for example. . 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 material of the porous semiconductor layer 5 is preferably an n-type semiconductor whose conduction band is lower than that of the dye 6 in the electron energy level.

  The porous semiconductor layer 5 is made of the above-mentioned material and has a large number of fine pores (having a pore diameter of preferably about 10 to 40 nm, and a peak of photoelectric conversion efficiency at 22 nm). A good n-type oxide semiconductor layer or the like is preferable. When the pore diameter of the porous semiconductor layer 5 is less than 10 nm, the osmotic adsorption of the dye 6 is hindered, it is difficult to obtain a sufficient amount of the dye 6 adsorbed, and the diffusion resistance increases because the diffusion of the electrolyte is hindered. For this reason, the photoelectric conversion efficiency tends to decrease. If it exceeds 40 nm, the specific surface area of the porous semiconductor layer 5 is reduced, so that the amount of adsorption of the dye 6 is reduced. Further, the light is hardly transmitted and the dye 6 cannot absorb the light. In addition, since the movement distance of the charge injected into the porous semiconductor layer 5 becomes longer, the loss due to the recombination of charges becomes larger, and further, the diffusion distance of the electrolyte also increases so that the diffusion resistance increases. Conversion efficiency tends to decrease.

  The porous semiconductor layer 5 is 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 is a porous body. The surface area for adsorbing the dye 6 is increased, and the photoelectric conversion efficiency can be increased. The porous semiconductor layer 5 may be a porous body having a porosity of 20 to 80%, more preferably 40 to 60%. By making porous, the surface area as the light working electrode layer can be increased by 1000 times or more compared to the case of a dense body, and light absorption, photoelectric conversion, and electron conduction can be performed efficiently.

  The porosity of the porous semiconductor layer 5 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 Ionization) method, The pore volume can be obtained by the DH (Dollimore-Heal) method or the like and obtained from the particle density of the sample.

  The shape of the porous semiconductor layer 5 is preferably that the surface area is large and the electric resistance is small. For example, the porous semiconductor layer 5 is preferably composed of fine particles or fine linear bodies. The average particle diameter or average wire diameter is preferably 5 to 500 nm, and more preferably 10 to 200 nm. Here, if the lower limit of the average particle diameter or the average wire diameter of 5 to 500 nm is less than this, the material cannot be miniaturized, and if the upper limit exceeds this, the junction area becomes smaller and the photocurrent is remarkably reduced. By becoming.

  By forming the porous semiconductor layer 5 as a porous body of fine particles, the dye 6 is supported in the micropores, the surface becomes uneven, and a light confinement effect is brought about, so that the photoelectric conversion efficiency can be further increased.

  The thickness of the porous semiconductor layer 5 is preferably 1 to 15 μm. Here, the lower limit value at 1 to 15 μm is not suitable for practical use because the photoelectric conversion action is remarkably reduced when the thickness is smaller than this, and the upper limit value is larger than this and the thickness becomes thicker. Insulation of the conductive layer 8 becomes difficult.

The porous semiconductor layer 5 is formed by printing and sintering a paste in which the oxide semiconductor is dispersed in a polymer and a solvent. For example, when the porous semiconductor layer 5 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 translucent conductive layer 3 at a constant speed by a doctor blade method or a bar coating method, and heated in the atmosphere at 400 to 600 ° C. for 10 to 60 minutes, preferably 20 to 40 minutes. By processing, the porous semiconductor layer 5 is formed. This method is simple and preferable.

Further, if necessary, a post-process may be performed on the porous semiconductor layer 5 by a low temperature growth method. As the low temperature growth method, an electrodeposition method, an electrophoretic electrodeposition method, a hydrothermal synthesis method and the like are preferable. As a post-treatment for improving electron transport properties, a microwave treatment, a plasma treatment by a CVD method, a thermal catalyst treatment, etc. UV irradiation treatment is preferable. The porous semiconductor layer 5 formed by the low temperature growth method is preferably composed of a porous ZnO layer formed by the electrodeposition method, a porous TiO ₂ layer formed by the electrophoretic electrodeposition method, and the like.

