JP4172239B2 - Photoelectric conversion element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photoelectric conversion element used for a dye-sensitized solar cell or the like.
[0002]
[Prior art]
A new type of dye-sensitized solar cell proposed by Gretzell et al. Attracted attention because of its dramatically higher conversion efficiency (on the order of 7%) than conventional dye-sensitized solar cells. The dye-sensitized solar cell realizes photoelectric conversion by injecting into a semiconductor excited electrons generated by a dye that collects light. Therefore, it is important that a large amount of a sensitizing dye is supported on the semiconductor in order to increase the light collecting ability, and that electrons are injected 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).
[0003]
[Non-Patent Document 1]
Gratzel, 1 other, “Nature” (UK), Oct. 24, 1991, volume 353, p. 737-740
This Gretzel cell can be assembled by simply applying a paste in which ultrafine particles of titanium oxide are dispersed to a transparent electrode, carrying a sensitizing dye, and filling an electrolyte between the counter electrode. Compared to conventional solar cells, it can be manufactured with a simple device, and is attracting attention as one of the next-generation solar cells.
[0004]
Currently, one of the challenges of Gretzell cells is durability, and in particular, measures against electrolyte leakage are indispensable. That is, the electrolyte disposed between the transparent electrode coated with titanium oxide and the counter electrode must be maintained for a long time. The inventors have arranged a porous support such as a separator between the electrode on which the semiconductor layer has already been deposited and the counter electrode, and filled the electrolyte in the porous support so that the electrolyte can be supplied to both electrodes. It was proposed that it could be held for a long time (see Patent Document 1). In addition, there is an example in which countermeasures for leakage are performed by gelling the electrolyte (see Patent Document 2, Patent Document 3, and Patent Document 4).
[0005]
[Patent Document 1]
JP 2001-345126 A
[0006]
[Patent Document 2]
JP-A-9-27352
[0007]
[Patent Document 3]
Japanese Patent Laid-Open No. 11-126917
[0008]
[Patent Document 4]
JP 2001-160427 A
However, the countermeasures described in Patent Documents 1 to 4 are not sufficient for countermeasures against leakage. As described in these documents, it is indispensable not only to hold the electrolyte between both electrodes, but also to take a sealing measure so that the electrolyte does not leak from the cell even when a physical and chemical stimulus is applied to the cell. The main points of cell sealing are the selection of a sealing material considering the electrolyte composition and the sealing structure. Conventionally, a sealing structure has been proposed in which a silicone resin is used as a sealing material in contact with an electrolyte and an epoxy resin is disposed outside the sealing material (see, for example, Patent Document 5). It has also been proposed to use glass frit with excellent durability and chemical resistance as a sealing material (see, for example, Patent Document 6 and Patent Document 7).
[0009]
[Patent Document 5]
European Patent No. 855726
[0010]
[Patent Document 6]
JP 2000-348783 A
[0011]
[Patent Document 7]
JP 2001-185244 A
[0012]
[Problems to be solved by the invention]
The silicone resin, epoxy resin, and glass frit are excellent sealing materials, but there is a problem that the sealing effect is not exhibited unless these sealing materials are sufficiently cured and densified. As a result of intensive studies on this point, the present inventors have found that sealing of the electrolyte injection hole portion is the most important. That is, the sealing of the portion other than the electrolyte injection hole is possible in terms of manufacturing method, after the hardening and densification of the sealing material is completed, and the sealing strength can be sufficiently exhibited. . However, the electrolyte injection hole portion must be sealed in a state where the electrolyte and the sealing material are in contact with each other, and it is difficult to sufficiently cure and densify the sealing material. As a result, the strength of the sealing material for the electrolyte injection hole becomes insufficient, causing electrolyte leakage. Therefore, a sealing structure is required that can seal the sealing material and the electrolyte without making direct contact at the electrolyte injection hole.
[0013]
The present invention provides a photoelectric conversion element having excellent leakage resistance as a sealing structure in which the sealing portion of the electrolyte injection hole and the electrolyte are not in direct contact with each other.
