JP2007095370A - Dye-sensitized photoelectric conversion element, photoelectric conversion element module, electronic apparatus, moving body, and power generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye-sensitized simple and cheap photoelectric conversion element such as a dye-sensitized solar cell of which breakage of a sealing material under heat is prevented for improved durability, with no coolant circulation facility required. <P>SOLUTION: An infrared reflection film 6 is provided on one main surface of a transparent conductive substrate 1, while a dye carrying semiconductor micro particle layer 2 is provided on the other main surface. The infrared reflection film 6 is preferred to employ a heat mirror of three-layer structure of TiO<SB>2</SB>/TiN/TiO<SB>2</SB>. The dye carrying semiconductor micro particle layer 2 is made to face a conductive substrate 3 at least whose surface constitutes a counter electrode, and their peripheries are sealed with a sealing material 4. An electrolyte layer 5 is sealed up in the space between the dye carrying semiconductor micro particle layer 2 and the conductive substrate 3, constituting the dye-sensitized photoelectric conversion element. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dye-sensitized photoelectric conversion element, a photoelectric conversion element module, an electronic device, a moving body, and a power generation system, for example, a dye-sensitized solar cell using a dye-sensitized semiconductor electrode composed of semiconductor fine particles carrying a dye, and The dye-sensitized solar cell is suitable for application to various devices, apparatuses, systems and the like.

Solar cells, which are photoelectric conversion elements that convert sunlight into electrical energy, use sunlight as an energy source, and therefore have very little influence on the global environment, and are expected to become more widespread.
Various materials for solar cells have been studied, but many materials using silicon are commercially available. These are roughly divided into crystalline silicon solar cells using single-crystal or polycrystalline silicon, and non-crystalline materials. It is divided into crystalline silicon solar cells. Conventionally, monocrystalline or polycrystalline silicon, that is, crystalline silicon, has been used in many solar cells.

However, although the crystalline silicon solar cell has higher photoelectric conversion efficiency representing the ability to convert light (solar) energy into electric energy than the amorphous silicon solar cell, it requires much energy and time for crystal growth. Therefore, the productivity is low and the cost is disadvantageous.
Amorphous silicon-based solar cells are more light-absorbing than crystalline silicon-based solar cells, have a wide substrate selection range, and are easy to increase in area, but have a photoelectric conversion efficiency of crystalline silicon. Lower than solar cells. Furthermore, although the productivity of amorphous silicon solar cells is higher than that of crystalline silicon solar cells, a vacuum process is required for production in the same way as crystalline silicon solar cells, and the burden on facilities is still large.

On the other hand, many solar cells using an organic material instead of a silicon-based material have been studied for solving the above problems and further reducing the cost of the solar cell. However, many of these solar cells have a very low photoelectric conversion efficiency of about 1%, and have not been put into practical use.
Among them, the dye-sensitized solar cell proposed by Gretzell et al. In 1991 shows high photoelectric conversion efficiency at low cost, and unlike a conventional silicon-based solar cell, it does not require a large-scale device for production. (See, for example, Non-Patent Document 1).

  The general structure of this dye-sensitized solar cell is that a semiconductor porous electrode that combines a semiconductor porous film such as titanium oxide formed on a transparent conductive substrate with a sensitizing dye and a platinum layer are formed on the substrate. The counter electrode obtained in this manner is opposed to each other, and the peripheral portions thereof are sealed with a sealing material, and an organic electrolytic solution containing oxidation / reduction species such as iodine and iodide ions is filled between both electrodes.

On the other hand, in a general silicon-based solar cell, a method for removing heat by passing cooling water through the lower portion of the solar cell is known as a method for preventing a temperature rise associated with irradiation of sunlight.
A method for producing a TiO ₂ paste in which titanium oxide (TiO ₂ ) fine particles are dispersed is known (see, for example, Non-Patent Document 2).
Nature, 353, p.737 (1991) Hironori Arakawa “Latest Technology for Dye-Sensitized Solar Cells” (CMC) p.45-47 (2001)

One cause of deterioration of the dye-sensitized solar cell is liquid leakage due to tearing of the sealing material. The cause is that the sealing material cannot withstand heat or the electrolytic solution expands due to heat. For this reason, it is important to prevent the sealing material from being broken by preventing the temperature increase of the dye-sensitized solar cell and to improve the durability of the dye-sensitized solar cell.
However, in the above heat removal method used in general silicon-based solar cells, a facility for circulating cooling water is required separately from the solar cell system, which is not simple and increases the cost. There was a problem.

  Accordingly, the problem to be solved by the present invention is that a dye-sensitized solar cell that is highly durable because it can prevent tearing of the sealing material due to heat, and that does not require a cooling water circulation facility, is simple and low-cost. A dye-sensitized photoelectric conversion element, a photoelectric conversion element module using such an excellent dye-sensitized photoelectric conversion element, an electronic device, a moving body, and a power generation system.

In order to solve the above problem, the first invention is:
In a dye-sensitized photoelectric conversion element having an electrolyte layer between a semiconductor electrode carrying a sensitizing dye and a counter electrode,
An infrared reflection film is provided between the light receiving surface and / or the light receiving surface and the semiconductor electrode.

As the infrared reflection film, a film that can transmit visible light but can reflect infrared light is preferably used. Specifically, titanium oxide (TiO ₂ ) / titanium nitride (TiN) / A heat mirror having a three-layer structure of titanium oxide (TiO ₂ ) is most desirable, but a heat mirror having another structure, for example, a heat having a three-layer structure of hafnium oxide (HfO ₂ ) / silver (Ag) / hafnium oxide (HfO ₂ ). A mirror may be used. In the heat mirror with a three-layer structure of titanium oxide / titanium nitride / titanium oxide, the titanium nitride film has infrared reflection characteristics, both titanium oxide films have high visible light transmittance, and visible light is transmitted as a whole. Infrared light is reflected. In addition to this, titanium oxide (especially anatase type) is an excellent photocatalytic material, and by absorbing ultraviolet light, it is possible to directly decompose organic substances and to make the surface superhydrophilic. In the case of providing this heat mirror, it is possible to keep the light receiving surface clean and not to be fogged. In order to obtain visible light transmittance and infrared reflection characteristics, the thickness of the titanium nitride film is preferably 20 to 30 nm and the thickness of the titanium oxide film is preferably 30 to 50 nm. The method for forming the heat mirror is not particularly limited, and various coating methods can be used, but a coating method that can easily control the film thickness is more desirable. Specifically, as this coating method, a coating method using a vacuum process such as a vacuum deposition method or a sputtering method is desirable. This heat mirror may be formed, for example, by spin-coating and sintering a metal alkoxide solution.

In this dye-sensitized photoelectric conversion element, the semiconductor electrode is typically provided on one main surface of the transparent conductive substrate. The transparent conductive substrate may be one in which a transparent conductive layer is provided on a conductive or non-conductive transparent support substrate.
When the semiconductor electrode is provided on one main surface of the transparent conductive substrate, the other main surface of the transparent conductive substrate constitutes a light receiving surface, for example, an infrared reflective film is provided thereon. As a specific example in the case of having an infrared reflective film between the light receiving surface and the semiconductor electrode, the semiconductor electrode is provided on one main surface of the transparent support substrate via a transparent conductive layer, and this transparent support substrate The other main surface of this constitutes a light receiving surface, and an infrared reflection film is provided between the transparent support substrate and the transparent conductive layer. The infrared reflection film is preferably provided on the entire light receiving surface or the surface between the light receiving surface and the semiconductor electrode, but at least a part of the light receiving surface or the surface between the light receiving surface and the semiconductor electrode. It may be just provided.

  The material of the transparent support substrate is not particularly limited, and various base materials can be used as long as they are transparent. This transparent support substrate is preferably one that is excellent in moisture and gas barrier properties, solvent resistance, weather resistance, etc. entering from the outside of the photoelectric conversion element. Specifically, transparent inorganic substrates such as quartz and glass, polyethylene Terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, polyethylene, polypropylene, polyphenylene sulfide, polyvinylidene fluoride, tetraacetylcellulose, brominated phenoxy, aramids, polyimides, polystyrenes, polyarylates, polysulfones, polyolefins, etc. A transparent plastic substrate can be mentioned, and among these, it is preferable to use a substrate having a high transmittance in the visible light region, but it is not limited thereto. As this transparent support substrate, it is preferable to use a transparent plastic substrate in consideration of processability, lightness and the like. The thickness of the transparent support substrate is not particularly limited, and can be freely selected depending on the light transmittance, the shielding property between the inside and the outside of the photoelectric conversion element, and the like.

The lower the surface resistance (sheet resistance) of the transparent conductive substrate, the better. Specifically, the surface resistance of the transparent conductive substrate is preferably 500Ω / □ or less, and more preferably 100Ω / □ or less. When a transparent conductive layer is formed on a transparent support substrate, a known material can be used. Specifically, indium-tin composite oxide (ITO), fluorine-doped SnO ₂ (FTO), oxidation Tin (SnO ₂ ), zinc oxide (ZnO), indium-zinc composite oxide (IZO), and the like are exemplified, but the invention is not limited to these, and two or more of these can be used in combination. Further, for the purpose of reducing the surface resistance of the transparent conductive substrate and improving the current collection efficiency, a wiring made of a conductive material such as a highly conductive metal may be separately provided on the transparent conductive substrate. Although there is no restriction | limiting in particular in the electrically conductive material used for this wiring, It is desirable that corrosion resistance and oxidation resistance are high, and the leakage current of electrically conductive material itself is low. However, even a conductive material having low corrosion resistance can be used by separately providing a protective layer made of a metal oxide or the like. Further, for the purpose of protecting the wiring from corrosion or the like, the wiring is preferably installed between the transparent conductive substrate and the protective layer. Furthermore, various oxide thin film barrier layers can be provided for the purpose of reducing dark current from the substrate.

