JP5095237B2 - Dye-sensitized solar cell and method for producing the same - Google Patents

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 and grid-shaped current collecting electrode formed by applying and baking a 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. (For example, refer to 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 the side of the translucent substrate (referred to as “first base” for convenience) on which the semiconductor electrode is formed but the substrate having the counter electrode (referred to as “second base” for convenience). It is considered that a current collecting electrode should be provided on the side of). 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 power obtained by photovoltaic power generation through a current collecting conductor layer provided on the second substrate side. Another 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 problems, the invention described in claim 1 is directed to a first base (13) having translucency and a second base (20) disposed at a position facing the first base (13). ), A translucent conductive layer (14) provided on the side (12) of the first base (13) facing the second base (20), and on the translucent conductive layer (14) A semiconductor electrode (15) containing a sensitizing dye, a catalyst electrode (23) provided on a side (22) of the second base (20) facing the first base, and the first base (13) and an electrolytic solution (33) filled in a cell space (32) existing between the second substrate (20) and the catalyst electrode (23) by the second substrate (20). Current collecting conductor layers (41, 41A, 41B) arranged in a state of being in a state of being present and a solder layer (52) at least on the surface The light-transmitting conductive layer (14) is disposed between the first base (13) and the second base (20) in a state of being insulated from the catalyst electrode (23). And the current collector conductor layers (41, 41A, 41B), the plurality of relay connectors (51, 51A) and the plurality of relay connectors (51, 51A) individually enclosing the solder And a resin protective part (61, 62) that separates the layer (52) from the electrolytic solution (33), and the plurality of relay connectors (51, 51A) are formed by melting and solidifying the solder layer (52). The gist thereof is a dye-sensitized solar cell (1, 101, 111, 121, 131) that is bonded to the light-transmitting conductive layer (14).

  Therefore, according to the first aspect of the invention, the translucent conductive layer on the first substrate side and the current collector on the second substrate side are connected via the plurality of relay connectors disposed between the first substrate and the second substrate. The conductor layer 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, 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 through the current collecting conductor layer provided on the second substrate side. Therefore, a dye-sensitized solar cell having a structure advantageous for increasing the area can be realized. In addition, since the solder layer existing on the surface of the relay connection body has a relatively low resistance, electricity can flow efficiently, and the relay connection body is melted and solidified with respect to the translucent conductive layer. It is firmly joined. These also contribute to the realization of efficient power recovery.

  Since the first base having translucency is disposed on the side where light enters during use, the first base is formed using a translucent material such as glass or a resin sheet. When the first substrate is made of a resin sheet, the resins used for forming the resin sheet include various thermoplastic resins such as polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyphenylene sulfide, polycarbonate, polysulfone, and polyethyleneidene norbornene. Is mentioned. The thickness of the first substrate varies depending on the material and is not particularly limited. However, it is preferable that the following transmittance, which is a light-transmitting index, is 60% to 99%, particularly 85% to 99%. . 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” is provided on the side of the first base facing the second base. 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” is provided on the translucent conductive layer and contains a sensitizing dye. In other words, the semiconductor electrode is provided on the side of the first substrate facing the second 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. The semiconductor electrode is preferably heat-treated in order to improve its strength and adhesion with the first 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 1st base | substrate, it is preferable to heat-process at suitable 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 side facing the first substrate.

  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. As the second substrate that does not have translucency, for example, a ceramic substrate or a resin substrate can be used.

  The advantage of the resin substrate is that it is superior in cost and workability compared to a glass substrate or a ceramic substrate. The resin material in the resin substrate is not particularly limited and can be arbitrarily selected. However, it is preferable to select a resin material that is usually used for a printed wiring board, for example, EP resin (epoxy resin), PI resin (polyimide resin) ), PET resin (polyethylene terephthalate resin), BT resin (bismaleimide-triazine resin), PPE resin (polyphenylene ether resin), PEEK resin (polyether ether ketone resin) and the like are suitable. The second substrate may be configured to include one or two or more flexible resin substrates (for example, resin film materials). The reason is that the second base body itself is partially deformed, which advantageously works to eliminate variations in the particle size of the relay connection body and the distance between the electrodes, making it easier to ensure electrical connection between the electrodes. It is.

  The advantage of the ceramic substrate is that it has an excellent mechanical strength and is advantageous in improving the durability of the entire apparatus. 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. Of these, 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.

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

  This catalyst electrode can be formed of a substance having catalytic activity. 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.

  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.

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.

  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 ethylene glycol, polypropylene glycol, glycerin, (7) nitriles such as acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, (8) aprotic such as dimethyl sulfoxide, sulfolane, etc. 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.

  The “current collector layer” is disposed in a state of being insulated from the catalyst electrode by the second substrate (in other words, in a state of being physically separated). The current collecting conductor layer is electrically connected to the translucent conductive layer via a relay connection body and functions as a current collecting electrode 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 current collecting conductor layer may be disposed on the inner layer of the second base (that is, not exposed to the outer surface) or may be disposed on the outer surface.

