WO2014162641A1 - Electrolyte for dye-sensitised solar cell, and dye-sensitised solar cell - Google Patents

Electrolyte for dye-sensitised solar cell, and dye-sensitised solar cell Download PDF

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Publication number
WO2014162641A1
WO2014162641A1 PCT/JP2013/083826 JP2013083826W WO2014162641A1 WO 2014162641 A1 WO2014162641 A1 WO 2014162641A1 JP 2013083826 W JP2013083826 W JP 2013083826W WO 2014162641 A1 WO2014162641 A1 WO 2014162641A1
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Prior art keywords
dye
electrolyte
solar cell
basic substance
sensitized solar
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PCT/JP2013/083826
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French (fr)
Japanese (ja)
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大介 松本
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株式会社フジクラ
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Priority claimed from JP2013075449A external-priority patent/JP5380618B1/en
Priority claimed from JP2013075448A external-priority patent/JP5380617B1/en
Application filed by 株式会社フジクラ filed Critical 株式会社フジクラ
Publication of WO2014162641A1 publication Critical patent/WO2014162641A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/20—Light-sensitive devices
    • H01G9/2004—Light-sensitive devices characterised by the electrolyte, e.g. comprising an organic electrolyte
    • H01G9/2018—Light-sensitive devices characterised by the electrolyte, e.g. comprising an organic electrolyte characterised by the ionic charge transport species, e.g. redox shuttles
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/20—Light-sensitive devices
    • H01G9/2027—Light-sensitive devices comprising an oxide semiconductor electrode
    • H01G9/2031—Light-sensitive devices comprising an oxide semiconductor electrode comprising titanium oxide, e.g. TiO2
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/20—Light-sensitive devices
    • H01G9/2059—Light-sensitive devices comprising an organic dye as the active light absorbing material, e.g. adsorbed on an electrode or dissolved in solution
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/542—Dye sensitized solar cells

Definitions

  • the present invention relates to an electrolyte for a dye-sensitized solar cell and a dye-sensitized solar cell.
  • the dye-sensitized solar cell is a next-generation solar cell that has been developed by Gretzel et al. In Switzerland and has received attention because it has advantages such as high photoelectric conversion efficiency and low manufacturing cost.
  • a dye-sensitized solar cell generally includes a working electrode, a counter electrode, a photosensitizing dye supported on the oxide semiconductor layer of the working electrode, and an electrolyte disposed between the working electrode and the counter electrode.
  • the electrolyte contains a redox pair composed of, for example, halogen and halide ions.
  • Patent Document 1 discloses an electrolyte containing an ionic liquid, and according to this electrolyte, since the volatility of the electrolyte is reduced, the durability of the dye-sensitized solar cell can be improved. It is disclosed.
  • the dye-sensitized solar cell provided with the electrolyte described in Patent Document 1 still has room for improvement in photoelectric conversion characteristics. Therefore, when used as an electrolyte for a dye-sensitized solar cell, an electrolyte for a dye-sensitized solar cell that can further improve the photoelectric conversion characteristics of the dye-sensitized solar cell has been desired.
  • This invention is made
  • the present inventor conducted intensive studies focusing on the components of the electrolyte. As a result, the present inventors have found that the above-described problems can be solved by the following invention.
  • the present invention includes a halogen, a halide salt, a hydrogen halide, and at least one selected from the group consisting of a basic substance and a mixture of the basic substance and the salt of the hydrogen halide,
  • An oxidation-reduction pair is formed by the halogen and the halide salt, and the halogen, the halide salt, and the hydrogen halide have the same halogen atom, and the volume molarity C 1 of the halogen or the basic is molarity C 3 material, the molarity C 2 of the hydrogen halide, the basic substance and the total molarity C 20 larger dye with molarity C 4 salts of the hydrogen halide It is an electrolyte for a solar cell.
  • the photoelectric conversion characteristics of the dye-sensitized solar cell can be sufficiently improved.
  • the electrolyte for a dye-sensitized solar cell includes the halogen, the halide salt, and the hydrogen halide, and the volume molar concentration C 1 of the halogen is the volume molar concentration C 2 of the hydrogen halide. greater than the total molarity C 20 with molarity C 4 salts of said basic material and the hydrogen halide, that molarity C 4 salts of said basic material and the hydrogen halide is 0mM Is preferred.
  • the dye-sensitized solar cell electrolyte includes a halogen, a halide salt, and a hydrogen halide, and the halogen and the halide salt form an oxidation-reduction pair, and the halogen, the halide salt, and It is preferable that the hydrogen halide has the same halogen atom, and the volume molar concentration C 1 of the halogen is larger than the volume molar concentration C 2 of the hydrogen halide.
  • the photoelectric conversion characteristics of the dye-sensitized solar cell can be more sufficiently improved.
  • the present inventor presumes the reason why such an effect is obtained as follows. That is, when the electrolyte of the present invention is used as an electrolyte of a dye-sensitized solar cell having an oxide semiconductor layer made of an oxide semiconductor, hydrogen halide increases the level of the valence band of the oxide semiconductor layer. In addition, the electron injection efficiency between the dye and the oxide semiconductor can be improved. In addition, the HOMO (bonding orbital) level of the redox couple in the electrolyte is less likely to shift. In other words, it is possible to prevent the redox level from changing from an appropriate position due to hydrogen halide. For this reason, this inventor estimates that the photoelectric conversion characteristic of a dye-sensitized solar cell can fully be improved.
  • the volume molar concentration C 1 of the halogen is preferably twice or more the volume molar concentration C 2 of the hydrogen halide.
  • the photoelectric conversion characteristics of the dye-sensitized solar cell can be particularly sufficiently improved.
  • the halogenated molarity C 2 hydrogens is preferably 0.05 ⁇ 15 mM.
  • the electrolyte is, when used as an electrolyte of a dye-sensitized solar cell including an oxide semiconductor layer formed of an oxide semiconductor, as compared with the case C 2 is less than 0.05 mM, hydrogen halide oxide
  • the level of the valence band of the semiconductor can be increased, and the electron injection efficiency between the dye and the oxide semiconductor can be further improved. Further, as compared with the case where C 2 is more than 15 mM, it can be more sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell.
  • the halogen atom is preferably an iodine atom.
  • the HOMO (bonding orbital) level of the photosensitizing dye used in the dye-sensitized solar cell and the level of the redox pair in the electrolyte are in an appropriate position, the electron injection efficiency can be further improved. it can.
  • the iodine reduction reaction is superior to other halogen species, the photosensitized photosensitizing dye can be instantaneously returned to the ground state, and the reverse reaction by the photosensitizing dye can be prevented.
  • the electrolyte for a dye-sensitized solar cell includes the halogen, the halide salt, the basic substance, and the salt of the basic substance and the hydrogen halide, and the volume molar concentration of the basic substance.