[0014]
[Means for Solving the Problems]
The photoelectric conversion element of the present invention includes a first electrode on which a semiconductor layer carrying a sensitizing dye is deposited, a second electrode facing the semiconductor layer of the first electrode, and the first electrode A photoelectric conversion element having an electrolyte disposed between a semiconductor layer and the second electrode,
The electrolyte is filled in an electrolyte chamber having an electrolyte injection hole,
The electrolyte injection hole is blocked from the outside by a sealing portion,
The electrolyte injection hole is characterized in that a gap portion not filled with an electrolyte is provided between the electrolyte and the sealing portion.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0016]
  The photoelectric conversion element according to the embodiment of the present invention includes a first electrode on which a semiconductor layer carrying a sensitizing dye is deposited, a second electrode facing the semiconductor layer of the first electrode, and the first electrode. It is a photoelectric conversion element which has the electrolyte arrange | positioned between the semiconductor layer of said electrode, and the said 2nd electrode. The electrolyte is filled in an electrolyte chamber having an electrolyte injection hole, the electrolyte injection hole is blocked from the outside by a sealing portion, and the electrolyte injection hole has an electrolyte between the electrolyte and the sealing portion. An unfilled void is provided.The sealing portion is formed of at least one selected from the group consisting of silicone resin, epoxy resin, hot melt resin, glass frit, and ultraviolet curable resin.
[0017]
Since the electrolyte injection hole includes a gap portion that is not filled with the electrolyte between the electrolyte and the sealing portion, the electrolyte injection hole is cured without contacting the sealing material with the electrolyte when sealing the electrolyte injection hole. Since it can be densified, the strength of the sealing portion is increased, and a photoelectric conversion element having excellent leakage resistance can be provided.
[0018]
Moreover, it is preferable that the said electrolyte chamber consists of a main electrolyte chamber and a subelectrolyte chamber, and the said electrolyte injection hole is provided in the said subelectrolyte chamber. Thereby, even if the air in the void portion of the electrolyte injection hole flows into the electrolyte chamber, the air (bubbles) does not flow into the main electrolyte chamber.
[0019]
Moreover, it is preferable that the sealing part of the electrolyte injection hole is formed of a first sealing part and a second sealing part, and the second sealing part is disposed outside the first sealing part. The first sealing portion imparts basic liquid tightness to the electrolyte injection hole, and the second sealing portion serves to reinforce the mechanical, physical, and chemical strength of the first sealing portion.
[0020]
  The first sealing portion isSilicone resin, epoxy resin, hot melt resin, glass fritIt is preferably formed from at least one selected from the group consisting of This is because the first sealing portion of the electrolyte injection hole is formed after the electrolyte is injected, and therefore it is necessary to form the sealing portion in a short time. The second sealing portion isSilicone resin, epoxy resin, hot melt resin, glass frit,It is preferably formed from at least one selected from ultraviolet curable resins. This is because they are excellent in mechanical, physical and chemical strength.
[0021]
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an embodiment of the photoelectric conversion element of the present invention. FIG. 2 is a schematic plan view showing one embodiment of the photoelectric conversion element of the present invention, as seen from the incident light 23 side in FIG. 1 and 2, the photoelectric conversion element 1 includes an electrode 5 (first electrode) formed on one surface of a substrate 3. A semiconductor layer 7 carrying a sensitizing dye is formed on one surface of the electrode 5.
[0022]
Further, a counter electrode 19 (second electrode) is present opposite to the semiconductor layer 7 on which the sensitizing dye is supported. The counter electrode 19 is formed on one surface of another substrate 21. A main electrolyte chamber 9 is disposed between the semiconductor layer 7 and the counter electrode 19. The main electrolyte chamber 9 is connected between the electrode 5 and the counter electrode 19 in order to introduce an electrolyte into the main electrolyte chamber 9. A secondary electrolyte chamber 11 is disposed. The main electrolyte chamber 9 and the sub-electrolyte chamber 11 are formed of a first sealing portion 13a that is in contact with the electrolyte and a second sealing portion 15a that is disposed outside the first sealing portion 13a. An electrolyte injection hole 17 for injecting an electrolyte into the main electrolyte chamber 9 and the sub-electrolyte chamber 11 is drilled from the substrate 21 of the counter electrode 19 to the sub-electrolyte chamber 11. The electrolyte injection hole 17 is sealed by the first sealing portion 13b, and the second sealing portion 15b is disposed so as to cover the first sealing portion 13b.
[0023]
The electrolyte injection hole 17 includes a gap portion 17a that is not filled with electrolyte between the electrolyte and the first sealing portion 13b.
As a result of diligent efforts to solve the conventional problems, the inventors of the present invention provide the electrolyte injection hole 17 with a gap portion 17a that is not filled with electrolyte between the electrolyte and the first sealing portion 13b. Thus, it has been found that the electrolyte layer can be disposed between the semiconductor layer 7 and the counter electrode 19 without any gap, and the electrolyte layer can be sufficiently sealed.