  The current collection conductor layer should just have electroconductivity at least, and the material is not specifically limited. Specific examples thereof include copper, silver, gold, platinum, palladium, tungsten, nickel, titanium, and the like. It is preferable to use copper having high conductivity when corrosion resistance is not particularly required. The current collecting conductor layer can be formed, for example, by applying a paste containing conductive fine particles to 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. Further, the plurality of current collecting conductor layers can be formed by depositing metal or the like on the second substrate by sputtering, vapor deposition, ion plating, plating, or the like.

  The “resin protection portion” is a member that individually surrounds the plurality of relay connecting bodies, and plays a role of separating the solder layer on the surface of the relay connecting body from the electrolytic solution. The resin protection portion is arranged in a dot shape corresponding to a position where the plurality of relay connection bodies are present. 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 resin protection portion is formed, for example, in a ring shape having a center hole, and individual relay connectors are arranged in the center hole. An advantage of the configuration in which the relay connection body is surrounded by the resin protection portion is that the solder layer is not corroded by the electrolytic solution and suitable conductivity can be maintained. The resin used for the protective part made of resin is preferably made of a resin having higher corrosion resistance to the electrolyte than the solder layer. Specifically, epoxy resin, urethane resin, isobutylene resin, olefin resin, ionomer resin, etc. Can be mentioned. Since the resin material has suitable insulating properties, it is also preferable as a structure 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.

  For example, the resin protection part may have a single layer structure or a multilayer structure. In the case of adopting a multilayer structure, for example, a resin coat layer made of a resin having a higher corrosion resistance to an electrolytic solution than a solder layer, and a resin coat layer made of a resin having a higher corrosion resistance to an electrolytic solution than a solder layer. An enclosing resin ring may be formed. The advantage of the multilayer structure is that protection of the relay connection is more reliable.

  The “plurality of relay connection bodies” are arranged in the form of dots in a state of being insulated from the catalyst electrode between the first base and the second base, and both are brought into contact with the translucent conductive layer and the current collecting conductor layer. It plays the role of relaying the electrical connection between them (that is, the role of conducting between them). The relay connection body is a granular material, and at least the surface thereof has a solder layer as a conductive layer. The solder layer in the relay connection body is not simply in contact with the translucent conductive layer, but is bonded to the translucent conductive layer by melting and solidifying itself. Therefore, as a result of the relay connection body being firmly and securely fixed to the translucent conductive layer, the relay connection body can be interposed stably and the conduction resistance can be lowered. Further, according to such a fixing method, for example, even if the translucent conductive layer is a conductive oxide that is disadvantageous for contact conduction with metal, it is possible to connect with a predetermined conduction resistance.

  The plurality of relay connection bodies may be any structure provided with conductivity on the surface, and may have a structure in which a solder layer is present on at least the surface. Specifically, a structure in which the surface of the granular substrate is covered with a solder layer may be adopted, or there is no granular substrate and the entire structure consists of only a solder layer, or there is a solder layer only on the surface. A structure in which the inside is hollow may be employed. In this case, a structure in which the surface of the granular substrate is covered with a solder layer, in other words, a structure in which the granular substrate as a core exists in the relay connection body is preferable. The reason is as follows. That is, when there is no granular substrate, there is a possibility that the entire relay connection body cannot be held granular when the solder layer is melted. However, when there is a granular substrate, it is possible to hold particles having a predetermined diameter.

  Here, the shape of the relay connection body (the shape of the granular substrate) may be any shape, and specifically, any of a spherical shape, a prismatic shape, a cylindrical shape, and the like may be used. This is because the spherical relay connection body has no directionality, is easy to handle, and is relatively easy to manufacture.

  The solder layer constituting the relay connection body is made of a conductive alloy that melts at a relatively low melting point (for example, 500 ° C. or less). The solder which comprises a solder layer is not specifically limited, Arbitrary things can be used. Specifically, Pb-Sn solder such as 90Pb-10Sn, 95Pb-5Sn, 40Pb-60Sn can be used, Sn-Sb solder, Sn-Ag solder, Sn-Ag-Cu solder, Pb-free solders such as Au—Ge solders and Au—Sn solders can be used as well. In consideration of the influence on the environment, it is preferable to select Pb-free solder.

  The material for forming the granular substrate constituting the relay connection body is not particularly limited, and any material can be selected regardless of organic and inorganic materials as long as the solder layer can be coated on the surface thereof. Specifically, it is permissible to select a material for forming the granular substrate from resin, ceramic, metal, etc., but it is particularly preferable to select a spherical resin (resin sphere). In general, resins are not as hard as inorganic materials such as ceramics and metals, and have a certain degree of flexibility and elasticity. For this reason, it is because a relay connection body deform | transforms advantageously acts on elimination of the inter-electrode distance variation, and it becomes easy to ensure the electrical connection between both electrodes. Although it does not specifically limit as resin which is a formation material of a granular base, For example, an acrylic resin, an epoxy resin, a urethane resin, an isobutylene resin, an olefin resin, an ionomer resin etc. are mentioned.