  An ultrathin (thickness: about 200 nm) dense layer made of an n-type oxide semiconductor may be inserted between the porous semiconductor layer 5 and the translucent conductive layer 3, and the reverse current can be suppressed, so that the photoelectric conversion efficiency is increased.

  The porous semiconductor layer 5 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 3 side. The semiconductor layer 5 is preferably composed of a two-layer laminate in which the average particle diameters of the oxide semiconductor particles are different. Specifically, oxide semiconductor fine particles having a small average particle diameter are used on the translucent conductive layer 3, and oxide semiconductor fine particles (scattering particles) having a large average particle diameter are used on the formed semiconductor layer. The porous semiconductor layer 5 having a large average particle 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. Further, by increasing the number of laminated layers from two layers to three or more layers, or by coating and forming such that these boundaries do not occur, the average particle diameter is gradually increased from the translucent conductive layer 3 side in the thickness direction. It can be formed to be large.

  Examples of the method for adsorbing the dye 6 to the porous semiconductor layer 5 include a method of immersing the porous semiconductor layer 5 formed on the translucent substrate 3 in a solution in which the dye 6 is dissolved.

Solvents for dissolving the dye 6 when adsorbing the dye 6 on the porous semiconductor layer 5 include water, alcohols such as ethanol, ketones such as acetone, ethers such as diethyl ether, and nitrogen compounds such as acetonitrile. Or a mixture of two or more thereof. The concentration of the dye 6 in the solution is preferably about 5 × 10 ⁻⁵ to 2 × 10 ⁻³ mol / l (l (liter): 1000 cm ³ ).

  When adsorbing the dye 6 to the porous semiconductor layer 5, the conditions of the temperature of the solution and the atmosphere are not particularly limited, and examples thereof include atmospheric pressure or vacuum, room temperature, or heating conditions. The time required for adsorption of the dye 6 can be appropriately adjusted depending on the kind of the dye 6 and the solution, the concentration of the solution, the circulation amount of the solution of the dye 6 and the like. Thereby, the pigment | dye 6 can be made to adsorb | suck to the porous semiconductor layer 5. FIG.

Materials used for the porous insulating layer 7 include particles such as zirconium oxide (ZrO ₂ ) and aluminum oxide (Al ₂ O ₃ ).

  The size of the oxide insulator particles used for the porous insulating layer 7 is preferably about 40 to 100 nm. If the thickness is smaller than 40 nm, the formed micropores are small, so that the charge transfer agent does not easily penetrate. If it is larger than 100 nm, the formed fine pores become large, so that the carbon particles may be short-circuited through the fine pores.

The porous carbon conductive layer 8 is formed by printing on a porous insulating layer 7 and sintering a paste in which amorphous carbon, graphite carbon, and TiO ₂ are dispersed in a polymer and a solvent.

The porous insulating layer 7 and the porous carbon conductive layer 8 are formed as follows, for example. First, when ZrO ₂ is used for the porous insulating layer 7, after adding acetic acid to the ZrO ₂ nanoparticles, a paste of ZrO ₂ stabilized by a solvent and a polymer is kneaded with deionized water and ethanol. Prepare. The prepared paste is applied onto the porous semiconductor layer 5 at a constant speed by a doctor blade method, a bar coating method, or the like, and is heat-treated at 100 to 140 ° C. for 3 to 6 minutes in the air to thereby form an insulating layer. Form. Next, carbon particles mixed with amorphous carbon particles and graphite carbon particles and TiO ₂ are kneaded with deionized water and ethanol to prepare a carbon paste stabilized with a solvent and a polymer. On the formed insulating layer, the prepared carbon paste is applied at a constant speed by a doctor blade method, a bar coating method, or the like, and is heated at 100 to 140 ° C. for 3 to 6 minutes in the atmosphere, so that carbon is obtained. A conductive layer is formed. The formed electrode is heat-treated at 150 to 650 ° C. for 2 to 60 minutes in the atmosphere to obtain the porous insulating layer 7 and the porous carbon conductive layer 8.