  • C 3 is larger than the total molar molar concentration C 20 of the molar molar concentration C 2 of the hydrogen halide and the molar molar concentration C 4 of the basic substance and the salt of the hydrogen halide, and the volume of the hydrogen halide.
  • molar concentration C 2 may be 0 mM.
  • the dye-sensitized solar cell electrolyte includes a halogen, a halide salt, a basic substance, and a salt of the basic substance and a hydrogen halide, and is oxidized and reduced by the halogen and the halide salt. pair is formed, the halogen, the halide salt and the hydrogen halide has the same halogen atom, molarity C 3 of the basic substance, a salt with the hydrogen halide and said basic substance it may be a dye-sensitized solar cell electrolyte greater than the molarity C 4.
  • the photoelectric conversion characteristics of the dye-sensitized solar cell can be more sufficiently improved.
  • the present inventor presumes the reason why such an effect is obtained as follows. That is, when the electrolyte of the present invention is used as an electrolyte of a dye-sensitized solar cell having an oxide semiconductor layer made of an oxide semiconductor, a salt of a basic substance and a hydrogen halide is added to the oxide semiconductor layer.
  • the electron band level can be increased, and the electron injection efficiency between the dye and the oxide semiconductor can be improved.
  • the HOMO (bonding orbital) level of the redox couple in the electrolyte is less likely to shift. In other words, it is possible to prevent the redox level from changing from an appropriate position due to a salt of a basic substance and hydrogen halide. For this reason, this inventor estimates that the photoelectric conversion characteristic of a dye-sensitized solar cell can fully be improved.
  • molarity C 3 of the basic material is the basic material is three times or more molarity C 4 of the salt with the hydrogen halide.
  • the photoelectric conversion characteristics of the dye-sensitized solar cell can be more sufficiently improved.
  • the molar concentration C 4 of the salt of the basic substance and the hydrogen halide is preferably 0.05 to 15 mM.
  • the electrolyte is, when used as an electrolyte of a dye-sensitized solar cell including an oxide semiconductor layer formed of an oxide semiconductor, as compared with the case C 4 is less than 0.05 mM, basic substance and halogenated
  • the salt with hydrogen can raise the level of the valence band of the oxide semiconductor, and the electron injection efficiency between the dye and the oxide semiconductor can be further improved. Further, as compared with the case where C 4 exceeds 15 mM, it is possible to more sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell.
  • the present invention also provides a first electrode having a transparent substrate and a transparent conductive film provided on the transparent substrate, a second electrode facing the first electrode, and an oxidation provided on the first electrode or the second electrode.
  • a dye-sensitized solar cell comprising: an organic semiconductor layer; an electrolyte provided between the first electrode and the second electrode; and a photosensitizing dye adsorbed on the oxide semiconductor layer. It is a dye-sensitized solar cell which is an electrolyte for use.
  • the electrolyte is the above-described dye-sensitized solar cell electrolyte, the photoelectric conversion characteristics can be sufficiently improved.
  • the present invention also provides an electrolyte for preparing an electrolytic solution containing a halogen, a halide salt, a salt of a basic substance and a hydrogen halide, wherein a redox pair is formed by the halogen and the halide salt.
  • the halogen and the halide salt and having said hydrogen halide is the same halogen atom, in the basic material mixing step, molarity C 3 of the basic substance, molarity of the salt with the hydrogen halide and said basic substance it is the electrolyte and a manufacturing method of the basic substance and mixing the dye-sensitized solar cell electrolyte to be greater than C 4.
  • an electrolyte for a dye-sensitized solar cell that can sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell can be produced.
  • the electrolytic solution and the basic substance are mixed so that the volume molar concentration C 3 of the basic substance is less than three times the volume molar concentration C 4 of the salt of the basic substance and hydrogen halide.
  • the obtained electrolyte can more sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell.
  • a salt with a basic substance and a hydrogen halide of the valence band of the oxide semiconductor The level can be increased and the electron injection efficiency between the dye and the oxide semiconductor can be further improved. Further, as compared with the case where C 4 exceeds 15 mM, electrolyte obtained can be more sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell.
  • the halogen atom is preferably an iodine atom.
  • the electrolyte when used as an electrolyte of a dye-sensitized solar cell, the HOMO (bonding orbital) level of the photosensitizing dye used in the dye-sensitized solar cell and the level of the redox pair in the electrolyte are Since the position is appropriate, the electron injection efficiency can be further improved. Moreover, since the reduction reaction of iodine is superior to other halogen species, when the electrolyte is used as an electrolyte of a dye-sensitized solar cell, the photosensitized photosensitizing dye can be instantaneously returned to the ground state, The reverse reaction by a photosensitizing dye etc. can be prevented.
  • the basic substance refers to a substance that can form a salt with hydrogen halide.
  • an electrolyte for a dye-sensitized solar cell and a dye-sensitized solar cell that can sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell are provided.
  • FIG. 1 is a cross-sectional view showing an embodiment of the dye-sensitized solar cell of the present invention.
  • the dye-sensitized solar cell 100 connects a working electrode 10 having a transparent conductive substrate 15, a counter electrode 20 facing the transparent conductive substrate 15, and the transparent conductive substrate 15 and the counter electrode 20.
  • the cell space formed by the transparent conductive substrate 15, the counter electrode 20 and the sealing portion 30 is filled with an electrolyte 40.
  • the counter electrode 20 includes a conductive substrate 21 and a catalyst layer 22 provided on the working electrode 10 side of the conductive substrate 21 and contributing to the reduction of the electrolyte 40.
  • the second electrode is constituted by the conductive substrate 21.
  • the working electrode 10 has a transparent conductive substrate 15 and at least one oxide semiconductor layer 13 provided on the transparent conductive substrate 15.
  • the transparent conductive substrate 15 includes a transparent substrate 11 and a transparent conductive film 12 provided on the transparent substrate 11.
  • the oxide semiconductor layer 13 is disposed inside the sealing portion 30.
  • a photosensitizing dye is adsorbed on the oxide semiconductor layer 13.
  • the first electrode is constituted by the transparent conductive substrate 15.
  • the electrolyte 40 includes at least one selected from the group consisting of halogens, halide salts, hydrogen halides, and mixtures of basic substances, basic substances, and salts of hydrogen halides.
  • a redox pair is formed by the halogen and the halide salt.
  • the halogen, the halide salt and the hydrogen halide have the same halogen atom.
  • molarity C 1 of the halogen, the total molarity of the molarity C 2 hydrogen halide, the molarity C 4 salts of a basic substance and hydrogen halides C It is larger than 20 .
  • molarity C 4 salts of a basic substance and hydrogen halide is 0 mM. That is, molarity C 1 halogen is larger than the molarity C 2 hydrogen halide.
