JP2007317454A - Dye-sensitized solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to secure an enough area where a semiconductor electrode can be formed on a glass plate, for a dye-sensitized solar cell made up by interposing electrolyte solution between a porous semiconductor electrode made to carry sensitizing dyes formed on a translucent conductive layer and a catalyst electrode as a counter electrode. <P>SOLUTION: An anode-side current-collecting electrode layer 91 is formed through an insulating layer 81 at a side of the catalyst electrode 61 opposite to a side facing the semiconductor electrode 31. The anode-side current-collecting electrode layer 91 and the translucent conductive layer 21 are electrically connected using a conductive adhesive 5 at a number of points separated from each other with intervals in plan view. Since the anode-side current-collecting electrode layer 91 is not extended as a line nor expanded as a plane on the glass plate 11 like a conventional one, an area for forming the semiconductor electrode 31 can be secured in a great scale. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dye-sensitized solar cell that converts light energy into electrical energy.

  In solar power generation, solar cells using single crystal silicon, polycrystalline silicon, amorphous silicon, and a combination of these with the use of HIT (Heterojunction with Intrinsic Thin Layer) or the like are widely put into practical use. Such silicon-based solar cells also have excellent photoelectric conversion efficiency, and recently some of them have reached nearly 20%. However, silicon-based solar cells have an energy cost for manufacturing the material. In addition to high costs, there are many issues in terms of environmental impact.

  In these circumstances, the dye-sensitized solar cell proposed by Gratzel et al. Has recently attracted attention as an inexpensive solar cell (for example, Patent Document 1 and Non-Patent Document 1). The basic structure of such a dye-sensitized solar cell is interposed between a porous semiconductor electrode (for example, a titania porous electrode) carrying a sensitizing dye, and a counter electrode as a counter electrode. The electrolyte solution (iodine solution) is simple and its structure is simple. In addition, since a silicon semiconductor is not used, the conversion efficiency is lower than that of a silicon-based solar cell, but many expectations are given as a low-cost solar cell.

  In such a dye-sensitized solar cell, normally, a collector electrode is provided on each of the semiconductor electrode and the catalyst electrode in order to efficiently collect current from the respective electrodes. The current collecting electrode connected to the semiconductor electrode is formed by printing or applying a silver paste in a linear or lattice shape on a light-transmitting substrate such as a glass plate on which the semiconductor electrode is formed, and baking it. It is normal (for example, patent document 2). In addition, it is also known to form a collecting electrode by forming and depositing a metal film by sputtering or vapor deposition instead of such baking.

By the way, an electrolytic solution used for a dye-sensitized solar cell (hereinafter also simply referred to as a solar cell) is extremely corrosive. For this reason, in the case where the collecting electrode is formed by baking a silver paste, it is necessary to prevent the collecting electrode from coming into contact with or being exposed to the electrolytic solution. Therefore, the surface of the current collecting electrode (layer) is usually covered (coated) with a corrosion-resistant resin to protect it.
Japanese Patent Laid-Open No. 1-220380 Nature magazine (Vol. 353, pp, 730-740, 1991) JP 2000-285777 A

  However, when a negative electrode side collecting electrode is formed in a lattice shape or the like on a translucent substrate (usually a glass plate) for forming a semiconductor electrode, and a resin layer is formed thereon so as to cover the negative electrode side collecting electrode. Therefore, the area of the translucent substrate in which the semiconductor electrode can be formed is reduced by the area of these formation surfaces. For this reason, in the conventional dye-sensitized solar cell, since the area which can form a semiconductor electrode cannot be ensured efficiently, there existed a problem of causing the fall of power generation efficiency.

  Therefore, instead of baking such a silver paste, a metal having high corrosion resistance to an electrolytic solution is formed as a metal wiring layer (film) on a light-transmitting substrate by sputtering or vapor deposition, and this is deposited thick to reduce the resistance. It is also conceivable to form a current collecting electrode. However, when a metal film is formed by sputtering or vapor deposition to form a current collecting electrode, even if a glass plate is used as the translucent substrate, it cannot be said that it has sufficient heat resistance. It is difficult to form a thick film. For this reason, even when the current collecting electrode is formed by a metal film by sputtering or the like, the formation area has to be increased in order to obtain a low resistance electrode. The area where the electrodes can be formed is reduced.

  The present invention has been made to solve these problems, and an object of the present invention is to make it possible to secure as large an area in which a semiconductor electrode can be formed on a light-transmitting substrate as much as possible, thereby increasing dye generation with high power generation efficiency. It is to provide a sensitive solar cell.