  The porous insulating layer 7 is preferably formed with a thickness of 30 to 40 μm. When the thickness is smaller than 30 μm, the probability that the carbon particles of the porous carbon conductive layer 8 enter the micropores of the porous insulating layer 7 and cause a short circuit increases. When the thickness is larger than 40 μm, the distance between the porous semiconductor layer 5 and the porous carbon conductive layer 8 is increased, and the resistance of the charge transport layer is increased, so that the photoelectric characteristics are deteriorated.

  When forming the porous insulating layer 7 and the porous carbon conductive layer 8, after forming the insulating layer from the prepared paste, the insulating layer is heated in the atmosphere at 150 to 650 ° C. for 2 to 60 minutes. When the carbon conductive layer is first contracted to form the carbon conductive layer, cracking and peeling of the carbon conductive layer can be suppressed.

  Amorphous carbon and graphite carbon used for the porous carbon conductive layer 8 have the lowest resistance when the porous carbon conductive layer 8 is formed when the mass ratio is about 2: 3.

  The thickness of the porous carbon conductive layer 8 is preferably 50 to 200 μm in order to make the resistance value as small as possible. If it is smaller than 50 μm, the resistance of the porous carbon conductive layer 8 becomes high, and the photoelectric characteristics are reduced. If it is larger than 200 μm, cracks and peeling are likely to occur when the porous carbon conductive layer 8 is formed.

  The sealing member 9 preferably has a thickness (height) of about 100 to 1000 μm. If it is less than 100 μm, it becomes thinner than the thickness of the porous semiconductor layer 5, the porous insulating layer 7, and the porous carbon conductive layer 8, so that it is difficult to seal the charge transport layer 10. If the thickness exceeds 1000 μm, the charge transport layer 10 becomes too thick and the internal resistance increases, so that the photoelectric conversion efficiency of the photoelectric conversion element 1 tends to decrease.

  The sealing member 9 is made of a resin adhesive such as polyethylene, polypropylene, epoxy resin, fluororesin or silicone resin, or an inorganic adhesive such as glass frit or ceramics.

  Since the charge transport layer 10 is sealed by the sealing member 9, the durability and reliability of the photoelectric conversion element 1 against light irradiation and high-temperature heating can be effectively maintained. That is, leakage of the charge transport layer 10 from the photoelectric conversion element due to light irradiation and high-temperature heating can be effectively suppressed.

  The charge transport layer 10 is preferably a liquid electrolyte or a gel electrolyte. Photoelectric conversion efficiency is improved by using a liquid electrolyte or a gel electrolyte excellent in charge transport characteristics. The charge transport layer 10 is made 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. It may be a thing.

  The charge transport layer 10 includes iodine / iodide salt, bromine / bromide salt, cobalt complex, potassium ferrocyanide, and the like.

  The thickness of the charge transport layer 10 is preferably about 40 to 300 μm. When the thickness is less than 40 μm, the micropores of the porous semiconductor layer 5, the porous insulating layer 7, and the porous carbon conductive layer 8 cannot be filled, and electrons are not transferred. If it exceeds 300 μm, the photoelectric conversion efficiency is likely to decrease due to an increase in the charge transport layer 10 that is a resistance component, and if the charge transport layer 10 is a liquid electrolyte, a sealing failure due to an increase in the liquid portion is likely to occur. .

  The photovoltaic device of the present invention has a configuration in which the photoelectric conversion element 1 of the present invention is used as a power generation means, and the generated power of the power generation means is supplied to a load. Specifically, the photovoltaic device has a configuration including a photoelectric conversion element 1, a load such as an inverter device that converts a direct current output from the photoelectric conversion device 1 into an alternating current, an electric motor, a lighting device, and the like. Used as a solar cell or the like installed on the roof or wall of an object.