  • the electrolyte 40 since the electrolyte 40 has the above configuration, the photoelectric conversion characteristics can be sufficiently improved.
  • the working electrode 10 includes the transparent conductive substrate 15 and at least one oxide semiconductor layer 13 provided on the transparent conductive substrate 15.
  • the transparent conductive substrate 15 includes a transparent substrate 11 and a transparent conductive film 12 provided on the transparent substrate 11.
  • the material which comprises the transparent substrate 11 should just be a transparent material, for example, as such a transparent material, glass, such as borosilicate glass, soda lime glass, white plate glass, quartz glass, polyethylene terephthalate (PET), for example , Polyethylene naphthalate (PEN), polycarbonate (PC), and polyethersulfone (PES).
  • PET polyethylene terephthalate
  • PEN Polyethylene naphthalate
  • PC polycarbonate
  • PES polyethersulfone
  • the thickness of the transparent substrate 11 is appropriately determined according to the size of the dye-sensitized solar cell 100 and is not particularly limited, but may be in the range of 50 to 40,000 ⁇ m, for example.
  • the transparent conductive film 12 As a material constituting the transparent conductive film 12, for example, tin-doped indium oxide (Indium-Tin-Oxide: ITO), tin oxide (SnO 2 ), and fluorine-doped tin oxide (Fluorine-doped-Tin-Oxide: FTO). And conductive metal oxides such as The transparent conductive film 12 may be a single layer or a laminate of a plurality of layers made of different conductive metal oxides. When the transparent conductive film 12 is composed of a single layer, the transparent conductive film 12 is preferably composed of FTO because it has high heat resistance and chemical resistance. The thickness of the transparent conductive film 12 may be in the range of 0.01 to 2 ⁇ m, for example.
  • the oxide semiconductor layer 13 is composed of oxide semiconductor particles.
  • the oxide semiconductor particles include titanium oxide (TiO 2 ), zinc oxide (ZnO), tungsten oxide (WO 3 ), niobium oxide (Nb 2 O 5 ), strontium titanate (SrTiO 3 ), and tin oxide (SnO 2 ).
  • the thickness of the oxide semiconductor layer 13 may be 0.1 to 100 ⁇ m, for example.
  • the counter electrode 20 includes the conductive substrate 21 and the conductive catalyst layer 22 provided on the working electrode 10 side of the conductive substrate 21 and contributing to the reduction of the electrolyte 40.
  • the conductive substrate 21 is, for example, a corrosion-resistant metal material such as titanium, nickel, platinum, molybdenum, tungsten, aluminum, or stainless steel, or a film made of a conductive oxide such as ITO or FTO on the transparent substrate 11 described above. Consists of.
  • the thickness of the conductive substrate 21 is appropriately determined according to the size of the dye-sensitized solar cell 100 and is not particularly limited, but may be, for example, 0.005 to 4 mm.
  • the catalyst layer 22 is composed of platinum, a carbon-based material, a conductive polymer, or the like.
  • carbon nanotubes are suitably used as the carbon-based material.
  • sealing portion 30 examples include thermoplastic resins such as modified polyolefin resins and vinyl alcohol polymers, and resins such as ultraviolet curable resins.
  • modified polyolefin resins include ionomers, ethylene-vinyl acetic anhydride copolymers, ethylene-methacrylic acid copolymers, and ethylene-vinyl alcohol copolymers. These resins can be used alone or in combination of two or more.
  • the electrolyte 40 contains halogen, a halide salt, and hydrogen halide.
  • a redox pair is formed by the halogen and the halide salt.
  • the halogen, the halide salt and the hydrogen halide have the same halogen atom.
  • the volume molar concentration C 1 of the halogen is larger than the volume molar concentration C 2 of the hydrogen halide, that is, the value of C 1 / C 2 is larger than 1.
  • examples of the halogen atom constituting the halogen, halide salt and hydrogen halide include a bromine atom and an iodine atom.
  • the halogen atom constituting the halogen, halide salt and hydrogen halide is preferably an iodine atom. That is, it is preferable that the halogen is iodine, the halide salt is an iodide salt, and the hydrogen halide is hydrogen iodide.
  • the HOMO (bonding orbital) level of the photosensitizing dye used in the dye-sensitized solar cell 100 and the redox level in the electrolyte are in proper positions, the electron injection efficiency is further improved.
  • the iodine reduction reaction is superior to other halogen species, the photosensitized photosensitizing dye can be instantaneously returned to the ground state, and the reverse reaction by the photosensitizing dye can be prevented.
  • halide salt contained in the electrolyte 40 examples include lithium bromide, sodium bromide, potassium bromide, tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, tetrahexylammonium bromide, 1-hexyl-3- Bromide salts such as methyl imidazolium bromide, 1-ethyl-3-propyl imidazolium bromide, dimethyl imidazolium bromide, ethyl methyl imidazolium bromide, dimethylpropyl imidazolium bromide, butyl methyl imidazolium bromide, methyl propyl imidazolium bromide, iodine Lithium iodide, sodium iodide, potassium iodide, tetramethylammonium iodide, tetraethylammonium i
  • examples of the hydrogen halide contained in the electrolyte 40 include hydrogen bromide and hydrogen iodide.
  • Examples of the redox pair formed by halogen and a halide salt include combinations of halide ions and polyhalide ions. Specific examples include I ⁇ / I 3 — and Br ⁇ / Br 3 — .
  • molarity C 1 halogen twice more molarity C 2 hydrogen halide that is, the value of C 1 / C 2 is preferably by 2 or more.
  • C 1 / C 2 is more preferably 2.5 to 300, and further preferably 10 to 250.
  • Molarity C 1 halogen as described above, may be greater than the volume molar concentration C 2 of the hydrogen halide.
  • the volume molar concentration C 2 of hydrogen halide is preferably 0.05 to 15 mM.
  • the photoelectric conversion characteristics of the dye-sensitized solar cell 100 can be more sufficiently improved than when C 2 exceeds 15 mM. Can do. Further, when the volume molar concentration C 2 of hydrogen halide is in the range of 0.05 to 15 mM, the hydrogen halide is in the valence band of the oxide semiconductor as compared with the case where C 2 is less than 0.05 mM. The level can be increased and the electron injection efficiency between the dye and the oxide semiconductor can be further improved.
  • C 2 is more preferably 0.06 to 14 mM, and further preferably 0.07 to 13 mM.
  • Electrolyte 40 may further contain an organic solvent.
  • organic solvents include acetonitrile, methoxyacetonitrile, methoxypropionitrile, propionitrile, ethylene carbonate, propylene carbonate, diethyl carbonate, ⁇ -butyrolactone, valeronitrile, pivalonitrile, glutaronitrile, methacrylonitrile, isobutyronitrile, Phenylacetonitrile, acrylonitrile, succinonitrile, oxalonitrile, pentanitrile, adiponitrile and the like can be used. These may be used alone or in combination of two or more.