  This dye-sensitized photoelectric conversion element can be produced in various shapes depending on the application, and the shape is not particularly limited. In this dye-sensitized photoelectric conversion element, typically, a plate-like transparent conductive substrate on which a semiconductor electrode carrying a dye is formed and a plate-like counter electrode face each other, and an electrolyte layer therebetween. However, the present invention is not limited to this and may take other forms. For example, in this dye-sensitized photoelectric conversion element, a semiconductor electrode and an electrolyte layer carrying a dye are sequentially provided on the inner surface (the inner surface of a tube) of a tubular transparent conductive substrate, and the central portion of the tubular transparent conductive substrate is provided. It may have a structure in which a counter electrode is inserted. The cross-sectional shape of the tubular transparent conductive substrate is not limited, and may be a circle, an ellipse, a polygon (triangle, quadrangle, pentagon, hexagon, etc.), a part or all of these shapes, A part or all of the cross-sectional shape in the longitudinal direction may change. The tubular transparent conductive substrate may be linear or curved, and a linear portion and a curved portion may be mixed. Further, the length, outer diameter, and inner diameter of the tubular transparent conductive substrate can be determined as needed. In the case where a transparent conductive substrate having a transparent conductive layer formed thereon is used as the tubular transparent conductive substrate, the transparent conductive layer is formed by wet coating a precursor of a transparent conductive material and thermally decomposing it. Is preferred. As this wet coating method, various methods such as a spray coating method, a dip coating method, and a spin coating method can be used. Moreover, after the coating of the precursor of the transparent conductive material, it is preferable to perform heating for the purpose of decomposition of impurities and crystal growth for enhancing conductivity. Application and heating may be performed simultaneously, and for this purpose, it is particularly preferable to use a spray pyrolysis method because it is simple. This spray pyrolysis method is extremely advantageous in that the thickness of a layer that can be formed by one coating is several tens of times larger than that of a dip coating method or a spin coating method. Specifically, the thickness of the layer that can be formed by one coating by the spray pyrolysis method is, for example, about several hundred nm, and can be 500 nm or more. In order to form the transparent conductive layer, the transparent conductive layer may be formed by doping the inner surface of the tubular transparent support substrate with an impurity capable of imparting conductivity to the transparent material to be used.

By the way, in a dye-sensitized photoelectric conversion element such as a dye-sensitized solar cell, a liquid hole (or a dye-supporting porous semiconductor layer) made of an n-type semiconductor as a dye-sensitized semiconductor electrode is usually used. Since the structure is soaked with an electrolyte that is a hole) moving layer, there is a portion where the electrolyte is in direct contact with the transparent conductive substrate or the transparent conductive layer, and from the transparent conductive substrate or the transparent conductive layer to the electrolyte. Leakage current due to reverse electron transfer reaction becomes a problem. Since this leakage current lowers the fill factor and open circuit voltage of the dye-sensitized photoelectric conversion element, it becomes a big problem in improving the photoelectric conversion efficiency. Therefore, it is important to significantly reduce the leakage current due to the reverse electron transfer reaction from the transparent conductive substrate or transparent conductive layer to the electrolyte. For this purpose, it is effective to provide a structure in which a transparent protective layer made of a metal oxide is provided on a transparent conductive substrate or transparent conductive layer, and a dye-carrying semiconductor fine particle layer is provided on the inner surface of this protective layer. As a result, the transparent conductive substrate or transparent conductive layer is covered with a protective layer made of a metal oxide and is shielded from the electrolyte, and the transparent conductive substrate or transparent conductive layer is not in direct contact with the electrolyte. The current can be greatly reduced. A dye-sensitized photoelectric conversion element having such a structure has a high fill factor and an open circuit voltage, and can realize a dye-sensitized photoelectric conversion element excellent in photoelectric conversion efficiency. The metal oxide constituting the protective layer is, for example, at least one selected from the group consisting of Nb ₂ O ₅ , Ta ₂ O ₅ , TiO ₂ , Al ₂ O ₃ , ZrO ₂ , TiSrO ₃ and SiO ₂ . Metal oxides can be used. The thickness of the protective layer is not particularly limited, but if it is too thin, the barrier between the transparent conductive substrate or the transparent conductive layer and the electrolyte is poor, and conversely if it is too thick, the transmittance decreases and the transparent conductive substrate or Since a loss of electron injection into the transparent conductive layer occurs, a preferable thickness exists. This thickness is usually from 0.1 to 500 nm, particularly preferably from 1 to 100 nm.

As a material for the semiconductor fine particles constituting the semiconductor electrode, various compound semiconductors, compounds having a perovskite structure, and the like can be used in addition to the elemental semiconductor represented by silicon. These semiconductors are preferably n-type semiconductors in which conduction band electrons become carriers under photoexcitation and give an anode current. Specifically, these semiconductors are TiO ₂ , ZnO, WO ₃ , Nb ₂ O ₅ , TiSrO ₃ , SnO _2, etc. Among these, anatase type TiO ₂ is particularly preferable. The types of semiconductor are not limited to these, and two or more of these can be used in combination. Furthermore, the semiconductor fine particles can take various forms such as particles, tubes, and rods as required.

  Although there is no restriction | limiting in particular in the particle size of semiconductor fine particle, 1-200 nm is preferable at the average particle diameter of a primary particle, Most preferably, it is 5-100 nm. It is also possible to improve the quantum yield by mixing semiconductor fine particles having an average particle size larger than the average particle size into semiconductor fine particles having an average particle size and scattering incident light by the semiconductor fine particles having a large average particle size. is there. In this case, the average particle diameter of the semiconductor fine particles to be mixed separately is preferably 20 to 500 nm.

  The semiconductor fine particle layer preferably has a large surface area so that it can adsorb many dyes. For this reason, the surface area of the semiconductor fine particle layer formed on the support is preferably 10 times or more, more preferably 100 times or more the projected area. The upper limit is not particularly limited, but is usually about 1000 times. In general, as the thickness of the semiconductor fine particle layer increases, the amount of the supported dye increases per unit projected area and thus the light capture rate increases. However, the diffusion distance of injected electrons increases and the loss due to charge recombination also increases. . Accordingly, a preferable thickness exists in the semiconductor fine particle layer, but the thickness is generally 0.1 to 100 μm, more preferably 1 to 50 μm, and particularly preferably 3 to 30 μm. . After the semiconductor fine particle layer is formed on the support, the semiconductor fine particles are preferably brought into contact with each other electronically and fired to improve the film strength and the adhesion to the support. Although there is no restriction | limiting in particular in the range of a calcination temperature, Since resistance of a support body will become high and it may fuse | melt if it raises temperature too much, Usually, it is 40-700 degreeC, More preferably, it is 40-650 degreeC. is there. The firing time is not particularly limited, but is usually about 10 minutes to 10 hours. For example, a titanium tetrachloride aqueous solution or a titanium oxide ultrafine particle sol having a diameter of 10 nm or less may be dipped for the purpose of increasing the surface area of the semiconductor fine particle layer or increasing necking between the semiconductor fine particles after firing. In the case where a plastic substrate is used as the support for the transparent conductive substrate, it is possible to apply a paste containing a binder onto the substrate and to perform pressure bonding to the substrate by a heating press.

There are no particular restrictions on the method for producing the semiconductor fine particle layer, but in view of physical properties, convenience, production cost, etc., a wet film-forming method is preferable, and a paste in which semiconductor fine particle powder or sol is uniformly dispersed in a solvent such as water. The method of preparing and coating on a transparent conductive substrate or a transparent conductive layer is preferable. Coating is not particularly limited in its method and can be performed according to a known method, for example, dipping method, spray method, wire bar method, spin coating method, roller coating method, blade coating method, gravure coating method, As the wet printing method, for example, various methods such as letterpress, offset, gravure, intaglio, rubber plate, and screen printing can be used. When crystalline titanium oxide (TiO ₂ ) is used as the material for the semiconductor fine particles, the crystal type is preferably anatase type from the viewpoint of photocatalytic activity. The anatase type titanium oxide may be a commercially available powder, sol, or slurry, or may be made with a predetermined particle diameter by a known method such as hydrolysis of titanium oxide alkoxide. When using a commercially available powder, it is preferable to eliminate secondary aggregation of the particles, and it is preferable to pulverize the particles using a mortar, ball mill or the like when preparing the coating solution. At this time, acetylacetone, hydrochloric acid, nitric acid, a surfactant, a chelating agent, or the like can be added in order to prevent the particles after the secondary aggregation from being aggregated again. For the purpose of thickening, various thickeners such as polymers such as polyethylene oxide and polyvinyl alcohol, and cellulose-based thickeners can be added.

