JP2010198834A - Method for manufacturing photoelectric conversion element module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily manufacturing a photoelectric conversion element module, in which photoelectric conversion elements each having an electrode using titanium are connected. <P>SOLUTION: The method for manufacturing the photoelectric conversion element 200 includes a photoelectric conversion element-preparing step of preparing a plurality of photoelectric conversion elements 100 each including a first electrode 10 having a metal plate 4 comprising titanium or a titanium alloy and a second electrode 20 facing the first electrode 10, and a connecting step of connecting the first electrode 10 of at least one photoelectric conversion element 100 and the second electrode 20 of at least one other photoelectric conversion element 100 with high melting point solder 9. In the connection step, the high melting point solder 9 is heat-melted and connected to the metal plate 4 of the first electrode 10 by applying ultrasonic waves. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a photoelectric conversion element module.

  The dye-sensitized solar cell was developed by Gretzell et al. In Switzerland and has the advantages of high photoelectric conversion efficiency and low manufacturing cost, and is attracting attention as a new type of solar cell.

  The schematic structure of the dye-sensitized solar cell is as follows: a working electrode in which a porous oxide semiconductor layer carrying a photosensitizing dye is provided on a transparent substrate provided with a transparent conductive film; The electrolyte containing the redox pair is surrounded and filled with a sealing material between the working electrode and the counter electrode.

  In this type of dye-sensitized solar cell, electrons generated by a photosensitizing dye that absorbs incident light such as sunlight are injected into the oxide semiconductor fine particles, and an electromotive force is generated between the working electrode and the counter electrode. It functions as a photoelectric conversion element that converts light energy into electric power.

As an electrolyte, it is common to use an electrolytic solution in which a redox ^couple such as I ⁻ / I ³⁻ is dissolved in an organic solvent such as acetonitrile. In addition, a configuration using a non-volatile ionic liquid, a liquid There are known a structure in which the electrolyte is gelled with an appropriate gelling agent to make it pseudo-solid, a structure using a solid semiconductor such as a p-type semiconductor, and the like.

  The counter electrode needs to be made of a material that can prevent corrosion due to a chemical reaction with the electrolyte. As such a material, a titanium substrate formed of platinum, a glass electrode substrate formed of platinum, or the like can be used.

  However, a glass electrode substrate on which platinum is formed has a problem that the thickness of the photoelectric conversion element is increased because the glass must have a certain thickness or more in order to ensure the strength of the glass. For this reason, there exists a request | requirement of forming a counter electrode with the titanium substrate which can maintain intensity | strength even if thin. However, since a titanium substrate has an oxide film formed on the surface of titanium, it is difficult to connect a conductive member such as a lead wire to the titanium substrate. Therefore, it is difficult to configure a photoelectric conversion element module by connecting the photoelectric conversion elements using a titanium substrate to such a counter electrode with a conductive member.

  Therefore, in the following Patent Document 1, in order to connect the conductive member on the surface opposite to the working electrode side of the counter electrode, a dissimilar metal (Cu) that can be easily soldered is formed on the surface of the electrode constituted by the titanium substrate. Etc.) has been proposed (see Patent Document 1).

JP 2007-280849 A

  However, in the photoelectric conversion element described in Patent Document 1, it is necessary to use a vacuum apparatus or the like in order to form the film made of the different metal by a sputtering method or the like. Accordingly, there is a problem that it is not easy to form a film, and it is not easy to manufacture a photoelectric conversion element in which a conductive member can be connected to a counter electrode using a titanium substrate. Therefore, the photoelectric conversion element module using a plurality of photoelectric conversion elements described in Patent Document 1 has a problem that it is difficult to manufacture. Moreover, there was room for further improvement in the force for joining the film and the titanium substrate.

  Therefore, the present invention has been made in view of the above circumstances, and can easily manufacture a photoelectric conversion element module in which photoelectric conversion elements having electrodes using titanium are firmly connected to each other. It aims at providing the manufacturing method of a module, and the photoelectric conversion element module manufactured by it.

  The method for producing a photoelectric conversion element module according to the present invention includes a photoelectric conversion element including a plurality of photoelectric conversion elements each including a first electrode having a metal plate made of titanium or an alloy containing titanium, and a second electrode facing the first electrode. A conversion element preparation step, a connection step of connecting a first electrode of at least one photoelectric conversion element and a second electrode of at least one other photoelectric conversion element with a high melting point solder, The high melting point solder is heated and melted and is applied with an ultrasonic wave to be connected to the metal plate of the first electrode.

  According to such a method for manufacturing a photoelectric conversion element module, a plurality of photoelectric conversion elements are prepared, and a first electrode of at least one photoelectric conversion element and a second electrode of at least one other photoelectric conversion element are provided. It is set as a photoelectric conversion element module by connecting. The first electrode of this photoelectric conversion element has a metal plate made of titanium or an alloy containing titanium, and a high melting point solder is used for connection between the first electrode and the second electrode. At the time of connection, since the high melting point solder is heated and melted and ultrasonic waves are applied, the wettability of the first electrode to the metal plate is improved. Therefore, the high melting point solder can be firmly connected to the metal plate made of titanium or an alloy containing titanium easily. Thus, a photoelectric conversion element module including a plurality of photoelectric conversion elements using titanium for the first electrode of the photoelectric conversion element can be easily manufactured without using a vacuum apparatus or the like.