  Hereinafter, the Example of the photoelectric conversion element 1 of this invention is described. A photoelectric conversion element having the configuration shown in FIG. 1 was produced as follows.

As the translucent substrate 2 having the first translucent conductive layer 3 and the second translucent conductive layer 4, a SnO ₂ : F layer (fluorine-doped SnO) having a sheet resistance of 10Ω / □ (square) and a thickness of 1 μm. the first transparent conductive layer 3 and the glass substrate in which the second transparent conductive layer 4 is formed on one principal surface (size 25 mm × 15cm consisting of ₂ layers), was prepared thickness 2 mm).

  A porous semiconductor layer 5 made of titanium oxide was formed on the translucent conductive layer 3. Titanium oxide was applied by laminating a paste composed of nanoparticles having an average particle size of 30 nm by screen printing to a thickness of 10 μm, followed by heat treatment at 500 ° C. for 60 minutes.

  The porous insulating layer 7 is formed by coating 30 μm by screen printing so as to cover the porous semiconductor layer 5, the translucent conductive layer 3 and the translucent conductive layer 4, and the porous insulating layer is dark brown at 500 ° C. It was heat-processed for about 3 minutes until it became. Alternatively, heating at 200 ° C. for 30 minutes has the same effect.

  A carbon paste was laminated and applied to the light-transmitting conductive layer 4 from the heat-treated porous insulating layer 7 by a screen printing method, and heat-treated at 400 ° C. for 60 minutes.

  In this state, since the titanium oxide remains burned, it was heated again at 500 ° C. for 5 minutes in order to remove the burn.

  As the dye 6, Ru metal complex Z907 was used. This Z907 was dissolved in a mixed solvent of acetonitrile and t-butyl alcohol (volume ratio 1: 1) to prepare a 0.3 mM dye solution, which was adsorbed on the porous semiconductor layer 5 made of titanium oxide.

Next, a liquid electrolyte containing iodine (I ₂ ), 1-methyl-2-propylimidazolium iodide (MPII) and tetrabutylpyridine, which are charge transport layers 10, is used as a porous carbon conductive layer on the porous semiconductor layer 5. Soaked from 8.

  Thereafter, the sealing member 9 was sealed so as to surround the porous insulating layer 7 and the porous carbon conductive layer 8 with a thermoplastic adhesive (manufactured by Mitsui-Dupont Polychemical Co., Ltd., trade name “HIMILAN”).

As a comparative example, as shown in FIG. 2, a translucent conductive layer made of SnO ₂ : F layer (fluorine-doped SnO ₂ layer) having a sheet resistance of 10Ω / □ (square) and a thickness of 1 μm is formed on one main surface. A glass substrate (size 25 mm × 25 cm, thickness 2 mm) on which a Pt was applied by thermal decomposition on a light-transmitting conductive layer was prepared and used instead of the porous carbon conductive layer.

FIG. 2 is a graph showing photoelectric characteristics of a monolithic dye-sensitized solar cell using a porous carbon conductive layer and a Pt-processed fluorine-doped tin oxide glass substrate.
Carbon electrode cell: short-circuit current density 6.29 mA / cm ² , open circuit voltage 0.599 V, fill factor 0.455, photoelectric conversion efficiency 1.69%
Pt electrode cell: short-circuit current density 6.91 mA / cm ² , open-circuit voltage 0.544 V, fill factor 0.592, photoelectric conversion efficiency 2.22%

About the photoelectric conversion element of an Example and a comparative example, the light (100mW / cm < ² >) of the solar simulator of AM1.5 was irradiated, and the photoelectric characteristic was measured. The photoelectric conversion element 1 using the dye 6 of the present embodiment shown in FIG. 1 has a short-circuit current density of 6.29 mA / cm ² , an open-circuit voltage of 0.599 V, a fill factor of 0.455, and a photoelectric conversion efficiency of 1. It was 69%.