  The sensitizing dye supported on the semiconductor fine particle layer is not particularly limited as long as it exhibits a sensitizing action, but an acid functional group that adsorbs to the semiconductor is necessary. Specifically, a carboxy group and a phosphate group are required. Those having a carboxy group are particularly preferable. Specific examples of the sensitizing dye include xanthene dyes such as rhodamine B, rose bengal, eosin and erythrosine, cyanine dyes such as merocyanine, quinocyanine and cryptocyanine, basics such as phenosafranine, fogry blue, thiocin and methylene blue. Examples thereof include porphyrin compounds such as dyes, chlorophyll, zinc porphyrin, and magnesium porphyrin, and others include azo dyes, phthalocyanine compounds, coumarin compounds, bipyridine complex compounds, anthraquinone dyes, and polycyclic quinone dyes. Among these, a sensitizing dye of a complex of at least one metal selected from the group consisting of Ru, Os, Ir, Pt, Co, Fe and Cu, wherein the ligand (ligand) includes a pyridine ring or an imidazolium ring Is preferable because of its high quantum yield. In particular, cis-bis (isothiocyanato) -N, N-bis (2,2′-dipyridyl-4,4′-dicarboxylic acid) -ruthenium (II) or tris (isothiocyanato) -ruthenium (II) — A sensitizing dye molecule having 2,2 ': 6', 2 "-terpyridine-4,4 ', 4" -tricarboxylic acid as a basic skeleton has a wide absorption wavelength range and is preferable. However, the sensitizing dyes are not limited to these, and two or more kinds of these sensitizing dyes may be mixed and used.

As described above, the sensitizing dye supported on the semiconductor fine particle layer is preferably a dye molecule having a carboxy group-containing carboxylic acid as an adsorbing group. However, the dye molecule having the carboxylic acid as an adsorbing group is preferably a sensitizing dye. In the dye-sensitized photoelectric conversion element used as the carboxylic acid, since the carboxylic acid easily forms an association, when the dye causes an association on the semiconductor surface, the electron trap between the dyes prevents the electron injection into the semiconductor, There is a disadvantage that a decrease in photoelectric conversion efficiency is unavoidable. Therefore, a method for solving this drawback and enabling high photoelectric conversion efficiency to be obtained even when a dye having an acid functional group such as a carboxylic acid that easily forms an aggregate is used as an sensitizing dye. Study was carried out. As an example, let us consider a case where a molecule of a sensitizing dye has a plurality of carboxy groups as acid functional groups. Association occurs when the carboxy groups of the molecules of the sensitizing dye are hydrogen-bonded to each other. In order to prevent this association, it was considered to neutralize the acid functional group of the molecule of the sensitizing dye with an alkali compound such as NaOH. This neutralization, COOH sensitizing dye molecules COO ^- and became things by bonding Na ⁺ COO ^- has a state ^- but the Na ^+, in solution COO because of the dissociation. Since the neutralized and dissociated COO ⁻ is an anion, the sensitizing dye molecules are less likely to associate with each other due to repulsive force (charge repulsion) acting between the negative charges of the anion. For this reason, for example, when the semiconductor fine particle layer is immersed in this dye solution to support the dye, the dye molecules are less likely to associate on the semiconductor surface, and the electron traps between these dyes can be greatly reduced. The above can basically be established also in the case of other acid functional groups such as phosphate groups and other alkaline compounds such as KOH. That is, in order to eliminate the above-mentioned drawbacks, a dye molecule having a plurality of acid functional groups for adsorbing to the semiconductor fine particle layer is used, and some of these acid functional groups are replaced with Li, Na, K Neutralizing with an alkali compound comprising at least one metal selected from the group consisting of tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, imidazolium compounds and pyridinium compounds or a hydroxide of a compound. . Among these metals or compounds, Na, K, tetramethylammonium, tetraethylammonium, tetrapropylammonium, and 1-ethyl-3-methylimidazolium compounds are preferable, and among these, Na and K which are inorganic alkalis (alkali metals) are preferable. Particularly preferred. These inorganic alkalis have the effect of improving the conductivity of the semiconductor fine particle layer made of titanium oxide and the like, and since the ionic radius is small, the adsorption density of the dye to the semiconductor fine particle layer can be increased. There is no particular limitation on the method of neutralizing the dye molecule, but for example, it can be carried out by mixing in a specified amount based on the number of moles of the dye and the alkali compound, or titration with pH. The partial neutralization of the dye may be performed before preparing the dye solution, or may be neutralized by mixing a predetermined amount of alkali in the dye solution. When neutralization of the dye molecules is performed in the dye solution, water is generated by the neutralization, and therefore, a water removal operation may be performed separately. The dye molecule has a plurality of acid functional groups, and some of them will be neutralized, but if the amount of partial neutralization of the dye molecule is too small, the association inhibition between the dye molecules is insufficient. On the other hand, if the amount is too large, sufficient photoelectric conversion cannot be performed due to a decrease in the adsorptive power of the dye molecules, so that an appropriate neutralization amount exists. The specific neutralization amount is preferably from 0.25 to 0.75, particularly preferably from 0.35 to 0.65, based on the number of acid functional groups in the dye molecule. This neutralization amount can be rephrased as a ratio to the total number of acid functional groups of the entire dye molecule.

  The method for supporting (adsorbing) the dye on the semiconductor fine particle layer is not particularly limited. For example, alcohols, nitriles, nitromethane, halogenated hydrocarbons, ethers, dimethyl sulfoxide, amides, N-methylpyrrolidone can be used. , 1,3-dimethylimidazolidinone, 3-methyloxazolidinone, esters, carbonates, ketones, hydrocarbons, water, etc., are dissolved in a semiconductor fine particle layer, or a dye solution is used as a semiconductor. It can be applied on the fine particle layer. Further, deoxycholic acid or the like may be added for the purpose of reducing association between the dye molecules. Furthermore, you may use a ultraviolet absorber together.

  After the dye is adsorbed on the semiconductor fine particle layer, the surface of the semiconductor fine particle layer may be treated with amines for the purpose of promoting the removal of the excessively adsorbed dye. Examples of amines include pyridine, 4-tert-butylpyridine, polyvinylpyridine, and the like. When these are liquid, they may be used as they are, or may be used after being dissolved in an organic solvent.

  Incidentally, in a dye-sensitized photoelectric conversion element such as a dye-sensitized solar cell, an additive composed of a substance that is bonded to the dye-carrying semiconductor fine particle layer is usually added in order to prevent reverse electron transfer in the electrolytic solution. As this additive, tert-butylpyridine, 1-methoxybenzimidazole, phosphonic acid having a long-chain alkyl group (about C = 13) or the like is used. The characteristics of these additives are that they can be mixed uniformly in the electrolyte and have functional groups that can be bonded to the dye-carrying semiconductor fine particle layer. However, according to the knowledge of the present inventors, in the conventional dye-sensitized photoelectric conversion element, the dye previously adsorbed on the surface of the semiconductor fine particle layer is eluted after the electrolytic solution is sealed, and the photoelectric conversion efficiency is increased. It was confirmed that it deteriorated rapidly. Therefore, it is necessary to improve the photoelectric conversion efficiency by preventing elution of the dye previously adsorbed on the semiconductor fine particle layer while preventing the reverse electron transfer reaction. For this purpose, instead of adding an additive to the electrolytic solution, the dye and additive are adsorbed in advance on the semiconductor fine particle layer, and at this time, the additive is adsorbed in a gap portion between the dyes, It is effective not to include additives. As the method, for example, the dye is adsorbed on the surface of the semiconductor fine particle layer in the space between the dyes by immersing the semiconductor fine particle layer on which the dye is adsorbed in a solution containing the additive, and then the dye. In addition, an electrolyte containing no additive is sealed between the semiconductor fine particle layer on which the additive is adsorbed and the counter electrode. By doing so, the additive adsorbed on the dye-carrying semiconductor fine particle layer can prevent the reverse electron transfer reaction, and can prevent the dye from being eluted by the electrolytic solution, thereby effectively preventing the deterioration of photoelectric conversion efficiency over time. be able to. As an additive, it has a functional group (imidazolyl group, carboxy group, phosphone group, etc.) that binds to the semiconductor fine particle layer, does not cause desorption as a result of bonding, and suppresses exposure of the surface of the semiconductor fine particle layer as a result of adsorption. Specifically, for example, phosphonic acid having a long-chain alkyl group (about C = 13) such as tert-butylpyridine, 1-methoxybenzimidazole, and decanephosphoric acid is used.

  Any material can be used as the counter electrode as long as it is a conductive material, but an insulating material can also be used as long as a conductive layer is provided on the side facing the semiconductor electrode. However, as the counter electrode material, an electrochemically stable material is preferably used, and specifically, platinum, gold, carbon, a conductive polymer, or the like is preferably used. For the purpose of improving the catalytic effect of redox, it is preferable that the side facing the semiconductor electrode has a fine structure and the surface area is increased. It is desired to be in a porous state. The platinum black state can be formed by a method such as platinum anodization or chloroplatinic acid treatment, and the porous carbon can be formed by a method such as sintering of carbon fine particles or firing of an organic polymer. Moreover, it can also be used as a transparent counter electrode by wiring a metal having a high redox catalytic effect such as platinum on a transparent conductive substrate or treating the surface with chloroplatinic acid. The shape of the counter electrode is not limited. However, when a tubular transparent conductive substrate is used, the shape of the counter electrode may be any of a rod shape, a tube shape, a wire shape, and the like, but the shape along the inner surface of the transparent substrate. Is preferred.