  • the electrolyte 40 may further contain an additive.
  • the additive include 4-t-butylpyridine, guanidinium thiocyanate, 1-methylbenzimidazole, and 1-butylbenzimidazole.
  • a nano-composite gel electrolyte which is a pseudo-solid electrolyte formed by kneading nanoparticles such as SiO 2 , TiO 2 , carbon nanotubes, etc. into the electrolyte, may be used, and polyvinylidene fluoride may be used.
  • an electrolyte gelled with an organic gelling agent such as a polyethylene oxide derivative or an amino acid derivative may be used.
  • the photosensitizing dye examples include a ruthenium complex having a ligand containing a bipyridine structure, a terpyridine structure, and the like, and organic dyes such as porphyrin, eosin, rhodamine, and merocyanine.
  • a ruthenium complex having a ligand containing a terpyridine structure is preferable. In this case, the photoelectric conversion characteristics of the dye-sensitized solar cell 100 can be further improved.
  • a ruthenium complex having a ligand containing a bipyridine structure may be used as the photosensitizing dye. preferable.
  • a transparent conductive substrate 15 formed by forming a transparent conductive film 12 on one transparent substrate 11 is prepared.
  • a sputtering method As a method for forming the transparent conductive film 12, a sputtering method, a vapor deposition method, a spray pyrolysis method (SPD), a CVD method, or the like is used.
  • an oxide semiconductor layer 13 is formed on the transparent conductive film 12.
  • the oxide semiconductor layer 13 is formed by printing a porous oxide semiconductor layer forming paste containing oxide semiconductor particles, followed by firing.
  • the oxide semiconductor layer forming paste contains a resin such as polyethylene glycol and a solvent such as terpineol in addition to the oxide semiconductor particles described above.
  • a method for printing the oxide semiconductor layer forming paste for example, a screen printing method, a doctor blade method, a bar coating method, or the like can be used.
  • the firing temperature varies depending on the material of the oxide semiconductor particles, but is usually 350 to 600 ° C.
  • the firing time also varies depending on the material of the oxide semiconductor particles, but is usually 1 to 5 hours.
  • a photosensitizing dye is adsorbed on the surface of the oxide semiconductor layer 13 of the working electrode 10.
  • the working electrode 10 is immersed in a solution containing a photosensitizing dye, the photosensitizing dye is adsorbed on the oxide semiconductor layer 13, and then the excess photosensitizer is added with the solvent component of the solution.
  • the photosensitizing dye may be adsorbed to the oxide semiconductor layer 13 by washing away the dye and drying it.
  • the photosensitizing dye may be adsorbed to the oxide semiconductor layer 13 by applying a solution containing the photosensitizing dye to the oxide semiconductor layer 13 and then drying the solution.
  • the electrolyte 40 contains the halogen, halide salt, and hydrogen halide described above, and is obtained by adjusting the C 1 / C 2 value to be greater than 1. At this time, in the electrolyte 40, a redox pair is formed by the halogen and the halide salt.
  • the electrolyte 40 is disposed on the oxide semiconductor layer 13.
  • the electrolyte 40 can be disposed by a printing method such as screen printing.
  • the sealing part forming body can be obtained, for example, by preparing a sealing resin film and forming one rectangular opening in the sealing resin film.
  • the sealing portion forming body is bonded onto the working electrode 10.
  • adhesion of the sealing portion forming body to the working electrode 10 can be performed by, for example, heating and melting the sealing portion forming body.
  • the sealing portion forming body may be bonded to the counter electrode 20 in advance, and the sealing portion forming body may be bonded to the sealing portion forming body on the working electrode 10 side.
  • Lamination of the counter electrode 20 to the sealing portion forming body may be performed under atmospheric pressure or under reduced pressure, but is preferably performed under reduced pressure.
  • the dye-sensitized solar cell 100 is obtained as described above.
  • FIG. 2 is a cross-sectional view showing a second embodiment of the dye-sensitized solar cell of the present invention.
  • the dye-sensitized solar cell 200 of the present embodiment is different from the dye-sensitized solar cell 100 of the first embodiment in that an electrolyte 240 is used instead of the electrolyte 40.
  • the electrolyte 240 includes a halogen, a halide salt, a basic substance, and a salt of the basic substance and hydrogen halide.
  • a redox pair is formed by halogen and a halide salt.
  • the halogen, the halide salt and the hydrogen halide have the same halogen atom.
  • the total molarity of molarity C 3 of the basic substance, the molarity C 2 hydrogen halide, the molarity C 4 salts of a basic substance and a hydrogen halide It is greater than C 20.
  • molarity C 2 hydrogen halide is in the 0 mM. That is, molarity C 3 of the basic substance is greater than the molarity C 4 of the salt with the basic substance and the hydrogen halide. That is, the value of C 3 / C 4 is larger than 1.
  • examples of the halogen atom contained in the halogen, halide salt, and hydrogen halide include a bromine atom and an iodine atom.
  • the halogen atom which a halogen, a halide salt, and a hydrogen halide have is an iodine atom. That is, it is preferable that the halogen is iodine, the halide salt is an iodide salt, and the hydrogen halide is hydrogen iodide.
  • the electrolyte 240 can instantaneously return the photosensitized photosensitizing dye to the ground state, and hinder the reverse reaction by the photosensitizing dye. it can.
  • the basic substance examples include lithium hydroxide, sodium hydroxide, potassium hydroxide, tetramethylamine, tetraethylamine, tetrabutylamine, tetrahexylamine, 1-hexyl-3-methylimidazole, and 1-ethyl.
  • -3-Propylimidazole, dimethylimidazole, ethylmethylimidazole, dimethylpropylimidazole, butylmethylimidazole, methylpropylimidazole, methylbenzimidazole, butylbenzimidazole, t-butylpyridine, guanidinium thiocyanate and the like are preferably used.
  • a basic substance may be used individually by 1 type, or may be used in combination of 2 or more types.
  • molarity C 3 of the basic substance is a basic substance and more than three times the molarity C 4 of the salts with hydrogen halides, i.e. the value of C 3 / C 4 is 3 or more It is preferable.
  • the photoelectric conversion characteristics of the dye-sensitized solar cell 200 can be particularly sufficiently improved.
  • the C 3 / C 4 value is more preferably 3 to 1000, and even more preferably 7 to 900.
  • the volume molar concentration C 3 of the basic substance may be larger than the volume molar concentration C 4 of the salt of the basic substance and hydrogen halide as described above.
  • volume molar concentration C 4 of the salt of the basic substance and the hydrogen halide is preferably 0.05 to 15 mM.
  • the electrolyte 4 can sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell 200 as compared with the case where C 4 exceeds 15 mM.
