JP2008176948A - Dye-sensitized solar cell and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye-sensitized solar cell capable of efficiently recovering power obtained by optical power generation through current-collecting electrodes provided on a second base body side, and with a structure advantageous for area enlargement. <P>SOLUTION: The dye-sensitized solar cell 1 is provided with a first base body 11, a second base body 21, electrolyte solution 33, a plurality of current-collecting electrodes 41 and a plurality of relay connection bodies 51. The plurality of current-collecting electrodes 41 exist in points in a state insulated from catalyst electrodes 23 on an inner side face 22 of the second base body 21. The plurality of relay connection bodies 51 are arranged between the first base body 11 and the second base body 21, in contact with the plurality of current-collecting electrodes 41 and a translucent conductive layer 14, so as to electrically connect the both 41, 14. The plurality of relay connection bodies 51 are so structured that the surface of each granular base body 53 made of a material with more elasticity than the first base body 11 and the second base body 21 is coated with a conductive layer 52. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dye-sensitized solar cell that directly converts light energy into electric energy and a method for manufacturing the same.

  At present, in solar power generation, solar cells using single crystal silicon, polycrystalline silicon, amorphous silicon, a combination of these with HIT (Heterojunction with Intrinsic Thin-layer), etc. have been put into practical use and have become the main technology. These solar cells are excellent with photoelectric conversion efficiency of nearly 20%. However, silicon-based solar cells have a high energy cost for material production, have many problems in terms of environmental impact, and have limitations in terms of price and material supply. On the other hand, in recent years, a dye-sensitized solar cell proposed by Gratzel et al. Has attracted attention as an inexpensive solar cell (for example, see Non-Patent Document 1 and Patent Document 1). The dye-sensitized solar cell has a structure in which an electrolyte is interposed between a titania porous electrode (so-called semiconductor electrode) carrying a sensitizing dye and a catalyst electrode as a counter electrode. This type of solar cell has the demerit that the photoelectric conversion efficiency is lower than that of the current silicon-based solar cell, but has the advantage that the cost can be significantly reduced in terms of materials and manufacturing method.

By the way, a semiconductor electrode in this type of dye-sensitized solar cell is often provided so as to cover a light-transmitting conductive layer provided on a light-transmitting substrate such as a glass substrate. However, since the translucent conductive layer is required to have transparency, there are certain restrictions on the reduction in resistance. Therefore, the larger the area of the dye-sensitized solar cell, the more difficult it is to efficiently collect power generated by photoelectric conversion at the semiconductor electrode. Therefore, usually, a low-resistance, strip-shaped or grid-shaped current collecting electrode formed by applying and baking silver paste is separately provided on a light-transmitting substrate, and a semiconductor electrode is electrically connected to the current collecting electrode to collect current. Electricity is generated (see, for example, Patent Document 2). Further, instead of such baking, it has been conventionally proposed to form a current collecting electrode by forming and depositing a metal film by sputtering or vapor deposition.
Nature (Vol. 353, pp. 737-740, 1991) Japanese Patent Laid-Open No. 1-220380 JP 2000-285777 A

  However, when such a collector electrode is provided, it is necessary to increase either the width or the thickness. However, when the width is increased, for example, a semiconductor electrode cannot be formed in that portion. For this reason, the effective real area for photoelectric conversion is reduced, and the photoelectric conversion efficiency per unit area is reduced. Further, when the thickness is increased, the distance between the semiconductor electrode and the counter electrode, that is, the thickness of the electrolytic solution layer is increased, so that the ion moving speed is decreased, and as a result, the photoelectric conversion efficiency is also decreased.

  In order to solve the above problem, for example, not on the side of the translucent substrate with a semiconductor electrode (referred to as “first base” for convenience) but on the substrate with a counter electrode (referred to as “second base” for convenience). It is considered that a collecting electrode should be provided on the side. Further, in such a structure, it is necessary to dispose some kind of conductor for relaying and electrically connecting the semiconductor electrode and the second base-side current collecting electrode. However, a dye-sensitized solar cell having such a structure has not been specifically proposed yet.

  The present invention has been made in view of the above problems, and a first object of the present invention is to be able to efficiently recover the electric power obtained by photovoltaic power generation via a collecting electrode provided on the second substrate side, An object of the present invention is to provide a dye-sensitized solar cell having a structure advantageous for increasing the area. A second object of the present invention is to provide a production method capable of obtaining the above excellent dye-sensitized solar cell relatively easily and at low cost.

In order to solve the above-mentioned problem, the invention described in means 1 includes a translucent substrate (13) and a translucent conductive layer (14) provided on an inner surface (12) of the translucent substrate (13). And a first substrate (11) including a sensitizing dye and having a semiconductor electrode (15) provided on the translucent conductive layer (14), and facing the first substrate (11, 11A). Between the second substrate (21, 21A) having the catalyst electrode (23) on the inner surface (22) thereof, and between the first substrate (11, 11A) and the second substrate (21, 21A). The electrolyte solution (33) filled in the existing cell space (32) and the catalyst electrode (23) are insulated from the inner surface (22) of the second base (21, 21A). A plurality of current collecting electrodes (41), the first base (11, 11A) and the second base (2) , 21A) and in contact with the plurality of collecting electrodes (41) and the light transmitting conductive layer (14), the plurality of collecting electrodes (41) and the light transmitting conductive A plurality of relay connectors (51) for conducting the layer (14), wherein the plurality of relay connectors (51) include the first base (11, 11A) and the second base (21, 21A). A dye-sensitized solar cell (1, 100, 120, 140, 160) having a structure in which the surface of a granular substrate (53) made of a more elastic material is covered with a conductive layer (52). is there.

  Therefore, according to the invention described in the means 1, the translucent conductive layer on the first substrate side and the plurality of relay substrate on the second substrate side via the plurality of relay connecting members arranged between the first substrate and the second substrate. The current collecting electrode is electrically connected. Therefore, unlike the prior art in which the current collecting electrode is provided on the first substrate side, the effective real area for photoelectric conversion is maintained without increasing the area where the semiconductor electrode cannot be formed. Therefore, it is possible to avoid a decrease in photoelectric conversion efficiency per unit area, and it is possible to efficiently recover the electric power obtained by photovoltaic power generation via the collector electrode provided on the second substrate side. Moreover, since the low resistance conductive layer exists on the surface of the relay connection body, the translucent conductive layer and the collecting electrode can be reliably conducted through the conductive layer. Furthermore, since the relay connection body includes a granular base made of a material that is more elastic than the first base and the second base, it can be elastically deformed as a whole. For this reason, even if the distance between the electrodes varies due to, for example, warping or undulation of the substrate, the relay connection body is elastically deformed and applied to both the plurality of collecting electrodes and the light-transmitting conductive layer. It can contact reliably and can be made to conduct | electrically_connect between both reliably. Therefore, a dye-sensitized solar cell having a structure advantageous for increasing the area can be provided.

  The “translucent substrate” constituting the first substrate is formed using a translucent material such as glass or a resin sheet because the “translucent substrate” is disposed on the light incident side in use. When the translucent substrate is made of a resin sheet, the resin used for forming the resin sheet includes various thermoplastics such as polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyphenylene sulfide, polycarbonate, polysulfone, and polyethyleneidene norbornene. Resin. The thickness of the light-transmitting substrate varies depending on the material and is not particularly limited. However, the light-transmitting substrate may have a transmittance of 60% to 99%, particularly 85% to 99%. preferable. Here, translucency means that the transmittance of visible light having a wavelength of 400 nm to 900 nm is 10% or more. This transmittance is preferably 60% or more, particularly 85% or more. Hereinafter, the meaning of translucency and preferable transmittance are all the same.