Electrolytes include combinations of iodine (I ₂ ) and metal iodide or organic iodide, bromine (Br ₂ ) and metal bromide or organic bromide, ferrocyanate / ferricyanate, ferrocene / ferri Metal complexes such as sinium ion, sodium polysulfide, sulfur compounds such as alkyl thiol / alkyl disulfide, viologen dye, hydroquinone / quinone, and the like can be used. Lithium, Na, K, Mg, Ca, Cs and the like are preferable as the cation of the metal compound, and quaternary ammonium compounds such as tetraalkylammonium, pyridinium, and imidazolium are preferable as the cation of the organic compound. There is no limitation, and two or more of these may be mixed and used. Among these, an electrolyte obtained by combining I ₂ and a quaternary ammonium compound such as LiI, NaI or imidazolium iodide is preferable. The concentration of the electrolyte salt is preferably 0.05 to 10M, more preferably 0.2 to 3M with respect to the solvent. The concentration of I ₂ or Br ₂ is preferably 0.0005 to 1M, more preferably 0.001 to 0.5M. Various additives such as 4-tert-butylpyridine and benzimidazolium can also be added for the purpose of improving the open circuit voltage and the short circuit current.

  Water, alcohols, ethers, esters, carbonate esters, lactones, carboxylic acid esters, phosphoric acid triesters, heterocyclic compounds, nitriles, ketones, amides as a solvent constituting the electrolyte composition Nitromethane, halogenated hydrocarbons, dimethyl sulfoxide, sulfolane, N-methylpyrrolidone, 1,3-dimethylimidazolidinone, 3-methyloxazolidinone, hydrocarbons and the like, but are not limited thereto, Moreover, these can also be used in mixture of 2 or more types. Furthermore, it is also possible to use a room temperature ionic liquid of a tetraalkyl, pyridinium, or imidazolium quaternary ammonium salt as a solvent.

  For the purpose of reducing the leakage of the photoelectric conversion element or the volatilization of the electrolyte, it is possible to dissolve the gelling agent, polymer, crosslinking monomer, etc. in the above electrolyte composition and use it as a gel electrolyte. The ratio of the gel matrix to the electrolyte composition is such that the more the electrolyte composition, the higher the ionic conductivity, but the mechanical strength decreases. Conversely, if the electrolyte composition is too small, the mechanical strength increases but the ionic conductivity. Therefore, the electrolyte composition is desirably 50 to 99 wt%, more preferably 80 to 97 wt% of the gel electrolyte. It is also possible to realize an all-solid photoelectric conversion element by dissolving the electrolyte and the plasticizer in a polymer and volatilizing and removing the plasticizer.

  The manufacturing method of the photoelectric conversion element is not particularly limited. For example, the electrolyte composition can be liquid or gelled inside the photoelectric conversion element. In the case of a liquid electrolyte composition before introduction, the semiconductor electrode and The counter electrode is opposed to each other, and sealing is performed using a portion where the semiconductor electrode is not formed so that these two electrodes do not contact each other. At this time, although there is no restriction | limiting in particular in the magnitude | size of the clearance gap between a semiconductor electrode and a counter electrode, Usually, it is 1-100 micrometers, More preferably, it is 1-50 micrometers. If the distance between these electrodes is too long, the photocurrent decreases due to the decrease in conductivity. The sealing method is not particularly limited, but it is preferable to use a material having light resistance, insulation, and moisture resistance. Epoxy resin, ultraviolet curable resin, acrylic resin, polyisobutylene resin, EVA (ethylene vinyl acetate), ionomer resin Ceramics, various heat-sealing resins, etc. can be used, and various welding methods can be used. Moreover, although the inlet which injects the solution of electrolyte composition is required, the place of an inlet is not specifically limited. Although there is no restriction | limiting in particular in the liquid injection method, The method of injecting into the inside of the element sealed beforehand and opened the injection port of the solution is preferable. In this case, a method of dropping a few drops of the solution at the injection port and injecting the solution by capillary action is simple. In addition, the injection operation can be performed under reduced pressure or under heating as necessary. After the solution is completely injected, the solution remaining at the inlet is removed and the inlet is sealed. Although there is no restriction | limiting in particular also in this sealing method, If necessary, it can also seal by affixing a glass plate or a plastic substrate with a sealing agent. In the case of a gel electrolyte using a polymer or the like, or an all solid electrolyte, a polymer solution containing an electrolyte composition and a plasticizer is volatilized and removed on a semiconductor electrode by a casting method. After completely removing the plasticizer, sealing is performed in the same manner as in the above method. This sealing is preferably performed using a vacuum sealer or the like under an inert gas atmosphere or under reduced pressure. After sealing, in order to fully immerse the electrolyte in the semiconductor electrode, it is possible to perform heating and pressurizing operations as necessary.

  The dye-sensitized photoelectric conversion element is most typically configured as a dye-sensitized solar cell. This dye-sensitized photoelectric conversion element can be used for almost any device that requires electric power and may be of any size. For example, the dye-sensitized photoelectric conversion device is used for an electronic device, a moving body, a power device, a construction machine, a machine tool, a power generation system, etc. The output, size, shape, etc. are determined depending on the application. However, the dye-sensitized photoelectric conversion element may be other than a dye-sensitized solar cell, for example, a dye-sensitized photosensor.

The second invention is
In the photoelectric conversion element module in which a plurality of photoelectric conversion elements are arranged and wired,
At least one of the photoelectric conversion elements is
In a dye-sensitized photoelectric conversion element having an electrolyte layer between a semiconductor electrode carrying a sensitizing dye and a counter electrode,
A light receiving surface and / or an infrared reflective film is provided between the light receiving surface and the semiconductor electrode.

In this case, all of the plurality of photoelectric conversion elements may be the above dye-sensitized photoelectric conversion elements, or the above-described dye-sensitized photoelectric conversion elements and other photoelectric conversion elements, specifically, conventional general-purpose photoelectric conversion elements. A combination with a typical dye-sensitized photoelectric conversion element or a silicon photoelectric conversion element may also be used. For the plurality of photoelectric conversion elements, in order to effectively use light in a wider wavelength band of the sunlight spectrum, it is preferable that at least two types of the above dye-sensitized photoelectric converters capable of photoelectrically converting light in different wavelength bands. A conversion element may be included.
The form of this photoelectric conversion element module is not particularly limited, and can be determined as necessary. In addition, the arrangement method of the plurality of photoelectric conversion elements is not particularly limited and can be determined as necessary. Specifically, for example, two-dimensionally arranging them in parallel or stacking a plurality of stages to form a tertiary It can be arranged originally. The wiring method between the plurality of photoelectric conversion elements may be either serial or parallel.
In the second invention, what has been described in relation to the first invention is valid as far as it is not contrary to the nature thereof.

The third invention is
In electronic equipment using one or more photoelectric conversion elements,
At least one of the photoelectric conversion elements is
In a dye-sensitized photoelectric conversion element having an electrolyte layer between a semiconductor electrode carrying a sensitizing dye and a counter electrode,
A light receiving surface and / or an infrared reflective film is provided between the light receiving surface and the semiconductor electrode.

This electronic device may basically be any type, and includes both portable and stationary types. Specific examples include cell phones, mobile devices, robots, personal computers, and the like. Computers, game devices, in-vehicle devices, home appliances, industrial products, etc.
In the third aspect of the invention, what has been described in relation to the first aspect of the invention other than the above is valid as long as it is not contrary to the nature thereof.

The fourth invention is:
In a moving body using one or more photoelectric conversion elements,
At least one of the photoelectric conversion elements is
In a dye-sensitized photoelectric conversion element having an electrolyte layer between a semiconductor electrode carrying a sensitizing dye and a counter electrode,
A light receiving surface and / or an infrared reflective film is provided between the light receiving surface and the semiconductor electrode.

This moving body may be basically any type, and specific examples include automobiles, two-wheeled vehicles, aircraft, rockets, and space ships.
In the fourth invention, the matters other than the above are explained in relation to the first invention unless they are contrary to the nature.

The fifth invention is:
In a power generation system using one or more photoelectric conversion elements,
At least one of the photoelectric conversion elements is
In a dye-sensitized photoelectric conversion element having an electrolyte layer between a semiconductor electrode carrying a sensitizing dye and a counter electrode,
A light receiving surface and / or an infrared reflective film is provided between the light receiving surface and the semiconductor electrode.
This power generation system may be basically any type, and its scale is not limited.
In the fifth invention, what has been described in relation to the first invention holds true for matters other than those described above, unless they are contrary to the nature thereof.

  In the present invention configured as described above, an infrared reflection film is provided between the light receiving surface and / or the light receiving surface and the semiconductor electrode so that infrared light, that is, heat rays are incident on the light receiving surface. In addition, visible light that mainly contributes to photoelectric conversion passes through the infrared reflection film, and thus photoelectric conversion can be performed without any problem.