  • the salt of the basic substance and the hydrogen halide is in the valence band of the oxide semiconductor as compared to the case where C 4 is less than 0.05 mM. The level can be increased and the electron injection efficiency between the dye and the oxide semiconductor can be further improved.
  • C 4 is more preferably 0.06 to 14 mM, and further preferably 0.07 to 13 mM.
  • the method for manufacturing the dye-sensitized solar cell 200 is different from the method for manufacturing the dye-sensitized solar cell 100 in that the electrolyte 240 is used instead of the electrolyte 40.
  • the electrolyte 240 includes a halogen, a halide salt, a salt of a basic substance and a hydrogen halide, and an electrolyte solution preparing step of preparing an electrolyte solution in which a redox pair is formed by the halogen and the halide salt. And a basic substance mixing step of mixing the electrolytic solution and the basic substance to obtain the electrolyte 240. At this time, in the electrolytic solution preparation step, the halogen, halide salt, and hydrogen halide have the same halogen atom. In the basic substance mixing step, the electrolytic solution and the basic substance are mixed so that the volume molar concentration C 3 of the basic substance is larger than the volume molar concentration C 4 of the salt of the basic substance and hydrogen halide. Mix.
  • a halogen and a halide salt are dissolved in the organic solvent described above to prepare a solution containing a redox pair formed by the halogen and the halide salt.
  • the electrolyte 240 is obtained. According to the manufacturing method of the electrolyte 240 described above, the obtained electrolyte 240 can sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell 200.
  • the photoelectric conversion characteristics of the dye-sensitized solar cell 200 can be more sufficiently improved by the electrolyte 240 thus obtained.
  • the electrolytic solution and the basic substance so that the value of C 3 / C 4 is 3 to 1000, and the electrolytic solution and the basic substance are mixed so as to be 7 to 900. More preferably.
  • molarity C 4 of salt with a basic substance and hydrogen halide is mixed with the electrolytic solution and the basic substance so that 0.05 ⁇ 15 mM.
  • the electrolyte 240 can sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell 200 as compared with the case where C 4 exceeds 15 mM.
  • the salt of the basic substance and the hydrogen halide is in the valence band of the oxide semiconductor as compared to the case where C 4 is less than 0.05 mM. The level can be increased and the electron injection efficiency between the dye and the oxide semiconductor can be further improved.
  • the present invention is not limited to the above embodiment.
  • the porous oxide semiconductor layer 13 is provided on the transparent conductive substrate 15 to receive light from this side, but the base material on which the porous oxide semiconductor layer 13 is formed is provided.
  • An opaque material for example, a metal substrate
  • a transparent material may be used for the base material on which the counter electrode 20 is formed
  • a structure for receiving light from the counter electrode side may be used.
  • molarity C 1 of iodine in the electrolyte is 30 mM
  • molarity C 1 iodine by ultraviolet-visible (UV-vis) absorption spectroscopy using a spectrophotometer
  • molarity of hydrogen iodide was determined by neutralization titration with potassium hydroxide.
  • the salt molar concentration C 4 was 0 mM as described in Table 1.
  • an electrolyte for a dye-sensitized solar cell was prepared. In this electrolyte, an oxidation-reduction pair was formed by iodine and hydrogen iodide.
  • an FTO / glass substrate having an FTO film formed on a glass substrate was prepared. Then, this FTO / glass substrate is cleaned, this substrate is subjected to UV-O 3 treatment, and a titanium oxide nanoparticle paste containing titanium oxide is applied onto the substrate by screen printing to produce a 50 ⁇ 50 mm film. And dried at 150 ° C. for 10 minutes. Thus, an unfired substrate was obtained. Thereafter, this unfired substrate was put in an oven, and the titanium oxide nanoparticle paste was fired at 500 ° C. for 1 hour to form a porous titanium oxide layer having a thickness of 14 ⁇ m on the FTO film, thereby obtaining a working electrode.
  • the photosensitizing dye Z907 dye was dissolved in a mixed solvent of acetonitrile and t-butyl alcohol mixed at 1: 1 (volume ratio) to prepare a dye solution. Then, the working electrode was immersed in this dye solution for 24 hours, and the photosensitizing dye was supported on the porous titanium oxide layer.
  • the FTO / glass substrate used in the production of the working electrode was prepared, and Pt was deposited on this substrate by a sputtering method. In this way, a counter electrode was obtained.
  • an annular thermoplastic resin sheet made of ionomer Himiran (trade name, manufactured by Mitsui DuPont Polychemical Co., Ltd.) was placed on the working electrode.
  • the porous titanium oxide layer was arranged inside the annular thermoplastic resin sheet.
  • the thermoplastic resin sheet was heated and melted at 180 ° C. for 5 minutes to adhere to the working electrode.
  • the electrolyte prepared as described above was applied by screen printing so as to cover the porous titanium oxide layer on the working electrode.
  • the counter electrode was superposed on the working electrode so that the electrolyte was sandwiched between the working electrode and the sealed portion was heated and melted under reduced pressure (1000 Pa) to adhere the counter electrode and the sealed portion.
  • NMBIm methylbenzimidazole
  • NBP butylbenzimidazole
  • TBP t-butylpyridine
  • GNSCN guani Represents thiocyanate.
  • the volume molar concentration C 4 in the electrolyte is adjusted to the volume molar concentration described as “salt concentration C 4 ” in Tables 2 to 6 in the above mixture. Dissolved.
  • the volume molar concentration C 4 of the salt of the basic substance and hydrogen iodide was quantified by a quantitative titration method. In the obtained electrolyte, an oxidation-reduction pair was formed by iodine and hydrogen iodide.
  • the molarity C 3 of the basic substance in the electrolyte was set to 100 mM.
  • Examples 20 to 24 and Comparative Examples 16 to 18 shown in Table 6 were prepared so that the NMBIm had a molar molar concentration of 50 mM and the GuSCN had a molar molar concentration of 50 mM.
  • Molarity C 3 of the basic substance was quantified by quantitative titration.
  • the volume molar concentration C 2 of the hydrogen iodide in the electrolyte was 0 mM.
  • the volume molar concentration of hydrogen iodide was determined by neutralization titration with potassium hydroxide.
  • an FTO / glass substrate having an FTO film formed on a glass substrate was prepared. Then, this FTO / glass substrate is cleaned, this substrate is subjected to UV-O 3 treatment, and a titanium oxide nanoparticle paste containing titanium oxide is applied onto the substrate by screen printing to produce a 50 ⁇ 50 mm film. And dried at 150 ° C. for 10 minutes. Thus, an unfired substrate was obtained. Thereafter, this unfired substrate was put in an oven, and the titanium oxide nanoparticle paste was fired at 500 ° C. for 1 hour to form a porous titanium oxide layer having a thickness of 14 ⁇ m on the FTO film, thereby obtaining a working electrode.