  Furthermore, in the method for manufacturing a photoelectric conversion element module, it is preferable that the connection between the first electrode and the high melting point solder and the connection between the second electrode and the high melting point solder are performed simultaneously.

  By setting it as such a manufacturing method, the man-hour required for the connection of the photoelectric conversion elements in manufacture of a photoelectric conversion element module reduces, and a photoelectric conversion element module can be manufactured more easily.

  Moreover, in the manufacturing method of a photoelectric conversion element module, each said photoelectric conversion element encloses and seals a porous oxide semiconductor layer and an electrolyte between the 1st electrode and the 2nd electrode. And on the surface of the second electrode on the first electrode side, a current collector wiring made of metal and provided from the region surrounded by the outer periphery of the sealing material to the outside of the outer periphery of the sealing material; The refractory solder at a position overlapping the current collector wiring in a region surrounded by the outer periphery of the sealing material when the first electrode is viewed along a direction perpendicular to the surface of the first electrode. It is preferable to be connected to the first electrode.

  According to such a method of manufacturing a photoelectric conversion element module, the surface of the second electrode on the first electrode side is provided from a region surrounded by the outer periphery of the sealing material to a region outside the outer periphery of the sealing material. Provide current collector wiring. Since the current collector wiring is made of metal, it has excellent thermal conductivity. Further, when the first electrode is viewed from a direction perpendicular to the surface of the first electrode, the high melting point solder is connected to the first electrode at a position overlapping the current collecting wiring in the region surrounded by the outer periphery of the sealing material. Connected. Therefore, the position where the high melting point solder is connected to the first electrode is close to the position of the current collector wiring, and when the high melting point solder is connected to the first electrode, it is conducted to the inside of the outer periphery of the sealing material via the first electrode. The heat to be transmitted is easily conducted to the current collector wiring. The heat conducted to the current collector wiring is released to the outside of the outer periphery of the sealing material by the excellent heat conduction of the current collector wiring. In this way, it is possible to suppress deterioration of the photosensitizing dye and electrolyte carried on the porous oxide semiconductor layer due to heat conducted through the first electrode when the high melting point solder is connected to the first electrode. it can.

  In the method for manufacturing a photoelectric conversion element module, the high melting point solder may be connected to a terminal provided on the second electrode.

  Moreover, the photoelectric conversion element module of this invention is manufactured by the manufacturing method of the said photoelectric conversion element module.

  According to such a photoelectric conversion element module, wettability of the high melting point solder to the surface of the metal plate in the first electrode is improved in the manufacturing process, and the first electrode using titanium and the high melting point solder are firmly bonded. For this reason, the connection between the photoelectric conversion elements becomes strong, and the connection between the photoelectric conversion elements can be prevented from being disconnected by an external force applied to the photoelectric conversion element module.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the photoelectric conversion element module which can manufacture easily the photoelectric conversion element module in which the photoelectric conversion elements which have an electrode using titanium are mutually connected firmly, and it is manufactured by it A photoelectric conversion element module is provided.

It is sectional drawing which shows the photoelectric conversion element module which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the photoelectric conversion element module which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the modification of the photoelectric conversion element shown in FIG.

  Hereinafter, a preferred embodiment of a photoelectric conversion element module according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic cross-sectional view showing a photoelectric conversion element module according to an embodiment of the present invention.

  As shown in FIG. 1, the photoelectric conversion element module 200 includes a pair of photoelectric conversion elements 100 and 100 and a high melting point solder 9 as a conductive member that connects the photoelectric conversion elements 100 and 100.

  First, the photoelectric conversion elements 100 and 100 will be described. In addition, since one set of photoelectric conversion elements 100 and 100 are mutually the same structures, only one photoelectric conversion element 100 is demonstrated.

  The photoelectric conversion element 100 includes a working electrode 11, a counter electrode 12 disposed so as to face the working electrode 11, an electrolyte 5 disposed between the working electrode 11 and the counter electrode 12, and a sealing surrounding the electrolyte 5. The material 14 is provided as a main component.

(Working electrode)
The working electrode 11 is provided on the transparent substrate 1 and the second electrode 20 composed of the transparent substrate 2 and the transparent conductor 1 provided on one surface of the transparent substrate 2, and carries a photosensitizing dye. A porous oxide semiconductor layer 3.

  The transparent substrate 2 is constituted by a substrate made of a light transmissive material. Examples of such materials include glass, polyethylene terephthalate (PET), polycarbonate (PC), polyethersulfone (PES), polyethylene naphthalate (PEN), and are usually used as a transparent substrate for photoelectric conversion elements. Any material can be used. The transparent substrate 2 is appropriately selected from these in consideration of resistance to the electrolyte and the like. Further, the transparent substrate 2 is preferably a substrate that is as excellent in light transmission as possible, and more preferably a substrate having a light transmittance of 90% or more.

The transparent conductor 1 is a transparent conductive film, and is a thin film formed on a part of one surface or the entire surface of the transparent substrate 2. In order to obtain a structure that does not significantly impair the transparency of the working electrode 11, the transparent conductor 1 is preferably a thin film made of a conductive metal oxide. Examples of such conductive metal oxides include indium tin oxide (ITO), fluorine-added tin oxide (FTO), and tin oxide (SnO ₂ ). The transparent conductor 1 may be a single layer or a laminate of a plurality of layers made of different conductive metal oxides. When the transparent conductor 1 is composed of a single layer, the transparent conductor 1 is preferably ITO or FTO from the viewpoint of easy film formation and low manufacturing cost, and has high heat resistance and chemical resistance. From the viewpoint of having, it is more preferable that it is composed of FTO.