In order to achieve the above object, the present invention according to claim 1 is provided with a light-transmitting conductive layer having a semiconductor electrode carrying a sensitizing dye formed on one surface side of a light-transmitting substrate, In a dye-sensitized solar cell comprising a catalyst electrode facing the semiconductor electrode and forming a counter electrode, and an electrolyte solution interposed between the two electrodes,
On the opposite side of the catalyst electrode from the side facing the semiconductor electrode, a negative current collecting electrode layer is formed via an insulating layer,
The negative current collector electrode layer and the translucent conductive layer are electrically spaced from each other in a plan view and electrically insulated from the catalyst electrode by a conductive adhesive at a number of locations. It is characterized by being connected.

According to a second aspect of the present invention, a translucent conductive layer having a semiconductor electrode carrying a sensitizing dye formed on the surface thereof is provided on one surface side of the translucent substrate, and the counter electrode is opposed to the semiconductor electrode. In a dye-sensitized solar cell comprising a catalyst electrode that comprises: an electrolyte solution interposed between both electrodes,
On the opposite side of the catalyst electrode to the side facing the semiconductor electrode, a negative electrode side collector electrode layer is formed via an insulating layer. The negative electrode side collector electrode layer is spaced apart from each other in plan view. And through holes are provided in many places,
The negative electrode side collecting electrode layer and the translucent conductive layer are electrically connected to the catalyst electrode while being electrically insulated by a conductive adhesive at a plurality of through-hole portions, and An electrolyte leakage prevention layer that prevents the electrolyte from passing through the through hole and leaking outside is formed on the negative electrode side collector electrode layer on the side opposite to the catalyst electrode formation surface. It is characterized by.

  The present invention according to claim 3 is the dye-sensitized solar cell according to claim 2, wherein the electrolyte leakage prevention layer is made of a metal plate or a glass plate. The present invention according to claim 4 is characterized in that a positive collector electrode layer electrically connected to the catalyst electrode is formed between the catalyst electrode and the insulating layer. It is a dye-sensitized solar cell of Claim 1, 2, or 3.

  In the present invention, the negative electrode side collecting electrode layer and the translucent conductive layer are electrically insulated from the catalyst electrode by a conductive adhesive at a number of locations in a plan view, spaced apart from each other. It has a structure that is held and electrically connected. That is, in the present invention, the negative electrode side collecting electrode layer does not extend in the form of a line or a line in the form of a line or a lattice on the surface of the translucent substrate as in the prior art. Therefore, in the present invention, compared to the conventional dye-sensitized solar cell, the formation area of the negative electrode side collecting electrode layer in the translucent substrate can be greatly reduced, so that the semiconductor electrode that can be formed on the translucent substrate Since a large formation area can be secured, power generation efficiency can be increased.

  Moreover, the following remarkable effects are also obtained in the present invention. That is, when the negative electrode side collector electrode layer is formed of a metal plate (metal foil or metal film), the metal plate does not allow the electrolyte solution to pass through. Leakage to the outside can be effectively prevented, and entry of foreign matter such as moisture into the battery from the outside is effectively prevented. That is, compared to the resin plate, the metal plate can prevent the electrolyte solution from penetrating, so that the electrolyte solution can be prevented from leaking to the outside, so that the durability as a solar cell is enhanced.

  In the present invention described in claim 2, the same effect as that of the present invention described in claim 1 can be obtained. In any of the above-described dye-sensitized solar cells of the present invention, since both electrodes are filled with an electrolyte solution, the gap between the electrodes is sealed between the electrodes. The space between both electrodes is sealed by interposing an adhesive for sealing (for sealing). In this case, in the first aspect, when an adhesive is used for the sealing, both electrodes face the translucent substrate on which the semiconductor electrode is formed and the counter electrode side substrate on which the catalyst electrode is formed. In this way, they are superposed, pressure-bonded, and bonded. In this bonding, the conductive adhesive is bonded and cured simultaneously with the sealing adhesive. On the other hand, in the invention of claim 2, the conductive adhesive is bonded from the through-hole of the negative current collecting electrode layer after adhering the periphery with a sealing adhesive, It is also possible to form an electrolyte leakage prevention layer. In other words, in the invention of claim 2, from the structure, after sealing both electrodes with a surrounding sealing adhesive, a conductive adhesive is used in a separate step, and the negative electrode side collector electrode layer and the transparent electrode layer are transparent. Since it can maintain electrical continuity with the photoconductive layer, it is possible to adopt and use sealing adhesives and conductive adhesives with different adhesive conditions such as thermosetting conditions. The selectivity of can be expanded.