  The solder layer constituting the relay connection body is formed so as to cover at least a part of the surface of the granular substrate, and is preferably formed so as to cover the entire surface. The average thickness of the solder layer is not particularly limited, but is preferably at least 1 μm or more, preferably 10 μm or more, in order to realize a reduction in conduction resistance. In addition, although the solder layer may be directly formed with respect to the surface of a relay connection body, it may be formed through base layers, such as copper and silver, for example.

  In addition, the relay connection body which uses a solder layer as a conductive layer is, for example, a relay connection using a material (so-called conductive rubber or the like) in which conductive metal particles as a filler are dispersed in a resin matrix such as rubber. Compared to the body, it is superior in the following points. That is, the latter using conductive rubber or the like has a certain degree of conductivity, but is not made of only a conductive metal, and therefore has a high electrical resistance and poor conductor properties. Therefore, it is not preferable to use conductive rubber as the conductive layer constituting the relay connection body. On the other hand, the former using a solder layer has a suitable electrical conductivity, and therefore has a low electrical resistance and is superior to the characteristics as a conductor. Therefore, it can be said that it is suitable as a 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 achieve excellent current collection efficiency.

  In order to solve the above another problem, the invention described in means 2 is a method for producing the dye-sensitized solar cell (1, 101, 111, 121, 131) described in means 1, A translucent conductive layer forming step of forming a translucent conductive layer (14) on the side (12) of the first base (13) facing the second base (20); and the translucent conductive layer ( 14) A semiconductor electrode forming step of forming a semiconductor electrode (15) containing a sensitizing dye, and the plurality of relay connectors (51, 51A) on the translucent conductive layer (14). And bonding the plurality of relay connectors (51, 51A) to the translucent conductive layer (14) by reflowing and melting the solder layer (52) by heating. And a process for producing a dye-sensitized solar cell.

  Therefore, according to the invention described in the means 2, the first base and the plurality of relay connecting bodies are used, and the plurality of relay connecting bodies are arranged in a dot shape on the light-transmitting conductive layer of the first base. Heat and reflow. Then, the solder layer melts with heat and becomes familiar with the surface of the translucent conductive layer, and further solidifies, whereby a plurality of relay connection bodies are firmly joined to the translucent conductive layer, and a plurality of relay connections are made. The body cannot be displaced in the surface direction of the first base. Then, the above-described excellent dye-sensitized solar cell can be obtained relatively easily and at low cost by stacking the second substrate and the like thereafter. Further, according to this manufacturing method, there is no need to process the first base body or the second base body in order to fix a plurality of relay connection bodies, and to form a fixing structure such as a recess in advance, and the corresponding amount is reduced. It becomes easy to plan cost.

  In the melt-bonding process, a plurality of relay connecting bodies are arranged in a dot shape on the translucent conductive layer before reflowing, and they are not misaligned until the molten solder layer is completely solidified. It is preferable to temporarily fix it. The method of temporary fixing is not limited, and for example, there is a method of pressing and holding using a jig, and a method of sticking and holding on a translucent conductive layer using a viscous material. As an example of a suitable temporary fixing method, for example, a plurality of relay connection bodies may be adhered and held on the light-transmitting conductive layer using a flux. “Flux” refers to a soldering flux, and is a chemical used to reduce the surface tension of the solder so that the surfaces to be joined are easily wetted by the solder. The advantages of the above method using a flux are as follows.

  That is, flux is usually used during soldering, and since this flux has a suitable viscosity, it is not necessary to separately prepare a viscous material for temporarily fixing the relay connection body. Therefore, even if this method is adopted, the number of man-hours is not particularly increased, and the decrease in productivity and cost can be prevented.

  The type of the flux is not particularly limited, and for example, any of a resin flux, an organic acid flux, and an inorganic acid flux can be used. The resin-based flux means a rosin, modified rosin, or synthetic resin as a main component, and an amine halogen salt, an organic acid, an amine organic acid salt, or the like, which is an active ingredient, added as necessary. The organic acid-based flux refers to a water-based or solvent-based main component to which an amine halogen salt, organic acid or amine organic acid salt as an active ingredient is added as necessary. Inorganic acid fluxes include water-soluble main ingredients or non-water-soluble main ingredients such as petrolatum, as required, such as amine halogen salts, organic acids or amine organic acid salts, ammonium halides, and zinc halides. What you did. In addition, in order to temporarily fix the relay connection body securely, the flux should have a certain degree of high viscosity.

  The method for supplying the flux is not particularly limited, and for example, any method such as a spin coating method, a curtain coating method, a dip coating method, a dispenser method, or the like can be adopted. Further, the flux may be one that requires cleaning (aqueous cleaning type or organic cleaning type), or one that does not require cleaning (so-called no-cleaning type).