  Transmittance (%) = (transmitted light amount / incident light amount) × 100

The “translucent conductive layer” constituting the first base is provided on the inner surface of the translucent substrate. The translucent conductive layer only needs to have translucency and conductivity, and the material is not particularly limited. Examples of the translucent conductive layer include a thin film made of a conductive oxide, a carbon thin film, and the like. Examples of the conductive oxide include indium oxide, tin-doped indium oxide, tin oxide, and fluorine-doped tin oxide (FTO). The thickness of the translucent conductive layer varies depending on the material and is not particularly limited, but the surface resistance is preferably 100 Ω / cm ² or less, particularly 1 Ω / cm ² or more and 10 Ω / cm ² or less. .

  In addition, the translucency meaning and preferable visible light transmittance | permeability of this translucent conductive layer are the same as that of the translucent board | substrate.

  The “semiconductor electrode” constituting the first substrate includes a sensitizing dye and is provided on the light-transmitting conductive layer. That is, this semiconductor electrode is provided on the inner side surface of the first substrate and is disposed facing the cell space.

  This semiconductor electrode has, for example, a structure in which a sensitizing dye is attached to a porous electrode substrate. The porous electrode substrate can be formed of a metal oxide, a metal sulfide or the like. Examples of the metal oxide include titania, tin oxide, zinc oxide, niobium oxide such as niobium pentoxide, tantalum oxide, and zirconia. A composite oxide such as strontium titanate, calcium titanate, and barium titanate can also be used. Furthermore, examples of the metal sulfide include zinc sulfide, lead sulfide, and bismuth sulfide.

  The method for forming the porous electrode substrate is not particularly limited. For example, a paste containing semiconductor fine particles such as a metal oxide or a metal sulfide is applied to the surface of a light-transmitting substrate or the like to form an unfired porous electrode substrate. After forming, a procedure of firing can be employed. The method for applying the paste is not particularly limited, and specific examples thereof include a screen printing method, a doctor blade method, a squeegee method, and a spin coating method. The semiconductor electrode substrate thus formed has a form of an aggregate formed by aggregating semiconductor fine particles.

  The firing conditions in this case are not particularly limited. For example, the firing temperature is set to 400 ° C. to 600 ° C., particularly 450 ° C. to 550 ° C., and the firing time is 10 minutes to 300 minutes, particularly 20 minutes to 40 It may be set to a minute or less. The firing atmosphere may be an oxidizing atmosphere such as an air atmosphere, or may be an inert atmosphere such as a rare gas such as argon or a nitrogen gas.

  The thickness of the semiconductor electrode is not particularly limited, but may be from 0.1 μm to 100 μm, preferably from 1 μm to 50 μm, particularly from 2 μm to 40 μm, and more preferably from 5 μm to 30 μm. If this thickness is in the range of 0.1 μm or more and 100 μm or less, photoelectric conversion is sufficiently performed, and power generation efficiency can be improved. In addition, the semiconductor electrode is preferably subjected to heat treatment in order to improve its strength and adhesion with a light-transmitting substrate. The temperature and time of the heat treatment are not particularly limited, but the heat treatment temperature is preferably 40 ° C. or more and 700 ° C. or less, particularly preferably 100 ° C. or more and 500 ° C. or less, and the heat treatment time is 10 minutes or more and 10 hours or less, particularly 20 minutes or more. 5 hours or less is preferable. In addition, when using a resin sheet as a translucent board | substrate, it is preferable to heat-process at appropriate temperature so that resin may not deteriorate with a heat | fever.

  The “sensitizing dye” possessed by the semiconductor electrode plays a role of improving the photoelectric conversion action, and specifically, complex dyes and organic dyes that improve the photoelectric conversion action can be used. Examples of complex dyes include metal complex dyes, and examples of organic dyes include polymethine dyes and merocyanine dyes. Examples of the metal complex dye include a ruthenium complex dye and an osmium complex dye, and a ruthenium complex dye is particularly preferable. Furthermore, in order to expand the wavelength range in which photoelectric conversion is performed and improve the photoelectric conversion efficiency, two or more sensitizing dyes having different wavelength ranges in which a sensitizing action is exhibited can be used in combination. In this case, it is preferable to set the type of sensitizing dye to be used in combination and the amount ratio thereof depending on the wavelength range and intensity distribution of the irradiated light. The sensitizing dye preferably has a functional group for bonding to the semiconductor electrode. Examples of this functional group include a carboxyl group, a sulfonic acid group, and a cyano group.

  The method for attaching the sensitizing dye to the porous electrode substrate is not particularly limited. For example, after immersing the porous electrode substrate in a solution in which the sensitizing dye is dissolved in the organic solvent and impregnating the solution, the organic solvent The method of removing can be employed. A method of removing the organic solvent after applying this solution to the porous electrode substrate can also be employed. Examples of the solution coating method in this case include a wire bar method, a slide hopper method, an extrusion method, a curtain coating method, a spin coating method, and a spray coating method. Furthermore, this solution can also be applied by a printing method such as offset printing, gravure printing or screen printing.

  The adhesion amount of the sensitizing dye is preferably 0.01 mmol or more and 1 mmol or less, particularly 0.5 mmol or more and 1 mmol or less with respect to the semiconductor electrode 15. If the adhesion amount is set within a range of 0.01 mmol or more and 1 mmol or less, photoelectric conversion is efficiently performed in the semiconductor electrode. Moreover, if the sensitizing dye that has not adhered to the semiconductor electrode is liberated around the electrode, the conversion efficiency may be lowered. For this reason, it is preferable to remove the excess sensitizing dye by washing the semiconductor electrode after the treatment for attaching the sensitizing dye. This removal can be performed by washing with a polar solvent such as acetonitrile and an organic solvent such as an alcohol solvent using a washing tank. In order to attach a large amount of sensitizing dye to the electrode substrate, it is preferable to heat the semiconductor electrode and perform a treatment such as dipping or coating. In this case, in order to avoid water adsorbing on the surface of the semiconductor electrode, it is preferable to perform the treatment promptly at 40 ° C. or more and 80 ° C. or less without heating to room temperature after heating.

  On the other hand, the “second substrate” arranged to face the first substrate has a catalyst electrode on the inner surface thereof.

  The second substrate may have a light-transmitting property or may not have a light-transmitting property. As the second substrate having translucency, for example, a glass substrate or a resin substrate can be used. For example, a ceramic substrate can be used as the second substrate that does not have translucency. The ceramic substrate has high mechanical strength, and this substrate can serve as a support substrate to provide a dye-sensitized solar cell having excellent durability. The ceramic used for forming the ceramic substrate is not particularly limited. For example, various ceramics such as oxide ceramics, nitride ceramics, and carbide ceramics can be used. Examples of the oxide ceramic include alumina, mullite, zirconia and the like. Examples of the nitride ceramic include silicon nitride, sialon, titanium nitride, and aluminum nitride. Further, examples of the carbide-based ceramic include silicon carbide, titanium carbide, and aluminum carbide. As the ceramic, alumina, silicon nitride, zirconia and the like are preferable, and alumina is particularly preferable. The reason is that in addition to being excellent in mechanical strength, it has suitable insulating properties, so that it is also suitable as a support for forming electrodes, conductive layers and the like.

  When the second substrate is a ceramic substrate, the thickness is not particularly limited, but can be 100 μm or more and 5 mm or less, 300 μm or more and 4 mm or less, particularly 500 μm or more and 2 mm or less. If the thickness of the ceramic substrate is 100 μm or more, sufficient mechanical strength required as a support substrate can be imparted, and therefore, by using this, a dye-sensitized solar cell having excellent durability can be obtained.