  The electrolyte solution leakage preventing layer in claim 2 is exemplified by a metal plate or a glass plate as described in claim 3, but it is only necessary to prevent the leakage, and is not limited thereto. Further, as in the invention described in claim 4, in the case where the positive electrode side collector electrode layer electrically connected to the catalyst electrode is formed between the catalyst electrode and the insulating layer, the catalyst Even if the electrode is thin, the positive electrode side collecting electrode layer can reduce the resistance of the circuit in the battery.

  The best mode for carrying out the present invention will be described in detail with reference to FIGS. FIG. 1 is a longitudinal sectional view schematically (schematically) showing a dye-sensitized solar cell 1 having a single cell structure embodied as the present embodiment. FIG. 2 is an exploded longitudinal sectional view for explanation prior to assembly by laminating and crimping them, and FIG. 3 is a plan view seen from the semiconductor electrode 31 side in FIG. FIG. 5 is a plan view (viewed from an arrow B) viewed from the catalyst electrode 61 side in FIG. 2, and FIG. 5 is an exploded longitudinal sectional view for explaining the laminated body forming the catalyst electrode 61 side in FIG. 2.

  The solar cell 1 of this example has a constant thickness (for example, 5 mm) as a whole and is formed in a plate shape that exhibits a square shape in plan view (see FIGS. 3 and 4). And as a translucent board | substrate, the square (for example, square) and the glass plate (plate glass) 11 of fixed thickness are used, The translucency is substantially on the whole surface (the lower surface of FIG. 1, FIG. 2). As the light-transmitting conductive layer 21 having conductivity, a thin film made of a conductive oxide (for example, tin oxide, fluorine-doped tin (FTO), indium oxide, tin-doped indium, etc.) has a predetermined thickness (for example, 200 nm). ).

On the surface of the translucent conductive layer 21 (the lower surface in FIGS. 1 and 2), a porous semiconductor electrode 31 carrying a sensitizing dye is formed as a layer on a substantially entire surface with a constant thickness (for example, 30 μm). ing. However, the semiconductor electrode 31 has a large number of openings (for example, a circular opening having a diameter of 3.0 mm, see FIG. 3) at predetermined intervals (pitch) P (for example, 10.0 mm) in the vertical and horizontal directions (a grid pattern). 33 is provided. That is, there is a portion (opening 33) where the semiconductor electrode 31 is not formed on the surface of the translucent conductive layer 21, and the translucent conductive layer 21 formed on the glass plate 11 is transmitted through the opening 33. A large number of photoconductive layer portions 23 (circular portions of the openings) are exposed. As shown in FIG. 3, when the glass plate 11 is viewed from the surface on which the semiconductor electrode 31 is formed, the translucent conductive layer. Many parts 23 are provided in groups (see FIG. 3). In FIG. 3, nine openings 33 are shown, but this number may be hundreds, thousands, or tens of thousands depending on the size of the glass plate 11. Further, the semiconductor electrode 31 is not provided for a predetermined width along the periphery (side) of the glass plate 11, and a laminated body (substrate) including the catalyst electrode 61 described below is bonded to the portion. A bonding margin (bonding margin) for bonding with the agent 41 is provided. In this embodiment, the semiconductor electrode 31 loaded with a sensitizing dye is composed of, for example, a porous electrode base made of titania (TiO ₂ ) and a sensitizing dye attached to the inside and the surface of the porous electrode base. ing.

  On the other hand, the catalyst electrode 61 constituting the counter electrode constituting the dye-sensitized solar cell 1 is made of Pt (platinum), and is formed on the surface of the metal thin plate (metal foil or metal film) 71 (upper surface in FIG. 1), for example. A layer having a predetermined thickness (for example, 200 nm) is formed by sputtering. In this embodiment, the thin metal plate 71 is formed to form a positive current collecting electrode layer (hereinafter also referred to as a positive current collecting electrode layer 71). However, the positive-side current collecting electrode layer 71 is made of a thin metal plate (thickness: 200 μm) such as titanium or stainless steel (SUS), and has a constant thickness (for example, 50 μm) as an electrically insulating insulating layer 81. In this embodiment, an adhesive layer (hereinafter referred to as an insulating layer 81) made of a resin (for example, an epoxy resin or an ionomer resin) is bonded to the upper surface of FIG. The positive electrode side collecting electrode layer 71 has the same size and shape as the glass plate 11, but is formed on one side (left side in FIG. 1) so as to protrude outward. The electrode terminal 75 is provided. In this specification, when simply referred to as “adhesive” or “resin”, these are electrically insulating (non-conductive).

