JP4639657B2 - Photoelectric conversion element and manufacturing method thereof - Google Patents

Description

  The present invention relates to a photoelectric conversion element suitable for use in a dye-sensitized solar cell and a method for producing the photoelectric conversion element.

  The dye-sensitized solar cell proposed by Gretzell et al. In 1991 has been attracting attention because it operates by a mechanism different from that of a silicon semiconductor pn junction and exhibits high conversion efficiency. The dye-sensitized solar cell realizes photoelectric conversion by injecting excited electrons generated by a dye that collects light into a semiconductor. Therefore, it is important to support a large amount of a sensitizing dye on a semiconductor in order to increase the light collecting ability, and to inject electrons from the sensitizing dye into the semiconductor as soon as possible. This new dye-sensitized solar cell, also referred to as a Gretzel cell, solves this problem by supporting a ruthenium complex, which is a sensitizing dye, on a porous film made of ultrafine titanium oxide (for example, non-particles). (See Patent Document 1).

  The Gretzel cell can be assembled by simply applying a paste in which ultrafine particles of titanium oxide are dispersed to a transparent electrode to carry a sensitizing dye and filling an electrolyte between the counter electrode. Therefore, compared with the conventional solar cell, it can be manufactured with a simple device, and is attracting attention as one of the next generation solar cells.

  A manufacturing method of filling a cell including a pair of electrode substrates with an electrolyte is similar to a manufacturing method of a liquid crystal display device in which a liquid crystal material is injected from an opening formed on one side of the cell (see, for example, Patent Document 1). ). When the electrolyte is filled from the opening of the cell by applying such a known technique, the electrolyte does not simply hold the electrolyte between both electrodes, but is applied to the cell by applying physical and chemical stimuli. Establishing a sealing technique that does not leak from the cell is essential to ensure long-term reliability and safety of the dye-sensitized solar cell.

  In a conventional method for manufacturing a wet solar cell related to a sealing technique, a manufacturing method includes a step of forming an opening or a hole in a cell, a step of injecting an electrolyte from the opening or the hole, and a step of sealing the opening or the hole. A method is known (for example, refer to Patent Document 2).

  Further, it is known that the opening or hole (injection port) is disposed in the electrode substrate portion, and the injection port is sealed with a polyisobutylene resin (see, for example, Patent Document 3).

  On the other hand, when sealing the electrolytic solution in a state where the electrolytic solution is contained in a cell having a pair of electrode substrates, acetonitrile or the like as a solvent of the electrolytic solution is used even if the sealing resin is thickly applied and cured. However, since it melts the resin, it was difficult to stably seal for a long time. In order to solve this, there has been proposed a method of stably encapsulating an electrolyte in a cell for a long period of time by fixing glass or plastic together with a resin as a solid for sealing in a sealing portion (for example, , See Patent Document 4).

  In addition, from the standpoint that it is very difficult to completely seal the electrolyte solution sealed in the main body of the dye-sensitized solar cell, the cell is provided with at least two liquid outlets that can be opened and closed. A method has been proposed in which the electrolytic solution stored in the electrolytic solution storage unit is replenished from the inlet / outlet to obtain long-term reliability of the cell (for example, see Patent Document 5).

  Further, in the formation of a sealing material for a dye-sensitized solar cell, a resin composition having a glass transition temperature of 80 ° C. or higher and / or a solvent-resistant resin composition is essential rather than using a known epoxy resin or silicon rubber. It is known that leakage of the electrolyte can be sufficiently prevented by using a curable resin obtained as follows or a curable resin essentially comprising a resin having an aromatic ring (see, for example, Patent Document 6).

Furthermore, for the purpose of producing a solar cell module from solar cells, the periphery of the assembly of solar cells is covered with a two-component mixed curable resin, so that the cell is not subjected to mechanical or thermal load. There has been proposed a method for obtaining a highly durable seal without impairing the performance of (see, for example, Patent Document 7).
Gratzel, 1 other, “Nature” (UK), Oct. 24, 1991, volume 353, p. 737-740 Japanese Patent Application Laid-Open No. 7-234412 JP 2000-30767 A JP 2002-31443 A (FIG. 1) JP 2000-173680 A JP 2002-280085 A JP 2003-223939 A JP 2003-86822 A

  In the method for producing a dye-sensitized solar cell, it is difficult to fill the cell with an electrolyte and prevent leakage for a long period only by diverting the method for producing a liquid crystal display device. This is because the contact interface between the sealing portion and the electrode support has a sufficient physical and chemical sealing strength against the electrolyte in order to prevent electrolyte leakage from the cell over a long period of time. Because it is essential. That is, in order to obtain a sufficient sealing strength at the contact interface, it is necessary to firmly adhere, fuse, or stick the sealing material used for the sealing portion to the electrode support. However, when a resin is used as the sealing material, if an electrolyte is present at the contact interface in the process where the resin adheres to the electrode support, it causes adhesion inhibition due to the composition of the electrolyte, and sufficient sealing strength is achieved. There is a possibility that it cannot be obtained. For example, there are concerns such as dissolution of a resin by an electrolyte solvent and inhibition of resin curing by iodine which is a redox couple of an electrolytic substance.

  Therefore, as described in Patent Document 2, the conventional method for sealing an electrolyte is sufficiently formed by previously forming a hole for filling the cell with the electrolyte and forming a sealing portion other than the hole with a sealing material. A method is adopted in which an electrolyte is filled from the hole after ensuring a sufficient adhesive strength, and finally the hole is sealed. The sealing material that forms the sealing portion in advance is called a main sealing material, and the sealing material that seals the hole is called an end sealing material. In this sealing method, a sufficient sealing strength can be obtained with the main sealing material. However, the sealing with the end sealing material can provide a sufficient sealing strength by inhibiting adhesion due to the composition of the electrolyte existing in the vicinity of the hole. It may not be possible. Therefore, it is the gist of the sealing technique that the sealing strength of the contact interface between the sealing part and the electrode support constituting the dye-sensitized solar cell is sufficient. As described in Patent Document 3, Even if a polyisobutylene resin with high durability against the electrolyte is used as an end seal material that seals the inlet for injecting the electrolyte, there is a risk of curing inhibition due to the composition of the electrolyte in the curing process of the polyisobutylene resin, Unless the placement position of the inlet and the sealing method in consideration of the inhibition of curing are not studied, the maximum sealing ability of the sealing material cannot be expressed, and it is difficult to realize long-term reliability.

  In addition, as described in Patent Document 4, when the electrolyte is sealed in a state where the electrolyte is contained in the cell, even if a sealing solid is installed in a part of the sealing portion. Since the sealing material resin and the electrolytic solution are in contact with each other at the contact interface, there is a possibility that the adhesive strength of the resin can only obtain the same effect as the conventional sealing method.

  On the other hand, as described in Patent Document 5, the cell structure in which the opening / closing opening of the liquid component that can be opened and closed is a method that avoids the difficulty of sealing with the end seal material, It has not solved any problems.

