JP5185550B2 - Photoelectric conversion element and manufacturing method thereof - Google Patents

Description

  The present invention relates to a photoelectric conversion element and a manufacturing method thereof. More specifically, the present invention relates to a photoelectric conversion element having excellent sealing reliability by a new sealing structure and a method for manufacturing the photoelectric conversion element.

  Against the backdrop of environmental problems and resource problems, solar cells as clean energy are attracting attention. Some solar cells use single crystal, polycrystalline or amorphous silicon. However, conventional silicon-based solar cells still have problems such as high manufacturing costs and insufficient supply of raw materials.

  In addition, compound solar cells such as Cu-In-Se (also referred to as CIS) have been developed and have excellent characteristics such as high photoelectric conversion efficiency, but problems such as cost and environmental impact There are also concerns.

  On the other hand, the dye-sensitized solar cell has been proposed by a group such as Gretzel in Switzerland, and has attracted attention as a photoelectric conversion element that can obtain high photoelectric conversion efficiency at low cost (see Non-Patent Document 1). reference).

FIG. 7 is a cross-sectional view showing an example of a conventional dye-sensitized solar cell.
This dye-sensitized solar cell 100 includes a first substrate 101 on which a porous semiconductor layer 103 carrying a sensitizing dye is formed on one surface, a second substrate 105 on which a transparent conductive layer 104 is formed, The main component is an electrolyte layer made of, for example, a gel electrolyte enclosed between them.

As the first substrate 101, a light transmissive plate material is used, and a transparent conductive layer 102 is disposed on the surface of the first substrate 101 in contact with the dye-sensitized semiconductor layer 103 in order to provide conductivity. A working electrode 108 is formed by one substrate 101, the transparent conductive layer 102, and the porous semiconductor layer 103.
As the second substrate 105, a conductive layer 104 made of, for example, carbon, platinum, platinum / transparent conductive film, or the like is provided on the surface in contact with the electrolyte layer 106 to provide conductivity. A counter electrode 109 is configured by 104.

The first substrate 101 and the second substrate 105 are arranged at a predetermined interval so that the porous semiconductor layer 103 and the conductive layer 104 face each other, and a sealant made of a thermosetting resin is provided in the peripheral portion between the two substrates. 107 is provided.
The two substrates 101 and 105 are bonded to each other through the sealant 107 and the cells are stacked, and oxidation / reduction of iodine / iodide ions or the like between the electrodes 108 and 109 through the electrolyte inlet 110 is performed. An example is one in which an organic electrolyte solution containing an electrode is filled and an electrolyte layer 106 for charge transfer is formed.

However, in the conventional photoelectric conversion element adopting the sealing structure as described above, since the sealing is generally performed using a thermoplastic resin, a thermosetting resin, or the like, the electrolyte or the increase in the thermal process at the time of sealing. There was a problem that the dye was deteriorated and the power generation characteristics were lowered.
In addition, when the electrolyte contains iodine in an electrolyte such as a general dye-sensitized solar cell, an adhesive that inhibits the reaction by iodine, such as one using a radical reaction for curing, if the electrolyte remains in the sealing part Then, the curing reaction is hindered, and a good sealing state cannot be secured. That is, the choice of the sealing material that can be used is also greatly reduced.
Furthermore, if it is essential that the sealing material has both resistance to electrolytes and resistance to the outside air, the choices of sealing materials that can be used are further narrowed. It had been.
O '' Regan B., Graetzel M., A low cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films, Nature 1991; 353: 737-739

The present invention has been devised in view of such a conventional situation, and it is the first to provide a photoelectric conversion element having excellent sealing reliability and wide selectivity of a sealing material. The purpose.
A second object of the present invention is to provide a method for manufacturing a photoelectric conversion element that can provide a wide selectivity of a sealing material and can separate functions inside and outside by forming a multilayer structure when sealing.