  The catalyst electrode 61 formed on the surface (upper surface in FIG. 1) of the positive electrode side collecting electrode layer 71 has the same arrangement, the same planar shape and the same as the formation surface of the semiconductor electrode 31 formed on the glass plate 11 described above. It is formed as a layer with the same area or a larger area. The catalyst electrode 61 is disposed so as to hold a predetermined gap (space) K so as to face the semiconductor electrode 31, and is bonded to a portion near the outer peripheral edge of the glass plate 11 with an adhesive 41. The inside of the battery between the electrodes 31 and 61 is kept sealed by the surrounding adhesive 41, and the inside (inside the space) is filled with the electrolyte solution Y (not shown). In addition to the electrolyte, the electrolyte solution Y contains a solvent such as propylene carbonate, an additive, and the like. And as electrolyte, what is necessary is just to select suitably from what is used as electrolyte of the conventional solar cell, and to use.

  On the other hand, on the opposite side of the insulating layer 81 from the surface on which the catalyst electrode 61 is formed, a metal layer that forms the negative current collecting electrode layer 91 is bonded in a laminated state. The negative electrode side collecting electrode layer 91 is a thin metal plate (metal foil or metal film) having the same thickness (200 μm) and made of the same material as the positive electrode side collecting electrode layer 71, and the same outer surface as the glass plate 11. It has a shape and size. However, a negative electrode terminal 95 formed so as to protrude outward is provided on one side (the right side in FIG. 1) of the negative collector electrode layer 91. Further, on the side opposite to the surface on which the catalyst electrode 61 is formed (the lower surface in FIG. 1) in the negative current collecting electrode layer 91, a constant thickness (50 μm) is provided so as to cover the entire surface of the negative current collecting electrode layer 91. A resin layer (for example, ionomer resin) 101 is adhered in a laminated state, and forms a protective film (skin material) for the negative-side current collecting electrode layer 91. Of the layers from the catalyst electrode 61 to the insulating layer 81, the portion corresponding to the translucent conductive layer portion 23 in the plan view has the same size and shape as the opening 3 as shown in FIG. A large number of negative electrode side collector electrode layers 91 are exposed as negative electrode side collector electrode layer portions 93 (circular portions of the openings 3). In addition, the catalyst electrode 61 side which makes such a counter electrode is the one in which the catalyst electrode 61 is formed on the surface of the metal thin plate with the opening 3 forming the positive electrode side collector electrode layer 71 and the negative electrode side collector electrode on the resin layer 101. It is formed by adhering a laminated material in which metal thin plates (metal foil or metal film) forming the layer 91 are laminated via an insulating layer 81.

  Thus, a large number of light-transmitting conductive layer portions 23 provided at intervals P between the negative-electrode side collecting electrode layer 91 and the light-transmitting conductive layer 21 in a plan view correspond to these. For example, the conductive electrode 5 is electrically connected to the negative electrode side collecting electrode layer portion 93 so as to be electrically insulated from the catalyst electrode 61 by the conductive adhesive 5 arranged in a columnar shape with a circular cross section. (See FIG. 1). In other words, in the present embodiment, the conductive adhesive 5 is applied to a large number of the light-transmitting conductive layer portions 23 (see FIG. 3) and the negative-side current collecting electrode layer portion 93 (see FIG. 3) arranged to face them. As the interconnector, the negative current collecting electrode layer 91 and the translucent conductive layer 21 are electrically connected at a number of locations. The conductive adhesive 5 is disposed so as to be maintained at a central position in each opening 3 so as to be maintained at a distance from the inner wall surface so that electrical insulation from the catalyst electrode 61 is maintained. Yes. Further, as shown in FIG. 1, each conductive adhesive 5 is set to a height at which a predetermined gap K is held between the electrodes 31 and 61 when the solar battery 1 is formed.

  In this embodiment, as shown in FIG. 2, a laminate (lower laminate in FIG. 2) 200 including each layer from the catalyst electrode 61 to the resin layer 101 forming the counter electrode, and a glass plate on which the semiconductor electrode 31 is formed. 11 is bonded to the outer peripheral edge via an adhesive 41, but before the laminated body 200 itself on the catalyst electrode 61 side is bonded to the glass plate 11, It is in the form of a flexible (or soft) sheet.

  The solar cell 1 of this embodiment is configured such that a wire is connected between the electrode terminals 75 and 95 for taking out the wiring formed to protrude from each side portion of the positive electrode side collecting electrode layer 71 and the negative electrode side collecting electrode layer 91. Are connected to each other to form an electric circuit, and light is irradiated from the translucent conductive layer 21 side (upper side in FIG. 1) to form a dye-sensitized solar cell that forms an electric circuit between the electrodes 31 and 61. However, there are the following actions or effects.