  In addition, as described in Patent Document 6, even if a curable resin that is resistant to the solvent used in the electrolyte is provided, the solvent resistance is a resin obtained by curing the precursor resin. When the curable resin is applied to an end seal material, the composition of the electrolyte becomes an adhesion inhibiting factor in the step of curing the precursor resin, and the curable resin has sufficient sealing strength. May not reach.

  Furthermore, the durability of the module of the dye-sensitized solar cell is a collection of at least the durability of the individual cells constituting the module, and as described in Patent Document 7, In order to obtain long-term durability by a method of filling a two-component mixed curable resin around the periphery, it is necessary for each cell to have long-term durability. However, Patent Document 7 does not describe a method of filling and sealing individual cells of a dye-sensitized solar cell, and solves the problem of electrolyte leakage from individual cells during long-term storage. Not.

  Therefore, in order to solve the above problems, the present invention provides a photoelectric conversion element that can store an electrolyte in a cell for a long period of time, has safety and high durability, and a method for manufacturing the photoelectric conversion element.

  The present invention includes a first substrate having a first electrode having a semiconductor layer carrying a dye, and a second substrate having a second electrode facing the semiconductor layer of the first electrode. A photoelectric conversion element that is opposed to each other while holding an electrolyte between the first electrode and the second electrode, wherein the electrolyte is interposed between the first electrode and the second electrode. A sealing part for holding is formed around the electrolyte, and the sealing part provides a photoelectric conversion element including an electrolyte injection part sealed with a sealing material.

  The present invention also provides (a) a first substrate formed with a first electrode having a semiconductor layer carrying a dye, and a second substrate formed with a second electrode. A step of making the semiconductor layer of one electrode and the second electrode face each other, and (b) bonding the first substrate and the second substrate with a sealing material to form a sealing portion Forming an electrolyte holding portion inside the sealing portion and between the first electrode and the second electrode, and forming an electrolyte injection portion in the sealing portion; (C) A method for manufacturing a photoelectric conversion element including a step of injecting an electrolyte from the electrolyte injection portion into the electrolyte holding portion and (d) a step of sealing the electrolyte injection portion is provided.

  INDUSTRIAL APPLICABILITY The present invention can provide a photoelectric conversion element that has high electrolyte holding characteristics and power generation characteristics, can hold the electrolyte inside the cell for a long period of time, has safety and high durability, and a method for manufacturing the photoelectric conversion element.

<Embodiment of photoelectric conversion element>
As a result of intensive studies, the inventors of the present invention have been able to prevent leakage of the electrolyte held between the pair of electrode supports constituting the dye-sensitized solar cell and realize long-term durability. It is essential that the sealing strength at the contact interface between the electrode support and the electrode support is sufficient. In particular, it is important that the sealing strength at the contact interface between the end seal material and the electrode support is sufficient. I found it. Furthermore, when the electrolyte support is provided by drilling the electrode support, only the end seal material that sealed the perforated part of the electrode support deteriorates in the cell after the high-temperature storage test, and the main seal material deteriorates at all. The phenomenon which does not do was confirmed. This phenomenon was confirmed more conspicuously when the material constituting the electrode support was a resin film rather than glass, so that the internal pressure of the cell increased in a high-temperature environment and concentrated mechanically in the perforated part of the electrode support. It was considered that the composition of the electrolyte entered the contact interface between the end seal material and the electrode support, and that the end seal material was deteriorated. Accordingly, the present inventors have found that the electrolyte injection part can be sealed with sufficient sealing strength with an end seal material if the cell structure has no electrolyte injection part on the electrode support.

  That is, an example of the photoelectric conversion element of the present invention includes a first substrate provided with a first electrode having a semiconductor layer carrying a dye, and a second electrode facing the semiconductor layer of the first electrode. The second substrate is a photoelectric conversion element that is opposed to the first electrode and the second electrode while holding the electrolyte. In addition, a sealing portion for holding the electrolyte between the first electrode and the second electrode is formed around the electrolyte, and the sealing portion is sealed with a sealing material. An electrolyte injection part. Furthermore, the sealing portion can be formed between the first electrode and the second electrode.

  As a sealing material (end seal material) for sealing the electrolyte injection part, if it is a curable adhesive, there is a risk of curing inhibition due to the composition of the electrolyte during the curing process. Is preferred. In addition, since the fusion time of the hot-melt resin is shorter than the curing time of the curable type, there is an advantage that the hot-melt resin is not easily affected by sealing inhibition due to the composition of the electrolyte.

  The temperature range of the melting point of the hot melt resin is preferably 60 ° C. or more and 200 ° C. or less because the hot melt resin is firmly fused to the electrode support and sufficient sealing strength is obtained.

  Further, the sealing material (main sealing material) for sealing other than the electrolyte injection part comes into contact with the electrolyte after the sealing material is sufficiently bonded and fused and the adhesive strength is sufficiently achieved. There is little risk of hindering sealing by minutes. Therefore, it is not always necessary to use hot melt resin as the main seal material, but hot melt resin may be used.

<Embodiment of manufacturing method of photoelectric conversion element>
An example of the method for producing a photoelectric conversion element of the present invention includes (a) a first substrate formed with a first electrode having a semiconductor layer carrying a dye, and a second substrate formed with a second electrode. And (b) the first substrate and the second substrate with a sealing material, the step of making the substrate opposite to each other so that the semiconductor layer of the first electrode and the second electrode face each other A sealing part is formed by bonding, an electrolyte holding part is formed between the first electrode and the second electrode inside the sealing part, and an electrolyte is injected into the sealing part A step of forming a portion, (c) a step of injecting an electrolyte from the electrolyte injection portion into the electrolyte holding portion, and (d) a step of sealing the electrolyte injection portion. In the step (b), a sealing portion can be formed between the first electrode of the first substrate and the second electrode of the second substrate.

  In the step (d), the electrolyte injection portion is sealed with a hot melt resin (end seal material), and the electrolyte injection portion is further heated to firmly bond the hot melt resin and the electrode support. In addition, by applying further pressure, the hot-melt resin can be actively brought into close contact with the electrode support to obtain a further sealing strength. The heating and the pressurization are preferably performed simultaneously.

  Moreover, it is preferable that melting | fusing point of the said hot-melt resin is 60 degreeC or more and 200 degrees C or less. Furthermore, the heating temperature is preferably 60 ° C. or higher and 250 ° C. or lower, and the pressurizing pressure is preferably 0.3 MPa or higher and 2.0 MPa or lower.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing an example of the photoelectric conversion element of the present invention. FIG. 2 is a cross-sectional view taken along the line II of FIG. As shown in FIGS. 1 and 2, the photoelectric conversion element 1 of this embodiment has a transparent electrode 3 (first electrode) formed on one surface of a transparent support 2. A semiconductor layer 4 carrying a pigment is formed on one surface of the transparent electrode 3. The transparent support 2, the transparent electrode 3, and the semiconductor layer 4 are integrated to form a substrate (first substrate).

  Further, a counter electrode 7 (second electrode) is present opposite to the semiconductor layer 4 carrying the dye. The counter electrode 7 is formed on one surface of another support 8. The counter electrode 7 and the support 8 are integrated to form a substrate (second substrate).