The photoelectric conversion element according to claim 1 of the present invention includes a counter electrode having a conductive first base material, an insulating transparent second base material having an area different from that of the first base material, A porous oxide semiconductor layer disposed on one surface of the second base material via a transparent conductive film and having a dye supported at least in part, the porous oxide semiconductor layer comprising one surface of the first base material; A working electrode disposed oppositely, and an electrolyte layer disposed on at least a portion between the counter electrode and the working electrode, and a narrow area of the first base material and the second base material A sealing member disposed so as to cover at least a side surface portion of any one of the base materials and a side of the electrolyte layer, the sealing member including a plurality of layers , the innermost layer of the layers is characterized in Rukoto such a UV-curable adhesive resin.
A photoelectric conversion element according to a second aspect of the present invention is the photoelectric conversion element according to the first aspect, wherein a part or all of the sealing member is an outer edge portion on the surface of the one substrate opposite to the other substrate. It is arranged so that it may coat | cover.

A photoelectric conversion element according to a third aspect of the present invention is the photoelectric conversion element according to the first aspect, wherein the plurality of layers constituting the sealing member are made of the same material.
The photoelectric conversion element according to claim 4 of the present invention is the photoelectric conversion element according to claim 1, wherein the innermost layer of the sealing member and at least one of the outer layers arranged to cover the innermost layer are made of different materials. It is characterized by.

The manufacturing method of the photoelectric conversion element according to claim 5 of the present invention includes a counter electrode having a conductive first base material, and an insulating transparent second base material having an area different from that of the first base material. And a porous oxide semiconductor layer disposed on one surface of the second base material via a transparent conductive film and supporting a dye at least in part, the porous oxide semiconductor layer comprising the first base material A working electrode disposed opposite to the one surface, and an electrolyte layer disposed on at least a part between the counter electrode and the working electrode, the first substrate and the second substrate A sealing member is disposed so as to cover at least a side surface portion of any one of the base materials having a narrow area and a side of the electrolyte layer, and the sealing member includes a plurality of layers. , wherein the plurality of innermost layer among the layers a manufacturing method of a photoelectric conversion element ing from UV-curable adhesive resin, prior to Sealing member, after forming the innermost layer, is performed to remove the electrolyte components at least in the area in which the outer layer is arranged, then, it is characterized by providing an outer layer so as to cover the innermost layer.

  According to the present invention (invention 1), at least a side surface portion of one of the first base material and the second base material having a narrow area and a side of the electrolyte layer are covered. By providing the sealing member arranged as described above and forming the sealing member from a plurality of layers, the outer layer positioned outside the innermost layer is not directly exposed to the electrolytic solution. Therefore, select the material with excellent electrolytic solution resistance for the innermost layer that is always exposed to the electrolytic solution, and select the material with excellent adhesiveness and air resistance for the outer layer outside the innermost layer as required. In addition, the thickness of each layer and the combination of materials can be freely provided according to the area covered by each layer. Therefore, the present invention can provide a photoelectric conversion element having excellent sealing reliability and having a wide selectivity of the sealing material.

  According to the present invention (Claim 5), in forming the sealing member, after the innermost layer is formed, the electrolyte component is removed at least in a portion where the outer layer is disposed, and then the innermost layer is covered. An outer layer is provided. Therefore, select the material with excellent electrolytic solution resistance for the innermost layer that is always exposed to the electrolytic solution, and select the material with excellent adhesiveness and air resistance for the outer layer outside the innermost layer as required. In addition, the thickness of each layer and the combination of materials can be freely provided according to the area covered by each layer. Therefore, when sealing, it is possible to provide a method for manufacturing a photoelectric conversion element that has a wide selectivity of a sealing material and can also separate functions inside and outside by forming a multilayer structure. In particular, the multi-layered sealing member enables the arrangement of appropriate members in accordance with the functions required inside and outside, so that the degree of freedom in designing the photoelectric conversion element can be improved at the same time.

  Hereinafter, an embodiment of a semiconductor device according to the present invention will be described with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a photoelectric conversion element 10A (10) according to the present invention.
The photoelectric conversion element 10 of the present invention includes a counter electrode 12 made of a conductive first base material 11, an insulating transparent second base material 13 having an area different from that of the first base material, and the second base material 13. A porous oxide semiconductor layer 15 disposed on one surface of a base material 13 via a transparent conductive film 14 and carrying a pigment at least partially, the porous oxide semiconductor layer 15 being the first base material 11 The working electrode 16 is disposed so as to face one surface, and the electrolyte layer 17 is disposed on at least a part between the counter electrode 11 and the working electrode 16.

  And the photoelectric conversion element of this invention was distribute | arranged so that the side part of either one base material which has a narrow area among said 1st base material and said 2nd base material, and the said electrolyte layer might be coat | covered at least. A sealing member 18 is provided, and the sealing member 18 includes a plurality of layers.