[0024]
That is, in order to suppress electrolyte leakage, sealing of the electrolyte injection hole 17 is the most important. In order to obtain sufficient sealing strength, it is necessary to sufficiently cure and densify the sealing material. Therefore, in sealing the electrolyte injection hole 17, it is necessary to cure and densify the sealing material without directly contacting the electrolyte. In the present embodiment, in order to prevent the electrolyte and the sealing material from coming into direct contact, in the electrolyte injection hole 17, the gap portion 17 a is provided between the electrolyte and the first sealing portion 13 b (sealing material). Thereby, since the sealing material of the electrolyte injection hole 17 is not brought into contact with the electrolyte until it is completely cured and densified, the liquid tightness of the sealing portion of the electrolyte injection hole 17 can be improved. Further, if this gap portion 17a is present, even if the photoelectric conversion element is exposed to a high temperature condition, the gap portion 17a serves as a damper that relaxes the expansion of the electrolyte layer, and the effect of suppressing deterioration of the sealing material. There is expected.
[0025]
In the present embodiment, since the sub-electrolyte chamber 11 is provided separately from the main electrolyte chamber 9, bubbles do not enter the electrolyte layer of the main electrolyte chamber 9. The sub-electrolyte chamber 11 may have any shape as long as it has a connecting portion with the main electrolyte chamber 9 through which the electrolyte can flow to the main electrolyte chamber 9, and the volume of the sub-electrolyte chamber 11 includes the sub-electrolyte chamber 11 and the electrolyte injection hole 17. It suffices that the gap 17a in the connecting portion can be expanded and contracted in the sub-electrolyte chamber 11.
[0026]
The first sealing portion 13a serves as a wall of the main electrolyte chamber 9 and the sub-electrolyte chamber 11, and is in direct contact with the electrolyte. The material of the first sealing portion 13a is preferably one that is chemically stable even when in contact with the electrolyte, rather than having excellent mechanical or physical strength. Therefore, the material of the first sealing portion 13a is preferably a silicone resin, an epoxy resin, a hot melt resin, a glass frit, or the like. In particular, when a nitrile solvent or a carbonate solvent is used as the electrolyte solvent, a silicone resin or a hot melt resin (for example, an ionomer resin) having low compatibility with these solvents is preferable as the material of the first sealing portion 13a. Further, when glass is used for the substrate 3 and the substrate 21, a glass frit having excellent chemical stability, denseness of the sealing material, adhesion to the substrate, etc. is used as the material of the first sealing portion 13a. Particularly preferred.
[0027]
The second sealing portion 15a is disposed outside the first sealing portion 13a and is not in contact with the electrolyte. The role of the 2nd sealing part 15a is to supplement the intensity | strength of the 1st sealing part 13a, and to suppress the deterioration. Therefore, the sealing material of the second sealing portion 15a is preferably a silicone resin, an epoxy resin, a hot melt resin, a glass frit, or the like. In particular, an epoxy resin is preferable because it is excellent in adhesive strength and low moisture permeability. In addition, a filler may be mixed into this epoxy resin in consideration of the elastic modulus and thermal expansion coefficient of the material of the substrate 3 and the substrate 21, for example, glass or synthetic resin film.
[0028]
The first sealing portion 13b for sealing the electrolyte injection hole 17 is sealed after the injection of the electrolyte, so that the injection hole can be sealed in a short time, for example, silicone adhesive tape, quick-drying epoxy resin, hot-melt resin Etc. are preferably used. The second sealing portion 15b for sealing the electrolyte injection hole 17 is disposed so as to cover the first sealing portion 13b, and it is preferable to use an epoxy resin, an ultraviolet curable resin, or the like as the material. .
[0029]
The material of the substrate 3 is not particularly limited as long as it is a light-transmitting material, but glass or a transparent film is usually used. Since the transparent film has flexibility, it is suitable for applications requiring flexibility. Moreover, the higher the light transmittance of the substrate 3, the better. A preferable light transmittance is 50% or more, and more preferably 80% or more.
[0030]
For the substrate 21, a metal or the like can be used in addition to the same glass or transparent film as the substrate 3. The substrate 21 may be opaque, but is preferably transparent in that light can be incident from the substrates on both sides of the cell.
[0031]
The electrode 5 formed on one surface of the substrate 3 functions as a negative electrode of the photoelectric conversion element 1 and is formed of a metal itself, or is formed by laminating a conductive material layer on a film. Preferred conductive materials include, for example, metals such as platinum, gold, silver, copper, aluminum, rhodium and indium, or carbon, or indium-tin composite oxide, tin oxide doped with antimony, tin oxide doped with fluorine, etc. The electroconductive metal oxide of these is mentioned.