  According to the present invention, the infrared light incident on the light receiving surface of the dye-sensitized photoelectric conversion element can be reflected, whereby the sealing material and the electrolyte layer are heated due to the absorption of the infrared light. Can be prevented. For this reason, since deterioration of the sealing material due to heat and expansion of the electrolyte layer can be prevented, tearing of the sealing material due to heat can be prevented, and durability of the dye-sensitized photoelectric conversion element can be improved. be able to. In addition, since this dye-sensitized photoelectric conversion element does not require a circulating facility for cooling water, it is simple and low-cost. By using such an excellent dye-sensitized photoelectric conversion element, it is possible to obtain a high-performance photoelectric conversion element module, an electronic device, a moving body, and a power generation system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings of the embodiments, the same or corresponding parts are denoted by the same reference numerals.
FIG. 1 shows a dye-sensitized photoelectric conversion element according to the first embodiment of the present invention.
As shown in FIG. 1, in this dye-sensitized photoelectric conversion element, a dye-carrying semiconductor fine particle layer 2 (dye-sensitized semiconductor electrode) is formed on a transparent conductive substrate 1, and at least its surface has a counter electrode. The transparent conductive substrate 1 and the peripheral portion of the conductive substrate 3 are sealed in a state where the dye-carrying semiconductor fine particle layer 2 and the conductive substrate 3 face each other at a predetermined interval. They are bonded and sealed to each other by a stopper 4. The distance between the dye-carrying semiconductor fine particle layer 2 and the conductive substrate 3 is, for example, 1 to 100 μm, typically several tens to 100 μm, preferably 1 to 50 μm. As the sealing material 4, for example, those already described can be used. An electrolyte layer 5 is enclosed in a space surrounded by the dye-carrying semiconductor fine particle layer 2, the conductive substrate 3, and the sealing material 4. Further, although not shown in the drawings, for example, the entirety of these is housed and sealed in a case, or instead of being housed in the case, the whole is resin-sealed. The transparent conductive substrate 1 and the conductive substrate 3 both have, for example, a rectangular shape, but may have other shapes. The transparent conductive substrate 1 and the conductive substrate 3 are electrically connected to each other by a conducting wire or the like, and a load is connected between them. In this case, light is applied to the dye-carrying semiconductor fine particle layer 2 from the transparent conductive substrate 1 side.

In FIG. 2, in particular, the transparent conductive substrate 1 is obtained by forming the transparent electrode 1b on the transparent substrate 1a, and the conductive substrate 3 is obtained by forming the counter electrode 3b on the transparent or opaque substrate 3a. 1 shows a dye-sensitized photoelectric conversion element.
The transparent conductive substrate 1 (or the transparent substrate 1a and the transparent electrode 1b), the dye-carrying semiconductor fine particle layer 2, the conductive substrate 3 (or the substrate 3a and the counter electrode 3b), the sealing material 4 and the electrolyte layer 5 have already been mentioned. You can choose from those as needed.

What is characteristic about this dye-sensitized photoelectric conversion element is that an infrared reflection film 6 is provided on the light-receiving surface formed of one main surface of the transparent conductive substrate 1. As the infrared reflection film 6, a heat mirror having a three-layer structure of TiO ₂ / TiN / TiO ₂ is preferably used. Here, in order to optimize the visible light transmittance and infrared reflection characteristics of the heat mirror, the thickness of the TiN film is preferably selected to be 20 to 30 nm, and the thickness of the TiO ₂ film is preferably set to 30 to 50 nm. By providing the infrared reflection film 6 on the light receiving surface in this way, infrared light can be selectively reflected among light incident on the dye-sensitized photoelectric conversion element, and contributes mainly to photoelectric conversion. Visible light that passes through can reach the dye-carrying semiconductor fine particle layer 2.

Next, the manufacturing method of this dye-sensitized photoelectric conversion element is demonstrated.
First, the transparent conductive substrate 1 is prepared. Next, a TiO ₂ film, a TiN film, and a TiO ₂ film are sequentially formed on one main surface serving as a light receiving surface of the transparent conductive substrate 1 by a vacuum process such as vacuum deposition or sputtering. Next, a paste in which semiconductor fine particles are dispersed is applied to the other main surface of the transparent conductive substrate 1 in a predetermined gap (thickness). Next, the transparent conductive substrate 1 is heated to a predetermined temperature to sinter the semiconductor fine particles. Next, the semiconductor fine particles are supported on the dye by, for example, immersing the transparent conductive substrate 1 on which the semiconductor fine particles are sintered in the dye solution. Thus, the dye-carrying semiconductor fine particle layer 2 is formed.

  On the other hand, a conductive substrate 3 is prepared separately. Then, the transparent conductive substrate 1 and the conductive substrate 3 are opposed to each other with a predetermined distance, for example, 1 to 100 μm, preferably 1 to 50 μm, between the dye-carrying semiconductor fine particle layer 2 and the conductive substrate 3. In addition, a space in which the electrolyte layer 5 is enclosed by the sealing material 4 is formed, and the electrolyte layer 5 is injected from a liquid injection port formed in advance in this space. Thereafter, the liquid injection port is closed. Thus, a dye-sensitized photoelectric conversion element is manufactured.

Next, the operation of this dye-sensitized photoelectric conversion element will be described.
Of the light incident on the infrared reflecting film 6 provided on the light receiving surface of the transparent conductive substrate 1, infrared light is reflected by the heat mirror 7, and only visible light passes through the infrared reflecting film 6. The light passes through the transparent conductive substrate 1 and enters the dye-carrying semiconductor fine particle layer 2. The light thus incident on the dye-carrying semiconductor fine particle layer 2 excites the sensitizing dye in the dye-carrying semiconductor fine particle layer 2 to generate electrons. The electrons are quickly transferred from the dye to the semiconductor fine particles of the dye-carrying semiconductor fine particle layer 2. On the other hand, the dye that has lost the electrons receives electrons from the ions of the electrolyte layer 5, and the molecules that have transferred the electrons receive electrons again on the surface of the conductive substrate 3. By this series of reactions, an electromotive force is generated between the transparent conductive substrate 1 and the conductive substrate 3 that are electrically connected to the dye-carrying semiconductor fine particle layer 2. In this way, photoelectric conversion is performed.

  As described above, according to the first embodiment, since the infrared reflection film 6 is provided on the light receiving surface of the dye-sensitized photoelectric conversion element, sealing is performed by heat generated by absorption of infrared light. There is no problem that the material 4 and the electrolyte layer 5 are heated. For this reason, the sealing material 4 does not deteriorate or the electrolyte layer 5 expands due to heat, so that the sealing material 4 can be effectively prevented from being broken, and leakage of the electrolyte layer 5 can be prevented. it can. Thereby, the durability of the dye-sensitized photoelectric conversion element can be improved, and as a result, the life and reliability can be improved. And since the cooling water circulation facility for heat removal is unnecessary, it is simple and low-cost.

<Example 1>
An FTO (fluorine-doped SnO ₂ ) substrate was used as the transparent conductive substrate 1, and TiO ₂ film was formed in a thickness of 30 nm on one main surface by vacuum deposition of TiO under an oxygen atmosphere. Next, a TiN film having a thickness of 30 nm was formed on the TiO ₂ film by sputtering using TiN as a target. Next, TiO ₂ film was formed to a thickness of 30 nm on this TiN film by vacuum deposition of TiO in an oxygen atmosphere. In this way, a heat mirror having a three-layer structure of TiO ₂ / TiN / TiO ₂ was formed as the infrared reflecting film 6 on the light receiving surface.

TiO ₂ fine particles were used as the semiconductor fine particles. A paste in which TiO ₂ fine particles were dispersed was prepared as follows with reference to Non-Patent Document 2. 125 ml of titanium isopropoxide was slowly added dropwise to 750 ml of 0.1 M nitric acid aqueous solution with stirring at room temperature. When the dropping was completed, this solution was transferred to a constant temperature bath at 80 ° C. and stirred for 8 hours to obtain a cloudy translucent sol solution. The sol solution was allowed to cool to room temperature, filtered through a glass filter, and then made up to 700 ml. The obtained sol solution was transferred to an autoclave, hydrothermally treated at 220 ° C. for 12 hours, and then subjected to dispersion treatment by performing ultrasonic treatment for 1 hour. Next, this solution was concentrated by an evaporator at 40 ° C. to prepare a TiO ₂ content of 20 wt%. To the concentrate sol solution was added anatase TiO ₂ of 30 wt% of the particle size 200nm TiO ₂ with in the paste and 20 wt% polyethylene glycol (molecular weight 500,000) with respect to TiO ₂ in the paste, these The mixture was uniformly mixed with a stirring deaerator to obtain a thickened TiO ₂ paste.

The TiO ₂ paste obtained as described above was applied to the other main surface of the FTO substrate by a blade coating method with a size of 5 mm × 5 mm and a gap (thickness) of 200 μm, and then held at 500 ° C. for 30 minutes, TiO ₂ was sintered on this FTO substrate. Next, a 0.1 M TiCl ₄ aqueous solution was dropped on the TiO ₂ film thus sintered, and kept at room temperature for 15 hours, washed, and then fired again at 500 ° C. for 30 minutes.
Next, for the purpose of removing impurities and increasing the activity of the TiO ₂ sintered body thus produced, ultraviolet exposure was performed for 30 minutes with an ultraviolet irradiation device.

Next, fully purified bis (2,2′-dipyridyl-4,4′-dicarboxylic acid) -ruthenium (II) ditetrabutylammonium complex (commonly known as N719 dye) was added at a concentration of 0.3 mM acetonitrile: tert- Butanol was dissolved in a 1: 1 mixed solvent. Next, the semiconductor fine particle layer was immersed in the dye solution at room temperature for 24 hours to carry the dye. Thus, a dye-supported TiO ₂ fine particle layer was obtained as the dye-supported semiconductor fine particle layer 2. The dye-supported TiO ₂ fine particle layer was washed with an acetonitrile solution of 4-tert-butylpyridine and acetonitrile in order, and dried in the dark.

As a counter electrode, a Cr film was formed on a FTO substrate, in which a 0.5 mmφ injection hole was previously opened, and then a Pt film was formed in succession by a sputtering method with a thickness of 100 nm, and isopropyl chloroplatinic acid was formed thereon. An alcohol (IPA) solution was spray coated and heated at 385 ° C. for 15 minutes.
Next, the TiO ₂ surface of the dye-supported TiO ₂ fine particle layer prepared as described above is opposed to the Pt surface of the counter electrode, and an ionomer resin film having a thickness of 30 μm and an acrylic ultraviolet curable resin with the outer periphery as a sealing material 4 And sealed with.