  The “catalyst electrode” of the second substrate may be provided directly on the inner side surface of the second substrate, or may be indirectly provided via the second substrate-side conductor layer. It does not specifically limit as a 2nd base | substrate side conductor layer, The material will not ask | require if it has electroconductivity. In this case, for example, the same material as the translucent conductive layer in the first substrate may be used as the second substrate-side conductor layer.

  This catalytic electrode can be formed of at least one of a substance having catalytic activity or a metal containing a substance having catalytic activity, a conductive oxide, and a conductive polymer. Examples of the substance having catalytic activity include noble metals such as platinum, gold, and rhodium. Silver is also a noble metal, but is not preferred because of its low corrosion resistance to electrolytes and the like. Examples of substances having catalytic activity other than noble metals include carbon black. Any of the substances listed here has suitable conductivity. Since noble metals have catalytic activity and are electrochemically stable, they are suitable as a material for forming a catalyst electrode. Among them, platinum having high catalytic activity and high corrosion resistance to an electrolyte is particularly suitable.

  Examples of the metal containing a substance having catalytic activity include aluminum, copper, chromium, nickel, and tungsten. Examples of the conductive oxide containing a substance having catalytic activity include indium oxide, tin-doped indium oxide, tin oxide, and fluorine-doped tin oxide (FTO). Examples of the conductive polymer containing a substance having catalytic activity include polyaniline, polypyrrole, and polyacetylene.

  The thickness of the catalyst electrode is not particularly limited, but can be 3 nm or more and 10 μm or less, particularly 3 nm or more and 2 μm or less in both cases of single layer and multilayer. When the thickness of the catalyst electrode is in the range of 3 nm or more and 10 μm or less, a catalyst electrode having a sufficiently low resistance can be obtained.

  A catalytic electrode made of a substance having catalytic activity can be formed by applying a paste containing fine particles of a substance having catalytic activity to the surface of the second substrate. A catalyst electrode made of a metal or a conductive oxide containing a substance having catalytic activity can also be formed by the same method as that for a substance having catalytic activity. Examples of the coating method include various methods such as a screen printing method, a doctor blade method, a squeegee method, and a spin coating method. Furthermore, this catalyst electrode can also be formed by depositing metal or the like on the surface of the second substrate by sputtering, vapor deposition, ion plating or the like.

  In addition, a catalyst electrode made of a conductive polymer containing a substance having a catalytic activity is composed of a conductive polymer and a substance having a catalytic activity such as a powder or a fiber, a Banbury mixer, an internal mixer, an open roll. It is also possible to form a resin composition prepared by kneading with an apparatus such as a film and then bonding the film to the surface of the second substrate. Further, a solution or dispersion prepared by dissolving or dispersing the resin composition in a solvent can be applied to the surface of the second substrate, dried, the solvent removed, and heated as necessary. . When the catalyst electrode is a mixed layer, it can be formed by an appropriate method among the various methods described above, depending on the type of material contained.

  The second substrate may have a current collecting conductor layer on its outer surface, or may have a via conductor connected to the current collecting conductor layer. Such a current collecting conductor layer and via conductor can be formed of a conductive material, specifically, printing and baking a metal paste containing metal particles such as aluminum, tungsten, titanium, and the like. It can be formed by doing.

  For example, a spacer is arranged between the first substrate and the second substrate, and as a result of the arrangement, a cell space is defined between the two. The material of the spacer is not particularly limited, and resin or glass can be used, but it is preferable to select a material having corrosion resistance. The thickness of the spacer is set to, for example, 10 μm or more and 100 μm or less, preferably 20 μm or more and 80 μm or less in order to form a cell space having a desired height.

  The “electrolytic solution” is filled in the cell space existing between the first base and the second base, and is interposed at least between the semiconductor electrode and the catalyst electrode. The electrolyte solution may be injected into the cell space from the first substrate side or from the second substrate side. In this case, it is preferable to provide an injection port on the side where it is easy to perforate and to inject the electrolytic solution from this injection port. One injection port may be provided, but another hole may be provided for venting air. Thus, if the hole for venting air is provided, the electrolyte can be injected more easily and reliably.

Examples of the electrolyte in the electrolytic solution include (1) I ₂ and iodide, (2) Br ₂ and bromide, (3) metal complexes such as ferrocyanate-ferricyanate, ferrocene-ferricinium ion, (4) Examples include electrolytes containing sulfur compounds such as sodium polysulfide and alkylthiol-alkyldisulfides, (5) viologen dyes, (6) hydroquinone-quinone, and the like. As iodide in (1) is, LiI, NaI, KI, CsI, metal iodide such as CaI _2, and tetraalkylammonium iodide, pyridinium iodide, imidazolium iodide iodine salt of quaternary ammonium compounds such as id, etc. Is mentioned. As the bromide in (2), LiBr, NaBr, KBr, CsBr, CaBr 2 , etc. of the metal bromide, and tetra-alkyl ammonium bromide, bromine salts of quaternary ammonium compounds such as pyridinium bromide and the like. Among these electrolytes, an electrolyte obtained by combining I ₂ and an iodine salt of a quaternary ammonium compound such as LiI, pyridinium iodide, and imidazolium iodide is particularly preferable. These electrolytes may use only 1 type and may use 2 or more types.

  The electrolyte can be blended in a solvent together with various additives and used as an electrolytic solution. This solvent preferably has a low viscosity, a high ion mobility, and sufficient ion conductivity. Examples of such solvents include (1) carbonates such as ethylene carbonate and propylene carbonate, (2) heterocyclic compounds such as 3-methyl-2-oxazolidinone, (3) ethers such as dioxane and diethyl ether, (4 ) Chain ethers such as ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, (5) methanol, ethanol, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, polyethylene glycol monoalkyl Monoalcohols such as ether and polypropylene glycol monoalkyl ether, (6) ethylene glycol, propylene glycol, polyethylene Polyhydric alcohols such as polyglycol, polypropylene glycol and glycerin, (7) nitriles such as acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, and (8) aprotic such as dimethyl sulfoxide and sulfolane. Examples include polar substances. These solvent may use only 1 type and may use 2 or more types.

  Furthermore, a normal temperature molten salt can be used as the electrolyte, and in this case, an electrolyte can be obtained using a solvent. Also, the electrolyte can be used alone. As this room temperature molten salt, a room temperature molten salt of iodide can be used. Examples of room temperature molten salts of iodide include various room temperature molten salts such as imidazolium salts, pyridinium salts, pyrrolidinium salts, pyrazolidium salts, isothiazolidinium salts, isoxazolidinium salts, and the like. Of the room temperature molten salts of iodide, imidazolium salts are preferred. These room temperature molten salts can be used in combination of two or more different types.

  A plurality of “collecting electrodes” are present on the second substrate side. More specifically, the plurality of collecting electrodes are present in the form of dots while being insulated from the catalyst electrode on the inner surface of the second substrate (in other words, physically separated). Yes. These current collecting electrodes are electrically connected to the translucent conductive layer and function as current collecting electrodes for a semiconductor electrode which is a negative electrode. Thus, by providing the current collecting electrode on the second substrate side, an effective real area for photoelectric conversion can be maintained.

  The plurality of collecting electrodes are only required to have conductivity, and the material is not particularly limited. However, when a corrosive electrolytic solution is used, it is desirable to form a collecting electrode made of a conductive material having high corrosion resistance. Examples of the conductive material having high corrosion resistance include tungsten, nickel, and titanium. The plurality of collecting electrodes can be formed, for example, by applying a paste containing conductive fine particles to the inner surface of the second substrate. Examples of the coating method include various methods such as a screen printing method, a doctor blade method, a squeegee method, and a spin coating method. Furthermore, the plurality of collecting electrodes can be formed by depositing metal or the like on the inner side surface of the second substrate by sputtering, vapor deposition, ion plating, or the like. Note that, even when any of the above methods is employed, the thickness of the collecting electrode is preferably 10 μm or more and 100 μm or less, and particularly preferably 30 μm or more and 100 μm or less. If the thickness is within this range, the resistance of the current collecting electrode can be lowered, and the current collecting efficiency is easily improved. The plurality of current collecting electrodes may be, for example, pads formed in a pattern or may be end faces of via conductors. Moreover, it is preferable that the plurality of collecting electrodes are electrically connected to the collecting conductor layer provided on the outer surface of the second base via the plurality of via conductors. With this structure, the wiring can be taken out from the plurality of collecting electrodes relatively easily.