  In the photoelectric conversion element 10 </ b> A (10) illustrated in FIG. 1, the first base material 11 has a smaller area than the second base material 13. Further, in the photoelectric conversion element 10A (10), the sealing member 18 includes two layers of a sealing layer 19a that is an innermost layer and a sealing layer 19b that is an outer layer disposed so as to cover the innermost layer. However, the present invention is not limited to this, and the sealing member 18 may be composed of three or more layers.

  By disposing the sealing member 18 so as to cover at least the side surface portions of the counter electrode 12 having a smaller area than the working electrode 16 and the electrolyte layer 17, and forming the sealing member 18 from a plurality of layers, The outer layer located outside the innermost layer is in a form that is not directly exposed to the electrolyte. Therefore, select the material with excellent electrolytic solution resistance for the innermost layer that is always exposed to the electrolytic solution, and select the material with excellent adhesiveness and air resistance for the outer layer outside the innermost layer as required. In addition, the thickness of each layer and the combination of materials can be freely provided according to the area covered by each layer. Thereby, the adhesiveness of a sealing part improves and the fall of the adhesive strength by electrolyte solution can be prevented. As a result, the photoelectric conversion element 10 has excellent sealing reliability.

The plurality of sealing layers constituting the sealing member 18 may be made of the same material, or the innermost layer of the sealing member and at least one of the outer layers arranged to cover the innermost layer. May be composed of different materials.
By configuring the plurality of sealing layers from the same material, a favorable sealing portion can be configured without significant changes such as material handling conditions.

In addition, by configuring at least one of the innermost layer and the outer layer from different materials, it is possible to use materials having different functions in the innermost layer and the outer layer, so it is possible to select an appropriate material according to the characteristics. it can. Moreover, the film thickness of each layer and the combination of materials can be freely provided according to the area | region which each layer coat | covers.
For example, in the innermost layer, there is a restriction that a reaction system that is inhibited by the iodine electrolyte cannot be selected at the time of curing. (Examples of reaction inhibition by the iodine electrolyte include, for example, polymerization and curing by radical reaction. In the outer layer, the above-mentioned restrictions can be avoided, so it is only necessary to select an appropriate material based on indices such as adhesive strength, barrier properties, and flexibility, and a wider choice can be obtained. .

  The material of the sealing layer is not particularly limited. For example, acrylic, epoxy, urethane, olefin, and siloxane resins can be used alone or in plural, and heating, light irradiation can be used. Those that cure by two-component mixing, humidification, oxygen removal, humidity removal, etc. can be selected. Not only a curing reaction type resin but also a thermoplastic resin sheet may be applied. Further, an inorganic material (for example, low melting point glass) that can form a dense layer other than the resin can also be used. As an example when using low-melting glass, a paste containing a low-melting glass frit is applied to the adherend surface using a printing machine, a dispenser, etc., and is densely sealed by locally heating by laser irradiation or the like. Can be formed.

  Part or all of the sealing member 18 also covers the outer edge of the one substrate (first base material 11) on the surface opposite to the other substrate (second base material 13). It is preferable that it is arranged. Thereby, sealing performance improves and it can prevent reliably the sealing reliability fall by electrolyte solution.

  The photoelectric conversion element 10B (10) shown in FIG. 2 is arranged so that the sealing layer 19b, which is the outer layer, covers the outer edge portion of the surface of the first base material 11 opposite to the second base material 13. This is an example. In addition, the photoelectric conversion element 10C (10) illustrated in FIG. 3 includes both the sealing layer 19a that is the inner layer and the sealing layer 19b that is the outer layer, and the second base material 13 of the first base material 11. In this example, the outer edge on the opposite surface is also covered.

  Such a sealing member 18 may have a shape that bites into a laminated body in which the working electrode 16, the electrolyte layer 17, and the counter electrode 12 are overlaid, as in the photoelectric conversion element 10 </ b> D (10) illustrated in FIG. 4. I do not care.

  In the present invention, at least the sealing structure as described above may be included in the element structure, and another structure may be provided outside the element structure. For example, the sealing structure described above is used as primary sealing, and a sealing layer (secondary sealing layer) is separately provided on the outer side of the element, or the element is incorporated in a housing that also serves as secondary sealing ( You can store it).