  In addition, the resin protective part for individually enclosing the plurality of relay connecting bodies and separating the solder layer from the electrolyte can be disposed regardless of before and after the melt bonding process. It is preferable to arrange it later. In other words, if the fusion bonding process is performed after the resin protective part is disposed, the resin protective part may be exposed to high temperatures during reflow and deteriorate or deteriorate, causing a decrease in device reliability. It becomes. On the other hand, if the melt-bonding step is performed before the resin protective portion is provided, deterioration and alteration of the resin protective portion due to heat can be avoided, and deterioration of the reliability of the apparatus can be prevented. In addition, after providing the protective part made of resin, the current collecting conductor layer is then disposed so as to come into contact with the solder layer.

  In the case of manufacturing a dye-sensitized solar cell using a second substrate configured to include a flexible resin film material, for example, the following steps are performed after the melt bonding step. May be. Specifically, after performing the fusion bonding step, performing a protective portion disposing step of individually enclosing a plurality of relay connecting bodies and providing a resin protective portion for separating the solder layer from the electrolyte, A first film material disposing step of laminating and disposing the first film material provided with the catalyst electrode on the first base is performed, and then the second film material provided with the current collecting conductor layer on the surface thereof is used as the first film. A second film material disposing step is performed in which the solder layer is brought into contact with the current collecting conductor layer while being laminated and adhered onto the material. According to this procedure, the dye-sensitized solar cell having the above structure can be manufactured relatively easily. In addition, even if there is a slight variation in the particle size of the plurality of relay connecting bodies, the influence of the particle size variation is eliminated by the deformation of the second film material when performing the second film material disposing step. Each of the relay connection bodies is securely bonded to the translucent conductive layer. In addition, the first film material provided with the catalyst electrode and the second film material provided with the current collecting conductor layer on the surface thereof are laminated and bonded first, and then the first film material and the second film material. May be laminated on the first substrate. Even by this procedure, the dye-sensitized solar cell having the above structure can be manufactured relatively easily.

[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 base 13 and a second base 20 are arranged to face each other with a spacer 31 interposed therebetween. A cell space 32 is formed between the first base 13 and the second base 20, and the cell space 32 is filled with an electrolytic solution 33 having corrosive properties.

  On the side 12 of the first base 13 having translucency facing the second base 20, 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 second substrate 20 is a resin laminated substrate, and more specifically, a multilayer resin wiring substrate in which resin film materials 24 and 25 are laminated. On the side 22 of the second substrate 20 facing the first substrate 13, a catalyst electrode 23 made of platinum is provided facing the semiconductor electrode 15. The catalyst electrode 23 is formed over almost the entire surface of the side 22 of the second base 20 facing the first base 13 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.

  The first resin film material 24 located in the inner layer of the second substrate 20 that is a laminated substrate has an inner layer conductor pattern 27 and a via conductor 26 that conducts the inner layer conductor pattern 27 and the catalyst electrode 23. . On the other hand, the second resin film material 25 located in the outer layer of the second base 20 has a current collecting conductor layer 41. The inner layer conductor pattern 27, the via conductor 26, and the current collecting conductor layer 41 are all made of copper having excellent conductivity. The conductor group including the catalyst electrode 23, the via conductor 26, and the inner layer conductor pattern 27 and the current collecting conductor layer 41 are electrically separated from each other inside the second base body 20, and are insulated from each other. . The first resin film material 24 and the second resin film material 25 are integrated by being bonded via an adhesive layer 28 provided on the first resin film material 24 side. A plurality of holes 29 having a predetermined shape are formed at a plurality of locations in the first resin film material 24.

  As shown in FIGS. 1 and 2, a plurality of spherical interconnectors 51 (relay connection bodies) are provided between the first base 13 and the second base 20 at positions corresponding to the punched holes 29. Each is arranged. These interconnectors 51 have a structure in which the entire surface of a resin ball 53 (granular substrate) is covered with a solder layer 52 which is a conductive layer. The resin sphere 53 in this embodiment is formed using a synthetic resin material that is more elastic than the glass that forms the main body of the first base 13. In this embodiment, a spherical epoxy resin is used as such a resin material. The average particle diameter of the interconnector 51 is about 700 μm to 800 μm.

  In the plurality of interconnectors 51, the solder layer 52 on the surface thereof is in contact with the current collecting conductor layer 41 of the second base 20. Further, on the side 12 of the first base 13 having translucency facing the second base 20, the semiconductor electrode 15 is not provided at a location facing the plurality of interconnectors 51, and the translucent conductive layer is provided. 14 is exposed. The solder layer 52 of the interconnector 51 is joined to the light-transmitting conductive layer 14 exposed in this way by melting and solidifying the solder layer 52 itself. As a result, the current collecting conductor layer 41 and the translucent conductive layer 14 are electrically connected via the plurality of interconnectors 51. Accordingly, the wiring for the semiconductor electrode 15 can be taken out from the second base 20 side through the path of the semiconductor electrode 15 → the translucent conductive layer 14 → the solder layer 52 of the interconnector 51 → the current collecting conductor layer 41. ing.