On the other hand, 0.030 g of sodium iodide (NaI), 1.0 g of 1-propyl-2,3-dimethylimidazolium iodide, 0.10 g of iodine (I ₂ ), 4-tert-butylpyridine 054 g was dissolved to prepare an electrolyte composition.
The above mixed solution was injected from the injection port of the element formed in advance on the FTO substrate using a liquid feed pump, and the pressure inside the element was reduced to expel bubbles inside the element. Next, the inlet was sealed with an ionomer resin film, an acrylic resin, and a glass substrate to obtain a dye-sensitized photoelectric conversion element.

<Comparative example 1>
Except that a heat mirror having a three-layer structure of TiO ₂ / TiN / TiO ₂ is not formed as an infrared reflecting film 6 on one main surface of the FTO substrate as the transparent conductive substrate 1, the dye increase is performed in the same manner as in Example 1. A photoelectric conversion element was produced.

Compared with Example 1 in which a heat mirror having a three-layer structure of TiO ₂ / TiN / TiO ₂ was formed as an infrared reflecting film 6 on one main surface of the FTO substrate as the transparent conductive substrate 1, that is, the light receiving surface. The measurement result of the ultraviolet-visible-near infrared transmission spectrum with the FTO substrate as the transparent conductive substrate 1 in Example 1 is shown in FIG. Moreover, the current (I) -voltage (V) curve at the time of the pseudo sunlight (AM1.5, 100 mW / cm < ² >) irradiation of the dye-sensitized photoelectric conversion element of Example 1 and Comparative Example 1 produced as described above. Table 1 shows the measurement results of the short-circuit current, open-circuit voltage, fill factor, and photoelectric conversion efficiency.

FIG. 3 shows that when a heat mirror having a three-layer structure of TiO ₂ / TiN / TiO ₂ is formed as the infrared reflecting film 6 on the light receiving surface, infrared light is effectively cut.
Further, from Table 1, the dye-sensitized photoelectric conversion element of Example 1 is the dye-sensitized dye of Comparative Example 1 in which a heat mirror having a three-layer structure of TiO ₂ / TiN / TiO ₂ is not formed on the light receiving surface as the infrared reflection film 6. It can be seen that there is almost no difference in photoelectric conversion characteristics compared to the photoelectric conversion element.

Next explained is a dye-sensitized photoelectric conversion element according to the second embodiment of the invention.
As shown in FIG. 4, in this dye-sensitized photoelectric conversion element, an infrared reflection film 6 is provided between the transparent substrate 1a and the transparent conductive layer 1b of the transparent conductive substrate 1.
Other than the above, this is the same as the dye-sensitized photoelectric conversion element according to the first embodiment.
According to the second embodiment, the same advantages as those of the first embodiment can be obtained.

Next explained is a dye-sensitized photoelectric conversion element according to the third embodiment of the invention.
As shown in FIG. 5, in this dye-sensitized photoelectric conversion element, a transparent metal oxide layer 7 is provided on a transparent conductive layer 1b, and a dye-carrying semiconductor fine particle layer 2 is provided thereon. Specifically, for example, after forming the transparent conductive layer 1b, an Nb ₂ O ₅ layer having a thickness of 20 nm is formed as the metal oxide layer 7 by a wet coating method, for example, a spray pyrolysis method.
Other than the above, this is the same as the dye-sensitized photoelectric conversion element according to the first embodiment.

  According to the third embodiment, in addition to the same advantages as those of the first embodiment, the following advantages can be obtained. That is, since the metal oxide layer 7 prevents the transparent conductive layer 1b and the electrolytic solution used as the electrolyte layer 5 from being in direct contact with each other, the leakage current due to the reverse electron transfer reaction can be greatly reduced, thereby The fill factor and the open circuit voltage can be increased, and the photoelectric conversion efficiency can be further improved.

Next explained is a dye-sensitized photoelectric conversion element according to the fourth embodiment of the invention.
As shown in FIG. 6, in this dye-sensitized photoelectric conversion element, not only the sensitizing dye 8 is adsorbed to the dye-supporting semiconductor fine particle layer 2 but also in a gap portion between the sensitizing dyes 8. Additive 9 is also adsorbed. In this case, no additive is added to the electrolyte solution constituting the electrolyte layer 5 unlike the conventional case. The sensitizing dye 8 and the additive 9 can be selected, for example, from those already mentioned as necessary.
Other than the above, this is the same as the dye-sensitized photoelectric conversion element according to the first embodiment.

Next, the manufacturing method of this dye-sensitized photoelectric conversion element is demonstrated.
First, the dye-carrying semiconductor fine particle layer 2 is formed on the transparent conductive substrate 1 in the same manner as in the first embodiment. The dye-carrying semiconductor fine particle layer 2 in this state is schematically shown in FIG. 7A. The dye-carrying semiconductor fine particle layer 2 is formed in the same manner as in the first embodiment.
Next, as shown in FIG. 7B, a transparent conductive substrate 1 in which a solution 11 in which an additive 9 is dissolved in a solvent is placed in a container 10, and a dye-carrying semiconductor fine particle layer 2 is formed in the solution 11. Then, the container 10 is further covered with a lid 12 to adsorb the additive 9 to the dye-carrying semiconductor fine particle layer 2. Specifically, as the solution 11, NaI 0.1M, 1-propyl-2,3 dimethylimidazolium iodide (DMP II) 0.6M, I ₂ 0.05M, an additive tert-butylpyridine (TBP) ) Prepare an electrolyte solution consisting of 0.5M methoxyacetonitrile (MeACN) solution, immerse the dye-carrying semiconductor fine particle layer 2 in this electrolyte solution for 5 to 10 minutes, and the dye-carrying semiconductor fine particle layer at the site where the dye could not be adsorbed Tert-butylpyridine is adsorbed on the surface of 2 as an additive 9. Thereafter, the electrolytic solution adhering to the dye-carrying semiconductor fine particle layer 2 is rinsed off with methoxyacetonitrile and air-dried.

After the additive 9 is thus adsorbed, the transparent conductive substrate 1 on which the dye-carrying semiconductor fine particle layer 2 is formed is taken out from the container 10. Thereafter, the surface of the dye-carrying semiconductor fine particle layer 2 is washed. The dye-carrying semiconductor fine particle layer 2 in this state is schematically shown in FIG. 7C.
Thereafter, in the same manner as in the first embodiment, the dye-carrying semiconductor fine particle layer 2 and the conductive substrate 3 are opposed to each other, and the electrolyte layer 5 is sealed between them, as shown in FIG. 7D. A dye-sensitized photoelectric conversion element is manufactured.

  According to the fourth embodiment, the following advantages can be obtained in addition to the advantages similar to those of the first embodiment. That is, since the additive 9 is adsorbed in advance on the dye-carrying semiconductor fine particle layer 2 and the electrolyte solution to which the additive 9 is not added is used as the electrolyte layer 5, it is adsorbed in advance on the surface of the dye-carrying semiconductor fine particle layer 2. While the reverse electron transfer reaction is prevented by the additive 9 made, the deterioration of photoelectric conversion efficiency with time can be prevented, and the lifetime can be improved.

Next explained is a dye-sensitized photoelectric conversion element according to the fifth embodiment of the invention.
In this dye-sensitized photoelectric conversion element, in the dye-carrying semiconductor fine particle layer 2, the dye molecules are adsorbed to the semiconductor fine particles by the acid functional groups, and some of the acid functional groups of the dye molecules are Li, Na, K, tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, imidazolium compound and pyridinium compound neutralized by an alkali compound consisting of at least one metal selected from the group consisting of a compound or a hydroxide of a compound and an anion It has become. By doing so, association between the dye molecules is suppressed by the repulsive force acting between the anions, and an electron trap between the dye molecules can be greatly reduced.
Other than the above, this is the same as the dye-sensitized photoelectric conversion element according to the first embodiment.

  The method for producing the dye-sensitized photoelectric conversion element is as follows. In the dye solution, for example, a part of the acid functional group of the dye molecule is previously Li, Na, K, tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium. The dye sensitization according to the first embodiment except that it is neutralized with an alkali compound comprising at least one metal selected from the group consisting of an imidazolium compound and a pyridinium compound or a hydroxide of a compound to form an anion. It is the same as the manufacturing method of a photoelectric conversion element.

  According to the fifth embodiment, the following advantages can be obtained in addition to the advantages similar to those of the first embodiment. That is, by neutralizing a part of the acid functional group of the dye with an alkali compound, the acid functional group becomes an anion, and the repulsive force (charge repulsion) acting between the negative charges makes it difficult for the sensitizing dye molecules to associate with each other. Therefore, the electron traps between the dye molecules can be significantly reduced, whereby the current and voltage of the dye-sensitized photoelectric conversion element can be greatly increased, and the photoelectric conversion efficiency can be improved.

<Example 2>
A dye-sensitized photoelectric conversion element was produced in the same manner as in Example 1 except that the following process was used when the dye was supported after removing impurities from the TiO ₂ sintered body and further subjected to ultraviolet exposure.
That is, fully purified cis-bis (isothiocyanate) -N, N-bis (2,2′-dipyridyl-4,4′-dicarboxylic acid) -ruthenium (II) dihydrate at a concentration of 1 mM. Dissolved in methanol. Next, 0.5 times the amount of carboxylic acid was added to this solution and stirred sufficiently to neutralize the carboxy group, and then concentrated with an evaporator and recrystallized with diethyl ether. The precipitate was separated by filtration, washed with diethyl ether, and dried by vacuum drying at 50 ° C. for 24 hours.