  The working electrode 16 is schematically composed of a transparent substrate (second substrate) 13, a transparent conductive film 14 formed on one surface thereof, and a porous oxide semiconductor layer 15 carrying a sensitizing dye. Has been.

  As the transparent base material 13, a substrate made of a light-transmitting material is used, and glass, polyethylene terephthalate, polycarbonate, polyether sulfone, etc., as long as they are usually used as a transparent base material for the photoelectric conversion element 10. But it can also be used. The transparent substrate 13 is appropriately selected from these in consideration of resistance to the electrolytic solution and the like. Moreover, as a transparent base material 13, the board | substrate which is excellent in the light transmittance as much as possible is preferable on a use, and the board | substrate whose transmittance | permeability is 80% or more is more preferable.

The transparent conductive film 14 is a thin film formed on one surface of the transparent base material 13 in order to impart conductivity. In order to obtain a structure that does not significantly impair the transparency of the transparent conductive substrate, the transparent conductive film 14 is preferably a thin film made of a conductive metal oxide.
Examples of the conductive metal oxide that forms the transparent conductive film 14 include tin-added indium oxide (ITO), fluorine-added tin oxide (FTO), and the like. The transparent conductive film 14 is preferably a single layer film made of only FTO or a laminated film in which a film made of FTO is laminated on a film made of ITO.

  By making the transparent conductive film 14 a single-layer film made of only FTO or a laminated film in which a film made of FTO is laminated on a film made of ITO, the amount of light absorption in the visible region is small, and the conductivity And a transparent conductive substrate having high heat resistance can be formed.

The porous oxide semiconductor layer 15 is provided on the transparent conductive film 14, and a sensitizing dye is supported on the surface thereof. The semiconductor for forming the porous oxide semiconductor layer 15 is not particularly limited, and any semiconductor can be used as long as it is usually used for forming a porous oxide semiconductor for a photoelectric conversion element. As such a semiconductor, for example, titanium oxide (TiO ₂ ), tin oxide (SnO ₂ ), tungsten oxide (WO ₃ ), zinc oxide (ZnO), niobium oxide (Nb ₂ O ₅ ), or the like can be used. .

  As a method for forming the porous oxide semiconductor layer 15, for example, a dispersion in which commercially available oxide semiconductor fine 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, a 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 is applied, and then the coating film is dried and baked. Can be applied.

  As sensitizing dyes, ruthenium complexes containing bipyridine structure, terpyridine structure, etc. as ligands, metal-containing complexes such as porphyrin, phthalocyanine, organic dyes such as eosin, coumarin, rhodamine, merocyanine and other organic dyes can be applied. Of these, those exhibiting behavior suitable for the application and the semiconductor used can be selected without particular limitation.

  The electrolyte layer 17 is formed by impregnating an electrolyte solution between both electrodes including the porous oxide semiconductor layer 15, or the electrolyte solution is gelled (pseudo-solidified) using an appropriate gelling agent. Things are used.

As the electrolytic solution, an organic solvent containing a redox species, a room temperature molten salt (ionic liquid), or the like can be used. In addition, the electrolyte is made solid by introducing an appropriate gelling agent (polymer gelling agent, low molecular gelling agent, various nanoparticles, carbon nanotubes, etc.), so-called gel electrolyte is used. It doesn't matter. There are no particular limitations on the solvent, but organic solvents such as acetonitrile, methoxyacetonitrile, propionitrile, propylene carbonate, ethylene carbonate, diethyl carbonate, γ-butyrolactone, imidazolium cations, pyrrolidinium cations, pyridinium cations, etc. A room temperature molten salt composed of a cation having a quaternized nitrogen atom and the like, an iodide ion, a bistrifluoromethanesulfonylimide anion, a dicyanoamide anion, a thiocyanate anion, and the like can be selected. The redox species is not particularly limited, but one formed by adding iodine / iodide ions, bromine / bromide ions, etc. can be selected. For example, in the former case, an iodide salt (lithium salt, quaternary salt) is selected. Graded imidazolium salt derivatives, tetraalkylammonium salts, etc. can be used singly or in combination, and the electrolyte may further include 4-tert-butylpyridine, N-methylbenzimidazole, if necessary. Various additives such as guanidinium salt derivatives may be added.
However, when an ionic liquid is applied to the electrolyte, it is particularly likely to remain (because it is non-volatile). Further, since there is a concern of mixing into the electrolyte layer, washing with a solvent or the like is not preferable. Therefore, care must be taken in handling.