  That is, in the dye-sensitized solar cell 1 of the present embodiment, the light-transmitting conductive layer portion 23 in the light-transmitting conductive layer 21 formed on the glass plate 11 and the side facing the semiconductor electrode 31 are formed. In addition, a large number of negative electrode-side collecting electrode layer portions 93 in the negative electrode-side collecting electrode layer 91 are electrically connected with the conductive adhesive 5 as an interconnector at a number of locations between the layers. That is, it does not extend as a line or spread along the surface of the glass plate, like a conventional negative electrode current collecting electrode layer formed in a linear or lattice shape along the surface of the glass plate, When the glass plate 11 is viewed in plan, the conductive adhesive 5 arranged in a number of scattered points forms an interconnector, penetrates each layer in the thickness direction, and the transparent conductive layer 21 and the negative electrode side collector. The electrode layer 91 is connected. For this reason, the formation area does not become large along the surface of a glass plate like the conventional negative electrode side collector electrode. That is, in this example, when the glass plate 11 is viewed in plan, the area of the opening 33 from which the translucent conductive layer 21 is exposed only causes a reduction in the formation area of the semiconductor electrode 31 in the glass plate 11. The formation area of the semiconductor electrode 31 can be ensured without greatly deteriorating. Therefore, a solar cell with high current collection efficiency can be obtained accordingly.

  In this embodiment, the negative electrode side collecting electrode layer 91 forming the counter electrode side substrate is formed of a metal plate (metal foil or metal film) made of titanium or stainless steel corresponding to the glass plate 11. Therefore, it is possible to prevent the electrolyte Y from leaking to the outside through the substrate on the counter electrode side, and to effectively prevent entry of foreign matters such as moisture from the outside into the battery. Durability as a solar cell is enhanced. In addition, in this embodiment, since the laminate 200 itself on the side of the catalyst electrode 61 forming the counter electrode is flexible, the glass plate 11 on which the semiconductor electrode 31 is formed can be embodied as a curved solar cell. That is, a conductive adhesive is interposed between the translucent conductive layer portion 23 in the translucent conductive layer 21 in the glass plate 11 and the negative collector electrode portion 93 in the negative collector electrode layer 91. Then, by adhering the laminated body 200 so as to conform to the surface of the glass plate, even if the glass plate on which the semiconductor electrode is formed is a curved surface, it can be easily embodied as a solar cell.

  Further, in the present embodiment, since no special processing such as providing a through hole is provided in the metal plate forming the negative current collecting electrode layer 91, it is not necessary to reduce the thickness of the metal plate in consideration of workability. Therefore, the negative current collecting electrode layer 91 can be set to a sufficient thickness that does not increase the electrical resistance. In addition, this negative electrode side collector electrode layer 91 is not limited to one metal layer (metal foil or metal film), but may have a laminated structure including a plurality of layers. Furthermore, in this embodiment, since the positive electrode side collecting electrode layer 71 is provided in addition to the catalyst electrode 61, a circuit with low resistance can be obtained even if the thickness of the catalyst electrode 61 itself is thin. However, if the catalyst electrode 61 itself has a sufficient thickness (1.0 μm or more), the catalyst electrode 61 may be used as the positive electrode side collector electrode. Therefore, in this case, the catalyst electrode 61 may be the insulating layer 81. You may form directly on.

  In addition, as described above, the solar cell 1 according to the present embodiment includes the glass plate 11 on which the above-described laminated body 200 including the catalyst electrode 61 serving as the counter electrode and the semiconductor electrode 31 supporting the sensitizing dye are formed. Are separately manufactured, and an appropriate amount of conductive adhesive is printed or applied to each of the translucent conductive layer portions 23 and the respective negative electrode side collecting electrode portions 93, so that the electrodes 31 and 61 face each other. Thus, it is manufactured by injecting the electrolyte solution Y between the electrodes 31 and 61 by bonding at the periphery. The laminate 200 forming the counter electrode is manufactured as described above, but the glass plate 11 side on which the semiconductor electrode 31 supporting the sensitizing dye is formed may be manufactured as follows. .

  That is, the manufacturing process on the glass plate 11 side for forming the semiconductor electrode 31 carrying the sensitizing dye is as follows. A translucent conductive layer 21 is formed on the entire surface of the glass plate 11 (the lower surface in FIG. 2) by sputtering or the like. Thereafter, as shown in FIG. 3, the transparent conductive layer portion 23 is porous on the transparent conductive layer 21 so that the transparent conductive layer portions 23 are exposed by opening 33 in a predetermined shape with a predetermined interval P therebetween. A quality semiconductor electrode substrate (titania) is formed. The porous semiconductor electrode substrate may be formed by printing a commercially available titania paste on the light-transmitting conductive layer 21 in the above-described planar shape and then firing it under known conditions. For example, the thus formed semiconductor electrode substrate is immersed in a solution in which a sensitizing dye (complex dye, organic dye) is dissolved in an organic solvent together with the glass plate 11, and the solution is impregnated in the porous body. Thereafter, the organic solvent is removed to attach the sensitizing dye into the pores.