  An electrolyte layer 6 a exists between the semiconductor layer 4 and the counter electrode 7. A main seal material 5 and an end seal material 11 made of hot melt resin are arranged so as to hold the electrolyte layer 6 a between the semiconductor layer 4 and the counter electrode 7. The main sealing material 5 and the end sealing material 11 constitute a frame-shaped sealing portion of the photoelectric conversion element 1. In addition, the support body 8 may be formed with a light-transmitting material, or may be formed with a material that does not have light-transmitting properties. Reference numeral 9 denotes incident light.

  As is clear from FIG. 1, in the photoelectric conversion element 1 of this embodiment, the electrolyte injection part is not formed at least on the transparent electrode 3 and the counter electrode 7.

  3 to 6 are schematic cross-sectional views showing an example of a method for manufacturing the photoelectric conversion element shown in FIG. In the manufacturing method of the present embodiment, first, a transparent support 2 having a transparent electrode 3 on which a semiconductor layer 4 carrying a pigment is deposited, a support 8 having a counter electrode 7 on the surface, A main seal material 5 having a square shape, a rectangular end seal material 11 (hot melt resin), and a releasable resin sheet 12 for forming an electrolyte injection portion are prepared. Next, as shown in FIG. 3, the transparent support 2 and the support 8 are laminated via the main seal material 5, the end seal material 11 and the releasable resin sheet 12, and the semiconductor layer 4 of the transparent electrode 3 The counter electrode 7 is opposed.

  Subsequently, the main seal material 5 and the end seal material 11 are bonded to the transparent electrode 3 and the counter electrode 7 by applying pressure while heating from both sides of the transparent support 2 and the support 8. Thereby, the electrolyte holding part 6 b is formed between the semiconductor layer 4 of the transparent electrode 3 and the counter electrode 7. However, in this state, the end seal material 11 and the counter electrode 7 are not bonded to each other in the portion where the releasable resin sheet 12 is disposed (the portion serving as the electrolyte injection portion).

  Next, as shown in FIGS. 4 and 5, by removing the releasable resin sheet 12, the electrolyte injection portion 10 is formed between the end seal material 11 and the counter electrode 7. 5 is a cross-sectional view taken along the line II-II in FIG. Subsequently, an electrolyte is injected from the electrolyte injection unit 10 into the electrolyte holding unit 6b. Then, it pressurizes, heating from both sides of the transparent support body 2 and the support body 8, and seals by crushing the electrolyte injection part 10. FIG. Thereby, the electrolyte injection part 10 is sealed by the end seal material 11, and the photoelectric conversion element 1 of this embodiment shown in FIG. 1 is completed.

  The formation position of the electrolyte injection part 10 is not limited to the interface side between the counter electrode 7 and the end seal material 11 shown in FIGS. 4 and 5, but may be formed on the interface side between the transparent electrode 3 and the end seal material 11. Furthermore, the electrolyte injection part 10 is more preferably formed in the center part of the end seal material 11 (hot melt resin) as shown in FIG. The reason is that the hot melt resin adheres to the adherend by fusion bonding, so that interfacial peeling is more likely to occur than cohesive peeling, and the possibility of interfacial peeling is reduced. In order to form the electrolyte injection portion 10 at the center of the end seal material 11 (hot melt resin), the end seal material 11 is previously disposed on the transparent electrode 3 and the counter electrode 7, and is separated between the end seal materials 11. This can be done by disposing the moldable resin sheet 12. However, even in that case, the end seal 11 near the electrolyte injection portion 10, the transparent electrode 3, and the counter electrode 7 are not bonded in the same manner as described above.

  7 to 10 are schematic cross-sectional views illustrating another example of the method for producing a photoelectric conversion element of the present invention. In the manufacturing method of the present embodiment, first, a transparent support 2 provided on the surface with a transparent electrode 3 on which a semiconductor layer 4 carrying a dye is deposited, and a support 8 provided with a counter electrode 7 on the surface are prepared. To do. Next, as shown in FIG. 7, a liquid main seal material 5 is applied on the transparent electrode 3 in a frame shape. However, the main sealing material 5 is not applied to the electrolyte injection portion formation scheduled portion 10 ′. Subsequently, as shown in FIGS. 8, 9, and 10, the transparent support 2 and the support 8 are laminated via the main seal material 5, and the semiconductor layer 4 and the counter electrode 7 of the transparent electrode 3 are opposed to each other. Let 9 is a cross-sectional view taken along line III-III in FIG. 8, and FIG. 10 is a cross-sectional view taken along line IV-IV in FIG.

  Subsequently, the main sealing material 5 is bonded to the transparent electrode 3 and the counter electrode 7 by applying pressure while heating from both sides of the transparent support 2 and the support 8. Thereby, the electrolyte holding part 6b (FIG. 9) and the electrolyte injection part 10 (FIG. 10) are formed between the semiconductor layer 4 and the counter electrode 7 of the transparent electrode 3. However, in this state, the main sealing material 5 is not bonded to the transparent electrode 3 and the counter electrode 7 in the electrolyte injection part 10.

  Next, an electrolyte is injected from the electrolyte injection unit 10 into the electrolyte holding unit 6b. Then, the electrolyte injection part 10 is sealed by filling the electrolyte injection part 10 with the end seal material 11 heated and melted. At this time, the transparent support 2 and the support 8 may be heated and pressurized. Thereby, the photoelectric conversion element 1 of this embodiment shown in FIG. 11 is completed.

  Examples of the base material constituting the main seal material 5 include silicone resin, polyolefin, butyl rubber, ethylene-vinyl acetate copolymer, ethylene / α-olefin copolymer, ethylene-methyl acrylate copolymer, ethylene- Ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, low density polyethylene, acrylic resin, silicone resin, polyisobutylene resin, ionomer resin, polystyrene, polyolefin -Based, polydiene-based, polyester-based, polyurethane-based, fluororesin-based, and polyamide-based elastomers can be used. Among them, silicone resin, ionomer resin, polyolefin, polyisobutylene-based resin, butyl rubber, fluororesin-based elastomer Chromatography and the like are preferable. In addition, when using a nitrile solvent or a carbonate solvent as an electrolyte solvent, it is composed of a silicone resin, an ionomer resin, a polyisobutylene resin, a polyolefin, a thermosetting olefin resin, or the like that has low compatibility with those solvents. A hot melt resin is preferred. Moreover, in order to improve the weather resistance, the main sealing material 5 can be appropriately mixed with a crosslinking agent, an ultraviolet absorber and the like.

  Furthermore, a silane coupling agent or a titanate coupling agent may be added to the main sealing material 5 in order to increase the adhesive force between the counter electrode 7 and the transparent electrode 3. In addition, wet cleaning, chemical cleaning, plasma processing, ozone processing, ultraviolet irradiation processing, ultrasonic processing, surface polishing processing, etc. are performed on the counter electrode 7 and the transparent electrode 3 in advance to clean the surface and activate the surface. May be.