  In addition, it is preferable that the transparent conductor 1 is formed of a laminated body including a plurality of layers because the characteristics of each layer can be reflected. Among these, a laminated film in which a film made of FTO is laminated on a film made of ITO is preferable. In this case, the transparent conductor 1 having high conductivity, heat resistance, and chemical resistance can be realized, and a transparent conductive substrate with low light absorption in the visible range and high conductivity can be configured. The thickness of the transparent conductor 1 may be in the range of 0.01 μm to 2 μm, for example.

The oxide semiconductor for forming the porous oxide semiconductor layer 3 is not particularly limited, and any oxide semiconductor can be used as long as it is usually used for forming a porous oxide semiconductor for a photoelectric conversion element. Can do. Examples of such an oxide semiconductor include titanium oxide (TiO ₂ ), tin oxide (SnO ₂ ), tungsten oxide (WO ₃ ), zinc oxide (ZnO), niobium oxide (Nb ₂ O ₅ ), and strontium titanate. (SrTiO _3), indium oxide _{(In 3 O 3),} zirconium oxide _(ZrO 2), thallium oxide _{(Ta 2 O} 5), lanthanum oxide _{(La 2 O} 3), yttrium oxide _{(Y 2 O} 3), holmium oxide ( Ho ₂ O ₃ ), bismuth oxide (Bi ₂ O ₃ ), cerium oxide (CeO ₂ ), aluminum oxide (Al ₂ O ₃ ), and an oxide semiconductor composed of two or more of these. good.

  The average particle diameter of these oxide semiconductor particles is 1-1000 nm, the surface area of the oxide semiconductor covered with the dye is increased, that is, the field for photoelectric conversion is increased, and more electrons are generated. This is preferable. The porous oxide semiconductor layer 3 is preferably configured by stacking oxide semiconductor particles having different particle size distributions. In this case, light can be repeatedly reflected in the semiconductor layer, and incident light that escapes to the outside of the porous oxide semiconductor layer 3 can be reduced, and light can be efficiently converted into electrons. The thickness of the porous oxide semiconductor layer 3 may be, for example, 0.5 to 50 μm. In addition, the porous oxide semiconductor layer 3 can also be comprised with the laminated body of the some oxide semiconductor which consists of a different material.

  As a method for forming the porous oxide semiconductor layer 3, for example, a dispersion in which commercially available oxide semiconductor particles are dispersed in a desired dispersion medium or a colloidal solution that can be prepared by a sol-gel method is used as necessary. After adding a desired additive, the coating is performed by a known coating method such as a screen printing method, an ink jet printing method, a roll coating method, a doctor blade method, or a spray coating method, and then a void is formed by heat treatment or the like. It is possible to apply a method to make it.

  Examples of the photosensitizing dye include a ruthenium complex containing a bipyridine structure, a terpyridine structure or the like as a ligand, a metal-containing complex such as polyphylline or phthalocyanine, and an organic dye such as eosin, rhodamine or merocyanine. The thing which shows the behavior suitable for a use and a semiconductor to be used can be selected without particular limitation. Specifically, N3, N719, a black dye, or the like can be used.

(Electrolytes)
The electrolyte 5 is obtained by impregnating the porous oxide semiconductor layer 3 with an electrolytic solution, or after impregnating the porous oxide semiconductor layer 3 with the electrolytic solution, the electrolytic solution is appropriately gelled. Gelled (quasi-solidified) using an agent and formed integrally with the porous oxide semiconductor layer 3, or a gel electrolyte containing an ionic liquid, oxide semiconductor particles, or conductive particles Can be used.

  As said electrolyte solution, what melt | dissolved electrolyte components, such as an iodine, iodide ion, and tertiary butyl pyridine, in organic solvents, such as ethylene carbonate and methoxyacetonitrile, is used. Examples of the gelling agent used for gelling the electrolytic solution include polyvinylidene fluoride, a polyethylene oxide derivative, and an amino acid derivative.

Although it does not specifically limit as said ionic liquid, Room temperature meltable salt which is a liquid at room temperature and made the compound which has the quaternized nitrogen atom into a cation or an anion is mentioned. Examples of the cation of the room temperature melting salt include quaternized imidazolium derivatives, quaternized pyridinium derivatives, quaternized ammonium derivatives and the like. Examples of the anion of the ambient temperature molten _{salt, BF 4 -, PF 6 -} , F (HF) n-, bis (trifluoromethylsulfonyl) imide _{[N (CF 3 SO 2)} 2 -], and the like iodide ion. Specific examples of the ionic liquid include salts composed of a quaternized imidazolium cation and iodide ion or bistrifluoromethylsulfonylimide ion.

  The oxide semiconductor particles are not particularly limited in terms of the type and particle size of the substance, but those that are excellent in mixing with an electrolytic solution mainly composed of an ionic liquid and that gel the electrolytic solution are used. . In addition, the oxide semiconductor particles are required to have excellent chemical stability against other coexisting components contained in the electrolyte without reducing the conductivity of the electrolyte. In particular, even when the electrolyte contains a redox pair such as iodine / iodide ions or bromine / bromide ions, the oxide semiconductor particles are preferably those that do not deteriorate due to an oxidation reaction.