Like the photoelectric conversion element 10E (10) shown in FIG. 5, the counter electrode 12 is disposed on the conductive first base material 11 and one of the surfaces (the surface opposite to the working electrode 16). It is preferable that the first base material 11 and the coating film 20 made of a different metal are used.
As the first base material 11, a metal plate that is chemically stable with respect to the conductive iodine electrolyte solution is preferably used, but more preferably a titanium plate or a nickel plate.
The coating 20 is preferably composed of a solderable single metal such as Cu, or an alloy containing the metal as a main component.
In addition, a layer of platinum, carbon, conductive polymer, or the like is provided on the other surface of the first substrate 11 (the surface facing the working electrode 16).

By setting it as the above structures, the said film 20 functions as a joining layer of a solder and a titanium substrate. Thereby, it becomes possible to solder a lead wire on the coating 20 of the counter electrode 12, and the electrical connectivity between the counter electrode 12 and the external wiring can be improved.
The coating 20 only needs to enable soldering of the lead wires, and may be formed on the entire surface of the first base material 11 or may be formed only on a part thereof.

  In the photoelectric conversion element described above, the first base material 11 (counter electrode) has a smaller area than the second base material 13 (working electrode), but the photoelectric conversion element 10F (10 shown in FIG. 6). ), The second base material 13 (working electrode) may have a smaller area than the first base material 11 (counter electrode). Also in this case, similarly, the sealing member 18 is arranged so as to cover at least the side surfaces of the working electrode 16 having a smaller area than the counter electrode 12 and the electrolyte layer 17, and the sealing member 18 is formed of a plurality of layers. By comprising, the adhesiveness of a sealing part improves and it can prevent the sealing reliability fall by electrolyte solution.

  In the photoelectric conversion element 10F having such a configuration, the second base material 13 is an arbitrary substrate such as metal, resin, glass, ceramics, or carbon. At least the inner surface of the cell has conductivity and is chemically and electrochemically inert to the iodine electrolyte. Desirably, a metal substrate or a carbon substrate is preferable. More preferably, a metal substrate selected from titanium, nickel, and molybdenum. It is more preferable to form a material on the outer surface of the cell that is superior in conductivity to a copper layer or the like and that can be easily joined to an external arrangement such as soldering.

Next, a manufacturing method of the photoelectric conversion element 10A of this embodiment will be described.
First, a transparent conductive substrate having a transparent conductive film 14 formed on one surface of a transparent substrate (second substrate) 13 is prepared.
The method for forming the transparent conductive film 14 is not particularly limited, and examples thereof include thin film formation methods such as sputtering, CVD (chemical vapor deposition), spray pyrolysis (SPD), and vapor deposition. Can be mentioned.

Next, the porous oxide semiconductor layer 15 is formed on the transparent conductive film 14. The formation of the porous oxide semiconductor layer 15 mainly includes a coating process and a drying / firing process.
The coating process, for example, a TiO ₂ powder and a surfactant or the like formed by mixed at a predetermined ratio of the TiO ₂ paste is intended to be applied to the surface of the transparent conductive film 14. In this case, examples of the coating method include a doctor blade method and a screen printing method.

  The drying / firing step is, for example, in an air atmosphere or a nitrogen stream for an appropriate time, left at room temperature or under heating, dried the coating film, and then used an electric furnace or the like for an appropriate time of about 400 to 500 ° C. The method of baking at temperature is mentioned.

Next, a dye is supported on the porous oxide semiconductor layer 15 formed by the coating process and the drying / firing process.
As a dye solution for supporting a dye, for example, a solution prepared by adding an appropriate amount of dye (for example, ruthenium complex) powder to a solvent in which acetonitrile and t-butanol have a volume ratio of 1: 1 is prepared in advance. .
The porous oxide semiconductor layer 15 is immersed in the dye solution placed in the container, and immersed in a dark place, for example, all day and night. Thereafter, the porous oxide semiconductor layer 15 taken out from the dye solution is washed using a mixed solvent of acetonitrile and t-butanol.
Through the above-described steps, a working electrode 16 (also referred to as a window electrode) obtained by providing a porous oxide semiconductor layer 15 made of a dye-supported TiO ₂ thin film on a transparent substrate is obtained.