Next, the cis-bis (isothiocyanate) -N, N-bis (2,2 ′) thus obtained is obtained.
- dipyridyl-4,4 '- dicarboxylic acid) - ruthenium (II) the 2Na salt was dissolved at a concentration of 0.3 mM tert-butyl alcohol / acetonitrile mixed solvent (volume ratio 1: 1) of the above TiO ₂ sintered body Was immersed at room temperature for 24 hours to carry the dye. This TiO ₂ sintered body was washed sequentially with an acetonitrile solution of 4-tert-butylpyridine and acetonitrile and dried in the dark.
In the dye-sensitized photoelectric conversion element of Example 2 produced in this way, the fill factor and the open-circuit voltage were drastically improved as compared with those using a dye without partial neutralization and a dye with complete neutralization, and photoelectric conversion Excellent efficiency.

Next explained is a dye-sensitized photoelectric conversion element according to the sixth embodiment of the invention.
8 to 10 show the dye-sensitized photoelectric conversion element, FIG. 8 is a side view, FIG. 9 is a longitudinal sectional view, and FIG. 10 is a transverse sectional view.
As shown in FIGS. 8 to 10, in this dye-sensitized photoelectric conversion element, an infrared reflection film 6 is provided on the outer peripheral surface of a tubular transparent substrate 1a having a circular cross section, that is, a light receiving surface, and this tubular transparent substrate 1a. The transparent conductive layer 1b, the dye-carrying semiconductor fine particle layer 2 and the electrolyte layer 5 are sequentially provided on the inner surface of the tube, and the counter electrode 13 is inserted into the central portion of the tubular structure so as to extend along the central axis of the tubular structure. Has a structured. The counter electrode 13 has, for example, a rod shape, a tubular shape, or a wire shape. In this case, the counter electrode 13 is slightly longer than the tubular transparent substrate 1a, one end 13a thereof substantially coincides with one end of the tubular transparent substrate 1a, and the other end 13b of the tubular transparent substrate 1a. It protrudes slightly from the other end. The gap between one end of the tubular transparent substrate 1a and one end 13a of the counter electrode 13 and the other end of the tubular transparent substrate 1a and the other end 13b of the counter electrode 13 are sealed with a sealing material 4. The electrolyte layer 5 is prevented from leaking outside. Lead wires 14 and 15 are connected to the counter electrode 13 and the transparent conductive layer 1b, respectively.
The transparent material constituting the tubular transparent substrate 1a, the transparent conductive layer 1b, the dye-carrying semiconductor fine particle layer 2, the electrolyte layer 5 and the counter electrode 13 can be selected from those already mentioned as necessary.
Moreover, there is no restriction | limiting in particular in the length and diameter of this dye-sensitized photoelectric conversion element, and it determines suitably according to the use, output, etc. of this dye-sensitized photoelectric conversion element.
Other than the above, this is the same as the dye-sensitized photoelectric conversion element according to the first embodiment.

Next, the manufacturing method of this dye-sensitized photoelectric conversion element is demonstrated.
First, a tubular transparent substrate 1a made of a transparent material and having a predetermined length, outer diameter, and inner diameter is prepared. Next, the infrared reflective film 6 is formed on the outer peripheral surface of the tubular transparent substrate 1a. Next, the transparent conductive layer 1b is formed on the inner surface of the tubular transparent substrate 1a. For the formation of the transparent conductive layer 1b, for example, a wet coating method, preferably a spray pyrolysis method is used. Next, a paste in which semiconductor fine particles are dispersed is applied to a predetermined thickness on the inner surface of the transparent conductive layer 1b. Next, the whole of the tubular transparent substrate 1a and the transparent conductive layer 1b is heated to a predetermined temperature to sinter the semiconductor fine particles. Next, the semiconductor transparent particles are supported on the dye by, for example, immersing the entire tubular transparent substrate 1a and the transparent conductive layer 1b on which the semiconductor particles are sintered in a dye solution. Thus, the dye-carrying semiconductor fine particle layer 2 is formed.

  On the other hand, a counter electrode 13 having a predetermined length and diameter is prepared. The counter electrode 13 is inserted into the central portion of the tubular transparent substrate 1a, and the counter electrode 13 and the tubular transparent substrate 1a are inserted into the counter electrode 13 and the inner surface of the tubular transparent substrate 1a. Are held so as to face each other at a predetermined interval, for example, 1 to 100 μm, preferably 1 to 50 μm, and between one end of the tubular transparent substrate 1a and one end 13a of the counter electrode 13 and tubular The space between the other end portion of the transparent substrate 1a and the other end portion 13b of the counter electrode 13 is sealed with a sealing material 4 to create a space in which the electrolyte layer 5 is enclosed. An electrolyte layer 5 is injected. Thereafter, the inlet is closed. Next, lead wires 14 and 15 are connected to the counter electrode 13 and the transparent conductive layer 1b, respectively. In this way, a dye-sensitized photoelectric conversion element is manufactured.

  According to the sixth embodiment, in addition to the same advantages as those of the first embodiment, the following advantages can be obtained. That is, in the dye-sensitized photoelectric conversion element, the transparent conductive layer 1b, the dye-carrying semiconductor fine particle layer 2 and the electrolyte layer 5 are sequentially provided on the inner surface of the tubular transparent substrate 1a, and the counter electrode 13 is provided at the center of the tubular transparent substrate 1a. Is inserted into the surface of the tubular transparent substrate 1a, the photoelectric conversion is possible no matter which direction the light enters, and thus the change in the amount of power generation with respect to the incident angle of light is greatly reduced. be able to. In addition, since this dye-sensitized photoelectric conversion element has a very small sealing area, it has excellent durability outdoors.

<Example 3>
A quartz tube (inner diameter: 2.5 mmφ, length: 50 mm) is used as the tubular transparent substrate 1 a, and the outer peripheral surface thereof is made of TiO ₂ / TiN / TiO ₂ as the infrared reflecting film 6 on the light receiving surface in the same manner as in the first embodiment. A layered heat mirror was formed. Next, an FTO film was formed as a transparent conductive layer 1b on the inner surface of the quartz tube by spray pyrolysis using ammonium fluoride and an ethanol solution of dibutyltin diacetate. In addition, two holes of 0.5 mmφ were formed in this quartz tube as injection ports for electrolyte injection.
Next, the outer peripheral surface of the quartz tube is masked with a mask material, and the TiO ₂ paste obtained in the same manner as in Example 1 is dip coated on the FTO film as the transparent conductive layer 1b formed on the inner surface of the quartz tube. After coating by the method, it was kept at 450 ° C. for 30 minutes, and TiO ₂ was sintered on this FTO film. Next, the quartz tube thus sintered in TiO ₂ is immersed in a 0.05 M TiCl ₄ aqueous solution, kept at 70 ° C. for 30 minutes, washed, and then fired again at 450 ° C. for 30 minutes. It was.
Next, for the purpose of removing impurities and increasing the activity of the TiO ₂ sintered body thus produced, ultraviolet exposure was performed for 30 minutes with an ultraviolet irradiation device.

Next, a dye was supported on the TiO ₂ sintered body in the same manner as in Example 1. Thus, a dye-supported TiO ₂ fine particle layer was obtained as the dye-supported semiconductor fine particle layer 2. The dye-supported TiO ₂ fine particle layer was washed with an acetonitrile solution of 4-tert-butylpyridine and acetonitrile in order, and dried in the dark.
As the counter electrode 13, a Ti rod having a diameter of 2.4 mmφ and a length of 60 mm and subjected to Pt plating (thickness: 200 nm) was used.
Next, the Pt-plated Ti rod was inserted into the quartz tube prepared as described above, and the end of the quartz tube was sealed with an acrylic UV curable resin as the sealing material 4.

Meanwhile, 3 g of methoxyacetonitrile, 0.04 g of sodium iodide (NaI), 0.479 g of 1-propyl-2,3-dimethylimidazolium iodide, 0.0381 g of iodine (I ₂ ), 4-tert-butylpyridine 2 g was dissolved to prepare an electrolyte composition.
The mixed solution was injected from an injection port previously formed in the quartz tube using a liquid feed pump, and the bubbles inside the device were driven out by reducing the pressure. Next, an acrylic UV curable resin was dropped into the injection port, and the glass substrate was covered and cured to obtain a dye-sensitized photoelectric conversion element.
The effective area of the dye-sensitized photoelectric conversion element is 1 cm ² (0.25 cm (inner diameter of the quartz tube) × 4 cm (length of the TiO ₂ sintered body) with respect to the incident direction of light.

<Example 4>
As shown in FIGS. 11 and 12, a photoelectric conversion element module was prepared using the dye-sensitized photoelectric conversion element 20 prepared in Example 3. Here, FIG. 11 and FIG. 12 are a plan view and a cross-sectional view of the photoelectric conversion element module, respectively.
That is, as shown in FIG. 11 and FIG. 12, ten dye-sensitized photoelectric conversion elements 20 prepared in Example 1 are connected in series, and are arranged and sandwiched between two 50 mm square glass substrates 21 and 22, The two-component mixed silicone rubber 23 was filled in the gap and cured to obtain a photoelectric conversion element module 30. The effective area of the photoelectric conversion element module 30 is 10 cm ² (0.25 cm × 4 cm × 10 cells) with respect to the incident direction of light.