  As shown in FIG. 1, a relay connection body protection structure portion including a resin coat layer 61 and a resin ring 62 is provided between the first base 13 and the second base 20. Both the resin coat layer 61 and the resin ring 62 are made of an ionomer resin that has higher corrosion resistance to the electrolytic solution 33 than the solder layer 52. The resin coat layer 61 is disposed so as to surround each interconnector 51. The resin ring 62 is disposed so as to further surround the outside of the resin coat layer 61.

  The center hole of the resin ring 62 has a diameter larger than the diameter of the interconnector 51, and is specifically set to about 1 mm to 1.5 mm. On the other hand, the outer diameter of the resin ring 62 is set to about 2 mm to 5 mm. The upper end surface of the resin ring 62 is thermally fused to the translucent conductive layer 14 in the first base 13, and the lower end surface is thermally fused to the inner resin film material 24 in the second base 20. As a result, the interconnector 51 is isolated from the area on the cell space 32 side and is not directly exposed to the electrolytic solution 33.

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

  (1) Production of the first base 13, the translucent conductive layer 14, and the semiconductor electrode 15

  First, a first base 13 having translucency (a glass substrate manufactured by Nippon Sheet Glass Co., Ltd., length 25 mm, width 15 mm, thickness 1 mm) is prepared, and the entire surface of one side of the first base 13 having translucency is formed from FTO. A transparent conductive layer 14 having a thickness of 300 nm 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 screen-printed on the light-transmitting conductive layer 14 of the first substrate 13 having a light-transmitting property. Was applied to form a coating film having a thickness of 20 μm. 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 first substrate 13 having the above-described translucency with the porous electrode substrate formed thereon is immersed in the aqueous titanium tetrachloride solution, and the aqueous solution is heated and held at 70 ° C. for 30 minutes to perform the titanium chloride treatment. It was. Next, the treated first substrate 13 having translucency was taken out of the aqueous solution, washed sufficiently 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 first substrate 13 having translucency were immersed in this ruthenium complex solution for 18 hours. As a result, a ruthenium complex as a sensitizing dye was adhered to the porous electrode substrate to form a semiconductor electrode 15 having a thickness of 20 μm (see FIG. 2).

  (2) Fabrication of interconnector 51

  In producing the interconnector 51, a large number of spherical resin spheres 53 (average particle diameter 700 μm) made of epoxy resin are prepared, and solder plating is performed on these resin spheres 53 by a conventionally well-known method, and the entire surface thereof is prepared. A solder layer 52 having a thickness of about 1 μm to 10 μm was formed. In this case, solder plating may be performed after an underlayer such as copper or silver is formed on the surface of the resin ball 53 in advance. According to this method, the adhesion strength of the solder layer 52 to the resin ball 53 is increased, and the resistance of the interconnector 51 can be easily reduced. In this embodiment, a resin core solder ball “trade name, Micropearl SOL” manufactured by Sekisui Chemical Co., Ltd. is used as the interconnector 51.

  (3) Applying flux F1 and temporarily fixing interconnector 51

  A highly viscous flux F1 was uniformly applied to the entire surface of the first base 13 manufactured as described above on the side 12 facing the second base 20 by a conventionally known technique (see FIG. 3). In the present embodiment, resin-based flux F1 (trade name: TF-400, manufactured by Toyo Metal Co., Ltd.) was used. Thereafter, a plurality of interconnectors 51 are supplied to predetermined locations on the flux F1 application surface, and the plurality of interconnectors 51 are adhesively held on the translucent conductive layer 14 using the viscosity of the flux F1 and temporarily fixed. (See FIG. 4). In this case, a predetermined jig (not shown) was used in order to simultaneously arrange the plurality of interconnectors 51 at the correct positions. As described above, in the present embodiment, since the flux F1 originally necessary for soldering is effectively used, it is not necessary to separately prepare a viscous material for temporary fixing. Therefore, even if this method is adopted, the number of man-hours is not particularly increased, and the reduction in productivity and cost can be prevented. In addition, you may make it mount the interconnector 51 one by one in a predetermined position using apparatuses, such as a chip mounter.

  (4) Melt bonding of interconnector 51

  The plurality of interconnectors 51 are temporarily fixed on the translucent conductive layer 14 using the viscosity of the flux F1, and then the first base 13 is placed at a predetermined temperature (1 minute to 1 minute) using a conventionally known heating device in this state. 10 minutes), reflow was performed to heat to a predetermined temperature (250 ° C. to 350 ° C.). Then, the solder layer 52 melted by heat and became familiar with the surface of the translucent conductive layer 14, and further solidified, whereby the plurality of interconnectors 51 were firmly joined to the translucent conductive layer 14. Incidentally, a fillet 54 as shown in FIG. 5 is formed at the interface between the solder layer 52 and the translucent conductive layer 14, and as a result, a suitable bonding area is secured. The plurality of interconnectors 51 cannot be displaced in the surface direction of the first base 131 at this time. According to this method, in order to fix the plurality of interconnectors 51, it is not necessary to process the first base 13 or the second base 20 to form a fixing structure such as a recess in advance. This makes it easier to reduce costs.