  On the other hand, on one surface (surface opposite to the working electrode) of the first base material 11 made of a metal plate such as a titanium plate, a solderable single metal such as Cu, or the metal as a main component. A film 20 made of an alloy is formed by sputtering or the like, and a layer of platinum, carbon, conductive polymer or the like is formed on the other surface of the first base material 11 (the surface facing the working electrode 16). The counter electrode 12 is obtained by forming.

After the working electrode 16 is arranged so that the porous oxide semiconductor layer 15 made of a dye-supported TiO ₂ thin film is located above, an electrolyte (electrolyte, gel electrolyte, etc.) is placed on the porous oxide semiconductor layer 15. The counter electrode 12 is provided so as to overlap the working electrode 16 so that the porous oxide semiconductor layer 15 and the first base material 11 face each other.
Thereafter, sealing is performed by disposing a sealing member 18 composed of a plurality of sealing layers in the vicinity of the outer periphery where the working electrode 16 and the counter electrode 12 overlap.
At this time, it is preferable that the sealing layer is formed on the surface of the counter electrode 12 opposite to the working electrode 16 so as to cover the outer edge portion. Thereby, sealing property improves and it can prevent reliably the fall of the sealing reliability by electrolyte solution.

  Here, in the present invention, after forming the sealing layer 19a (innermost layer) in the formation of the sealing member 18, the electrolyte component is removed at least in the portion where the sealing layer 19b (outer layer) is disposed, and thereafter The sealing layer 19 is provided so as to cover the sealing layer 19a.

  That is, after the first layer is formed, the second and subsequent layers are separately formed. At that time, the adherend surface (the surface opposite to the working electrode facing surface of the counter electrode, the outer peripheral surface where the counter electrode on the working electrode does not overlap, the surface of the first layer, etc.) exudes or exudes by means such as cleaning or wiping Remove the electrolyte. The first layer has a role as a temporary stop to prevent the electrolyte from protruding during the sealing process, and the second and subsequent layers play the role of the main sealing. As a result, it is possible to solve the problem that the residual electrolyte on the adherend surface significantly lowers the adhesive strength of the sealing resin, that is, deteriorates the adhesive state of the interface and lowers the sealing reliability.

  The adherend surface should have a small area within a range that does not affect the properties, but on the other hand, when a liquid or solid electrolyte is used, it oozes out a little during the assembly process, Overhang will occur. If the deposition area is increased, the bonding reliability is improved, but the power generation area (at least the part that does not overlap with the counter electrode) is reduced. If the deposition area is too small, the sealing (bonding) reliability is ensured. Is difficult.

  The photoelectric conversion element thus obtained is arranged so as to cover at least the side surface of one of the first base and the second base having a narrow area and the electrolyte layer. By providing the sealing member 18 that is formed, and forming the sealing member 18 from a plurality of layers, the adhesiveness of the sealing portion can be improved, and a decrease in the adhesive strength due to the electrolytic solution can be prevented. As a result, excellent sealing reliability is obtained.

  The photoelectric conversion element according to the present invention has been described above. However, the present invention is not limited to the above example, and can be appropriately changed as necessary.

Various adhesive resins were tested for adhesion.
Sealing resin A (UV curable adhesive resin), sealing resin B (UV curable adhesive resin), sealing resin C (thermosetting adhesive resin), sealing resin D (thermoplastic resin sheet “HIMILAN” For each of 1652 "), the adhesive strength between the glass substrate and the Ti foil was measured under different conditions.

Condition 1 is the adhesive strength when a resin layer is formed on a clean glass surface, and Condition 2 is when the resin layer is formed after dripping and wiping lightly an ionic liquid type iodine electrolytic solution on the glass surface. Adhesive strength. The adhesive strength was evaluated by a 90 ° peel test. The results are shown in Table 1.