Examples of such oxide semiconductor particles include TiO ₂ , SnO ₂ , WO ₃ , ZnO, Nb ₂ O ₅ , In ₂ O ₃ , ZrO ₂ , Ta ₂ O ₅ , La ₂ O ₃ , SrTiO ₃ , Y ₂ O. ₃ , Ho ₂ O ₃ , Bi ₂ O ₃ , CeO ₂ , Al ₂ O ₃ are preferably selected from one or a mixture of two or more, and titanium dioxide fine particles (nanoparticles) are particularly preferable. The average particle diameter of the titanium dioxide is preferably about 2 nm to 1000 nm.

  As the conductive particles, conductive particles such as conductors and semiconductors are used. The range of the specific resistance of the conductive particles is preferably 1.0 × 10 −2 Ω · cm or less, and more preferably 1.0 × 10 −3 Ω · cm or less. Further, the type and particle size of the conductive particles are not particularly limited, and those that are excellent in miscibility with an electrolytic solution mainly composed of an ionic liquid and that gel the electrolytic solution are used. Such conductive particles are required to have excellent chemical stability with respect to other coexisting components contained in the electrolyte, since the conductivity is not easily lowered in the electrolyte. In particular, even when the electrolyte contains an oxidation / reduction pair such as iodine / iodide ion or bromine / bromide ion, an electrolyte that does not deteriorate due to oxidation reaction or the like is preferable.

  Examples of such conductive particles include those composed mainly of carbon, and specific examples include particles such as carbon nanotubes, carbon fibers, and carbon black. All methods for producing these substances are known, and commercially available products can also be used.

(Counter electrode)
The counter electrode 12 is configured by the first electrode 10. The first electrode 10 includes a metal plate 4 and a catalyst layer 6 made of titanium or a titanium alloy. The catalyst layer 6 that promotes the reduction reaction is formed on the surface of the metal plate 4 on the working electrode 11 side. The catalyst layer 6 is made of platinum or carbon.

(Encapsulant)
The sealing material 14 connects the working electrode 11 and the counter electrode 12, and the electrolyte 5 between the working electrode 11 and the counter electrode 12 is surrounded and sealed by the sealing material 14. Examples of the material constituting the sealing material 14 include an ionomer, an ethylene-vinyl acetic anhydride copolymer, an ethylene-methacrylic acid copolymer, an ethylene-vinyl alcohol copolymer, an ultraviolet curable resin, and a vinyl alcohol polymer. Is mentioned. In addition, the sealing material 14 may be comprised only with resin, and may be comprised with resin and an inorganic filler.

(Terminal)
A terminal 8 is formed on the transparent conductor 1 in an outer region surrounded by the outer periphery of the sealing material 14 on the surface of the working electrode 11 on the counter electrode 12 side. Examples of the material constituting the terminal 8 include metals such as gold, silver, copper, platinum, and aluminum.

  Next, connection between the photoelectric conversion elements 100 will be described.

  As shown in FIG. 1, in the photoelectric conversion element module 200, the transparent substrate 2 is commonly used in a set of photoelectric conversion elements 100 and 100. For this reason, the photoelectric conversion elements 100 and 100 are arranged in a planar shape with the same direction from the counter electrode 12 to the working electrode 11 being the same direction.

  The metal plate 4 in the counter electrode 12 of one photoelectric conversion element 100 in such a photoelectric conversion element module 200 is connected to the high melting point solder 9. Further, the terminal 8 on the working electrode 11 of the other photoelectric conversion element 100 is also connected to the high melting point solder 9. Thus, the pair of photoelectric conversion elements 100, 100 are connected in series.

  As the high melting point solder, it is preferable to use a solder having a melting point of 200 ° C. or higher (for example, 210 ° C. or higher). As such a high melting point solder, Sn-Cu type, Sn-Ag type, Sn-Ag-Cu type, Sn-Au type, Sn-Sb type, Sn-Pb type (Pb content is more than 85% by mass, for example) ), Etc., and one of these may be used alone, or two or more may be used in combination.

  Next, a method for manufacturing the photoelectric conversion element module 200 shown in FIG. 1 will be described.

  First, a set of photoelectric conversion elements 100 and 100 is prepared (photoelectric conversion element preparation process).

  In the photoelectric conversion element module 200, since the pair of photoelectric conversion elements 100, 100 use the transparent base material 2 in common, a set of photoelectric conversion elements 100, 100 can be manufactured at the same time. The conversion elements 100 and 100 are prepared. Hereinafter, only the production of one photoelectric conversion element 100 will be described.

  First, the working electrode 11 and the counter electrode 12 are prepared (preparation process).

  The working electrode 11 can be obtained by the following process. First, the transparent conductor 1 is formed on one surface of the transparent substrate 2 to form the second electrode 20. Next, the porous oxide semiconductor layer 3 is formed on the transparent conductor 1. Next, a photosensitizing dye is supported on the porous oxide semiconductor layer 3.

  Examples of the method for forming the transparent conductor 1 on the transparent substrate 2 include thin film forming methods such as sputtering, CVD (chemical vapor deposition), spray pyrolysis (SPD), and vapor deposition. . Of these, the spray pyrolysis method is preferable. By forming the transparent conductor 1 by spray pyrolysis, the haze ratio can be easily controlled. Further, the spray pyrolysis method is preferable because a vacuum system is unnecessary, and thus the manufacturing process can be simplified and the cost can be reduced.