  Next, an appropriate amount of each of the translucent conductive layer portion 23 and each negative electrode side collecting electrode portion 93 in the glass plate 11 with the semiconductor electrode 31 formed in this way and the laminated body 200 forming the counter electrode is provided. The conductive adhesive 5 is printed or applied, and an adhesive 41 for sealing the electrolytic solution Y is printed (or applied) around the opposing surface (facing surface), respectively, and each electrode 31, Position so that 61 opposes, and both are overlapped and pressure-bonded. In this way, the inside is sealed and adhered with the surrounding adhesive 41, and a large number of the translucent conductive layer portions 23 and the negative-side current collecting electrode portions 93 are adhered with the conductive adhesive 5. In addition, about the conductive adhesive 5, you may print only in any one of the translucent conductive layer part 23 and each negative electrode side current collection electrode part 93 which oppose, but in any case, it is appropriate. The thickness or amount of the conductive adhesive to be printed is set so that a predetermined gap K is maintained between the electrodes 31 and 61 after being pressed and bonded with an appropriate surface pressure. In addition, about the adhesive agent 41, the thickness, the width | variety, etc. are set so that electrolyte solution may not leak from the circumference after adhesion | attachment.

  When a thermosetting adhesive is used for the conductive adhesive 5 and the surrounding sealing adhesive 41, the adhesive portion is heated by irradiating laser light from the glass plate 11 side. What is necessary is just to harden. Then, for example, a required electrolyte solution Y is injected from a through hole (not shown) that is provided at an appropriate position of the surrounding sealing adhesive (layer) 41 and communicates with the gap K between the electrodes 31 and 61. The dye-sensitized solar cell (single cell) 1 of this embodiment can be obtained by filling and filling the through-holes after the filling.

  Note that the periphery of the conductive adhesive connecting the negative-electrode side collecting electrode layer and the translucent conductive layer at a number of locations is directly exposed to the electrolytic solution interposed between the two electrodes in the above embodiment. It will be. However, the periphery of the conductive adhesive is made of a coating layer (for example, resin, glass, oxide, or ceramic) that is resistant to the electrolyte so that it is not directly exposed to the electrolyte. It is better to coat with a coating layer or coating film). This is because the conductive adhesive does not directly touch the electrolytic solution, so that a decrease in electrical performance due to the corrosion of the conductive adhesive by the electrolytic solution is prevented. That is, the conductive adhesive is easily corroded when it is exposed (touched) to the electrolytic solution. By doing so, the conductive adhesive is coated with a coating layer that is resistant to the electrolytic solution. This problem can be solved. Furthermore, if it does in this way, since it can select and use a conductive adhesive, without having to consider the corrosion resistance with respect to electrolyte solution, the selection range can be expanded. In addition, since the conductive adhesive is not exposed to the electrolytic solution, it is possible to prevent reverse electron transfer from the conductive adhesive toward the electrolytic solution, thereby contributing to prevention of reduction in power generation efficiency.

  Now, another embodiment (second example) of the present invention will be described with reference to FIGS. However, since this form should be said to be a modification or improvement of the above-described form, the difference will be mainly described, and the same portions are only given the same reference numerals. That is, in the above-described form, the resin layer 101 formed on the negative electrode side collecting electrode layer 91 on the side opposite to the surface on which the catalyst electrode 61 is formed (the lower side in FIG. 1) forms a protective film (skin material). On the other hand, in the present embodiment, a through hole (circular opening) 94 penetrating in the interlayer direction is provided at the central portion of each negative electrode side collecting electrode layer portion 93 in the negative electrode side collecting electrode layer 91. The translucent conductive layer portion 23 and the negative electrode side collecting electrode layer portion 93 are electrically connected by the conductive adhesive 5 at the portions of the numerous through holes 94. The conductive adhesive 5 is electrically insulated from the catalyst electrode 61. In this embodiment, a metal thin plate (thickness: 500 μm) made of the same material as that of the negative current collector electrode layer 91 with the resin layer 101 as an adhesive layer on the side opposite to the formation side of the catalyst electrode 61 in the negative current collector electrode layer 91. The electrolyte leakage prevention layer 111 made of (1) is adhered in a laminated manner to seal the through hole 94 and the conductive adhesive 5 filled therein. That is, the electrolyte leakage prevention layer 111 forms a protective film covering the entire surface of the resin layer 101, and the electrolyte Y filled between the electrodes 31 and 61 passes through the through hole 94 and leaks to the outside. Is prevented.