  • the photosensitizing dye Z907 dye was dissolved in a mixed solvent of acetonitrile and t-butyl alcohol mixed at 1: 1 (volume ratio) to prepare a dye solution. Then, the working electrode was immersed in this dye solution for 24 hours, and the photosensitizing dye was supported on the porous titanium oxide layer.
  • the FTO / glass substrate used in the production of the working electrode was prepared, and Pt was deposited on this substrate by a sputtering method. In this way, a counter electrode was obtained.
  • an annular thermoplastic resin sheet made of ionomer Himiran (trade name, manufactured by Mitsui DuPont Polychemical Co., Ltd.) was placed on the working electrode.
  • the porous titanium oxide layer was arranged inside the annular thermoplastic resin sheet.
  • the thermoplastic resin sheet was heated and melted at 180 ° C. for 5 minutes to adhere to the working electrode.
  • the electrolyte prepared as described above was applied by screen printing so as to cover the porous titanium oxide layer on the working electrode.
  • the counter electrode was superposed on the working electrode so that the electrolyte was sandwiched between the working electrode and the sealed portion was heated and melted under reduced pressure (1000 Pa) to adhere the counter electrode and the sealed portion.
  • the photoelectric conversion efficiency ⁇ (%) of the dye-sensitized solar cells of Examples 5 to 24 and Comparative Examples 4 to 18 obtained as described above was measured.
  • Comparative Example 4 was used as a reference comparative example, and Examples 9 to 12 and Comparative Examples 7 to 7 using NBB as a basic substance were used.
  • Comparative Example 7 was used as a standard comparative example, and Examples 13 to 16 and Comparative Examples 10 to 12 using TBP as a basic substance were used as Comparative Examples 10 and GuSCN was used as a basic substance.
  • Comparative Example 13 was used as a reference comparative example, and for Examples 21 to 24 and Comparative Examples 16 to 18 using NMBIm and GuSCN as basic substances, Comparative Example 16 was used as a reference comparison.
  • the rate of increase in photoelectric conversion efficiency ⁇ was calculated based on the following formula. The results are shown in Tables 2-6.
  • Rate of increase in photoelectric conversion efficiency 100 ⁇ (photoelectric conversion efficiency of example or comparative example ⁇ photoelectric conversion efficiency of comparative example 1) / photoelectric conversion efficiency of comparative example 1
  • the photoelectric conversion efficiency was measured using a Xe lamp solar simulator (YSS-150, Yamashita Denso Co., Ltd.) and an IV tester (MP-160, Eiko Seiki Co., Ltd.).

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Abstract

Provided is an electrolyte for a dye-sensitised solar cell, said electrolyte including halogen, a halide salt, and at least one selected from the group consisting of: a hydrogen halide; and a mixture of a basic substance, and a salt of the basic substance and a hydrogen halide. A redox couple is formed by the halogen, and the halide salt. The halogen, the halide salt, and the hydrogen halide have the same halogen atom. The volume molar concentration (C1) of the halogen, or the volume molar concentration (C3) of the basic substance is greater than the total volume molar concentration (C20) of the volume molar concentration (C2) of the hydrogen halide, and the volume molar concentration (C4) of the salt of the basic substance and the hydrogen halide.

Description

色素増感太陽電池用電解質および色素増感太陽電池Electrolyte for dye-sensitized solar cell and dye-sensitized solar cell
　本発明は、色素増感太陽電池用電解質および色素増感太陽電池に関する。 The present invention relates to an electrolyte for a dye-sensitized solar cell and a dye-sensitized solar cell.
　色素増感太陽電池は、スイスのグレッツェルらによって開発されたものであり、光電変換効率が高く、製造コストが低いなどの利点を持つため注目されている次世代太陽電池である。 The dye-sensitized solar cell is a next-generation solar cell that has been developed by Gretzel et al. In Switzerland and has received attention because it has advantages such as high photoelectric conversion efficiency and low manufacturing cost.
　色素増感太陽電池は一般に、作用極と、対極と、作用極の酸化物半導体層に担持される光増感色素と、作用極及び対極間に配置される電解質とを備えている。そして電解質には、例えばハロゲン及びハロゲン化物イオンなどからなる酸化還元対が含まれている。 A dye-sensitized solar cell generally includes a working electrode, a counter electrode, a photosensitizing dye supported on the oxide semiconductor layer of the working electrode, and an electrolyte disposed between the working electrode and the counter electrode. The electrolyte contains a redox pair composed of, for example, halogen and halide ions.
　色素増感太陽電池においては光電変換特性及び耐久性を向上させることが重要であり、そのために、例えば電解質に着目した種々の提案がなされている。 In a dye-sensitized solar cell, it is important to improve photoelectric conversion characteristics and durability, and various proposals focusing on, for example, an electrolyte have been made.
　例えば下記特許文献１には、イオン液体を含む電解質が開示されており、この電解質によれば、電解質の揮発性が低減されるため、色素増感太陽電池の耐久性を向上させることができることが開示されている。 For example, Patent Document 1 below discloses an electrolyte containing an ionic liquid, and according to this electrolyte, since the volatility of the electrolyte is reduced, the durability of the dye-sensitized solar cell can be improved. It is disclosed.
特開２００２－２８９２６８号公報JP 2002-289268 A
　しかしながら、上記特許文献１に記載の電解質を備えた色素増感太陽電池は、光電変換特性について、未だ改善の余地があった。したがって、色素増感太陽電池の電解質に用いる場合に、色素増感太陽の光電変換特性をさらに向上させることのできる色素増感太陽電池用電解質が望まれていた。 However, the dye-sensitized solar cell provided with the electrolyte described in Patent Document 1 still has room for improvement in photoelectric conversion characteristics. Therefore, when used as an electrolyte for a dye-sensitized solar cell, an electrolyte for a dye-sensitized solar cell that can further improve the photoelectric conversion characteristics of the dye-sensitized solar cell has been desired.
　本発明は上記事情に鑑みてなされたものであり、色素増感太陽電池の光電変換特性を十分に向上させることができる色素増感太陽電池用電解質および色素増感太陽電池を提供することを目的とする。 This invention is made | formed in view of the said situation, and it aims at providing the electrolyte for dye-sensitized solar cells which can fully improve the photoelectric conversion characteristic of a dye-sensitized solar cell, and a dye-sensitized solar cell. And
　本発明者は上記課題を解決するために、電解質の成分に着目して鋭意研究を重ねた。その結果、本発明者は、下記の発明により上記課題を解決できることを見出した。 In order to solve the above-mentioned problems, the present inventor conducted intensive studies focusing on the components of the electrolyte. As a result, the present inventors have found that the above-described problems can be solved by the following invention.