  The end seal material 11 is made of a hot melt resin, and examples of the base material include ethylene-vinyl acetate copolymer, ethylene / α-olefin copolymer, ethylene-methyl acrylate copolymer, ethylene-acrylic acid. Ethyl copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, low density polyethylene, acrylic resin, silicone resin, ionomer resin, polystyrene, polyolefin, polydiene, polyester Polyurethane-based, fluororesin-based, and polyamide-based elastomers can be used, and can be appropriately selected from these according to the material of the adherend surface.

  Moreover, as a form of the main sealing material 5 and the end sealing material 11, a sheet form, a liquid form, a gel form etc. are mentioned, However, It is not limited to these.

  When a hot melt resin is used for the main seal material 5, the sealing portion of the photoelectric conversion element of the present embodiment is composed only of the hot melt resin, so that the main seal material 5 and the end seal material 11 are interposed between the electrode supports. There is no need to place them separately. For this reason, simplification of a manufacturing process can be promoted. For example, it is possible to produce a large number of sealing members by continuously punching sheet-like hot melt resin with a Thomson blade or the like having a patterned sealing portion structure.

  Moreover, since the thickness of the main sealing material 5 and the end sealing material 11 prescribes | regulates the interelectrode distance of the transparent electrode 3 and the counter electrode 7, what is necessary is just 0.001 mm or more and 1 mm or less. A more preferable thickness is 0.001 mm or more and 0.5 mm or less. If the distance between the electrodes exceeds 1 mm, the photoelectric conversion characteristics may be significantly deteriorated. Moreover, if it is less than 0.001 mm, a part of the transparent electrode 3 and a part of the counter electrode 7 come into contact with each other, and there is a disadvantage that a short circuit occurs. As a means for accurately defining the distance between the electrodes, it is preferable to include a spacer in at least one of the main seal material 5 and the end seal material 11. As another method, a spacer may be disposed on the electrolyte layer 6.

  The method of heating and pressurizing to seal the electrolyte injection portion 10 provided in the end seal material 11 disposed between the transparent electrode 3 and the counter electrode 7 is limited to a special method. Never happen. Moreover, as an apparatus which performs heating and pressurization simultaneously, a hot press machine, a heating roller type soldering iron, a laminator, etc. can be used, and the press apparatus provided with heat sources, such as a laser, can also be used.

  The environment in which the step of injecting the electrolyte from the electrolyte injection unit 10 to the electrolyte holding unit 6b and the step of sealing the electrolyte injection unit 10 is preferably normal temperature and normal pressure. Moreover, if it is under pressure reduction, since it can seal without pinching a bubble in the electrolyte holding part 6b, it is more preferable. Furthermore, if a clean room with a humidity of 2% or less and a class 1000 or higher is used, it is possible to reduce the mixing of moisture that may impair long-term durability into the electrolyte holding unit 6b. It is more preferable because insufficient sealing can be prevented.

  The heating temperature range is preferably 60 ° C. or higher and 250 ° C. or lower. The upper limit of the temperature range is appropriately selected in consideration of the temperature at which the support is not damaged and the melting point of the support and the sealing material. When the support is a resin film, it is preferably 200 ° C. or lower, and the support is made of glass. In this case, 250 ° C. or lower is preferable. When this temperature range is exceeded, there is a possibility that the support may be deformed or the dimensional stability of the hot melt resin cannot be maintained. Further, when the heating is performed at 60 ° C. or lower, the fusion between the hot melt resin and the electrode support may be insufficient.

  The pressurizing pressure is appropriately selected in consideration of the pressure at which the support of the pressurizing part does not break, but is preferably 0.3 MPa to 2.0 MPa, more preferably 0.3 MPa to 1 MPa. 0.0 MPa or less, and most preferably 0.3 MPa or more and 0.5 MPa or less. If the pressure is less than 0.3 MPa, sealing of the electrolyte injection part 10 becomes insufficient, it becomes difficult to hold the electrolyte in the electrolyte holding part 6b, and the electrolyte may leak from the electrolyte injection part 10 during pressurization. is there. On the other hand, when the pressure exceeds 2.0 MPa, an extra force is applied to the electrode substrate, and the electrode support may be cracked or deformed.

  The timing for performing the heating and the pressurization is appropriately selected in consideration of the melting point of the end seal material 11 placed between the transparent electrode 3 and the counter electrode 7, but it is preferable to perform the pressurization after the heating. It is most preferable to perform heating and pressurization simultaneously. The heating time for the heating and the pressurizing time for the pressurization are preferably set to 3.0 seconds or less in consideration of the volatilization of the electrolyte in the cell.

  It is preferable to provide at least one electrolyte injection part 10 per one cell of the photoelectric conversion element.

  Examples of the method for injecting the electrolyte from the electrolyte injection unit 10 to the electrolyte holding unit 6b include a method for injecting the electrolyte using a glass syringe or a plastic syringe. In this case, the outer diameter of the needle used is preferably 0.2 mm or more and 2.0 mm or less. Moreover, it can also inject | pour by a pressure reduction injection method. That is, the cell of the photoelectric conversion element 1 is placed in a vacuum desiccator, the inside of the cell is decompressed, and the pressure is returned to atmospheric pressure, whereby the electrolyte can be injected into the cell from the opening of the electrolyte injection unit 10.

  Although it will not specifically limit if it is a material which has translucency as a material of the transparent support body 2, Usually, glass and a transparent resin film are used. This is because by properly selecting the melting point temperature of the hot melt resin, the hot melt resin is firmly fused with the hot melt resin. Moreover, the higher the light transmittance of the transparent support 2, the better. A preferable light transmittance is 50% or more, and more preferably 80% or more.

  In addition to the same glass and transparent resin film as the transparent support 2, a metal or the like can be used for the support 8. The support 8 may be opaque, but is preferably transparent in that light can be incident from both substrates.

  Moreover, when a flexible transparent resin film is used for the support bodies 2 and 8, mass production of an electrode becomes easy and manufacturing cost can be reduced.

  Examples of the transparent resin film used for the transparent support 2 and the support 8 include regenerated cellulose film, diacetate cellulose film, triacetate cellulose film, tetraacetyl cellulose film, polyethylene film, polypropylene film, polyvinyl chloride film, and polyvinylidene chloride. Film, polyvinyl alcohol film, polyethylene terephthalate film, polycarbonate film, polyethylene naphthalate film, polyethersulfone film, polyetheretherketone film, polysulfone film, polyetherimide film, polyimide film, polyarylate film, cycloolefin polymer film , Norbornene resin film, polystyrene film, hydrochloric acid Film, nylon film, a polyacrylate film, polyvinyl fluoride films, such as polytetrafluoroethylene film. Among these, a polyethylene terephthalate film, a polyethylene naphthalate film, a polyether sulfone film, a polyimide film, a polyarylate film, a cycloolefin polymer film, a norbornene resin film and the like are particularly preferable because they are tough and excellent in heat resistance. . In addition, it can replace with a transparent resin film and can also use a transparent resin board.

  The transparent electrode 3 is desirably excellent in light transmission as well as conductivity. Examples of the material thereof include zinc oxide, indium-tin composite oxide (ITO), a conductor layer in which ITO and silver are laminated, and antimony. And tin oxide doped with fluorine and tin oxide doped with fluorine. Among these, tin oxide doped with fluorine is preferable from the viewpoint of conductivity and light transmittance.