  In the solar cell 2 of this embodiment, the same effect as that of the solar cell 1 of the above-described embodiment can be obtained. The electrolyte leakage prevention layer 111 forms a shielding film that prevents leakage of the electrolyte Y and entry of foreign matter from the outside. In this embodiment, in addition to such effects, the following specific effects can also be obtained. That is, in this embodiment, since the through-hole 94 is provided in each negative electrode side collecting electrode layer portion 93 in the negative electrode side collecting electrode layer 91, the solar cell 2 can be manufactured as follows. As shown in FIG. 7A, the positive-side collector electrode layer 71 and the catalyst electrode 61 are formed on the negative-side collector electrode layer 91 with the through-hole 94 via the insulating layer 81 as a counter electrode. Then, in this state, the work piece shown in FIG. 7B is obtained by bonding to the substrate on the glass plate 11 side including the semiconductor electrode 31 with the surrounding adhesive 41. At that stage (see FIG. 7B), the conductive adhesive 5 is filled into the through-hole 94 in the negative current collector electrode layer 91 from the outside (the lower side of FIG. 7-B), thereby transmitting the light. The conductive conductive layer portion 23 and the negative electrode side collecting electrode layer portion 93 are bonded and electrically connected (see FIG. 7C). Thereafter, as shown by a two-dot chain line in FIG. 7-C, an electrolyte leakage prevention layer 111 is laminated via the resin layer 101, and the electrolyte solution is contained in the interior in the same manner as in the production of the solar cell 1 described above. The solar cell 2 shown in FIG. 6 can be obtained.

  Thus, in this embodiment, the conductive adhesive 5 can be bonded to the surrounding adhesive 41 in a separate process. That is, in this embodiment, the electrodes 31 and 61 are sealed by bonding with the surrounding sealing adhesive 41, and then the negative-electrode side collecting electrode layer 91 and the light-transmitting conductive layer are sealed with the conductive adhesive 5. Therefore, the sealing adhesive 41 and the conductive adhesive 5 can be adopted and used with different adhesive conditions such as thermosetting conditions, so that the restrictions on the manufacturing process can be reduced. The conductive adhesive 5 can also be cured by heating, for example, by irradiating laser light from the outside of the glass plate 11. 7C, when the electrolyte leakage prevention layer 111 is laminated via the resin layer 101, the filled conductive adhesive 5 is compressed in the interlayer direction. It is good to make it.

  In this embodiment, the electrolyte leakage prevention layer 111 is made of a thin metal plate made of the same material as the negative current collecting electrode layer 91. However, for this, the electrolyte passes through a metal plate or glass plate made of other materials. What is necessary is just to form with the material which does not. Also in this embodiment, if the catalyst electrode 61 has a sufficient thickness (1.0 μm or more) in itself, the catalyst electrode 61 may be used as the positive electrode side current collecting electrode. 61 may be formed directly on the insulating layer 81.

  As for the conductive adhesive used in the solar cell of the present invention, the resin forming the base material is preferably a thermosetting resin or a photo-curing resin. This is because, as described above, it can be cured by irradiating a laser beam or the like through a light-transmitting substrate in the same manner as in the adhesion of the surrounding sealing adhesive. In addition, since the solar cell according to the present invention includes lamination and pressure bonding steps in its production, the conductive adhesive is improved in conductivity by being pressurized in order to increase the conductivity or its reliability. A conductive adhesive (pressurized conductive adhesive) may be used.

  In this invention, when setting it as a grid | lattice-like arrangement | positioning as above-mentioned, the space | interval (pitch) P which provides a conductive adhesive can illustrate setting in the range of 5.0-10.0 mm respectively in length and width. . In addition, these cross-sectional shapes (planar shapes) are usually circles, but can be embodied as any shape. However, the diameter or area of the cross section thereof may be appropriately set in consideration of the material (conduction resistance) and thickness.

  In addition, as a translucent board | substrate which makes the dye-sensitized solar cell of this invention, although you may form with a transparent resin board or a resin sheet (film) other than a glass plate, translucency (visible light transmission) is possible as much as possible. It is preferable to use one having a high rate) (at least 10% or more). Moreover, as above-mentioned as a translucent conductive layer, although tin oxide etc. are illustrated, it is preferable to make the film thickness into the range of 1 nm-100 nm. In addition to titanium oxide, zinc oxide, tantalum oxide, or the like can be used for the semiconductor electrode, and the film thickness is 5.0 to 30.0 μm, preferably 10.0 to 20.0 μm.