  Then, after the fusion bonding step of the interconnector 51, the flux F1 was washed away by washing. In addition, when the non-cleaning type is used, cleaning can be omitted.

  (5) Formation of resin protective part

  Next, a resin material for forming a protective part mainly composed of an ionomer resin was supplied in a dot shape with a dispenser device, and each interconnector 51 was covered with the resin material. Then, the resin material was dried and made non-fluidized to form a resin coat layer 61 that individually surrounds the plurality of interconnectors 51 (see FIG. 6). Subsequently, a resin ring 62 made of ionomer resin was disposed so as to surround the resin-coated interconnector 51 (see FIG. 7).

  (6) Production of second substrate 20 and catalyst electrode 23

  First, a first resin film material 24, which is a constituent element of the second base 20, was prepared (see FIG. 8). An inner layer conductor pattern 27 is previously formed on the resin film material 24 by a conventionally known pattern forming method such as a subtractive method. The via conductor 26 is formed by a technique such as via plating or paste printing. Further, a catalyst electrode 23 having a thickness of 1 μm is formed on one side surface of the first resin film material 24 by sputtering platinum (Pt) in a state where a mask (not shown) is arranged.

  Moreover, the 2nd resin film material 25 which is a component of the 2nd base | substrate 20 was prepared (refer FIG. 11). A current collecting conductor layer 41 made of copper is formed on the entire one side surface of the resin film material 25, and an adhesive layer 28 is formed on the current collecting conductor layer 41. The adhesive layer 28 may be formed on the entire current collecting conductor layer 41, but the contact portion of the interconnector 51 may not be formed.

  First, a spacer 31 (made by Mitsui DuPont Polychemical Co., Ltd., trade name “made of Mitsui Dupont Polychemical Co., Ltd.) is formed on the outer peripheral portion of the first base 13 having translucency on the side 12 facing the second base 20. High Milan 1702 ") was provided. Then, the first resin film material 24 was laminated on the first base 13 via the spacer 31 (see FIG. 8). Next, the first base 13 and the first resin film material 24 are heat-sealed and bonded via the spacer 31 and the resin ring 62 by heating to a predetermined temperature with a pressing force applied in the thickness direction of the base. (See FIG. 9). At this time, the leading end portion of each interconnector 51 slightly protrudes from the hole 29.

  Next, surface polishing was performed with a buffing apparatus or the like to remove a part of the resin coat layer 61, thereby exposing only the tip of the interconnector 51 (see the solder layer exposed portion 55 in FIG. 10).

  Next, the above-described second resin film material 25 is laminated on the first resin film material 24, and both are bonded at normal temperature via the adhesive layer 28 by applying a pressing force in the substrate thickness direction. (See FIG. 11). At this time, even if the particle diameters of the plurality of interconnectors 51 slightly vary, the second resin film material 25 is deformed when the second resin film material 25 is pressed and bonded. Then, by this partial deformation, the influence of the particle size variation is eliminated, and each of the plurality of interconnectors 51 is reliably bonded to the translucent conductive layer 14.

  Finally, the iodine electrolyte solution 33 was injected with a syringe through the gap between the first base 13 and the spacer 31 to complete the dye-sensitized solar cell 1 shown in FIG.

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, the light incident from the opposite side of the side 12 of the first substrate 13 facing the second substrate 25 is transmitted through the first substrate 13 and the light transmitting property. It passes through the 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, iodide ion (I ^-) to oxidize and triiodide (I 3 ^_-) changing to. 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 translucent conductive layer on the first base 13 side through the plurality of interconnectors 51 disposed between the first base 13 and the second base 20. 14 and the current collecting conductor layer 41 on the second substrate 20 side are electrically connected. Therefore, unlike the conventional technique in which the current collecting electrode is provided on the first base 13 side, the area where the semiconductor electrode 15 cannot be formed does not increase, and the effective real area for photoelectric conversion is maintained. 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 conductor layer 41 provided on the second substrate 20 side. Therefore, the dye-sensitized solar cell 1 having a structure advantageous for increasing the area can be realized.

  In addition, since the solder layer 52 existing on the surface of the interconnector 51 has a relatively low resistance, electricity can be efficiently flowed. Moreover, the interconnector 51 is melted and solidified by the solder layer 52 so that the translucent conductive layer 14 is flown. It is firmly joined to. These also contribute to the realization of efficient power recovery.

  (2) In this dye-sensitized solar cell 1, the solder layer 52 on the surface of the interconnector 51 is corrosive by providing the resin coat layer 61 and the resin ring 62 that individually surround and protect the interconnector 51. It is protected from the high electrolytic solution 33. Therefore, the solder layer 52 is not corroded by the electrolytic solution 33, and suitable conductivity can be maintained. Moreover, since it is not necessary to consider corrosion resistance, it becomes possible to select a solder material relatively freely.