Moreover, the dye-sensitized photoelectric conversion element was produced using the above sealing resin, and sealing property was evaluated.
Example 1
In this example, a photoelectric conversion element (structure 1) as shown in FIG. 3 was produced.
An FTO / ITO transparent conductive film was formed on a glass substrate (140 mm square) by spray pyrolysis. A porous layer made of TiO ₂ nanoparticles was formed on the transparent conductive film substrate to a thickness of about 10 μm. Specifically, a coating film containing TiO ₂ nanoparticles was formed by a screen printing method, dried, and then fired at 500 ° C. to obtain a porous film. In addition, a silver current grid and a wiring protective layer were also formed. A ruthenium complex (N719 dye) was supported as a sensitizing dye on the porous TiO ₂ layer. The above was taken as the working electrode.

A copper layer was formed on one surface and a Pt layer was formed on the other surface of a 40 μm-thick metal Ti foil. The above was taken as the counter electrode. The Pt forming surface is used facing the working electrode.
Further, a liquid electrolyte was prepared by dissolving I ₂ in the ionic liquid HMIm-I.
The manufactured working electrode and the counter electrode are stacked with an electrolyte interposed therebetween, and a sealing layer (inner layer) made of the sealing resin A is formed so as to cover at least the side surface portion of the counter electrode and the electrolyte layer, thereby covering the interior. Thus, the dye-sensitized photoelectric conversion element for a test was obtained by forming the sealing layer (outer layer) which consists of sealing resin A, and sealing. In addition, after forming an inner layer, before forming an outer layer, the iodine electrolyte solution adhering to a to-be-adhered surface was wiped off using the clean wiper which soaked acetonitrile.

(Example 2)
In this example, a dye-sensitized photoelectric conversion element was produced in the same manner as in Example 1 except that the sealing resin B was used as the sealing layer (outer layer).

(Example 3)
In this example, a dye-sensitized photoelectric conversion element was produced in the same manner as in Example 1 except that the sealing resin C was used as the sealing layer (outer layer).

Example 4
In this example, a dye-sensitized photoelectric conversion element was produced in the same manner as in Example 1 except that the sealing resin D was used as the sealing layer (outer layer).

(Example 5)
In this example, a dye-sensitized photoelectric conversion element was produced in the same manner as in Example 1 except that a gel electrolyte was used instead of the liquid electrolyte.
The gel electrolyte was a pseudo solid (gel) electrolyte by mixing 5 wt% SiO ₂ nanoparticles with the liquid electrolyte.

(Example 6)
In this example, a back-illuminated photoelectric conversion element (structure 2) as shown in FIG. 6 was produced.
A porous TiO ₂ layer was formed on one surface of a 40 μm-thick metal Ti foil with the same capacity as described above, and a sensitizing dye was supported in the same manner. A copper layer was formed on one surface of the metal Ti foil. The above was defined as a working electrode (Ti working electrode).
An ITO transparent conductive film, an Ag current collecting grid, and a wiring protective layer were formed on the PEN substrate, and a Pt layer was further formed on the substrate. The above was taken as the counter electrode.

  The manufactured working electrode and the counter electrode are stacked with an electrolyte interposed therebetween, and a sealing layer (inner layer) made of the sealing resin A is formed so as to cover at least the side surface portion of the counter electrode and the electrolyte layer, thereby covering the interior. Thus, the dye-sensitized photoelectric conversion element for a test was obtained by forming the sealing layer (outer layer) which consists of sealing resin A, and sealing. In addition, after forming an inner layer, before forming an outer layer, the iodine electrolyte solution adhering to a to-be-adhered surface was wiped off using the clean wiper which soaked acetonitrile.

(Comparative Example 1)
In this example, in the formation of the sealing layer, after forming the inner layer and before forming the outer layer, the dye was the same as in Example 1 except that the iodine electrolyte attached to the adherend was not wiped off. A sensitized photoelectric conversion element was produced.

(Comparative Example 2)
In this example, a dye-sensitized photoelectric conversion element was produced in the same manner as in Example 1 except that only one layer made of the sealing resin A was used as the sealing layer.

(Comparative Example 3)
In this example, a dye-sensitized photoelectric conversion element was produced in the same manner as in Example 5 except that only one sealing resin A layer was used as the sealing layer.

(Comparative Example 4)
In this example, a dye-sensitized photoelectric conversion element was produced in the same manner as in Example 6 except that only one sealing resin A layer was used as the sealing layer.
Table 2 summarizes the structure of each element and the sealing resin produced in Examples 1 to 6 and Comparative Examples 1 to 4.

  About the photoelectric conversion element of the Example produced as mentioned above and a comparative example, four points of (a)-(d) shown below became clear.