  In addition, when employ | adopting the structure which has a current collection conductor layer and a via conductor, it is suitable to comprise a 2nd base | substrate using a ceramic substrate instead of a glass substrate. That is, the ceramic substrate can easily have a multilayer structure, and the ceramic substrate, the current collecting conductor layer, and the via conductor can be simultaneously fired by appropriately selecting a conductive material and an insulating material.

  The “plurality of relay connection bodies” are disposed between the first base and the second base, and are in contact with the plurality of current collecting electrodes and the light-transmitting conductive layer, so that the plurality of current collecting electrodes and the light-transmitting conductive material are in contact with each other. It plays the role of relaying the electrical connection between the layers (ie, the role of conducting both). The relay connection body has a structure in which the surface of a granular substrate made of a material that is more elastic than the first substrate and the second substrate is covered with a conductive layer, and has a granular shape as a whole. The shape of the relay connection body (the shape of the granular base body) may be any shape as long as it is granular, and specifically, it may be any of a spherical shape, a prismatic shape, a cylindrical shape, etc. Among them, a spherical shape is particularly preferable. This is because the spherical relay connection is easy to handle and relatively easy to manufacture. Moreover, since it can roll on a surface if it is spherical, it may be advantageous when it is fixed to the substrate.

  The material for forming the granular substrate constituting the relay connection body is not particularly limited as long as it is more elastic than the first substrate and the second substrate, and any material can be selected. In addition, since the conductivity is not necessarily required for the granular substrate, a non-conductive material can be selected. The first substrate and the second substrate are often formed using a material such as glass or ceramic. In this case, as a material for forming the granular substrate, for example, a metal material or a synthetic material that is more elastic than these materials. A resin material or the like is preferably selected. It is particularly preferable to select a synthetic resin material that is richer in elasticity than inorganic materials such as glass, ceramic, and metal. A relay connection body using a granular substrate made of a synthetic resin material has an advantageous characteristic of being easily elastically deformed. Therefore, the conductive layer on the surface can be pressed against the translucent conductive layer or the like, the relay connection body can be stably inserted, and the conduction resistance is also reduced. It is also effective in ensuring electrical connection when there is a variation in the distance between the electrodes.

  The conductive layer constituting the relay connection body is formed so as to cover part or all of the surface of the granular substrate. The conductive layer can be formed using any conductive material, but preferably a conductive metal layer mainly composed of a conductive metal material, particularly preferably a conductive metal layer made of only a conductive metal material. It is good that it is. As a suitable metal material when corrosion resistance is not particularly required, tungsten, nickel, titanium, molybdenum, aluminum, copper, silver, gold, platinum, palladium, and the like can be given. Of course, an alloy containing one or more of these metals may be used. From the viewpoint of high conductivity, silver and copper are preferable, and copper is particularly preferable. In addition, when the electrolytic solution is a corrosive electrolytic solution and corrosion resistance is required, it is selected from at least a metal having corrosion resistance to the corrosive electrolytic solution, specifically tungsten, titanium and nickel. The at least one metal selected is preferred. Among these, nickel is particularly preferable. The conductive metal layer may be one layer or two or more layers.

  For example, a material in which conductive metal particles as a filler are dispersed in a resin matrix such as rubber (so-called conductive rubber) also has a certain degree of conductivity, but is not composed of only a conductive metal, High electrical resistance and inferior properties as a conductor. Therefore, it is not preferable to use conductive rubber as the conductive layer constituting the relay connection body.

  The size of the relay connection body is not particularly limited as long as it is a size that can be interposed in the gap between the first base and the second base, and can be, for example, about 10 μm to 1000 μm. A preferable size of the relay connection body is slightly larger than the size of the gap (that is, the height of the cell space or the thickness of the spacer), for example, 1.1 times or more and 3.0 times or less. When the height of the cell space is set to 20 μm or more and 80 μm or less, for example, the size of the relay connection body (average particle diameter) may be set to about 22 μm or more and 240 μm or less. If this size is set within the above preferred range, the relay connection body can be stably interposed in the gap between the first base and the second base, and the gap between the first base and the second base is sufficient. It can conduct reliably with low resistance.

  The plurality of relay connection bodies are spaced apart from each other along the base surface direction, and preferably are evenly arranged (for example, arranged in a lattice pattern) at equal intervals. By arranging in this way, it becomes possible to collect current evenly, and it becomes easy to realize excellent current collection efficiency. For example, if a plurality of collecting electrodes are arranged corresponding to the positions where the plurality of collecting electrodes are formed, the plurality of collecting electrodes are naturally arranged in a dot-like manner (that is, separated from each other along the substrate surface direction). Arranged).

  The plurality of relay connection bodies can be fixed to either the first base body or the second base body, but are preferably fixed to the second base body side. This is because the structure in which the plurality of relay connection bodies are fixed to the second substrate side is less likely to be accompanied by a reduction in the area of the semiconductor electrode than the structure in which the plurality of relay connection bodies are fixed to the first substrate side, and is advantageous in improving the photoelectric conversion efficiency. Therefore, it is preferable that the plurality of relay connection bodies be fixed to a fixing portion provided on the inner surface of the second base. Such a fixing portion is not particularly limited as long as it can stably fix the relay connection body. For example, the fixing portion is a plurality of depressions formed corresponding to locations where a plurality of collecting electrodes exist. Is preferred. A plurality of relay connecting bodies are fitted and fixed in each of the plurality of depressions. The advantage of this configuration is that the relay connection body is securely fixed by fitting and fixing to the recess, and the positional displacement in the plane direction is prevented in advance, so that the relay connection body can be stably fixed and held. Of course, adopting this configuration also improves the reliability of the apparatus. In addition, by adopting the method of fitting and fixing, it is not necessary to use a bonding material such as a conductive adhesive for fixing. As a result, the manufacturing process is simplified and it is easy to achieve cost reduction.

  The opening shape and the cross-sectional shape of the depression are not particularly limited, and any shape can be adopted as long as the relay connection body can be fitted and held. As a specific example of a suitable shape of the depression, for example, a cross-sectional shape with a narrowed opening can be cited. This is because if the recess has such a cross-sectional shape, the relay connection body is difficult to be removed when the relay connection body is fitted and held therein, and the fixing strength is increased. Further, the depth of the recess is preferably smaller than the diameter of the relay connection body, preferably 0.3 to 0.9 times the diameter, and particularly preferably 0.4 to 0.3 times the diameter. It is set to 8 times or less. That is, if the recess is too shallow, the relay connection body cannot be fitted and held. If the recess is too deep, it is difficult to project a part of the relay connection body from the opening of the recess.

  In addition, when adopting a configuration having a recess, particularly when adopting a configuration having a current collecting conductor layer and a via conductor in addition to the recess, the second substrate is configured using a ceramic substrate instead of a glass substrate. Is preferred. That is, it is because it may be complicated in a process and may lead to high cost to perform drilling and conductor formation on a glass substrate together. On the other hand, in the case of a ceramic substrate, a desired structure can be realized relatively easily by forming holes and conductors in an unfired state and then firing them. In the case of a glass substrate, the installation of a dent can usually cause cracks due to a decrease in strength, but the ceramic substrate has a high mechanical strength, so even if a dent is provided, a high mechanical strength can be obtained. Maintained.