  On the other hand, the metal (metal film) used as the catalyst electrode (counter electrode) is preferably platinum, but known materials such as activated carbon and conductive polymer can be used as the counter electrode of the conventional solar cell. Incidentally, the film thickness is 1 nm to 1 μm, preferably 100 nm to 500 nm. Further, the thickness of the electrolyte interposed between both the semiconductor electrode and the catalyst electrode is 200 μm or less, preferably 50 μm or less.

  In the above-described embodiment, the laminate including each layer formed on the side opposite to the side facing the semiconductor electrode from the catalyst electrode is flexible (or flexible). It can be embodied even if there is no. In the case where the collector electrode layer and the insulating resin layer are directly laminated (bonded), a resin (sheet or substrate) obtained by laminating a thin metal plate (metal foil) on one side may be used. That is, a sheet material such as a laminate material in which a metal layer (metal foil) is formed on an insulating resin layer (insulating resin film) may be used.

  The present invention is not limited to the above-described contents, and can be embodied with appropriate modifications within a range not departing from the gist thereof. In the above description, the solar cell has been described as a single cell structure. Of course, the solar cell can be embodied as a solar cell module in which a large number of solar cells are connected in series or in parallel, or a necessary exterior is provided. .

The longitudinal cross-sectional view which showed the dye-sensitized solar cell of this invention typically (schematically), and the principal part enlarged view. FIG. 2 is an exploded longitudinal sectional view for explanation before the dye-sensitized solar cell of FIG. 1 is laminated and pressed and assembled. The top view seen from the semiconductor electrode side of FIG. 2 (figure seen from arrow A). The top view seen from the catalyst electrode side of FIG. 2 (figure seen from arrow B). The exploded longitudinal cross-sectional view for description of the laminated body which makes the catalyst electrode side of FIG. The longitudinal cross-sectional view which showed the other example of the dye-sensitized solar cell of this invention typically (schematically), and its principal part enlarged view. The longitudinal cross-sectional view explaining the process of laminating | stacking and pressure-bonding and assembling the dye-sensitized solar cell of FIG.

Explanation of symbols

1, 2 Dye-sensitized solar cell 5 Conductive adhesive 11 Glass plate (translucent substrate)
21 translucent conductive layer 31 semiconductor electrode 61 catalyst electrode 71 positive electrode side current collecting electrode layer 73 first positive electrode side current collecting convex portion 75 tip 81 of first positive electrode side current collecting convex portion 81 insulating layer 91 negative electrode side current collecting Electrode electrode layer 93 Negative electrode side collector electrode layer part 94 Negative electrode side collector electrode layer through-hole 101 Resin layer 111 Electrolyte leakage prevention layer P Spacing between exposed transparent conductive layer parts Y Electrolyte solution K Void

Claims (4)

On one surface side of the translucent substrate, a translucent conductive layer having a semiconductor electrode carrying a sensitizing dye formed on the surface thereof is provided, while a catalyst electrode which is opposed to the semiconductor electrode and forms a counter electrode is provided. In a dye-sensitized solar cell in which an electrolyte is interposed between,
On the opposite side of the catalyst electrode from the side facing the semiconductor electrode, a negative current collecting electrode layer is formed via an insulating layer,
The negative current collector electrode layer and the translucent conductive layer are electrically spaced from each other in a plan view and electrically insulated from the catalyst electrode by a conductive adhesive at a number of locations. A dye-sensitized solar cell, characterized by being connected to each other. On one surface side of the translucent substrate, a translucent conductive layer having a semiconductor electrode carrying a sensitizing dye formed on the surface thereof is provided, while a catalyst electrode which is opposed to the semiconductor electrode and forms a counter electrode is provided. In a dye-sensitized solar cell in which an electrolyte is interposed between,
On the opposite side of the catalyst electrode to the side facing the semiconductor electrode, a negative electrode side collector electrode layer is formed via an insulating layer. The negative electrode side collector electrode layer is spaced apart from each other in plan view. And through holes are provided in many places,
The negative electrode side collecting electrode layer and the translucent conductive layer are electrically connected to the catalyst electrode while being electrically insulated by a conductive adhesive at a plurality of through-hole portions, and An electrolyte leakage prevention layer that prevents the electrolyte from passing through the through hole and leaking outside is formed on the negative electrode side collector electrode layer on the side opposite to the catalyst electrode formation surface. A dye-sensitized solar cell characterized by comprising:   The dye-sensitized solar cell according to claim 2, wherein the electrolyte leakage prevention layer is made of a metal plate or a glass plate.   4. The dye sensitizing dye according to claim 1, wherein a positive electrode side collector electrode layer electrically connected to the catalyst electrode is formed between the catalyst electrode and the insulating layer. 5. Sensitive solar cell.

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