[0032]
The lower the surface resistance of the electrode 5, the better. The range of the surface resistance is preferably 50Ω / □ or less, more preferably 30Ω / □ or less. The lower limit is not particularly limited, but is usually 0.1Ω / □ or more.
[0033]
The higher the light transmittance of the electrode 5, the better. A preferable light transmittance range is 50% or more, and more preferably 80% or more. The film thickness of the electrode 5 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 7. When the transparent electrode 5 is used, the light is preferably incident from the side of the substrate 3 on which the semiconductor layer 7 carrying the sensitizing dye is deposited.
[0034]
As the semiconductor layer 7 itself in the photoelectric conversion element of the present embodiment, the same semiconductor layer as that used in the conventional photoelectric conversion element can be used. The semiconductor layer 7 can obtain a photoelectric conversion element having high photoelectric conversion efficiency by supporting a sensitizing dye.
[0035]
The materials for forming the semiconductor layer 7 include Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, Si, Oxides of metallic elements such as Cr, SrTiO_Three, CaTiO_ThreePerovskite such as CdS, ZnS, In₂S_Three, PbS, Mo₂S, WS₂, Sb₂S_Three, Bi₂S_ThreeZnCdS₂, Cu₂Sulfides such as S, CdSe, In₂Se_Three, WSe₂, HgS, PbSe, CdTe and other metal chalcogenides, other GaAs, Si, Se, Cd₂P_Three, Zn₂P_Three, InP, AgBr, PbI₂, HgI₂, BiI_ThreeOr a composite containing at least one selected from the semiconductor materials, for example, CdS / TiO₂, CdS / AgI, Ag₂S / AgI, CdS / ZnO, CdS / HgS, CdS / PbS, ZnO / ZnS, ZnO / ZnSe, CdS / HgS, CdS_x/ CdSe_1-x, CdS_x/ Te_1-x, CdSe_x/ Te_1-xZnS / CdSe, ZnSe / CdSe, CdS / ZnS, TiO₂/ Cd_ThreeP₂, CdS / CdSeCd_yZn_1-yS, CdS / HgS / CdS, and the like. Above all, TiO₂However, it is preferable in the Gretzel cell because it can avoid photodissolution in the electrolytic solution and realize high photoelectric conversion characteristics.
[0036]
The semiconductor layer 7 is formed on the surface of the electrode 5 by applying a dispersion paint of semiconductor particles, for example, by 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 or the like. It can apply | coat and can form by heat processing and pressurization processing after that.
[0037]
The particle size of the semiconductor particles used for forming the semiconductor layer 7 is generally preferably in the range of 5 to 1000 nm. Within this range, the pore size of the semiconductor layer 7 becomes an appropriate pore size, the movement of the oxidation-reduction substance in the electrolyte solution becomes smooth, and the decrease in photocurrent does not occur. Further, since the surface area of the semiconductor layer 7 can be increased, a sufficient amount of sensitizing 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.
[0038]
The film thickness of the semiconductor layer 7 is preferably in the range of 0.1 to 100 μm. Within this range, a sufficient photoelectric conversion effect can be obtained, and the transmittance for visible light and near-infrared light is not deteriorated. A more preferable range of the film thickness of the semiconductor layer 7 is 1 to 50 μm, and a particularly preferable range is 5 to 30 μm.
[0039]
As the sensitizing dye used for supporting the semiconductor layer 7, any dye that is commonly used in conventional dye-sensitized photoelectric conversion elements can be used. Such dyes are, for example, RuL₂(H₂O)₂Type of ruthenium-cis-diaqua-bipyridyl complex or ruthenium-tris (RuL_Three), Ruthenium-bis (RuL)₂), Osmium-tris (OsL)_Three), Osmium-bis (OsL)₂) Type transition metal complex, or zinc-tetra (4-carboxyphenyl) porphyrin, iron-hexocyanide complex, phthalocyanine, and the like. 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. Of these, ruthenium-bis (RuL₂) Derivatives are particularly preferred because they have a broad absorption spectrum in the visible light range.