  The relay connection body is preferably surrounded by, for example, a ring-shaped protective member. In particular, when the electrolytic solution is a corrosive electrolytic solution, it is preferably surrounded by a ring-shaped protective member made of a corrosion-resistant material. Here, “enclose” means to protect the relay connection body by avoiding direct contact with the electrolyte solution by surrounding the relay connection body except for a predetermined portion that is in electrical contact with other members. means. The ring-shaped protective member is not essential, but in the case of the configuration provided with this, the range of selection of the relay connector forming material is widened. Examples of the corrosion resistant material include a corrosion resistant resin material, and specific examples include an epoxy resin, a urethane resin, an isobutylene resin, an olefin resin, and an ionomer resin. In addition, since the resin material has suitable insulation, it is preferable as a forming material for a ring-shaped protective member provided between the first base and the second base. Among the above resins, ionomer resins having excellent corrosion resistance and heat fusion properties are particularly preferable.

  In order to solve the above-mentioned another problem, the invention described in means 2 includes a translucent substrate (13) and a translucent conductive material provided on the inner surface (12) of the translucent substrate (13). A first substrate preparation step of preparing a layer (14), a first substrate (11) containing a sensitizing dye and having a semiconductor electrode (15) provided on the translucent conductive layer (14); The electrode (23) and a plurality of current collecting electrodes (41) that exist in the form of dots in a state of being insulated from the catalyst electrode (23) are provided on the inner side surface (22), A second substrate preparing step of preparing a second substrate (21, 21A) in which a plurality of depressions (43) are formed corresponding to the location where the current collecting electrode (41) is present, and the first substrate (11) And the surface of the granular substrate (53) made of a material more elastic than the second substrate (21, 21A). A relay connection body preparation step of preparing a plurality of relay connection bodies (51) having a structure covered with a layer (52), and temporary fixing the plurality of relay connection bodies (51) to the plurality of depressions (43), respectively. After the fixing step and the temporary fixing step, the first base body (11) and the second base body (21, 21A) are arranged to face each other, and are joined while applying a pressing force in the thickness direction. There is a method of manufacturing a dye-sensitized solar cell (1, 100, 120) including a main fixing step of fitting and fixing the plurality of relay connecting bodies (51) in the recess (43) .

  Therefore, according to the invention described in the means 2, by performing the temporary fixing step, the plurality of relay connection bodies enter the plurality of depressions existing on the inner surface of the second base body, and the plurality of relay connection bodies serve as the second base body. Temporarily fixed to the side. Thereafter, by performing the main fixing step, as a result of the pressing force acting in a predetermined direction, the plurality of temporarily connected relay connection bodies are fitted and fixed in the plurality of depressions. For this reason, the outstanding dye-sensitized solar cell concerning the said means 1 can be manufactured comparatively easily and at low cost.

[First Embodiment]

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 shows a dye-sensitized solar cell 1 used in the present embodiment. This dye-sensitized solar cell 1 has a structure in which a first substrate 11 and a second substrate 21 are arranged to face each other with a spacer 31 interposed therebetween. A cell space 32 is formed between the first substrate 11 and the second substrate 21, and the cell space 32 is filled with an electrolytic solution 33 having corrosive properties.

  On the inner side surface 12 of the glass-made translucent substrate 13 constituting the first base 11, a translucent conductive layer 14 is formed over almost the entire surface. Further, a semiconductor electrode 15 containing a sensitizing dye is provided on the translucent conductive layer 14. The semiconductor electrode 15 is disposed so as to face the cell space 32, and as a result, is exposed to the electrolytic solution 33 filled in the cell space 32.

  On the other hand, the ceramic substrate 20 made of alumina constituting the second base 21 is a ceramic multilayer wiring substrate in which two ceramic layers 25 are laminated. On the inner side surface 22 of the ceramic substrate 20, a catalyst electrode 23 made of platinum is provided so as to face the semiconductor electrode 15. The catalyst electrode 23 is formed over almost the entire inner surface 22 except for a predetermined portion. The catalyst electrode 23 is also arranged facing the cell space 32, and as a result, the catalyst electrode 23 is exposed to the electrolytic solution 33 filled in the cell space 32.

  A current collecting conductor layer 44 made of tungsten metallization is formed on the outer surface 27 of the ceramic substrate 20. A plurality of via conductors 42 made of tungsten metallization are provided in the outer ceramic layer 25, and a plurality of via conductors 24 made of tungsten metallization are provided in the inner ceramic layer 25, and the interface between these two ceramic layers 25 Is provided with an inner conductor layer 26 made of tungsten metallization. The catalyst electrode 23 is electrically connected to the inner conductor layer 26 through a plurality of via conductors 24. The plurality of via conductors 42 are electrically connected to the current collecting conductor layer 44. The conductor group consisting of the catalyst electrode 23, the via conductor 24, and the inner conductor layer 26 and the conductor group consisting of the current collecting conductor layer 44 and the via conductor 42 are electrically separated from each other inside the second base 21. And are insulated from each other.

  The plurality of via conductors 42 are present in the form of dots at equal intervals on the ceramic substrate 20 side. The inner ceramic layer 25 is provided with a plurality of depressions 43 corresponding to locations where the plurality of via conductors 42 are present. The recess 43 of the present embodiment has a larger diameter than the via conductor 42 and has a circular shape in plan view. The inner end surface of the via conductor 42 is exposed on the cell space 32 side by the installation of the depression 43. In the present embodiment, the inner end face of the via conductor 42 substantially functions as the current collecting electrode 41. Therefore, it can be understood that the current collecting electrode 41 is electrically connected to the current collecting conductor layer 44 via the via conductor 42. Further, the current collecting electrode 41 located at the center of the bottom surface of the recess 43 is provided on the inner side surface 22 of the second base 21 so as to be insulated from the surrounding catalyst electrode 23.

  As shown in FIGS. 1 and 2, a plurality of spherical interconnectors 51 (relay connection bodies) are fitted and fixed in the respective depressions 43. These interconnectors 51 have a structure in which the entire surface of a resin ball 53 (granular substrate) is covered with a conductive metal layer 52 (conductive layer). The resin sphere 53 in this embodiment uses a synthetic resin material that is more elastic than the glass translucent substrate 13 that forms the main body of the first substrate 11 and the alumina ceramic substrate 20 that forms the main body of the second substrate 21. Is formed. In this embodiment, a spherical acrylic resin is used as such a resin material. The conductive metal layer 52 is formed using nickel which is a metal having conductivity and excellent corrosion resistance.

  The plurality of interconnectors 51 are arranged between the first base body 11 and the second base body 21, and the conductive metal layer 52 on the surface thereof is in contact with the current collecting electrode 41. Further, on the inner side surface 12 of the first base 11, the semiconductor electrode 15 is not provided at a position facing each of the depressions 43, and the translucent conductive layer 14 is exposed. The conductive metal layer 52 of the interconnector 51 is in contact with the transparent conductive layer 14 exposed in this way. As a result of such contact, the plurality of collecting electrodes 41 and the translucent conductive layer 14 are electrically connected via the interconnector 51. Accordingly, the semiconductor electrode 15 → the translucent conductive layer 14 → the conductive metal layer 52 of the interconnector 51 → the current collecting electrode 41 → the via conductor 42 → the current collecting conductor layer 44, and the semiconductor electrode from the second base 21 side. The wiring for 15 can be taken out.

  Next, the preparation procedure of the dye-sensitized solar cell 1 of the present embodiment will be described.