　すなわち本発明は、ハロゲンと、ハロゲン化物塩と、ハロゲン化水素、並びに、塩基性物質と前記塩基性物質及び前記ハロゲン化水素の塩との混合物からなる群より選ばれる少なくとも１種とを含み、前記ハロゲンと前記ハロゲン化物塩とによって酸化還元対が形成され、前記ハロゲン、前記ハロゲン化物塩、及び前記ハロゲン化水素が同一のハロゲン原子を有し、前記ハロゲンの体積モル濃度Ｃ１又は前記塩基性物質の体積モル濃度Ｃ３が、前記ハロゲン化水素の体積モル濃度Ｃ２と、前記塩基性物質及び前記ハロゲン化水素の塩の体積モル濃度Ｃ４との合計体積モル濃度Ｃ２０より大きい色素増感太陽電池用電解質である。 That is, the present invention includes a halogen, a halide salt, a hydrogen halide, and at least one selected from the group consisting of a basic substance and a mixture of the basic substance and the salt of the hydrogen halide, An oxidation-reduction pair is formed by the halogen and the halide salt, and the halogen, the halide salt, and the hydrogen halide have the same halogen atom, and the volume molarity C 1 of the halogen or the basic is molarity C 3 material, the molarity C 2 of the hydrogen halide, the basic substance and the total molarity C 20 larger dye with molarity C 4 salts of the hydrogen halide It is an electrolyte for a solar cell.
　本発明の色素増感太陽電池用電解質によれば、色素増感太陽電池の光電変換特性を十分に向上させることができる。 According to the electrolyte for a dye-sensitized solar cell of the present invention, the photoelectric conversion characteristics of the dye-sensitized solar cell can be sufficiently improved.
　上記色素増感太陽電池用電解質は、前記ハロゲンと、前記ハロゲン化物塩と、前記ハロゲン化水素とを含み、前記ハロゲンの体積モル濃度Ｃ１が、前記ハロゲン化水素の体積モル濃度Ｃ２と、前記塩基性物質及び前記ハロゲン化水素の塩の体積モル濃度Ｃ４との合計体積モル濃度Ｃ２０より大きく、前記塩基性物質及び前記ハロゲン化水素の塩の体積モル濃度Ｃ４が０ｍＭであることが好ましい。すなわち上記色素増感太陽電池用電解質は、ハロゲンと、ハロゲン化物塩と、ハロゲン化水素とを含み、前記ハロゲンと前記ハロゲン化物塩とによって酸化還元対が形成され、前記ハロゲン、前記ハロゲン化物塩及び前記ハロゲン化水素が同一のハロゲン原子を有し、前記ハロゲンの体積モル濃度Ｃ１が前記ハロゲン化水素の体積モル濃度Ｃ２よりも大きい色素増感太陽電池用電解質であることが好ましい。 The electrolyte for a dye-sensitized solar cell includes the halogen, the halide salt, and the hydrogen halide, and the volume molar concentration C 1 of the halogen is the volume molar concentration C 2 of the hydrogen halide. greater than the total molarity C 20 with molarity C 4 salts of said basic material and the hydrogen halide, that molarity C 4 salts of said basic material and the hydrogen halide is 0mM Is preferred. That is, the dye-sensitized solar cell electrolyte includes a halogen, a halide salt, and a hydrogen halide, and the halogen and the halide salt form an oxidation-reduction pair, and the halogen, the halide salt, and It is preferable that the hydrogen halide has the same halogen atom, and the volume molar concentration C 1 of the halogen is larger than the volume molar concentration C 2 of the hydrogen halide.
　上記色素増感太陽電池用電解質によれば、色素増感太陽電池の光電変換特性をより十分に向上させることができる。 According to the dye-sensitized solar cell electrolyte, the photoelectric conversion characteristics of the dye-sensitized solar cell can be more sufficiently improved.
　このような効果が得られる理由について本発明者は以下のように推測している。すなわち、本発明の電解質が、酸化物半導体からなる酸化物半導体層を有する色素増感太陽電池の電解質として用いられる場合に、ハロゲン化水素が、酸化物半導体層の価電子帯の準位を上げ、色素-酸化物半導体間の電子注入効率を向上させることができる。また電解質中の酸化還元対のＨＯＭＯ（結合性軌道）の準位にずれが生じにくくなる。別言すると、ハロゲン化水素によりレドックス準位が適正位置から変化してしまうことを防ぐことができる。このため、色素増感太陽電池の光電変換特性を十分に向上させることができるのではないかと本発明者は推測する。 The present inventor presumes the reason why such an effect is obtained as follows. That is, when the electrolyte of the present invention is used as an electrolyte of a dye-sensitized solar cell having an oxide semiconductor layer made of an oxide semiconductor, hydrogen halide increases the level of the valence band of the oxide semiconductor layer. In addition, the electron injection efficiency between the dye and the oxide semiconductor can be improved. In addition, the HOMO (bonding orbital) level of the redox couple in the electrolyte is less likely to shift. In other words, it is possible to prevent the redox level from changing from an appropriate position due to hydrogen halide. For this reason, this inventor estimates that the photoelectric conversion characteristic of a dye-sensitized solar cell can fully be improved.
　上記色素増感太陽電池用電解質においては、前記ハロゲンの体積モル濃度Ｃ１が、前記ハロゲン化水素の体積モル濃度Ｃ２の２倍以上であることが好ましい。 In the dye-sensitized solar cell electrolyte, the volume molar concentration C 1 of the halogen is preferably twice or more the volume molar concentration C 2 of the hydrogen halide.
　この場合、色素増感太陽電池の光電変換特性を特に十分に向上させることができる。 In this case, the photoelectric conversion characteristics of the dye-sensitized solar cell can be particularly sufficiently improved.
　上記色素増感太陽電池用電解質においては、前記ハロゲン化水素の体積モル濃度Ｃ２が、０．０５～１５ｍＭであることが好ましい。 In the dye-sensitized solar cell electrolyte, the halogenated molarity C 2 hydrogens, is preferably 0.05 ~ 15 mM.
　この場合、電解質が、酸化物半導体からなる酸化物半導体層を有する色素増感太陽電池の電解質として用いられる場合に、Ｃ２が０．０５ｍＭ未満である場合に比べて、ハロゲン化水素が酸化物半導体の価電子帯の準位を上げ、色素-酸化物半導体間の電子注入効率をより向上させることができる。また、Ｃ２が１５ｍＭを超える場合に比べて、色素増感太陽電池の光電変換特性をより十分に向上させることができる。 In this case, the electrolyte is, when used as an electrolyte of a dye-sensitized solar cell including an oxide semiconductor layer formed of an oxide semiconductor, as compared with the case C 2 is less than 0.05 mM, hydrogen halide oxide The level of the valence band of the semiconductor can be increased, and the electron injection efficiency between the dye and the oxide semiconductor can be further improved. Further, as compared with the case where C 2 is more than 15 mM, it can be more sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell.