  The transparent electrode 3 is better as the surface resistance is lower. The range of the surface resistance is preferably 50 Ω / square or less, more preferably 30 Ω / square or less. The lower limit of the surface resistance is not particularly limited, but is usually 0.1Ω / square.

  The transparent electrode 3 is better as the light transmittance is higher. A preferable light transmittance is 50% or more, and more preferably 80% or more. The film thickness of the transparent electrode 3 is preferably in the range of 0.1 to 10 μm. This is because within this range, an electrode film having a uniform thickness can be formed, and light transmittance is not lowered, and sufficient light can be incident on the semiconductor layer 4. In this case, it is preferable that light is incident from the transparent electrode 3 on the side where the semiconductor layer 4 carrying the dye is deposited.

  The counter electrode 7 functions as a positive electrode of the photoelectric conversion element 1 and can be formed in the same manner as the transparent electrode 3 on the side where the semiconductor layer 4 carrying the dye is deposited. Furthermore, the counter electrode 7 is preferably formed of a material having a catalytic action to give electrons to the reductant of the electrolyte in order to function efficiently as the positive electrode of the photoelectric conversion element 1. Such a material is, for example, a metal such as platinum, gold, silver, copper, aluminum, rhodium, or indium, or a conductive metal oxide such as graphite or ITO or fluorine-doped tin oxide. Of these, platinum and graphite are particularly preferred. The support 8 on the side where the counter electrode 7 is disposed can also have a transparent conductive film (not shown) on the surface to which the counter electrode 7 is attached. This transparent conductive film can be formed, for example, from the same material as the transparent electrode 3 described above. In this case, the counter electrode 7 is also preferably transparent.

  In forming the semiconductor layer 4, a dispersion coating of semiconductor particles, for example, a coating method using a doctor blade or a bar coater, a spray method, a dip coating method, a screen printing method, a gravure printing method, a spin coating method, an electrodeposition method, etc. Thus, it is preferable to form a film on the surface of the transparent electrode 3, and then perform a fixing process of the semiconductor layer 4 as necessary. Examples of the immobilization treatment include heat treatment and pressure treatment. As the heat treatment, a heating method using an electric furnace, a hot plate, a microwave, an electron beam or the like is preferable, and the heating temperature is preferably about 400 to 600 ° C. when a glass substrate is used as the transparent support 2. When a resin film such as polyethylene naphthalate (PEN) is used as the transparent support 2, if the semiconductor layer 4 is heat-treated at a temperature within the above range, the resin film is deformed or the transparent electrode 3 such as ITO becomes a resin film. May peel off. Therefore, when the resin film is used, the semiconductor layer 4 can be formed by performing a heat treatment at a temperature of 200 ° C. or less or applying pressure to the semiconductor layer 4. Examples of the method for pressurizing the semiconductor layer 4 include a method using a press, a calendar, and the like.

  The thickness of the semiconductor layer 4 is preferably in the range of 0.1 to 100 μm. This is because, within this range, a sufficient photoelectric conversion effect can be obtained, and the light transmittance with respect to visible light and near infrared light is not deteriorated. A more preferable range of the thickness of the semiconductor layer 4 is 1 to 50 μm, a further preferable range is 5 to 30 μm, and a most preferable range is 10 to 20 μm.

Examples of semiconductor materials used for forming the semiconductor layer 4 include Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, and Sr. Metal oxides such as Ga, Si and Cr, perovskites such as SrTiO ₃ and CaTiO ₃ , or CdS, ZnS, In ₂ S ₃ , PbS, Mo ₂ S, WS ₂ , Sb ₂ S ₃ , Bi ₂ S ₃ , Sulfides such as ZnCdS ₂ , Cu ₂ S, metal chalcogenides such as CdSe, In ₂ Se ₃ , WSe ₂ , HgS, PbSe, CdTe, other GaAs, Si, Se, Cd ₂ P ₃ , Zn ₂ P ₃ , InP , AgBr, PbI ₂ , HgI ₂ , BiI ₃ , or a composite containing at least one selected from the above semiconductor materials, for example, CdS / TiO ₂ , CdS / AgI, Ag ₂ S / AgI, CdS / ZnO, CdS / HgS, CdS / PbS, ZnO / ZnS, ZnO / ZnSe, CdS / HgS, CdS _x / CdSe _1-x , CS _x / Te _1-x , CdSe _x / Te _{1 -x, ZnS / CdSe, ZnSe /} CdSe, CdS / ZnS, TiO 2 / Cd 3 P 2, CdS / CdSeCd y Zn 1-y S, such as CdS / HgS / CdS, and the like. Among these, TiO ₂ is preferable in the Gretzel cell in terms of avoiding photodissolution in the electrolyte and realizing high photoelectric conversion characteristics.

  Although the said semiconductor material is normally used with a particle shape, it is preferable that the particle size of the semiconductor particle in that case is generally in the range of 5-1000 nm. Within this range, the pore size of the semiconductor layer 4 becomes appropriate, the redox substance in the electrolyte solution can be easily moved, the photocurrent does not decrease, and the surface area of the semiconductor layer 4 is reduced. This is because a sufficient amount of dye can be obtained, and as a result, a large photocurrent can be obtained. A particularly preferable range of the particle diameter of the semiconductor particles is 10 to 100 nm.

  By controlling the thickness of the semiconductor layer 4 or the particle size of the semiconductor particles, the roughness factor that is the ratio of the actual area inside the semiconductor layer to the support area of the semiconductor layer 4 can be determined. The roughness factor is preferably 20 or more, more preferably 150 or more. This is because within this range, the amount of the dye supported becomes sufficient and the photoelectric conversion characteristics can be improved. The upper limit of the roughness factor is generally about 5000. The roughness factor increases as the thickness of the semiconductor layer 4 is increased, and the surface area of the semiconductor layer 4 is increased, and an increase in the amount of dye supported can be expected. However, when the thickness becomes too thick, an influence on the light transmittance and resistance loss of the semiconductor layer 4 starts to appear.

  Further, a surfactant, polyethylene glycol, cellulose-based material or the like is added to the formation of the semiconductor layer 4, and the semiconductor layer 4 is made porous by burning them during the heat treatment of the semiconductor layer 4, or the particle size of the semiconductor particles If the porosity of the semiconductor layer 4 is increased by changing the roughness, it is possible to increase the roughness factor without increasing the thickness. However, if the porosity becomes too high, the contact area between the semiconductor particles decreases, and the influence on the resistance loss must be taken into consideration. Therefore, the porosity of the semiconductor layer 4 is preferably 50% or more, and its upper limit is generally about 80%. The porosity of the semiconductor layer 4 can be calculated from the measurement result of the adsorption-desorption isotherm curve of nitrogen gas or krypton gas under liquid nitrogen temperature.