[0040]
Examples of the method of supporting the sensitizing dye on the semiconductor layer 7 include a method of immersing the substrate 3 provided with the semiconductor layer 7 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 sensitizing dyes such as water, alcohol, toluene, and dimethylformamide. Moreover, as the immersion method, when the substrate 3 provided with the semiconductor layer 7 is immersed in the sensitizing dye solution for a certain period of time, it can be heated to reflux or an ultrasonic wave can be applied. In order to remove the sensitizing dye remaining on the semiconductor layer 7 without being supported after the dye is supported on the semiconductor layer 7, it is preferably washed with alcohol or heated to reflux.
[0041]
The amount of the sensitizing dye supported on the semiconductor particles is 1 × 10^-8~ 1x10^-6mol / cm²It is preferable to be within the range. This is because within this range, the effect of improving the photoelectric conversion efficiency can be obtained economically and sufficiently.
[0042]
As the electrolyte used in the electrolyte layer in the photoelectric conversion element 1 of the present embodiment, the type is not particularly limited as long as the solvent contains a pair of redox constituents composed of an oxidant and a reductant, A redox-based constituent material in which the oxidized form and the reduced form have the same charge is preferable. The redox-system constituent material in this specification means a pair of substances that are present reversibly in the form of an oxidant and a reductant in a redox reaction. Examples of the redox constituents 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. Among them, iodine compound-iodine is preferable. 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 dimethylpropylimidazo iodide. Particularly preferred are diimidazolium iodide compounds such as lithium.
[0043]
The solvent used for dissolving the electrolyte is preferably a compound that can dissolve the redox constituents and has excellent ion conductivity. As the solvent, any of an aqueous solvent and an organic solvent can be used, but an organic solvent is preferable in order to further stabilize the redox component. For example, 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-dimethoxyethane, 1,3 -Ether compounds such as dioxosilane, tetrahydrofuran, 2-methyl-tetrahydrofuran, heterocyclic compounds such as 3-methyl-2-oxazodilinone, 2-methylpyrrolidone, nitrile compounds such as acetonitrile, methoxyacetonitrile, propionitrile, sulfolane, didimethyl Examples include aprotic polar compounds such as sulfoxide and dimethylformamide. These can be used alone or in combination of two or more. Of 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.
[0044]
The electrolyte used in the present embodiment is not limited to the above-described electrolyte solution, that is, the electrolyte solution, and is a gel electrolyte that is gelled by holding the electrolyte solution with a polymer support or the like, or a room temperature molten salt type An electrolyte or the like can also be used.
[0045]
The counter electrode 19 functions as a positive electrode of the photoelectric conversion element 1 and can be formed in the same manner as the electrode 5 on the side where the semiconductor layer 7 carrying the sensitizing dye is deposited. As the counter electrode 19 of the photoelectric conversion element 1 in the present embodiment, it is preferable to use a material having a catalytic action to give electrons to the electrolyte reductant in order to efficiently act as the positive electrode of the photoelectric conversion element 1. Such materials include, for example, metals such as platinum, gold, silver, copper, aluminum, rhodium and indium, graphite, carbon carrying platinum, indium-tin composite oxide, antimony-doped tin oxide, fluorine Conductive metal oxides such as tin oxide doped with. Of these, platinum and graphite are particularly preferred. The substrate 21 on which the counter electrode 19 is disposed can also have a transparent conductive film (not shown) on the surface to which the counter electrode 19 is attached. This transparent conductive film can be formed from the same material as the electrode 5, for example. In this case, the counter electrode 19 is also preferably transparent.
[0046]
In FIG. 1, the photoelectric conversion element 1 includes an external terminal 26.
[0047]
【Example】
Next, based on an Example, this invention is demonstrated more concretely. However, the present invention is not limited to the following examples.
[0048]
Example 1
0.01 g / dm of Sanyo Chemical Co., Ltd. surfactant “Nonipol 100” (trade name)^ThreeIn a mixed solution of water and acetylacetone (mixing volume ratio = 20/1), titanium oxide particles “P25” (trade name, average particle size of 20 nm) manufactured by Nippon Aerosil Co., Ltd. are adjusted to a concentration of about 38 mass%. To prepare a slurry liquid. Next, this slurry liquid was made into 1 mm thick conductive glass “F-SnO” manufactured by Asahi Glass Co., Ltd.₂"(Trade name, fluorine doped SnO₂After coating on the surface of the glass substrate with a transparent conductive film coated with conductivity and having a surface resistance of 10Ω / □) and drying, the resulting dried product was heated in air at 500 ° C. for 30 minutes, A titanium oxide film having a thickness of 10 μm was formed on the conductive glass to form the first electrode 5. The size of the obtained titanium oxide film was 10 mm long and 10 mm wide.