The method for forming the porous oxide semiconductor layer 3 on the transparent conductor 1 mainly includes a coating process and a drying / firing process. As the coating step, for example, a paste of TiO ₂ colloid obtained by mixing TiO ₂ powder, a surfactant and a thickener at a predetermined ratio is applied to the surface of the transparent conductor 1 that has been made hydrophilic. Can be mentioned. At this time, as a coating method, a pressing means is used so that the applied colloid keeps a uniform thickness while pressing the colloid on the transparent conductor 1 using a pressing means (for example, a glass rod). The method of moving on the transparent conductor 1 is mentioned. As the drying / firing step, for example, a method of leaving the coated colloid in an air atmosphere at room temperature for about 30 minutes and drying the applied colloid, followed by firing at a temperature of 450 ° C. for about 60 minutes using an electric furnace. Can be mentioned.

  As a method for supporting a photosensitizing dye on the porous oxide semiconductor layer 3, first, a very small amount of dye solution for supporting a dye, for example, a solvent having a volume ratio of 1: 1 acetonitrile and t-butanol. A solution prepared by adding N3 dye powder was prepared in advance.

Next, in a solution containing a photosensitizing dye as a solvent in a petri dish-like container, heat treatment is performed at about 120 to 150 ° C. separately in an electric furnace to form the porous oxide semiconductor layer 3. The second electrode 20 is immersed, and is immersed for a whole day and night (approximately 20 hours) in a dark place. Then, the 2nd electrode 20 in which the porous oxide semiconductor layer 3 was formed is taken out from the solution containing a photosensitizing dye, and it wash | cleans using the mixed solution which consists of acetonitrile and t-butanol. As a result, a working electrode 11 having a porous oxide semiconductor layer 3 made of a TiO ₂ thin film carrying a photosensitizing dye is obtained.

  The terminal 8 formed on the second electrode 20 of the working electrode 11 is formed, for example, by applying a silver paste by printing or the like, and heating and baking. The terminal 8 is preferably formed before the step of supporting the photosensitizing dye on the porous oxide semiconductor layer 3.

  On the other hand, to prepare the counter electrode 12, first, a metal plate 4 made of titanium or a titanium alloy is prepared. Then, a catalyst layer 6 made of platinum or the like is formed on the surface of the prepared metal plate 4. The catalyst layer 6 is formed by a sputtering method or the like. Thereby, the 1st electrode 10 which has the metal plate 4 and the catalyst layer 6 can be obtained, and the 1st electrode 10 becomes the counter electrode 12 as it is.

  Next, the electrolyte 5 is surrounded and sealed by the sealing material 14 between the working electrode 11 and the counter electrode 12 (sealing process).

  In order to perform sealing, first, a resin or its precursor for forming the sealing material 14 is formed on the working electrode 11. At this time, the resin or its precursor is formed so as to surround the porous oxide semiconductor layer 3 of the working electrode 11. When the resin is a thermoplastic resin, the molten resin is applied on the working electrode 11 and then naturally cooled at room temperature, or a film-like resin is brought into contact with the working electrode 11 and the resin is heated and melted by an external heat source. Then, the resin can be obtained by natural cooling at room temperature. As the thermoplastic resin, for example, an ionomer or an ethylene-methacrylic acid copolymer is used. When the resin is an ultraviolet curable resin, an ultraviolet curable resin that is a precursor of the resin is applied on the working electrode 11. When the resin is a water-soluble resin, an aqueous solution containing the resin is applied on the working electrode 11. For example, a vinyl alcohol polymer is used as the water-soluble resin.

  Next, a resin or a precursor thereof for forming the sealing material 14 is formed on the counter electrode 12. The resin or its precursor on the counter electrode 12 is formed at a position overlapping the resin on the working electrode 11 or its precursor when the working electrode 11 and the counter electrode 12 face each other. The resin on the counter electrode 12 or its precursor may be formed in the same manner as the resin or its precursor formed on the working electrode 11.

  Next, an electrolyte is filled in a region surrounded by the resin on the working electrode 11 or its precursor.

  Then, the working electrode 11 and the counter electrode 12 are opposed to each other, and the resin on the counter electrode 12 and the working electrode 11 are overlapped. Thereafter, when the resin is a thermoplastic resin in a reduced pressure environment, the resin is heated and melted to bond the working electrode 11 and the counter electrode 12 together. Thus, the sealing material 14 is obtained. When the resin is an ultraviolet curable resin, the ultraviolet curable resin of the resin on the counter electrode 12 and the working electrode 11 are overlapped, and then the ultraviolet curable resin is cured by ultraviolet rays, whereby the sealing material 14 is obtained. When the resin is a water-soluble resin, after the laminate is formed, the finger is dried at room temperature and then dried in a low-humidity environment, whereby the sealing material 14 is obtained.

  In this way, the photoelectric conversion element 100 shown in FIG. 1 is obtained.

  Next, the pair of photoelectric conversion elements 100, 100 are connected by the high melting point solder 9 (connection process). The connection between the pair of photoelectric conversion elements 100 and 100 is such that the metal plate 4 of the counter electrode 12 in one of the photoelectric conversion elements 100 obtained above and the terminal 8 on the working electrode 11 of the other photoelectric conversion element 100 have a high melting point. Connected simultaneously with soldering.