Any dye can be used as long as it is a sensitizing dye commonly used in conventional dye-sensitized photoelectric conversion elements. Such dyes are, for example, RuL ₂ (H ₂ O) ₂ type ruthenium-cis-diaqua-bipyridyl complexes or ruthenium-tris (where L is 4,4′-dicarboxyl-2,2′-bipyridine). RuL ₃ ), ruthenium-bis (RuL ₂ ), osnium-tris (OsL ₃ ), osnium-bis (OsL ₂ ) type transition metal complex, or zinc-tetra (4-carboxyphenyl) porphyrin, iron-hexocyanide complex, Examples include phthalocyanine. As organic dyes, 9-phenylxanthene dyes, coumarin dyes, acridine dyes, triphenylmethane dyes, tetraphenylmethane dyes, quinone dyes, azo dyes, indigo dyes, cyanine dyes, merocyanine dyes Examples thereof include dyes and xanthene dyes. Among these, ruthenium-bis (RuL ₂ ) derivatives are particularly preferable because they have a broad absorption spectrum in the visible light region.

  Examples of the method of supporting the sensitizing dye on the semiconductor layer 4 include a method of immersing the transparent support 2 on which the semiconductor layer 4 is applied in a solution in which the sensitizing dye is dissolved. Any solvent can be used as the solvent for the solution as long as it can dissolve the sensitizing dye, such as water, alcohol, toluene, and dimethylformamide. Further, as a dipping method, when the transparent support 2 having the semiconductor layer 4 adhered to the sensitizing dye solution is dipped for a certain period of time, it can be heated to reflux or an ultrasonic wave can be applied. After the dye is supported on the semiconductor layer 4, it is preferable to wash with acetonitrile in order to remove the sensitizing dye remaining on the semiconductor layer 4 without being supported. Furthermore, when alcohol is used as a solvent to coat the surface of the semiconductor particles on which no sensitizing dye is supported, it is preferable to dissolve t-butylpyridine in the alcohol. When t-butylpyridine is present in the alcohol, the surface of the semiconductor particle and the electrolyte can be separated by t-butylpyridine at the semiconductor particle / electrolyte interface, and leakage current can be suppressed. This is because the characteristics can be remarkably improved.

The amount of the sensitizing dye supported on the semiconductor particles may be in the range of 1 × 10 ⁻⁸ to 1 × 10 ⁻⁶ mol / cm ² , particularly 0.1 × 10 ^{−7 to} 9.0 × 10 ^{−. 7} mol / cm ² is preferred. This is because within this range, the effect of improving the photoelectric conversion efficiency can be obtained economically and sufficiently.

  The electrolytic substance constituting the electrolyte layer 6a is not particularly limited as long as it is a pair of redox constituents composed of an oxidant and a reductant. However, the oxidant and the reductant are redox constituents having the same charge. Preferably there is. In this specification, the redox-system constituent substance means a pair of substances that exist reversibly in the form of an oxidant and a reductant in a redox reaction. Examples of the redox-based constituent material that can be used in the present embodiment include chlorine compound-chlorine, iodine compound-iodine, bromine compound-bromine, thallium ion (III) -thallium ion (I), mercury ion (II) -mercury ion. (I), ruthenium ion (III) -ruthenium ion (II), copper ion (II) -copper ion (I), iron ion (III) -iron ion (II), vanadium ion (III) -vanadium ion (II ), Manganate ion-permanganate ion, ferricyanide-ferrocyanide, quinone-hydroquinone, fumaric acid-succinic acid and the like, but are not limited thereto. Among these, iodine compound-iodine is preferable, and examples of the iodine compound include metal iodides such as lithium iodide and potassium iodide, quaternary ammonium iodide compounds such as tetraalkylammonium iodide and pyridinium iodide, and dimethyl iodide. Particularly preferred are diimidazolium iodide compounds such as propylimidazolium.

  The solvent used for dissolving the electrolytic substance is preferably a compound that can dissolve the redox constituent and is excellent in ion conductivity. As the solvent, either an aqueous solvent or an organic solvent can be used, but an organic solvent is preferable in order to further stabilize the redox constituent. Examples of the organic solvent include carbonate compounds such as dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, and propylene carbonate, ester compounds such as methyl acetate, methyl propionate, and γ-butyrolactone, diethyl ether, 1,2- Ether compounds such as dimethoxyethane, 1,3-dioxosilane, tetrahydrofuran and 2-methyl-tetrahydrofuran, heterocyclic compounds such as 3-methyl-2-oxazodilinone and 2-methylpyrrolidone, nitriles such as acetonitrile, methoxyacetonitrile and propionitrile Examples thereof include aprotic polar compounds such as compounds, sulfolane, didimethyl sulfoxide and dimethylformamide. These can be used alone or in combination of two or more. Among these, carbonate compounds such as ethylene carbonate and propylene carbonate, heterocyclic compounds such as 3-methyl-2-oxazodilinone and 2-methylpyrrolidone, and nitrile compounds such as acetonitrile, methoxyacetonitrile and propionitrile are particularly preferable.

  The electrolyte is not limited to a liquid one, and other types can be used. For example, a liquid electrolyte may be held in a polymer matrix and used in a gel state. As such a polymer matrix, polymerizable monomers such as vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene, trifluoroethylene, ethylene, propylene, acrylonitrile, vinylidene chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, and styrene are used. A homopolymer obtained by polymerizing alone or a copolymer obtained by copolymerizing two or more of these monomers can be used.

  The photoelectric conversion element 1 of this embodiment can be entirely covered with a fluororesin (not shown). Thereby, the improvement of the intensity | strength and impact resistance of the photoelectric conversion element 1 can be aimed at. Since this fluororesin is used in the outermost layer of the photoelectric conversion element 1, it is preferable that it is excellent in gas barrier property against water vapor and the like, light resistance against ultraviolet rays, transparency, strength and weather resistance.

(Example)
Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples.

Nippon Aerosil Co., Ltd. in a mixed solution (volume mixing ratio: water / acetylacetone = 20/1) of water and acetylacetone containing 0.01 g / dm ³ of the surfactant “Nonipol 100” (trade name) manufactured by Sanyo Chemical Co., Ltd. Titanium oxide particles “P25” (trade name, average particle diameter of 20 nm) manufactured by the company were dispersed to a concentration of 2% by mass to prepare a slurry liquid. Next, conductive glass “F-SnO ₂ ” (trade name, thickness: 1 mm, manufactured by Asahi Glass Co., Ltd.), which is a glass substrate with a transparent electrode that is coated with SnO ₂ doped with fluorine to provide conductivity. The slurry solution was applied to a size of 1 cm × 1 cm on a transparent electrode having a surface resistance of 10Ω / square and dried. Thereafter, the obtained dried product was baked in air at 500 ° C. for 30 minutes to form a titanium oxide film having a thickness of 7 μm on the conductive glass. Subsequently, this substrate was coated with a sensitizing dye represented by [Ru (4,4′-dicarboxyl-2,2′-bipyridine) ₂ (NCS) ₂ ] at a concentration of 3 × 10 ⁻⁴ mol / dm ³ . The transparent electrode with a glass substrate was produced by immersing in the ethanol solution contained and performing dye adsorption treatment.

As the attached glass substrate counter electrode used was deposited to a thickness of 20nm platinum on the conductive glass "F-SnO _2" of Asahi Glass Co., Ltd.. The distance between both electrodes was 0.1 mm.