  (1) Production of the second base 21

  90.5% by weight of alumina powder, 1% by weight of magnesia powder and 4% by weight of silica powder as a sintering aid were mixed, wet ground by a ball mill for 12 hours, then dehydrated and dried. Next, this mixed powder was mixed with 3% by weight of isobutyl methacrylate as an organic binder, 1% by weight of nitrocellulose and 0.5% by weight of dioctyl phthalate, and trichloroethylene and n-butanol as solvents. Was formulated. This was mixed with a ball mill to prepare a slurry containing alumina powder. After this slurry was degassed under reduced pressure, it was cast into a sheet, and then this was removed and the solvent was volatilized to produce alumina green sheets 25A and 25B that would become part of the ceramic substrate 20. (See FIG. 3). Further, the through holes 28, 29, and 43A were formed at predetermined positions by drilling the 400 μm-thick alumina green sheets 25A and 25B obtained in this way by drilling (see FIG. 4). . Incidentally, the alumina green sheet 25 </ b> A is provided with a through hole 28 in which the via conductor 24 is to be formed later, and a through hole 43 </ b> A in which the recess 43 is to be formed later. The alumina green sheet 25B is provided with a through hole 29 in which the via conductor 42 is to be formed later. The diameter of the through holes 28 and 29 was set to about 300 μm, and the diameter of the through hole 43A was set to about 800 μm. In addition, the method of drilling is not limited, and may of course be punching or laser processing.

  On the other hand, a tungsten paste P1 for metallization containing tungsten powder was similarly prepared using a ball mill. Thereafter, the tungsten paste P1 was filled in the through holes 28 and 29 and printed on the sheet using a conventionally known screen printing apparatus (see FIG. 5). At this time, a mask (not shown) was arranged so that the through hole 43A was not filled with the tungsten paste P1.

  Next, the two alumina green sheets 25A and 25B on which paste printing had been performed were overlapped and a predetermined pressure was applied in the thickness direction to integrate them (see FIG. 6). The obtained green laminate was fired at 1500 ° C. in a reducing atmosphere to sinter alumina and simultaneously sinter tungsten paste P1. As a result, as shown in FIG. 7, the ceramic substrate 20 (25 mm long, 15 mm wide, about 0.8 mm thick) having via conductors 24 and 42, inner conductor layer 26, current collecting conductor layer 44, and depression 43 is obtained. Obtained.

  Next, sputtering is performed with a mask (not shown) disposed on the inner side surface 22 of the ceramic substrate 20 to deposit platinum (Pt), thereby forming a catalyst electrode 23 having a thickness of 1 μm. It was completed (refer FIG. 8).

  (2) Production of the first substrate 11

  First, a translucent substrate 13 (a glass substrate manufactured by Nippon Sheet Glass Co., Ltd., 25 mm long, 15 mm wide, 1 mm thick) is prepared, and a translucent substrate having a thickness of 300 nm made of FTO is formed on one side of the translucent substrate 13. A conductive layer 14 was formed. Next, a paste (Ti-Nanoxide D / SP 13 nm / 300 nm) containing titania particles having a particle size of 10 nm to 300 nm is applied on the light transmitting conductive layer 14 of the light transmitting substrate 13 by a screen printing method. A coating film having a thickness of 20 μm was formed. After that, preliminary drying was performed at 120 ° C. for 30 minutes, and then, the porous electrode substrate for producing the semiconductor electrode 15 was formed by holding and baking at 500 ° C. for 30 minutes using a muffle furnace.

  On the other hand, titanium tetrachloride was dissolved in ice-cooled water to prepare an aqueous solution having a concentration of 0.05 mol / liter. Thereafter, the translucent substrate 13 on which the porous electrode substrate had been formed was immersed in this titanium tetrachloride aqueous solution, and the aqueous solution was heated and held at 70 ° C. for 30 minutes to perform titanium chloride treatment. Next, after the treated translucent substrate 13 was taken out of the aqueous solution, it was sufficiently washed with distilled water and dried at room temperature for 30 minutes. Thereafter, the porous electrode substrate treated with titanium chloride was fired again by holding at 500 ° C. for 30 minutes using a muffle furnace.

Further, a ruthenium complex (trade name “N-719” manufactured by Kojima Chemical Co., Ltd.) is dissolved in a mixed solvent of acetonitrile and tert-butanol, and an acetonitrile / tert-butanol solution having a concentration of 5 × 10 ⁻⁴ mol / liter is obtained. Prepared. Next, the porous electrode substrate treated with titanium chloride and the translucent substrate 13 were immersed in this ruthenium complex solution for 18 hours. As a result, a ruthenium complex, which is a sensitizing dye, was adhered to the porous electrode substrate to form a semiconductor electrode 15 having a thickness of 20 μm, thereby manufacturing the first substrate 11.

  (3) Fabrication of interconnector 51

  A large number of spherical resin spheres 53 (average particle size 700 μm) made of acrylic resin are prepared, and electroless nickel plating is performed on these resin spheres 53 by a conventionally known method, and the entire surface has a thickness of 0.1 μm. A conductive metal layer 52 of about ˜5 μm was formed. Nickel may be plated after a base layer such as copper or silver is formed on the surface of the resin ball 53 in advance. According to this method, it is easy to obtain the interconnector 51 having excellent adhesion to the resin sphere 53 and high conductivity. In addition to the plating method, it is also possible to form the conductive metal layer 52 using a technique such as sputtering or CVD.

  (4) Temporary fixing of the interconnector 51

  The second base 21 manufactured as described above is prepared, and the inner surface 22 is disposed with its surface facing upward, and a plurality of interconnectors 51 are supplied on the surface (see FIGS. 2 and 9). In this case, the second base 21 may be slightly inclined to assist the flow (rolling) of the interconnector 51 on the surface. The interconnector 51 supplied on the second base 21 is temporarily fixed on the surface by rolling on the surface and slightly entering the recess 43. According to such a temporary fixing step, a small number and a large number of interconnectors 51 can be temporarily fixed to each recess 43 and arranged. Further, in this temporary fixing process, for example, an operation of placing the interconnectors 51 one by one at a predetermined position using a large apparatus such as a chip mounter is not required, so that the manufacturing cost can be avoided.

  (5) Bonding of substrates and final fixing of the interconnector 51

  A spacer 31 (made by Mitsui DuPont Polychemical Co., Ltd., trade name “HIMILAN 1702”) made of a thermoplastic resin is disposed on the outer peripheral portion of the inner surface 22 of the second substrate 21 where the catalyst electrode 23 is not formed. Then, the translucent substrate 13 was disposed so that the semiconductor electrode 15 faced the catalyst electrode 23 (see FIG. 10). Next, iodine electrolyte solution 33 was injected from the gap between translucent substrate 13 and spacer 31 with a syringe. Immediately after that, the first substrate 11 and the second substrate 21 which are arranged opposite to each other are sandwiched by clips, and a pressing force is applied in the thickness direction, and the first substrate 11 and the second substrate are heated to a predetermined temperature in this state. 21 was heat-sealed. Further, the plurality of interconnectors 51 were pressed toward the second base 21 by the pressing force at this time, and they were respectively fitted and fixed in the plurality of depressions 43. As a result, the dye-sensitized solar cell 1 shown in FIG. 1 was completed.

In the present embodiment, the iodine electrolyte 33 is methylpropylimidazolium iodide, which is an ionic liquid, 1.3 mol of I ₂ , 0.5 mol of LiI, and 0.58 mol of 4-tert-butylpyridine. It was decided to use what was mixed and prepared.

  Next, a method for using the dye-sensitized solar cell 1 completed as described above will be briefly described.