[0049]
A glass frit paste composed of 100 parts by weight of glass frit, 0.5 parts by weight of acrylic resin, and 50 parts by weight of terpineol was drawn in a pattern as shown in FIG. 3 on the first electrode 5 produced as described above. . Thereafter, drying was performed at 120 ° C. for 30 minutes to remove terpineol, followed by heating at 380 ° C. for 30 minutes to oxidatively remove (debinder) the acrylic resin. Subsequently, the 1st sealing part 13a which consists of glass frit which does not contain a bubble was formed by heating at 450 degreeC for 20 minute (s).
[0050]
The counter electrode 19 (second electrode) is the conductive glass “F-SnO” manufactured by Asahi Glass Co., Ltd.₂The platinum was sputtered to a thickness of 20 nm. The first sealing portion 13a on the counter electrode was formed in the same process as the first electrode 5 as shown in FIG. Thereafter, the electrolyte injection hole 17 and the hole 25 used for supporting the dye were drilled.
[0051]
Next, after overlapping the first sealing portion 13a of the first electrode 5 and the counter electrode 19 facing each other, the first sealing portion 13a is integrated by heating at 455 ° C. for 20 minutes, and the main electrolyte Chamber 9 and sub-electrolyte chamber 11 were formed. The metal foil was sandwiched as a spacer so that the distance between the electrodes was 30 μm, and after the first sealing portion 13a was completely cured and densified and integrated, the spacer was removed.
[0052]
Ru (4,4′-dicarboxyl-2,2′-bipyridine)₂(NCS)₂A sensitizing dye represented by 3 × 10^-Fourmol / dm^ThreeAn ethanol solution is prepared, and the electrolyte injection hole 17 and the hole 25 used for supporting the dye are connected by a silicone rubber tube or the like through a circulation pump, the dye solution is circulated for 20 hours, and the sensitizing dye is converted into titanium oxide. Supported. Then, it was made to dry after wash | cleaning with absolute ethanol.
[0053]
Then, the hole 25 used in carrying | supporting a pigment | dye was plugged up with the polyimide tape with a silicon adhesive, and it reinforced and sealed with the epoxy adhesive so that this might be covered. Next, the electrolyte injection hole 17 is placed in a beaker so that the electrolyte injection hole 17 faces down, the electrolyte is filled up to a position higher than the electrolyte injection hole 17 and is put into a desiccator, and the pressure is reduced until the electrolyte boils, and then returned to normal pressure. The electrolyte was injected. The electrolyte injected by such a method filled all the main electrolyte chamber 9 and the sub-electrolyte chamber 11. However, the inside of the electrolyte injection hole 17 was not filled with the electrolyte solution, and the void portion 17a was formed.
[0054]
As an electrolyte solution, 0.5 mol / dm^ThreeLithium iodide and 0.05 mol / dm^ThreeIodine, 0.5 mol / dm^Three3-methoxypropionitrile containing 4-tert-butylpyridine was used.
[0055]
A cell in which the sub-electrolyte chamber 11 is completely filled with the electrolyte solution has a large internal pressure increase due to a temperature rise and is inferior in reliability, and therefore requires an air space as a damper. A rubber tube or the like from a vacuum pump was applied to the electrolyte injection hole 17 to remove about half of the electrolyte in the sub-electrolyte chamber 11. Thereafter, the electrolyte injection hole 17 was sealed in the same manner as the hole 25.
[0056]
Next, the outside of the first sealing portion 13a made of glass frit was reinforced with an epoxy adhesive to form the second sealing portion 15a. The pressure was reduced to remove the air in the gap between the electrodes so that the epoxy adhesive entered the gap between the electrodes, and then the pressure was returned to normal pressure to fill the gap with the epoxy adhesive. After the epoxy adhesive was cured, a nickel foil was fixed to the electrode with a silver paste and reinforced with a quick-drying epoxy adhesive to form the external terminal 26, thereby producing a photoelectric conversion element of this example.
[0057]
(Example 2)
A 1% by weight binder solution in which ethyl cellulose “N300” (trade name) manufactured by Hercules was dissolved in ethanol was prepared. 6 g of the above-mentioned titanium oxide “P25” manufactured by Nippon Aerosil Co., Ltd. was added to 24 g of this binder solution and subjected to a planetary ball mill to prepare a titanium oxide dispersion. The content of titanium oxide in the dispersion was adjusted to 20% by mass. This dispersion was scraped into a polyethylene naphthalate (PEN) film (ITO / PEN film having a thickness of 125 μm and a surface resistance of 10Ω / □) coated with indium-tin composite oxide (ITO) manufactured by Oji Tobi. It was applied and dried with warm air to form a titanium oxide film on the ITO / PEN film. Next, a pressure of 100 MPa was applied to the titanium oxide film with a press machine to form a titanium oxide film having a length of 10 mm, a width of 10 mm, and a thickness of 15 μm. When pressure was applied, the press surface of the press machine was coated with a fluororesin to improve the releasability between the titanium oxide film and the press surface.