  (3) The dye-sensitized solar cell 1 employs a structure in which the surface of the resin sphere 53 that is a granular substrate is covered with the solder layer 52, in other words, a structure in which a spherical resin core is present inside. As a result, even when the solder layer 52 is melted or the like, the interconnector 51 as a whole can be maintained in a granular shape having a predetermined diameter. This also contributes to the realization of efficient power recovery.

(4) In this dye-sensitized solar cell 1, the solder layer 52 is in contact with the current collecting conductor layer 41 formed on the surface of the second resin film material 25 that forms a part of the second substrate 20. It is arranged like that. Here, since the 2nd resin film material 25 has a softness | flexibility and elasticity, the influence of the particle size variation of the some interconnector 51 is eliminated, and each of the some interconnector 51 is made into the translucent conductive layer 14. On the other hand, it can be reliably joined. Of course, this also contributes to the realization of efficient power recovery.
[Second Embodiment]

  Next, a dye-sensitized solar cell 101 according to a second embodiment that embodies this embodiment will be described with reference to FIG.

The dye-sensitized solar cell 101 basically has the same structure as the dye-sensitized solar cell 1 of the first embodiment, but the resin coat layer 61 is omitted. As a result, the protection part of the interconnector 51 is different from that of the first embodiment in that it has a single structure instead of a double structure. And even if it is this structure, there exists an effect similar to 1st Embodiment. Note that the manufacturing process can be simplified by the absence of the resin coat layer 61.
[Third Embodiment]

  Next, a dye-sensitized solar cell 111 according to a third embodiment that embodies this embodiment will be described with reference to FIG.

The second substrate 20 in the dye-sensitized solar cell 111 is different in structure from the second substrate 20 of the first embodiment. In other words, the second resin film material 25 is omitted here, and thereby the current collecting conductor layer 41 </ b> A is exposed on the outer surface of the second base 20. Further, the current collecting conductor layer 41A of the present embodiment is made of a copper plating layer. With this configuration, the current collecting conductor layer 41A can be formed relatively easily, and even if there are particle size variations in the plurality of interconnectors 51, the current collecting conductor layer 41A is surely brought into contact therewith. Can be conducted.
[Fourth Embodiment]

  Next, a dye-sensitized solar cell 121 according to a fourth embodiment that embodies this embodiment will be described with reference to FIG.

  The second substrate 20 in the dye-sensitized solar cell 121 is different in structure from the second substrate 20 of the first embodiment. That is, here, the resin coat layer 61 is omitted, and the second resin film material 25 is omitted, so that the current collecting conductor layer 41 </ b> B is exposed on the outer surface of the second substrate 20. Further, the current collecting conductor layer 41B of the present embodiment is formed of a copper paste printing layer. The copper paste has also entered the punched holes 29 so as to entirely enclose the solder layer 52. With this configuration, the current collecting conductor layer 41B can be formed relatively easily, and even if there are particle size variations in the plurality of interconnectors 51, the current collecting conductor layer 41B is surely brought into contact therewith. Can be conducted.

  In addition, you may change embodiment of this invention as follows.

For example, like the dye-sensitized solar cell 131 of another embodiment shown in FIG. 15, an interconnector 51 </ b> A that does not have a granular substrate and is entirely composed of the solder layer 52 may be used. Alternatively, an interconnector structure in which the solder layer 52 exists only on the surface and the inside is hollow may be employed.
In addition, in the above embodiment, after the protective portion forming step is performed, an exposure step is performed in which a part of the protective coat layer 61 is removed by polishing and a part of the solder layer 52 is exposed. Etching or the like may be performed.
In the above-described embodiment, the protective part providing step for forming the protective coat layer 61 and the like is performed after the melt bonding step for fixing the interconnector 51. However, this order may be reversed. Moreover, in the said embodiment, although the protective ring 62 was formed in the 1st base | substrate 13 side, you may make it form this in the 2nd base | substrate 20 side.

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

  (Technical Thought 1): A method for manufacturing a dye-sensitized solar cell (1, 101, 111, 121, 131), which is opposed to the second substrate (20) of the first substrate (13). A translucent conductive layer forming step for forming a translucent conductive layer (14) on the side, and a semiconductor electrode for forming a semiconductor electrode (15) containing a sensitizing dye on the translucent conductive layer (14) And forming the plurality of relay connecting bodies (51, 51A) in a dot-like manner on the translucent conductive layer (14) and reflowing to heat and melt the solder layer (52). Thus, after performing the fusion joining step of joining the plurality of relay connection bodies (51, 51A) to the translucent conductive layer (14) and the fusion joining step, the plurality of relay connection bodies (51 , 51A) individually to surround the solder layer (52) with the electrolyte ( 3) A protective part providing step for providing a resin protective part (61, 62) to separate from the protective part, and after performing the protective part arranging step, a part of the protective resin part (61, 62) is removed. Then, an exposure process for exposing a part of the solder layer (52) and a current collecting conductor layer arrangement for arranging the current collecting conductor layers (41, 41A, 41B) so as to be in contact with the exposed solder layer (52). A method for producing a dye-sensitized solar cell, comprising: an installation step.