  In the connection, first, the high melting point solder, the metal plate 4 of the counter electrode 12 in one photoelectric conversion element 100, and the terminal 8 on the working electrode 11 in the other photoelectric conversion element 100 are in contact with each other. Arrange so that the tip of the soldering iron is in contact.

  At this time, the tip portion of the soldering iron is heated so that the high melting point solder can be melted, and generates ultrasonic waves. Thus, the high melting point solder is melted by the heat transmitted from the tip of the soldering iron and vibrated by the ultrasonic waves from the tip of the soldering iron. Therefore, the high melting point solder improves the wettability with the metal plate 4 and adheres to the metal plate 4, and the molten high melting point solder adheres to the terminal 8.

  At this time, the temperature of the tip of the soldering iron is not particularly limited as long as the high melting point solder can be melted, but is preferably 200 to 450 ° C. from the viewpoint of sufficiently melting the solder, for example, 250 to 350. It is more preferable from the viewpoint of preventing oxidation of the solder and preventing the photosensitizing dye from being deteriorated by heat. Further, the vibration frequency of the ultrasonic wave generated from the tip of the soldering iron is preferably 10 kHz to 200 kHz, and more preferably 20 kHz to 100 kHz from the viewpoint of preventing the metal plate 4 from being damaged.

  Next, the high melting point solder 9 is separated from the molten high melting point solder, and the high melting point solder 9 is cooled and solidified, so that the high melting point solder 9 has the metal plate 4 of the counter electrode 12 in one photoelectric conversion element 100 and the other photoelectric element. It is connected to the terminal 8 on the working electrode 11 in the conversion element 100.

  In this way, the photoelectric conversion element module 200 can be obtained.

  According to the method for manufacturing the photoelectric conversion element module 200 according to the present embodiment, a pair of photoelectric conversion elements 100 and 100 are prepared, and the counter electrode 12 of one photoelectric conversion element 100 and the working electrode of the other photoelectric conversion element 100 are arranged. The photoelectric conversion element module 200 is formed by connecting the terminal 8. The counter electrode of the photoelectric conversion element 100 has a metal plate 4 made of titanium or an alloy containing titanium, and a high melting point solder 9 is used to connect the counter electrode 12 and the working electrode 11. At the time of connection, since the high melting point solder is heated and melted and ultrasonic waves are applied, the wettability of the counter electrode 12 to the metal plate 4 is improved. Therefore, the high melting point solder can be firmly connected to the metal plate 4 easily. Thus, the counter electrode 12 having the metal plate 4 made of titanium or an alloy containing titanium in one photoelectric conversion element 100 and the working electrode 11 in the other photoelectric conversion element 100 can be easily connected without using a vacuum device or the like. be able to. Therefore, a photoelectric conversion element module 200 including a pair of photoelectric conversion elements 100 and 100 using titanium for the counter electrode 12 of the photoelectric conversion element 100 can be easily manufactured.

  Moreover, in this embodiment, since the counter electrode 12 and the terminal 8 on the working electrode 11 are simultaneously connected by a high melting point solder, the number of steps required for connecting the photoelectric conversion elements 100 and 100 is small.

  Therefore, since the high melting point solder 9 connected to the counter electrode 12 using titanium is firmly joined to the photoelectric conversion element module 200 manufactured in the above manufacturing process, the photoelectric conversion elements 100 and 100 are firmly connected to each other. Therefore, it is possible to prevent the photoelectric conversion elements 100 and 100 from being disconnected by an external force applied to the photoelectric conversion element module 200 or the like.

(Second Embodiment)
Next, a second embodiment of the photoelectric conversion device of the present invention will be described with reference to FIG. In FIG. 2, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 2 is a schematic cross-sectional view showing the photoelectric conversion device of this embodiment. As shown in FIG. 2, the photoelectric conversion element module is different from the first embodiment in that current collection wiring is formed on the second electrode 20 in each photoelectric conversion element 110.

  The current collecting wiring 35 is formed from the region surrounded by the outer periphery of the sealing material 14 on the surface of the second electrode 20 to the outer periphery of the sealing material 14. Specifically, the current collecting wiring 35 is provided from the position overlapping the sealing material 14 to the outside of the outer periphery of the sealing material 14, and is connected to the terminal 8. The high melting point solder 9 is connected to the first electrode 10 at a position overlapping the current collecting wiring 35 when the first electrode 10 is viewed along the direction perpendicular to the first electrode 10.

  The current collecting wiring 35 is entirely covered with the wiring protective layer 36, and the contact between the electrolyte 5 and the current collecting wiring 35 is prevented. Note that the wiring protective layer 36 may or may not be in contact with the transparent conductor 1 of the working electrode 11 as long as the entire current collecting wiring 35 is covered.

  The material constituting the current collecting wiring 35 may be a metal having a resistance lower than that of the transparent conductor 1, and examples of such a material include metals such as gold, silver, copper, platinum, aluminum, titanium, and nickel. Is mentioned.

  Examples of the material constituting the wiring protective layer 36 include inorganic insulating materials such as non-lead-based transparent low melting point glass frit.