The dye-sensitized solar cell 1 of the present embodiment is used in a state where a load is connected between the wiring taken out from the catalyst electrode 23 side and the wiring taken out from the semiconductor electrode 15 side. When light is applied to the dye-sensitized solar cell 1, light incident from the outer surface of the first base 11 passes through the translucent substrate 13 and the translucent conductive layer 14 and reaches the semiconductor electrode 15. Then, in the semiconductor electrode 15, the sensitizing dye absorbs light and emits electrons into the semiconductor electrode 15. At this time, the holes left in the sensitizing dye oxidize iodide ions (I ⁻ ) and change them into triiodide ions (I ³⁻ ). On the other hand, electrons move to the catalyst electrode 23, which is the counter electrode, via a load electrically connected to the semiconductor electrode 15. The electrons reduce triiodide ions (I ³⁻ ) to iodide ions (I ⁻ ). As a result, in the dye-sensitized solar cell 1, light energy is converted into electric energy (that is, generated), and the generated electric power can be supplied to the load.

  Therefore, according to the present embodiment, the following effects can be obtained.

  (1) In the dye-sensitized solar cell 1 of the present embodiment, the semiconductor electrode 15 on the first substrate 11 side and the transparent electrode are disposed via the plurality of interconnectors 51 disposed between the first substrate 11 and the second substrate 21. The photoconductive layer 14 is electrically connected to the plurality of current collecting electrodes 41 on the second base 21 side. Therefore, unlike the prior art in which the current collecting electrode is provided on the first base 11 side, the effective area for photoelectric conversion is maintained without increasing the area where the semiconductor electrode 15 cannot be formed. Therefore, a decrease in photoelectric conversion efficiency per unit area can be avoided, and the electric power obtained by photovoltaic power generation can be efficiently recovered via the current collecting electrode 41 provided on the second base 21 side.

  (2) A low-resistance conductive metal layer 52 made of only nickel, which is a metal, is present on the entire surface of the resin sphere 53 constituting the interconnector 51. Therefore, the conductive metal layer 52 is brought into contact with the translucent conductive layer 14 and the current collecting electrode 41, thereby reliably conducting the translucent conductive layer 14 and the current collecting electrode 41 through the conductive metal layer 52. be able to. This structure contributes to improvement of photoelectric conversion efficiency. Moreover, since nickel also has suitable corrosion resistance, even if it is exposed to the electrolytic solution 33, it is not particularly altered or deteriorated. Therefore, there is an advantage that a structure for protecting the interconnector 51 may not be provided around the interconnector 51.

  (3) Since the interconnector 51 includes an acrylic resin ball 53 having an appropriate elasticity as a constituent element, the interconnector 51 can be elastically deformed as a whole. For this reason, even if the distance between the electrodes varies due to, for example, warping or undulation of the substrate, the interconnector 51 is elastically deformed and the plurality of current collecting electrodes 41 and the translucent conductive layer 14 It is possible to reliably contact both sides and to reliably establish conduction between the two. Incidentally, FIG. 11 shows the dye-sensitized solar cell 1 when the first substrate 11 is warped, for example, because the entire device has a large area. In the figure, the height of the cell space 32 becomes smaller toward the right side, and the distance between the electrodes is not equal. Further, the right interconnector 51 is more elastically deformed than the left interconnector 51. However, the left and right interconnectors 51 can reliably contact and conduct both the collecting electrode 41 and the translucent conductive layer 14. As can be seen from the above, according to the present embodiment, it is possible to provide the dye-sensitized solar cell 1 having a structure advantageous for increasing the area.

(4) According to the manufacturing method of the present embodiment described above, by performing the temporary fixing step and the main fixing step, the plurality of interconnectors 51 can be securely fitted into the plurality of depressions 43 without requiring a large-scale device. It can be fixed. For this reason, the dye-sensitized solar cell 1 of FIG. 1 can be manufactured relatively easily and at low cost.
[Second Embodiment]

  Next, a dye-sensitized solar cell 100 according to a second embodiment that embodies this embodiment will be described with reference to FIG.

The dye-sensitized solar cell 100 has basically the same configuration as the dye-sensitized solar cell 1 of the first embodiment except that the shape of the recess 101 is different. As shown in FIG. 12, the recess 101 of the present embodiment has a cross-sectional shape with a narrowed opening, or in other words, a reverse-tapered cross-sectional shape that gradually decreases in width toward the opening. Yes. Therefore, when the interconnector 51 is fitted and held in the recess 101 having such a shape, the edge of the opening portion easily bites into the interconnector 51. And this bite makes it difficult for the interconnector 51 to come off, and the fixing strength can be improved.
[Third Embodiment]

  Next, a dye-sensitized solar cell 120 according to a third embodiment that embodies this embodiment will be described with reference to FIG.

  This dye-sensitized solar cell 120 basically has the same configuration as that of the dye-sensitized solar cell 1 of the first embodiment, but in addition to this, a structure for protecting the interconnector 51 is provided. In addition. That is, in this embodiment, each interconnector 51 is surrounded by a ring-shaped protective member 121 made of ionomer resin and having a height of about 30 μm. The center hole 122 of the ring-shaped protection member 121 has a diameter at least equal to or larger than the diameter of the interconnector 51, and is specifically set to about 700 μm to 1500 μm. On the other hand, the outer diameter of the ring-shaped protection member 121 is set to about 2 mm to 5 mm. The upper end surface of the ring-shaped protection member 121 is heat-sealed to the translucent conductive layer 14 in the first base 11, and the lower end surface is heat-sealed to the inner ceramic layer 25 in the second base 21. . As a result, the central hole side region of the ring-shaped protection member 121 is isolated from the region on the cell space 32 side filled with the electrolytic solution 33, and the interconnector 51 accommodated therein is not directly exposed to the electrolytic solution 33.

  The ring-shaped protection member 121 shown in FIG. 13 can be disposed between the first base 11 and the second base 21 by any conventionally known method. As an example, for example, a ring-shaped protective member 121 is prepared and prepared in advance, and this is disposed on the second base 21 after the “(4) Temporary fixing of the interconnector 51”. “(5) Bonding of substrates and main fixing of interconnector 51” may be performed. The ring-shaped protection member 121 may be disposed after the spacer 31 is disposed. Alternatively, after the “(4) Temporary fixing of the interconnector 51”, a ring-shaped protective member-forming resin material imparted with photosensitivity is provided on the second base 21, and this is exposed and developed to form the ring-shaped protective member 121. Then, after that, “(5) Bonding of substrates and main fixing of interconnector 51” may be performed.

  The ring-shaped protective member 121 is disposed on the second base 21 in advance, and then “(4) Temporary fixing of the interconnector 51” and “(5) Bonding of the bases and permanent fixing of the interconnector 51”. It is also possible to carry out. However, with this method, it is necessary to fit and fix the interconnector 51 in a state where a convex portion is formed around the recess 43. From the viewpoint of workability, the interconnector 51 is thus formed in a flat state without the convex portion. The method of fitting and fixing is preferred.

And according to this embodiment demonstrated above, the interconnector 51 is reliably protected from the highly corrosive electrolyte 33 by arrange | positioning the ring-shaped protection member 121. FIG. As a result, the durability and reliability of the device can be improved. Moreover, since the interconnector 51 itself is not required to have corrosion resistance, the range of selection of the material for forming the interconnector 51 is widened. Therefore, for example, it is sufficiently possible to employ highly conductive copper or silver as the conductive metal layer 52.
[Fourth Embodiment]

  Next, a dye-sensitized solar cell 140 according to a fourth embodiment that embodies this embodiment will be described with reference to FIG.