[0058]
An ITO / PEN film provided with this titanium oxide film is referred to as [Ru (4,4′-dicarboxyl-2,2′-bipyridine).₂(NCS)₂] 3 × 10 sensitizing dye represented by bis-tetrabutylammonium^-Fourmol / dm^ThreeIt was immersed in a mixed acetonitrile / t-butyl alcohol mixed solution (mixed volume ratio = 50/50) for 10 hours to carry out a dye carrying treatment.
[0059]
A silicone adhesive was drawn in a pattern as shown in FIG. 3 on a ITO / PEN film (first electrode 5) having a titanium oxide film carrying a sensitizing dye, using a dispenser. Next, platinum was deposited with a thickness of 20 nm on the ITO side of the ITO / PEN film manufactured by Oji Tobi Co., Ltd., and a hole serving as an electrolyte injection hole 17 was formed to form a counter electrode 19 (first electrode) as shown in FIG. 2 electrodes). After disposing a non-woven fabric made of polybutylene terephthalate (PBT) that plays the role of preventing short circuit and holding electrolyte solution on the titanium oxide film, the counter electrode 19 is made to face the first electrode 5 so as to face the silicone adhesive. Made contact. In order to cure the silicone adhesive, the photoelectric conversion element was sandwiched and fixed between two thick glass plates while being allowed to stand at room temperature and room humidity for 4 days or longer.
[0060]
After the silicone adhesive was cured (after the formation of the first sealing portion 13a), the electrolytic solution was injected between the first electrode 5 and the counter electrode 19 by a reduced pressure injection method. However, the inside of the electrolyte injection hole 17 was not filled with the electrolyte solution, and the void portion 17a was formed. As the electrolytic solution, the same electrolytic solution as in Example 1 was used. After injection of the electrolytic solution, about half of the electrolytic solution in the sub-electrolyte chamber 11 was removed. After the electrolyte solution adhering to the periphery of the electrolyte injection hole 17 was thoroughly wiped with alcohol, the electrolyte injection hole 17 was closed with a polyimide tape with a silicone adhesive and covered with an ultraviolet curable resin. Furthermore, the entire element is laminated with a polychlorotrifluoride ethylene film “Accra” (trade name) manufactured by Honeywell so that external terminals can be taken out, and the entire element is reinforced with low moisture permeability and strength. The sealing part 15a was formed. As described above, the photoelectric conversion element of this example was manufactured.
[0061]
(Example 3)
0.01 g / dm of the above-mentioned surfactant “Nonipol 100” manufactured by Sanyo Kasei Co., Ltd.^ThreeA slurry solution is prepared by dispersing the titanium oxide particles “P25” manufactured by Nippon Aerosil Co., Ltd. in a mixed solution of water and acetylacetone (mixed volume ratio = 20/1) to a concentration of about 38% by mass. did. Next, the slurry liquid is made from the conductive glass “F-SnO” manufactured by Asahi Glass Co., Ltd. having a thickness of 1 mm.₂After being coated on the substrate and dried, the obtained dried product was heated in air at 500 ° C. for 30 minutes to form a titanium oxide film having a thickness of 10 μm on the conductive glass to form the first electrode 5. The size of the obtained titanium oxide film was 10 mm long and 10 mm wide.
[0062]
The first electrode 5 is made of [Ru (4,4′-dicarboxyl-2,2′-bipyridine).₂(NCS)₂] 3 × 10 sensitizing dye represented by bis-tetrabutylammonium^-Fourmol / dm^ThreeIt was immersed in a mixed acetonitrile / t-butyl alcohol mixed solution (mixed volume ratio = 50/50) for 10 hours to carry out a dye carrying treatment.