  The wiring protective layer 36 prevents contact between the electrolyte 5 and the current collector wiring 35 over a longer period of time, and generation of dissolved components of the wiring protective layer 36 when the electrolyte 5 comes into contact with the wiring protective layer 36. In order to prevent the above, the resistance of polyimide, fluororesin, ionomer, ethylene-vinyl acetic anhydride copolymer, ethylene-methacrylic acid copolymer, ethylene-vinyl alcohol copolymer, UV curable resin, vinyl alcohol polymer, etc. It is preferably coated with a chemical resin (not shown).

  Such a photoelectric conversion element module 210 is manufactured as follows.

  First, a set of photoelectric conversion elements 110 and 110 is prepared (photoelectric conversion element preparation process).

  The pair of photoelectric conversion elements 110 and 110 is prepared by using the current collector wiring 35 and the wiring protective layer 36 as the working electrode before the step of supporting the dye on the porous oxide semiconductor layer in the preparation step of the first embodiment. 11 is formed.

  The current collector wiring 35 is formed by coating the metal particles constituting the current collector wiring at the position where the sealing material 14 is formed after the porous oxide semiconductor layer 3 is formed, and heating and firing it. Obtainable. In addition, it is preferable to form the terminal 8 simultaneously with the formation of the current collecting wiring 35.

  Further, the wiring protective layer 36 is formed by, for example, a paste obtained by blending a thickener, a binder, a dispersant, a solvent, or the like with an inorganic insulating material such as the above-described low-melting glass frit as necessary. It can be obtained by coating so as to cover the entire current collecting wiring 35 by heating, and baking. In this way, the wiring protective layer 36 and the insulating member 15 are formed simultaneously. Other steps in the preparation step may be performed in the same manner as the preparation step in the first embodiment.

  Next, in the sealing step, the working electrode 11 and the counter electrode 12 are overlapped and sealed so that the sealing material 14 and the current collecting wiring 35 overlap. The sealing method may be performed in the same manner as the sealing process in the first embodiment.

  Other steps in the photoelectric conversion element preparation step may be performed in the same manner as in the first embodiment.

  Next, when the first electrode 10 is viewed along the direction perpendicular to the first electrode 10, the high melting point solder 9 is connected to the first electrode 10 at a position overlapping the current collecting wiring 35 (connection process). The connection may be performed by the same method as the connection step in the first embodiment.

  Thus, the photoelectric conversion element module 210 can be obtained.

  According to the method for manufacturing the photoelectric conversion element module 210 in the present embodiment, the sealing material 14 starts from the region surrounded by the outer periphery of the sealing material 14 on the surface of the working electrode 11 between the counter electrode 12 and the working electrode 11. Current collecting wiring 35 provided over an outer region of the outer periphery of the outer periphery. Since the current collecting wiring 35 is made of metal, it has excellent thermal conductivity. Further, when the counter electrode 12 is viewed from a direction perpendicular to the surface of the counter electrode 12, the high melting point solder 9 is connected to the counter electrode 12 at a position overlapping the current collecting wiring 35 in the region surrounded by the outer periphery of the sealing material 14. Connected. Therefore, the position where the high melting point solder 9 is connected to the counter electrode 12 and the current collector wiring 35 are close to each other, and when the high melting point solder 9 is connected to the counter electrode 12, the inside of the outer periphery of the sealing material 14 via the counter electrode 12. The heat conducted to the current is easily conducted to the current collector wiring 35. The heat conducted to the current collector wiring 35 is released to the outside of the outer periphery of the sealing material 14 due to the excellent heat conduction of the current collector wiring 35. Thus, it is possible to suppress deterioration of the photosensitizing dye and the electrolyte 5 carried on the porous oxide semiconductor layer 3 due to heat conducted through the counter electrode 12 when the high melting point solder 9 is connected to the counter electrode 12. Can do.

  The present invention has been described above by taking the first and second embodiments as examples, but the present invention is not limited to these.

  For example, in the first and second embodiments, the porous oxide semiconductor layer 3 is formed on the transparent conductor 1 of the second electrode 20. The working electrode 11 is composed of the second electrode 20 and the porous oxide semiconductor layer 3 carrying the photosensitizing dye, and the counter electrode 12 is composed of the first electrode 10. However, the present invention is not limited to these. FIG. 3 is a sectional view showing a modification of the photoelectric conversion element module 200 shown in FIG. As in the photoelectric conversion element 120 in the photoelectric conversion element module 220 shown in FIG. 3, the first electrode 10 is configured from the metal plate 4, and the porous oxide semiconductor layer 3 is formed on the first electrode 10. good. In this case, the catalyst layer 6 is formed on the transparent conductor 1, and the second electrode 20 includes the transparent substrate 2, the transparent conductor 1, and the catalyst layer 6. The working electrode 11 includes the first electrode 10 and the porous oxide semiconductor layer 3 on which the photosensitizing dye is supported, and the counter electrode 12 includes the second electrode 20. The catalyst layer 6 is made of, for example, platinum or the like that is thinly formed so that light can be transmitted.

  The photoelectric conversion element module 220 prepares a pair of photoelectric conversion elements 120 and 120, connects the high melting point solder 9 to the metal plate 4 on the working electrode 11 of one photoelectric conversion element 120, and the other photoelectric conversion. It can be obtained by connecting to the terminal 8 provided on the counter electrode 12 (second electrode 20) of the element 120. The connection method may be the same connection method as in the first embodiment.