* This paragraph will be deleted.

(A) In the element of an Example, it turned out that all have high adhesive strength compared with the element of a comparative example. In Comparative Example 1 in which the electrolytic solution adhering to the adherend surface was not wiped off before forming the outer layer, the adhesive strength was remarkably reduced on the surface where the iodine electrolytic solution remained.
(B) After preparing the test cell of the dye-sensitized solar cell, the sealing part was pinched with tweezers. As a result, the sealing resin peeled off easily in the element of the comparative example, and an appropriate sealing state was not obtained. It has been found. On the other hand, the element of the example was not peeled off even if the same operation was performed.
(C) When the element having the structure 1 was held in a constant temperature layer maintained at 50 ° C., the air remaining in the element expanded, and thus the leakage of the electrolyte was confirmed from the sealing portion of the comparative example. No abnormality was found in each of the elements.
(D) When the element of the structure 2 was gently bent, no abnormality was found in the element of the example. However, in the element of the comparative example, the sealing resin was peeled off, and leakage of the electrolyte was confirmed. .
From the above results, the effectiveness of the sealing structure according to the present invention was confirmed.

  The present invention is applicable to a photoelectric conversion element and a manufacturing method thereof.

It is a schematic sectional drawing which shows an example of the photoelectric conversion element which concerns on this invention. It is a schematic sectional drawing which shows another example of the photoelectric conversion element which concerns on this invention. It is a schematic sectional drawing which shows another example of the photoelectric conversion element which concerns on this invention. It is a schematic sectional drawing which shows another example of the photoelectric conversion element which concerns on this invention. It is a schematic sectional drawing which shows another example of the photoelectric conversion element which concerns on this invention. It is a schematic sectional drawing which shows another example of the photoelectric conversion element which concerns on this invention. It is a schematic sectional drawing which shows an example of the conventional photoelectric conversion element.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Photoelectric conversion element, 11 1st base material, 12 Counter electrode, 13 2nd base material, 14 Transparent electrically conductive film, 15 Porous oxide semiconductor layer, 16 Working electrode, 17 Electrolyte layer, 18 Sealing member, 19 Sealing layer 20 coating.

Claims (5)

A counter electrode having a conductive first substrate;
A porous substrate having an area different from that of the first substrate, an insulating transparent second substrate, a porous substrate disposed on one surface of the second substrate via a transparent conductive film, and at least partially supporting a dye A working electrode provided with an oxide semiconductor layer, wherein the porous oxide semiconductor layer is disposed to face one surface of the first substrate;
An electrolyte layer disposed at least in part between the counter electrode and the working electrode,
A sealing member arranged to cover at least a side surface portion of one of the base materials having a narrow area between the first base material and the second base material, and a side of the electrolyte layer;
The sealing member is composed of a plurality of layers, the photoelectric conversion element innermost layer, wherein Rukoto such an ultraviolet curing adhesive resin among the plurality of layers.  2. The sealing member according to claim 1, wherein a part or all of the sealing member is disposed so as to cover an outer edge portion of the surface of the one substrate opposite to the other substrate. Photoelectric conversion element.  The photoelectric conversion element according to claim 1, wherein the plurality of layers constituting the sealing member are made of the same material.  2. The photoelectric conversion element according to claim 1, wherein the innermost layer of the sealing member and at least one of the outer layers disposed so as to cover the innermost layer are made of different materials. A counter electrode having a conductive first substrate;
A porous substrate having an area different from that of the first substrate, an insulating transparent second substrate, a porous substrate disposed on one surface of the second substrate via a transparent conductive film, and at least partially supporting a dye A working electrode provided with an oxide semiconductor layer, wherein the porous oxide semiconductor layer is disposed to face one surface of the first substrate;
An electrolyte layer disposed at least in part between the counter electrode and the working electrode,
A sealing member arranged to cover at least a side surface portion of one of the base materials having a narrow area between the first base material and the second base material, and a side of the electrolyte layer;
The sealing member is composed of a plurality of layers, said plurality of innermost among the layers is a method of manufacturing the photoelectric conversion element ing from UV-curable adhesive resin,
After the innermost layer is formed, the sealing member removes an electrolyte component at least in a portion where the outer layer is disposed, and then provides the outer layer so as to cover the innermost layer. Method.

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