1 is a schematic cross-sectional view showing a dye-sensitized solar cell according to a first embodiment that embodies the present invention. 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 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 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 another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101,111,121,131 ... Dye-sensitized solar cell 12 ... Side opposite to 2nd base | substrate of 1st base | substrate 13 ... 1st base | substrate which has translucency 14 ... Translucent conductive layer 20 ... 2nd Base 22 ... Side of the second base facing the first base 23 ... Catalyst electrode 24 ... First resin film material as a film material 25 ... Second resin film material as a film material 27 ... On the first base of the second base Opposite side opposite side 32 ... cell space 33 ... electrolyte 41, 41A, 41B ... current collecting conductor layer 51, 51A ... a plurality of interconnectors as a plurality of relay connectors 52 ... solder layer 53 ... resin as a granular substrate Sphere 61 ... Resin coat layer as resin protective part 62 ... Resin ring as resin protective part F1 ... Flux

Claims (11)

A first substrate having translucency;
A second base disposed at a position facing the first base;
A translucent conductive layer provided on a side of the first substrate facing the second substrate;
A semiconductor electrode containing a sensitizing dye provided on the translucent conductive layer;
A catalyst electrode provided on a side of the second substrate facing the first substrate;
An electrolyte filled in a cell space existing between the first substrate and the second substrate;
A current collecting conductor layer disposed in a state of being insulated from the catalyst electrode by the second substrate;
It is a granular material having a solder layer on at least a surface, and is arranged in a dot shape between the first base and the second base in a state of being insulated from the catalyst electrode, and the translucent conductive layer and the current collector A plurality of relay connectors that conduct between the conductor layers;
A resin protective part that individually surrounds the plurality of relay connection bodies and separates the solder layer from the electrolyte solution, and the plurality of relay connection bodies are formed by melting and solidifying the solder layer. A dye-sensitized solar cell, which is bonded to a layer.   2. The dye-sensitized solar cell according to claim 1, wherein the plurality of relay connection bodies have a structure in which a surface of a granular substrate is covered with the solder layer.   The dye-sensitized solar cell according to claim 2, wherein the granular substrate is spherical.   The dye-sensitized solar cell according to claim 2 or 3, wherein the granular substrate is a resin sphere.   5. The dye-sensitized solar cell according to claim 1, wherein the resin protection part is made of a resin having higher corrosion resistance to the electrolytic solution than the solder layer.   The resin protective part includes a resin coat layer made of a resin having higher corrosion resistance to the electrolytic solution than the solder layer, and a resin coat layer made of a resin having higher corrosion resistance to the electrolytic solution than the solder layer. 6. The dye-sensitized solar cell according to claim 1, wherein the dye-sensitized solar cell is formed of a resin ring that surrounds the resin.   The solder layers of the plurality of relay connection bodies are arranged so as to contact the current collecting conductor layer formed on the surface of a film material forming a part of the second base. The dye-sensitized solar cell according to any one of claims 1 to 6, characterized in that A method for producing the dye-sensitized solar cell according to any one of claims 1 to 7,
A translucent conductive layer forming step of forming a translucent conductive layer on the side of the first base facing the second base;
Forming a semiconductor electrode containing a sensitizing dye on the translucent conductive layer; and
The plurality of relay connection bodies are arranged in a dot shape on the light-transmitting conductive layer, and the solder layer is heated and melted by reflowing, whereby the plurality of relays are connected to the light-transmitting conductive layer. A method for producing a dye-sensitized solar cell, comprising: a fusion bonding step of bonding a connected body.   9. The dye-sensitized solar cell according to claim 8, wherein in the fusion bonding step, reflow is performed after temporarily fixing the plurality of relay connection bodies on the light-transmitting conductive layer using a flux. Production method.   After performing the fusion bonding step, a resin protective part is provided to individually surround the plurality of relay connecting bodies and separate the solder layer from the electrolytic solution, and then collect current so as to contact the solder layer The method for producing a dye-sensitized solar cell according to claim 8 or 9, wherein a conductor layer is provided. After performing the melt bonding step,
A protective part disposing step of individually providing a resin protective part for individually surrounding the plurality of relay connecting bodies and separating the solder layer from the electrolyte;
A first film material disposing step of laminating and disposing the first film material provided with the catalyst electrode on the first substrate;
A second film material having the current collecting conductor layer provided on the surface thereof is laminated and bonded on the first film material, and the second film material is brought into contact with the current collecting conductor layer. A method for producing a dye-sensitized solar cell according to claim 8 or 9, comprising a disposing step.

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