<Comparative example 2>
Dye-sensitized photoelectric conversion as in Example 3 except that a 10 mm × 50 mm flat quartz substrate was used as the transparent substrate and a 10 mm × 50 mm flat Ti plate plated with Pt (thickness 200 nm) was used as the counter electrode. An element was produced. The effective area of the dye-sensitized photoelectric conversion element is 1 cm ² (0.25 cm × 4 cm) with respect to the incident direction of light.
<Comparative Example 3>
Ten dye-sensitized photoelectric conversion elements prepared in Comparative Example 2 were connected in series, sandwiched between two 50 mm square glass substrates, filled with a two-component mixed silicone rubber in the gap, cured, A photoelectric conversion element module was obtained. The effective area of the photoelectric conversion element module is 10 cm ² (0.25 cm × 4 cm × 10 cells) with respect to the incident direction of light.

In the dye-sensitized photoelectric conversion elements of Example 3 and Comparative Example 2 and the photoelectric conversion element modules of Example 4 and Comparative Example 3 produced as described above, when irradiated with artificial sunlight (AM1.5, 100 mW / cm ² ). FIG. 13 shows the maintenance ratio of the photoelectric conversion efficiency when the incident angle of light is changed from 90 ° to 0 °.
The photoelectric conversion element and the photoelectric conversion element module were exposed to the outdoors, and the photoelectric conversion efficiency was measured up to 90 days every 10 days. FIG. 14 shows the maintenance rate of the photoelectric conversion efficiency at this time.

From FIG. 14, it can be seen that the photoelectric conversion efficiency of the dye-sensitized photoelectric conversion element of Example 3 has no dependency on the incident angle of light. In addition, the photoelectric conversion element module of Example 4 also has less dependency on the incident angle of light of photoelectric conversion efficiency than the photoelectric conversion element module of Comparative Example 3, and can perform photoelectric conversion at a wider angle.
Moreover, it can be seen from FIG. 14 that the dye-sensitized photoelectric conversion element of Example 3 and the photoelectric conversion element module of Example 4 have a high photoelectric conversion efficiency maintenance rate in outdoor exposure.

<Example 5>
Black dye as a dye, that is, tris (isothiocyanate) -ruthenium (II) -2,2 ′: 6 ′, 2 ″ -terpyridine-4,4 ′, 4 ″ -tricarboxylic acid, tris-tetrabutylammonium salt Example except that (tris (isothiocyanato) -ruthenium (II) -2,2 ': 6', 2 ''-terpyridine-4,4 ', 4''-tricarboxylic acid, tris-tetrabutylammonium salt) was used In the same manner as in Example 3, a dye-sensitized photoelectric conversion element was produced. The effective area of the dye-sensitized photoelectric conversion element is 1 cm ² (0.25 cm × 4 cm) with respect to the incident direction of light.

As shown in FIG. 15, 10 dye-sensitized photoelectric conversion elements 20 prepared in Example 3 were connected in series, and 10 dye-sensitized photoelectric conversion elements 40 prepared in Example 5 were connected in series. Are stacked between two 50 mm square glass substrates 21 and 22, and the two-component mixed silicone rubber 23 is filled in the gap and cured, so that the photoelectric conversion element module 50 is Obtained. The effective area of the photoelectric conversion element module 50 is 10 cm ² (0.25 cm × 4 cm × 10 cells) with respect to the incident direction of light.

  In this photoelectric conversion element module 50, N719 used as a dye in the dye-sensitized photoelectric conversion element 20 of Example 3 has an absorption peak near the wavelength of 500 nm. In the dye-sensitized photoelectric conversion element 40 of Example 5, Since the black die used as the dye has an absorption peak near the wavelength of 650 nm and the absorption band has different wavelength ranges, only the dye-sensitized photoelectric conversion element 20 or only the dye-sensitized photoelectric conversion element 40 was used. Compared with the photoelectric conversion element module, light in a wider wavelength band of the sunlight spectrum can be photoelectrically converted, and higher quantum efficiency can be obtained. For this reason, power generation amount can be increased.

Although the embodiments and examples of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments and examples, and various modifications based on the technical idea of the present invention are possible. It is.
For example, the numerical values, structures, shapes, materials, raw materials, processes, and the like given in the above-described embodiments and examples are merely examples, and numerical values, structures, shapes, materials, raw materials, processes, and the like that are different from these as necessary. May be used.
Further, for example, two or more of the first to sixth embodiments may be combined.

It is sectional drawing of the principal part of the dye-sensitized photoelectric conversion element by 1st Embodiment of this invention. It is sectional drawing of the principal part of the dye-sensitized photoelectric conversion element by 1st Embodiment of this invention. It is a basic diagram which shows the ultraviolet-visible-near-infrared transmission spectrum measured in Example 1 of this invention. It is sectional drawing of the principal part of the dye-sensitized photoelectric conversion element by 2nd Embodiment of this invention. It is sectional drawing of the principal part of the dye-sensitized photoelectric conversion element by 3rd Embodiment of this invention. It is sectional drawing of the principal part of the dye-sensitized photoelectric conversion element by 4th Embodiment of this invention. It is a schematic diagram for demonstrating the manufacturing method of the dye-sensitized photoelectric conversion element by 4th Embodiment of this invention. It is a side view which shows the dye-sensitized photoelectric conversion element by 6th Embodiment of this invention. It is a longitudinal cross-sectional view which shows the dye-sensitized photoelectric conversion element by 6th Embodiment of this invention. It is a cross-sectional view showing a dye-sensitized photoelectric conversion element according to a sixth embodiment of the present invention. It is a top view which shows the photoelectric conversion element module by Example 3 of this invention. It is sectional drawing which shows the photoelectric conversion element module by Example 3 of this invention. It is a basic diagram which shows the incident angle dependence of light of the maintenance factor of the photoelectric conversion efficiency of the dye-sensitized photoelectric conversion element by Example 3 and Comparative Example 2 of this invention and the photoelectric conversion element module by Example 5 and Comparative Example 3. is there. It is a basic diagram which shows the outdoor exposure days dependence of the maintenance factor of the photoelectric conversion efficiency of the dye-sensitized photoelectric conversion element by Example 3 and Comparative Example 2 of this invention and the photoelectric conversion element module by Example 5 and Comparative Example 3. FIG. . It is sectional drawing which shows the photoelectric conversion element module by Example 5 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent conductive substrate, 1a ... Transparent substrate, 1b ... Transparent conductive layer, 2 ... Dye carrying | support semiconductor fine particle layer, 3 ... Conductive substrate, 3a ... Substrate, 3b ... Counter electrode, 4 ... Sealing material, 5 ... Electrolyte layer , 6 ... Infrared reflective film, 7 ... Metal oxide layer, 8 ... Sensitizing dye, 9 ... Additive, 10 ... Container, 11 ... Solution, 12 ... Lid, 13 ... Counter electrode, 14, 15 ... Lead wire

Claims (10)

In a dye-sensitized photoelectric conversion element having an electrolyte layer between a semiconductor electrode carrying a sensitizing dye and a counter electrode,
A dye-sensitized photoelectric conversion element comprising a light receiving surface and / or an infrared reflecting film between the light receiving surface and the semiconductor electrode.   The semiconductor electrode is provided on one main surface of the transparent conductive substrate, the other main surface of the transparent conductive substrate constitutes the light receiving surface, and the infrared reflective film is provided thereon. The dye-sensitized photoelectric conversion element according to claim 1, wherein   The semiconductor electrode is provided on one main surface of the transparent support substrate via a transparent conductive layer, and the other main surface of the transparent support substrate constitutes the light receiving surface, and the transparent support substrate and the transparent conductive substrate The dye-sensitized photoelectric conversion element according to claim 1, wherein the infrared reflection film is provided between the layers.   2. The dye-sensitized photoelectric conversion element according to claim 1, wherein the infrared reflection film is a heat mirror having a three-layer structure of titanium oxide / titanium nitride / titanium oxide.   2. The dye-sensitized photoelectric conversion element according to claim 1, wherein the semiconductor electrode comprises semiconductor fine particles.   The dye-sensitized photoelectric conversion element according to claim 1, wherein the dye-sensitized photoelectric conversion element is a dye-sensitized solar cell. In the photoelectric conversion element module in which a plurality of photoelectric conversion elements are arranged and wired,
At least one of the photoelectric conversion elements is
In a dye-sensitized photoelectric conversion element having an electrolyte layer between a semiconductor electrode carrying a sensitizing dye and a counter electrode,
A photoelectric conversion element module comprising a light receiving surface and / or an infrared reflective film between the light receiving surface and the semiconductor electrode. In electronic equipment using one or more photoelectric conversion elements,
At least one of the photoelectric conversion elements is
In a dye-sensitized photoelectric conversion element having an electrolyte layer between a semiconductor electrode carrying a sensitizing dye and a counter electrode,
An electronic device comprising a light receiving surface and / or an infrared reflecting film between the light receiving surface and the semiconductor electrode. In a moving body using one or more photoelectric conversion elements,
At least one of the photoelectric conversion elements is
In a dye-sensitized photoelectric conversion element having an electrolyte layer between a semiconductor electrode carrying a sensitizing dye and a counter electrode,
A moving body comprising a light receiving surface and / or an infrared reflecting film between the light receiving surface and the semiconductor electrode. In a power generation system using one or more photoelectric conversion elements,
At least one of the photoelectric conversion elements is
In a dye-sensitized photoelectric conversion element having an electrolyte layer between a semiconductor electrode carrying a sensitizing dye and a counter electrode,
A power generation system comprising: a light receiving surface and / or an infrared reflective film between the light receiving surface and the semiconductor electrode.

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