  In contrast, the photoelectric conversion element of the comparative example shown in FIG. 2 had a photoelectric conversion efficiency of 2.22%.

  The photoelectric conversion element 1 of this example was able to achieve a photoelectric conversion efficiency of 80% as compared with the photoelectric conversion element of the comparative example. This is a result of suppressing the resistance value of the porous carbon conductive layer 8. And the photoelectric conversion element far superior to the comparative example was obtained about the point that it is cheap and can obtain high durability, achieving the photoelectric conversion efficiency close | similar to a comparative example.

  It is to be noted that, by appropriately combining arbitrary embodiments of the various embodiments described above, the effects possessed by them can be produced.

  The photovoltaic device according to the present invention has a configuration in which the photoelectric conversion element 1 is used as a power generation means and the generated power of the power generation means is supplied to a load. More specifically, the direct current output from the photoelectric conversion element 1 is provided. It has a configuration including an inverter device that converts current into alternating current, an electric motor, a lighting device, and the like, and is used as a solar cell or the like installed on the roof or wall of a building.

1: Photoelectric conversion element 2: Translucent substrate 3: Translucent conductive layer 4: Translucent conductive layer 5: Porous semiconductor layer 6: Dye 7: Porous insulating layer 8: Porous carbon conductive layer 9: Sealing Stop member 10: charge transport layer

Claims (9)

  A translucent substrate, a first translucent conductive layer partially disposed on the main surface of the translucent substrate, and the first translucent conductive layer on the main surface of the translucent substrate A second light-transmitting conductive layer provided at a distance from the layer, a porous semiconductor layer provided on the first light-transmitting conductive layer, and a monomolecular layer on the surface of the porous semiconductor layer A dye adsorbed as a porous insulating layer, a porous insulating layer provided so as to cover the porous semiconductor layer, the first translucent conductive layer, and the second translucent conductor, and the porous insulation A porous carbon conductive layer continuously provided on the layer and the second translucent conductive layer, and the main surface of the first translucent conductive layer and the second translucent conductive layer A sealing member provided so as to surround the porous insulating layer and the porous carbon conductive layer, the porous semiconductor layer, the porous insulating layer, and the porous Photoelectric conversion element and a charge transport layer Bon provided micropores conductive layer surrounded by the sealing member. The porous carbon conductive layer is formed by printing and sintering a paste in which amorphous carbon, graphite carbon, and TiO ₂ are dispersed in a polymer and a solvent on the porous insulating layer. The photoelectric conversion element according to claim 1. The porous insulating layer is formed by printing and sintering a paste in which insulating particles such as ZrO ₂ and Al ₂ O ₃ are dispersed in a polymer and a solvent on the porous semiconductor layer. The photoelectric conversion element according to claim 1, wherein:   The photoelectric conversion element according to claim 1, wherein the porous insulating layer is heat-treated at 150 to 650 ° C. before forming the porous carbon conductive layer. The porous semiconductor layer is made of at least one of TiO ₂ , WO ₃ , ZnO, Nb ₂ O ₅ , Ta ₂ O ₅ , or SrTiO _3. The photoelectric conversion element as described in 2.   The translucent conductive layer is made of at least one of fluorine-doped tin oxide, indium tin oxide, gallium-doped zinc oxide, aluminum-doped zinc oxide, or niobium-doped titanium oxide. Item 6. The photoelectric conversion element according to any one of Items 1 to 5.   The photoelectric transport layer according to claim 1, wherein the charge transport layer is made of at least one of an iodide, a cobalt complex, an iron complex, CuI, CuSCN, or an organic hole transport material. Conversion element.   The photoelectric conversion element according to claim 1, wherein the dye comprises at least one of a metal complex dye such as a Ru complex dye, and an organic dye such as a porphyrin dye and an indoline dye. .   A photovoltaic device using the photoelectric conversion element according to any one of claims 1 to 8 as a power generation means, and supplying the generated power of the power generation means to a load.