A frame-shaped main sealing material having a width of 5 mm and a thickness of 35 μm is disposed between the transparent electrode and the counter electrode so as to surround the periphery of the titanium oxide film, and hot under conditions of 180 ° C. and 1.0 MPa. Heating and pressurization were simultaneously performed with a press. However, in order to form the electrolyte injection portion, a fluororesin sheet (release resin sheet) having a width of 2 mm and a thickness of 50 μm was sandwiched between the main seal material and the counter electrode. Thereafter, the fluororesin sheet was removed to form an electrolyte injection portion, and an electrolyte solution was injected from the electrolyte injection portion by a reduced pressure injection method. After wiping off the excess electrolyte solution adhering to the electrolyte injection part, only this electrolyte injection part was sealed by simultaneously performing heating and pressurization with a hot press machine under the same conditions as described above to produce a photoelectric conversion element. . As the electrolyte solution, a mixed solution of ethylene carbonate and acetonitrile containing 0.5 mol / dm ³ tetrapropylammonium iodide and 0.04 mol / dm ³ iodine (volume mixing ratio: ethylene carbonate / acetonitrile = 80 / 20) was used. As the main seal material, a hot-melt resin “Bynel” (trade name) manufactured by DuPont was used.

  A binder solution was prepared by dissolving 0.7% by mass of ethyl cellulose “N300” (trade name) manufactured by Hercules Co. in ethanol. To 23 g of this binder solution, 7.5 g of titanium oxide “P25” (trade name) manufactured by Nippon Aerosil Co., Ltd. was added, and titanium oxide was dispersed to prepare a slurry liquid. The slurry was prepared so that the concentration of titanium oxide in the slurry was 24% by mass. Next, a transparent electrode of a polyethylene naphthalate (PEN) film (ITO / PEN transparent electrode film having a thickness of 125 μm and a surface resistance of 10Ω / square) coated with an indium-tin composite oxide (ITO) manufactured by Tobi Co., Ltd. On top of this, the slurry solution was applied and dried to form a semiconductor layer made of a titanium oxide film having a length of 40 mm, a width of 15 mm, and a thickness of 50 μm. Next, a pressure of 80 MPa was applied to each semiconductor layer with a calendar to compress the thickness of the titanium oxide film constituting the semiconductor layer to 10 μm.

The ITO / PEN transparent electrode film provided with this titanium oxide film was coated with a sensitizing dye represented by [Ru (4,4′-dicarboxyl-2,2′-bipyridine) ₂ (NCS) ₂ ] at a concentration of 3 ×. The film was immersed in an acetonitrile / t-butyl alcohol mixed solution (mixing volume ratio = 50/50) containing 10 ⁻⁴ mol / dm ³ to carry the pigment on the semiconductor layer, thereby producing a transparent electrode with a film. Next, platinum having a film thickness of 20 nm was vapor-deposited on the same ITO / PEN transparent electrode film manufactured by Tobi Co., Ltd. to prepare a counter electrode with a film.

A hot melt resin “Himilan” (trade name) manufactured by DuPont is used as a frame-shaped main seal material having a width of 5 mm and a thickness of 70 μm so as to surround the titanium oxide film between the transparent electrode and the counter electrode. And heating and pressurization were simultaneously performed using a laminator under the conditions of 180 ° C. and 0.5 MPa. The electrolyte injection portion was formed using the same method as in Example 1. After injecting an electrolyte solution from the electrolyte injection part by a reduced pressure injection method, only the electrolyte injection part was sealed by simultaneously performing heating and pressurization with a laminator under the same conditions as described above to produce a photoelectric conversion element. . Examples of the electrolyte solution, with γ- butyrolactone containing iodine of tetrapropylammonium iodide and 0.5 mol / dm ³ of t- butylpyridine and 0.01 mol / dm ³ of 0.5 mol / dm ^3.

  A transparent electrode with a glass substrate and a counter electrode with a glass substrate prepared in the same manner as in Example 1 were prepared. “3” made by Sekisui Chemical Co., Ltd., a resin ball “Micropearl” (trade name, average particle size: 30 μm) added to the surface of the transparent electrode as a main sealing material. Three Bond 1152 ″ (trade name) was applied using an automatic dispenser with a width of 3 mm and a thickness of 80 μm as shown in FIG. 7 described above. When the transparent electrode and the counter electrode were bonded, an electrolyte injection part having a width of 2 mm and a thickness of 50 μm was disposed.

The main sealing material was cured by heating at 100 ° C. for 60 minutes. In this case, the transparent electrode and the counter electrode were left to pressurize using a bee-type clip so as not to shift. Moreover, after injecting the electrolyte solution from the electrolyte injection part by the reduced pressure injection method, the excess electrolyte solution adhering to the electrolyte injection part was wiped off. Thereafter, a hot melt resin “Bynel” (end seal material) manufactured by DuPont, which was heated and melted on a hot plate heated to 220 ° C. in the electrolyte injection portion, was applied at a pressure of 0.4 to 0.6 MPa for about 10 seconds. After sealing the end seal material by pressing, it was naturally cooled to produce a photoelectric conversion element. As the electrolyte solution, γ-butyrolactone containing 0.5 mol / dm ³ tetrapropylammonium iodide and 0.04 mol / dm ³ iodine was used.

  Silicone condensation reaction type resin “SE737” (trade name) manufactured by Toray Dow Corning Co., Ltd. is used as the main sealing material, and the transparent electrode with the glass substrate and the counter electrode with the glass substrate do not shift when the main sealing material is cured. Thus, a photoelectric conversion element was configured in the same manner as in Example 3 except that it was performed by using a bee-type clip and allowing to stand under pressure and normal temperature for 12 hours.

(Comparative Example 1)
A photoelectric conversion element having a conventional structure shown in FIG. 12 was produced as follows. In FIG. 12, the parts denoted by the same reference numerals as those in FIG. 1 correspond to the same parts as in FIG.

  First, the transparent electrode 3 with a glass substrate and the counter electrode 7 with a glass substrate prepared in the same manner as in Example 1 were prepared. An injection hole 13 having a diameter of 1.0 mm was drilled at the position shown in FIG. 12 of the counter electrode 7 using an electric blaster.

Next, the transparent electrode 3 and the counter electrode 7 are simultaneously heated and pressurized using a hot press machine at 180 ° C. and 1.0 MPa through the main sealant 5 in the same manner as in Example 1. went. Subsequently, after the electrolyte solution is injected from the injection hole 13, the injection hole 13 is sealed with the end seal material 14, and the surface of the end seal material 14 is further mixed with a two-component mixed epoxy resin “Quick 5” manufactured by Konishi. ”(Trade name). As the electrolyte solution, a mixed solution of ethylene carbonate and acetonitrile containing 0.5 mol / dm ³ tetrapropylammonium iodide and 0.04 mol / dm ³ iodine (volume mixing ratio: ethylene carbonate / acetonitrile = 80 / 20) was used. Further, as the main seal material 5 and the end seal material 13, hot melt resin “Bynel” (trade name) manufactured by DuPont was used.