In the first to third embodiments, the second base 21 having a plurality of depressions 43 is used, but in this embodiment, the second base 21A having no depressions 43 is used. ing. On the other hand, the second base 21A is provided with a ring-shaped protection member 121 as in the third embodiment, thereby protecting and positioning the interconnector 51. In the dye-sensitized solar cell 140, the ceramic layer 25 is only one layer, and the via conductor 24 and the inner conductor layer 26 are omitted. Therefore, according to this configuration, the structure of the second base 21 can be simplified.
[Fifth Embodiment]

  Next, a dye-sensitized solar cell 160 according to a fifth embodiment that embodies this embodiment will be described with reference to FIG.

  Also in this dye-sensitized solar cell 160, the second base 21A having no depression 43 is used as in the fourth embodiment. However, the structure of the first base 11 </ b> A is different from those of the first to fourth embodiments, and a plurality of depressions 162 are provided on the inner side surface 22 thereof. The interconnector 51 is fitted and fixed in these recesses 162. In addition, although the ring-shaped protection member 121 is omitted in FIG.

  The embodiment of the present invention is not limited to the above-described embodiments, and can be arbitrarily changed without departing from the gist thereof.

  Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the embodiments described above are listed below.

  The translucent conductive layer including the translucent substrate (13), the translucent conductive layer (14) provided on the inner surface (12) of the translucent substrate (13), and the sensitizing dye. (14) A first substrate preparation step of preparing a first substrate (11) having a semiconductor electrode (15) provided thereon, and the catalyst electrode (23) and the catalyst electrode (23) are insulated from each other. A plurality of current collecting electrodes (41) on the inner side surface (22), and a plurality of depressions corresponding to locations where the plurality of current collecting electrodes (41) are present on the inner side surface (22). A second base preparation step for preparing the second base (21, 21A) on which (43) is formed, and a material more elastic than the first base (11) and the second base (21, 21A). A plurality of relay connectors (51) having a structure in which the surface of the granular substrate (53) is covered with a conductive layer (52). A relay connection body preparation step to be prepared; a temporary fixing step of temporarily fixing the plurality of relay connection bodies (51) to the plurality of depressions (43); and after the temporary fixing step, the first base body (11) and The plurality of relay connectors (51) are fitted into the plurality of depressions (43) by arranging the second base bodies (21, 21A) facing each other and joining them while applying a pressing force in the thickness direction. After the temporary fixing step of fixing and fixing and before the temporary fixing step and before the main fixing step, either one of the first base body (11) and the second base body (21, 21A) is connected to the plurality of relay connection bodies ( 51), and a protective member disposing step of disposing a ring-shaped protective member (121) that surrounds 51). A method for producing a dye-sensitized solar cell (1, 100, 120).

1 is a schematic cross-sectional view showing a dye-sensitized solar cell according to a first embodiment that embodies the present invention. The principal part expansion perspective view which shows the hollow and relay connection body in the dye-sensitized solar cell of 1st Embodiment. The schematic sectional drawing for demonstrating the manufacturing method of the dye-sensitized solar cell of 1st Embodiment. The schematic sectional drawing for demonstrating a manufacturing method similarly. The schematic sectional drawing for demonstrating a manufacturing method similarly. The schematic sectional drawing for demonstrating a manufacturing method similarly. The schematic sectional drawing for demonstrating a manufacturing method similarly. The schematic sectional drawing for demonstrating a manufacturing method similarly. The schematic sectional drawing for demonstrating a manufacturing method similarly. The schematic sectional drawing for demonstrating a manufacturing method similarly. The schematic sectional drawing which shows the dye-sensitized solar cell of 1st Embodiment with a curvature in a 1st base | substrate. The schematic sectional drawing which shows the dye-sensitized solar cell of 2nd Embodiment. The schematic sectional drawing which shows the dye-sensitized solar cell of 3rd Embodiment. The schematic sectional drawing which shows the dye-sensitized solar cell of 4th Embodiment. The schematic sectional drawing which shows the dye-sensitized solar cell of 5th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100,120,140,160 ... Dye-sensitized solar cell 11, 11A ... 1st base | substrate 12 ... Inner side surface (of translucent substrate) 13 ... Translucent substrate 14 ... Translucent conductive layer 15 ... Semiconductor Electrodes 21, 21A ... second substrate 22 ... (inside of second substrate) 32 ... cell space 33 ... electrolyte solution 41 ... collecting electrode 42 ... via conductor 43 ... dent 44 ... collecting conductor layer 51 ... relay connector Interconnector 52 ... Conductive metal layer 53 as conductive layer 53 ... Resin sphere as granular substrate

Claims (11)

A first substrate having a translucent substrate, a translucent conductive layer provided on an inner surface of the translucent substrate, and a semiconductor electrode including a sensitizing dye and provided on the translucent conductive layer; ,
A second substrate disposed opposite the first substrate and having a catalyst electrode on an inner surface thereof;
An electrolyte filled in a cell space existing between the first substrate and the second substrate;
A plurality of current collecting electrodes present in the form of dots in a state of being insulated from the catalyst electrode on the inner surface of the second substrate;
The plurality of current collecting electrodes and the light transmissive conductive layer are disposed between the first base and the second base and are in contact with the plurality of current collector electrodes and the light transmissive conductive layer. A plurality of relay connecting bodies for conducting, the plurality of relay connecting bodies having a structure in which a surface of a granular base made of a material more elastic than the first base and the second base is covered with a conductive layer. A dye-sensitized solar cell characterized by   The dye-sensitized solar cell according to claim 1, wherein the granular substrate is spherical.   The dye-sensitized solar cell according to claim 1 or 2, wherein the granular substrate is a resin sphere.   The dye-sensitized solar cell according to any one of claims 1 to 3, wherein the conductive layer is a conductive metal layer.   The dye-sensitized solar cell according to claim 4, wherein the electrolytic solution is a corrosive electrolytic solution, and the conductive metal layer is made of a metal having at least corrosion resistance to the corrosive electrolytic solution.   The dye-sensitized solar cell according to claim 5, wherein the conductive metal layer is made of at least one metal selected from tungsten, titanium, and nickel.   The dye-sensitized solar cell according to any one of claims 1 to 6, wherein the plurality of relay connection bodies are fixed to the second substrate side.   The plurality of relay connection bodies are respectively fitted and fixed in a plurality of depressions formed corresponding to locations where the plurality of current collecting electrodes exist on the inner surface of the second base. Item 8. The dye-sensitized solar cell according to any one of Items 1 to 7.   The dye-sensitized solar cell according to claim 8, wherein the plurality of depressions have a cross-sectional shape with a narrowed opening.   The second base has a current collecting conductor layer provided on an outer surface thereof, and a plurality of via conductors for conducting the current collecting conductor layer and the plurality of current collecting electrodes. The dye-sensitized solar cell according to any one of claims 1 to 9, wherein the dye-sensitized solar cell is provided. A translucent substrate; a translucent conductive layer provided on an inner surface of the translucent substrate; and a first substrate including a sensitizing dye and having a semiconductor electrode provided on the translucent conductive layer. A first base preparation step to prepare;
The catalyst electrode and a plurality of current collecting electrodes that are present in the form of dots in a state of being insulated from the catalyst electrode are provided on the inner side surface, and a plurality of current collecting electrodes corresponding to locations where the plurality of current collecting electrodes exist on the inner side surface A second substrate preparation step of preparing a second substrate on which a depression is formed;
A relay connector preparation step of preparing a plurality of relay connectors having a structure in which a surface of a granular substrate made of a material more elastic than the first substrate and the second substrate is covered with a conductive layer;
Temporary fixing step of temporarily fixing the plurality of relay connection bodies to the plurality of depressions,
After the temporary fixing step, the first base body and the second base body are arranged to face each other and joined while applying a pressing force in the thickness direction, thereby fitting the plurality of relay connection bodies into the plurality of depressions. A method for producing a dye-sensitized solar cell, comprising: a main fixing step of fixing and fixing.

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