[0063]
A silicone adhesive was drawn as a first sealing portion 13a for sealing the electrolytic solution on the first electrode 5 carrying the sensitizing dye with a dispenser so as to surround the titanium oxide film. Next, the conductive glass “F-SnO” manufactured by Asahi Glass Co., Ltd.₂The platinum was deposited by sputtering with a film thickness of 20 nm, and a hole serving as the electrolyte injection hole 17 was formed as a counter electrode 19 (second electrode). The titanium oxide film of the first electrode 5 and the counter electrode 19 In order to cure the silicone adhesive, the photoelectric conversion element was sandwiched and fixed between two thick glass plates while being allowed to stand at room temperature and room humidity for 4 days or longer. After the silicone adhesive was cured (after the formation of the first sealing portion 13a), it was reinforced and sealed with an epoxy adhesive so as to surround the silicone adhesive.
[0064]
The same electrolytic solution as in Example 1 was injected between the first electrode 5 and the counter electrode 19 by a reduced pressure injection method. After the injection of the electrolytic solution, the electrolytic solution in the portion of the electrolyte injection hole 17 was removed, and a void portion 17a was formed in the portion of the electrolyte injection hole 17. After the electrolyte solution adhering to the periphery of the electrolyte injection hole 17 was thoroughly wiped with alcohol, the electrolyte injection hole 17 was closed with a polyimide tape with a silicone adhesive and covered with an epoxy resin to be reinforced and sealed.
[0065]
The photoelectric conversion element of this example obtained in this way was left in a drier set at a temperature of 60 ° C. to evaluate leakage resistance. As a result, leakage of the electrolyte solution was not visually observed over 150 days, and the photoelectric conversion efficiency was 4.2% and could be kept constant. The conversion efficiency of the photoelectric conversion element is simulated sunlight (AM1.5, 100 mW / cm²) Sample cell (light receiving area 1cm)²) And measured.
[0066]
(Comparative Example 1)
The photoelectric conversion element was fabricated in the same manner as in Example 3 except that the gap 17a was not formed in the electrolyte injection hole 17 and the electrolyte injection hole 17 was sealed with a polyimide tape with a silicone adhesive while the electrolyte injection hole 17 was filled with the electrolytic solution. Produced.
[0067]
The photoelectric conversion element of this comparative example thus obtained was left in a dryer set at a temperature of 60 ° C. After 90 days, leakage from the electrolyte injection hole 17 was visually confirmed, and the photoelectric conversion efficiency linearly decreased from 4.1% to 2.7%.
[0068]
【The invention's effect】
As described above, the present invention provides a photoelectric conversion element having excellent leakage resistance as a sealing structure in which the sealing portion of the electrolyte injection hole and the electrolyte are not in direct contact with each other.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a photoelectric conversion element in an embodiment of the present invention.
FIG. 2 is a schematic plan view of a photoelectric conversion element in an embodiment of the present invention.
FIG. 3 is a schematic plan view of a first electrode of a photoelectric conversion element in an embodiment of the present invention.
FIG. 4 is a schematic plan view of a counter electrode of the photoelectric conversion element in the embodiment of the present invention.
[Explanation of symbols]
1 Photoelectric conversion element
3 Substrate
5 electrodes
7 Semiconductor layer
9 Main electrolyte chamber
11 Sub-electrolyte chamber
13a, 13b first sealing portion
15a, 15b 2nd sealing part
17 Electrolyte injection hole
17a gap
19 Counter electrode
21 Substrate
23 Incident light
25 Holes used for dye loading
26 External terminal

Claims (3)

A first electrode on which a semiconductor layer carrying a sensitizing dye is deposited, a second electrode facing the semiconductor layer of the first electrode, a semiconductor layer of the first electrode, and the second electrode A photoelectric conversion element having an electrolyte disposed therebetween,
The electrolyte is filled in an electrolyte chamber having an electrolyte injection hole,
The electrolyte injection hole is blocked from the outside by a sealing portion,
The electrolyte injection hole includes a void portion that is not filled with an electrolyte between the electrolyte and the sealing portion ,
The sealing part is formed of at least one selected from the group consisting of a silicone resin, an epoxy resin, a hot melt resin, a glass frit, and an ultraviolet curable resin .   The photoelectric conversion element according to claim 1, wherein the electrolyte chamber includes a main electrolyte chamber and a sub-electrolyte chamber, and the electrolyte injection hole is provided in the sub-electrolyte chamber. A sealing portion of the electrolyte injection hole is formed by a first sealing portion and a second sealing portion disposed outside the first sealing portion, and the first sealing portion is made of silicone resin, epoxy Formed of at least one selected from the group consisting of resin, hot melt resin, and glass frit, and the second sealing portion is at least selected from silicone resin, epoxy resin, hot melt resin, glass frit, and ultraviolet curable resin. The photoelectric conversion element of Claim 1 or 2 currently formed from one type .

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