(Comparative Example 2)
A photoelectric conversion element having substantially the same structure as that of Comparative Example 1 was produced as follows. First, a transparent electrode with a film and a counter electrode with a film were produced in the same manner as in Example 2. A liquid injection hole having a diameter of 1.0 mm was drilled at the same position as Comparative Example 1 of the counter electrode using a needle.

Next, the transparent electrode and the counter electrode were simultaneously heated and pressurized using a laminator through the main seal material at 180 ° C. and 1.0 MPa in the same manner as in Example 2. Subsequently, after pouring the electrolyte solution from the liquid injection hole, the liquid injection hole was sealed with a silicone adhesive tape, and the surface of the silicone adhesive tape was further coated with a one-component ultraviolet curable resin “PHOTOREC” manufactured by Sekisui Chemical Co., Ltd. Covered with A-780 "(trade name). Examples of the electrolyte solution, with γ- butyrolactone containing iodine of tetrapropylammonium iodide and 0.5 mol / dm ³ of t- butylpyridine and 0.01 mol / dm ³ of 0.5 mol / dm ^3. As the main seal material, a hot-melt resin “Himilan” (trade name) manufactured by DuPont was used.

  Next, electrolyte retention characteristics and power generation characteristics were evaluated using the photoelectric conversion elements of Examples 1 to 4 and Comparative Examples 1 and 2.

<Evaluation of electrolyte retention characteristics>
The electrolyte retention characteristics were evaluated by measuring the mass reduction ratio of each of the photoelectric conversion elements under a certain condition. The measurement conditions were that each photoelectric conversion element was stored at a temperature of 60 ° C. and a humidity of 2.0% for 400 hours, and the ratio of the mass after storage to the mass of the photoelectric conversion element before storage was calculated as a mass retention rate (%). The results are shown in Table 1.

<Evaluation of power generation characteristics>
The power conversion characteristics were evaluated by measuring the energy conversion efficiency of each of the photoelectric conversion elements under a certain condition. The measurement conditions are that each photoelectric conversion element is stored at a temperature of 60 ° C. and a humidity of 2.0% for 400 hours, and the ratio of the energy conversion efficiency after storage to the energy conversion efficiency of the photoelectric conversion element before storage is the conversion efficiency maintenance ratio (%) Calculated as

The photocurrent-voltage characteristic was measured using simulated sunlight (10 mW / cm ² , AM1.5) by a solar simulator. The energy conversion efficiency (%) was calculated from the open-circuit photovoltage (V), the short-circuit photocurrent density (mA / cm ² ), and the shape factor according to the following formula.

Energy conversion efficiency (%) = open end photovoltage (V) × short circuit photocurrent density (mA / cm ² ) × form factor / 10 (mW / cm ² ) × 100
The results are shown in Table 2.

  From Table 1 and Table 2, it can be seen that Examples 1 to 4 have higher mass retention characteristics and power generation characteristics than Comparative Examples 1 and 2.

  As described above, since the photoelectric conversion element of the present invention has high electrolyte retention characteristics and power generation characteristics, it is possible to prevent leakage of the electrolyte over a long period of time, and provide a photoelectric conversion element having safety and high durability. Can contribute to the practical application of dye-sensitized solar cells.

It is a schematic sectional drawing which shows an example of the photoelectric conversion element of this invention. It is sectional drawing of the II line | wire of FIG. It is a schematic sectional drawing which shows an example of the manufacturing method of the photoelectric conversion element of this invention. It is a schematic sectional drawing which shows an example of the manufacturing method of the photoelectric conversion element of this invention. It is sectional drawing of the II-II line | wire of FIG. It is a schematic sectional drawing which shows an example of the manufacturing method of the photoelectric conversion element of this invention. It is a schematic plan view which shows another example of the manufacturing method of the photoelectric conversion element of this invention. It is a schematic plan view which shows another example of the manufacturing method of the photoelectric conversion element of this invention. It is sectional drawing of the III-III line of FIG. It is sectional drawing of the IV-IV line of FIG. It is a schematic sectional drawing which shows another example of the photoelectric conversion element of this invention. It is a schematic sectional drawing which shows an example of the conventional photoelectric conversion element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoelectric conversion element 2 Transparent support body 3 Transparent electrode (1st electrode)
4 Semiconductor Layer 5 Main Seal Material 6a Electrolyte Layer 6b Electrolyte Holding Part 7 Counter Electrode (Second Electrode)
DESCRIPTION OF SYMBOLS 8 Support body 9 Incident light 10 Electrolyte injection part 10 'Electrolyte injection part formation scheduled part 11 End seal material 12 Releaseable resin sheet 13 Injection hole 14 End seal material

Claims (11)

A first substrate having a first electrode having a semiconductor layer carrying a dye; and a second substrate having a second electrode facing the semiconductor layer of the first electrode. A photoelectric conversion element that is opposed to each other while holding an electrolyte between an electrode and the second electrode,
A sealing portion for holding the electrolyte between the first electrode and the second electrode is formed around the electrolyte;
The photoelectric conversion device characterized by having an electrolyte injecting section Ru sealed by the sealing portion by heat and pressure from both sides of the first electrode and the second electrode during the sealing portion .   The photoelectric conversion element according to claim 1, wherein the sealing portion is formed between the first electrode and the second electrode. Wherein the sealing portion of the portion to be the electrolyte injection part, the photoelectric conversion element according to claim 1 is a hot melt resin.   The photoelectric conversion element according to claim 3, wherein the melting point of the hot melt resin is 60 ° C. or higher and 200 ° C. or lower. (A) a first substrate formed with a first electrode having a semiconductor layer carrying a dye, and a second substrate formed with a second electrode, the semiconductor layer of the first electrode And facing the second electrode so as to face each other,
(B) The first substrate and the second substrate are bonded with a sealing material to form a sealing portion, and the first electrode and the second electrode are inside the sealing portion. Forming an electrolyte holding part between the two and forming an electrolyte injection part in the sealing part,
(C) injecting an electrolyte from the electrolyte injection part into the electrolyte holding part;
(D) heating and pressurizing from both sides of the first electrode and the second electrode to seal the electrolyte injection part with the sealing part;
The manufacturing method of the photoelectric conversion element characterized by including.   The photoelectric conversion element according to claim 5, wherein in the step (b), a sealing portion is formed between the first electrode of the first substrate and the second electrode of the second substrate. Manufacturing method.   The method for manufacturing a photoelectric conversion element according to claim 5, wherein in the step (d), the electrolyte injection part is sealed with a hot melt resin.   The method for producing a photoelectric conversion element according to claim 7, wherein the melting point of the hot melt resin is 60 ° C. or higher and 200 ° C. or lower. The said heating and the said pressurization are the manufacturing methods of the photoelectric conversion element of Claim 5 performed simultaneously. The method for manufacturing a photoelectric conversion element according to claim 5 , wherein the heating temperature is 60 ° C. or higher and 250 ° C. or lower. The method for producing a photoelectric conversion element according to claim 5 , wherein the pressure of the pressurization is 0.3 MPa or more and 2.0 MPa or less.

Images