  Preparation of the photoelectric conversion element 120 is performed as follows. First, the 1st electrode 10 comprised from the metal plate 4 is prepared. Next, the porous oxide semiconductor layer 3 is formed on the first electrode 10. The method of forming the porous oxide semiconductor layer 3 on the first electrode 10 may be performed in the same manner as the step of forming the porous oxide semiconductor layer 3 on the transparent conductor 1 in the first embodiment. Next, a photosensitizing dye is supported on the porous oxide semiconductor layer 3. The photosensitizing dye may be supported in the same manner as the step of supporting the photosensitizing dye on the porous oxide semiconductor layer 3 in the first embodiment. Thus, the working electrode 11 in which the porous oxide semiconductor layer 3 is formed on the first electrode 10 is obtained.

  Next, the counter electrode 12 is prepared. The counter electrode 12 is prepared by forming the transparent conductor 1 on the transparent substrate 2 and then forming the catalyst layer 6 on the transparent conductor 1 to form the second electrode 20. The method for forming the transparent conductor 1 may be performed in the same manner as the method for forming the transparent conductor 1 on the transparent substrate 2 in the first embodiment. In order to form the catalyst layer on the transparent conductor 1, in the first embodiment, a method similar to the method of forming the catalyst layer on the metal plate 4 may be performed. The second electrode 20 obtained in this way becomes the counter electrode 12.

  Next, the porous oxide semiconductor layer 3 and the electrolyte 5 are sealed with a sealing material 14 between the working electrode 11 and the counter electrode 12. The sealing method may be performed in the same manner as the sealing process in the first embodiment.

  In this way, the photoelectric conversion element 120 is obtained.

  In the first and second embodiments, the photoelectric conversion element module 200 includes a pair of photoelectric conversion elements, but the photoelectric conversion element module of the present invention may include three or more photoelectric conversion elements. . In the photoelectric conversion element module having three or more photoelectric conversion elements, the high melting point solder connects the first electrode 10 of at least one photoelectric conversion element and the second electrode 20 of at least one other photoelectric conversion element. good. The connection between the high melting point solder and the first electrode 10 and the second electrode 20 may be performed in the same manner as in the first embodiment.

  In the first and second embodiments, the counter electrode 12 and the working electrode 11 are simultaneously connected by the high melting point solder. However, the counter electrode 12 and the high melting point solder need not be connected at the same time. Alternatively, the high melting point solder connected to the counter electrode 12 and the working electrode 11 may be connected by a high melting point solder.

  Moreover, although the 2nd electrode 20 was set as the structure which uses the transparent base material 2 in common, you may isolate | separate the 2nd electrode 20, respectively.

  In the first and second embodiments, the high melting point solder 9 and the second electrode 20 are connected via the terminal 8, but the second terminal 8 is not always necessary, and the high melting point solder 9 and The transparent conductor 1 may be directly connected. According to such a photoelectric conversion element module, it can be set as simple as the terminal 8 is not formed, and a photoelectric conversion element module can be manufactured at low cost.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the photoelectric conversion element module which can manufacture easily the photoelectric conversion element module in which the photoelectric conversion elements which have an electrode using titanium are mutually connected, and the photoelectric conversion manufactured by it An element module is provided.

DESCRIPTION OF SYMBOLS 1 ... Transparent conductor 2 ... Transparent base material 3 ... Porous oxide semiconductor layer 4 ... Metal plate 5 ... Electrolyte 6 ... Catalyst layer 8 ... Terminal 9 ... High melting point solder 10 ... first electrode 11 ... working electrode 12 ... counter electrode 14 ... sealing material 20 ... second electrode 35 ... current collecting wiring 36 ... wiring protective layer 100 110, 120 ... photoelectric conversion element 200, 210, 220 ... photoelectric conversion element module

Claims (5)

A photoelectric conversion element preparation step of preparing a plurality of photoelectric conversion elements each including a first electrode having a metal plate made of titanium or an alloy containing titanium, and a second electrode facing the first electrode;
A connection step of connecting a first electrode of at least one photoelectric conversion element and a second electrode of at least one other photoelectric conversion element with a high melting point solder;
With
In the connecting step, the high melting point solder is heated and melted and ultrasonic waves are applied to be connected to the metal plate of the first electrode.   The method for manufacturing a photoelectric conversion element module according to claim 1, wherein the connection between the first electrode and the high melting point solder and the connection between the second electrode and the high melting point solder are performed simultaneously. The photoelectric conversion element is
A porous oxide semiconductor layer supporting a photosensitizing dye, an electrolyte, and a sealing material surrounding and sealing the porous oxide semiconductor layer and the electrolyte between the first electrode and the second electrode When,
On the surface of the second electrode on the first electrode side, a current collector wiring made of metal and provided from a region surrounded by the outer periphery of the sealing material to the outside of the outer periphery of the sealing material;
With
When the first electrode is viewed along a direction perpendicular to the surface of the first electrode, the refractory solder has the first electrode at a position overlapping the current collecting wiring in a region surrounded by the outer periphery of the sealing material. The method of manufacturing a photoelectric conversion element module according to claim 1, wherein the photoelectric conversion element module is connected to one electrode.   The method for manufacturing a photoelectric conversion element module according to claim 1, wherein the high melting point solder is connected to a terminal provided on the second electrode.   A photoelectric conversion element module manufactured by the method for manufacturing a photoelectric conversion element module according to any one of claims 1 to 4.

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