　上記色素増感太陽電池用電解質においては、前記ハロゲン原子がヨウ素原子であることが好ましい。 In the dye-sensitized solar cell electrolyte, the halogen atom is preferably an iodine atom.
　この場合、色素増感太陽電池に用いる光増感色素のＨＯＭＯ（結合性軌道）準位と電解質中の酸化還元対の準位が適正な位置となるため、電子注入効率をより向上させることができる。またヨウ素の還元反応が他のハロゲン種よりも優れているため、光励起した光増感色素を瞬時に基底状態に戻すことができ、光増感色素による逆反応等を妨げることができる。 In this case, since the HOMO (bonding orbital) level of the photosensitizing dye used in the dye-sensitized solar cell and the level of the redox pair in the electrolyte are in an appropriate position, the electron injection efficiency can be further improved. it can. In addition, since the iodine reduction reaction is superior to other halogen species, the photosensitized photosensitizing dye can be instantaneously returned to the ground state, and the reverse reaction by the photosensitizing dye can be prevented.
　上記色素増感太陽電池用電解質は、前記ハロゲンと、前記ハロゲン化物塩と、前記塩基性物質と、前記塩基性物質と前記ハロゲン化水素との塩とを含み、前記塩基性物質の体積モル濃度Ｃ３が、前記ハロゲン化水素の体積モル濃度Ｃ２と、前記塩基性物質及び前記ハロゲン化水素の塩の体積モル濃度Ｃ４との合計体積モル濃度Ｃ２０より大きく、前記ハロゲン化水素の体積モル濃度Ｃ２が０ｍＭであってもよい。すなわち上記色素増感太陽電池用電解質は、ハロゲンと、ハロゲン化物塩と、塩基性物質と、前記塩基性物質とハロゲン化水素との塩とを含み、前記ハロゲンと前記ハロゲン化物塩とによって酸化還元対が形成され、前記ハロゲン、前記ハロゲン化物塩及び前記ハロゲン化水素が同一のハロゲン原子を有し、前記塩基性物質の体積モル濃度Ｃ３が、前記塩基性物質と前記ハロゲン化水素との塩の体積モル濃度Ｃ４よりも大きい色素増感太陽電池用電解質であってもよい。 The electrolyte for a dye-sensitized solar cell includes the halogen, the halide salt, the basic substance, and the salt of the basic substance and the hydrogen halide, and the volume molar concentration of the basic substance. C 3 is larger than the total molar molar concentration C 20 of the molar molar concentration C 2 of the hydrogen halide and the molar molar concentration C 4 of the basic substance and the salt of the hydrogen halide, and the volume of the hydrogen halide. molar concentration C 2 may be 0 mM. That is, the dye-sensitized solar cell electrolyte includes a halogen, a halide salt, a basic substance, and a salt of the basic substance and a hydrogen halide, and is oxidized and reduced by the halogen and the halide salt. pair is formed, the halogen, the halide salt and the hydrogen halide has the same halogen atom, molarity C 3 of the basic substance, a salt with the hydrogen halide and said basic substance it may be a dye-sensitized solar cell electrolyte greater than the molarity C 4.
　上記色素増感太陽電池用電解質によれば、色素増感太陽電池の光電変換特性をより十分に向上させることができる。 According to the dye-sensitized solar cell electrolyte, the photoelectric conversion characteristics of the dye-sensitized solar cell can be more sufficiently improved.
　このような効果が得られる理由について本発明者は以下のように推測している。すなわち、本発明の電解質が、酸化物半導体からなる酸化物半導体層を有する色素増感太陽電池の電解質として用いられる場合に、塩基性物質とハロゲン化水素との塩が、酸化物半導体層の価電子帯の準位を上げ、色素-酸化物半導体間の電子注入効率を向上させることができる。また電解質中の酸化還元対のＨＯＭＯ（結合性軌道）の準位にずれが生じにくくなる。別言すると、塩基性物質とハロゲン化水素との塩によりレドックス準位が適正位置から変化してしまうことを防ぐことができる。このため、色素増感太陽電池の光電変換特性を十分に向上させることができるのではないかと本発明者は推測する。 The present inventor presumes the reason why such an effect is obtained as follows. That is, when the electrolyte of the present invention is used as an electrolyte of a dye-sensitized solar cell having an oxide semiconductor layer made of an oxide semiconductor, a salt of a basic substance and a hydrogen halide is added to the oxide semiconductor layer. The electron band level can be increased, and the electron injection efficiency between the dye and the oxide semiconductor can be improved. In addition, the HOMO (bonding orbital) level of the redox couple in the electrolyte is less likely to shift. In other words, it is possible to prevent the redox level from changing from an appropriate position due to a salt of a basic substance and hydrogen halide. For this reason, this inventor estimates that the photoelectric conversion characteristic of a dye-sensitized solar cell can fully be improved.
　上記色素増感太陽電池用電解質においては、前記塩基性物質の体積モル濃度Ｃ３が前記塩基性物質と前記ハロゲン化水素との塩の体積モル濃度Ｃ４の３倍以上であることが好ましい。 In the dye-sensitized solar cell electrolyte, it is preferred molarity C 3 of the basic material is the basic material is three times or more molarity C 4 of the salt with the hydrogen halide.
　この場合、色素増感太陽電池の光電変換特性をより十分に向上させることができる。 In this case, the photoelectric conversion characteristics of the dye-sensitized solar cell can be more sufficiently improved.
　上記色素増感太陽電池用電解質においては、前記塩基性物質と前記ハロゲン化水素との塩の体積モル濃度Ｃ４が０．０５～１５ｍＭであることが好ましい。 In the dye-sensitized solar cell electrolyte, the molar concentration C 4 of the salt of the basic substance and the hydrogen halide is preferably 0.05 to 15 mM.
　この場合、電解質が、酸化物半導体からなる酸化物半導体層を有する色素増感太陽電池の電解質として用いられる場合に、Ｃ４が０．０５ｍＭ未満である場合に比べて、塩基性物質とハロゲン化水素との塩が酸化物半導体の価電子帯の準位を上げ、色素-酸化物半導体間の電子注入効率をより向上させることができる。また、Ｃ４が１５ｍＭを超える場合に比べて、色素増感太陽電池の光電変換特性をより十分に向上させることができる。 In this case, the electrolyte is, when used as an electrolyte of a dye-sensitized solar cell including an oxide semiconductor layer formed of an oxide semiconductor, as compared with the case C 4 is less than 0.05 mM, basic substance and halogenated The salt with hydrogen can raise the level of the valence band of the oxide semiconductor, and the electron injection efficiency between the dye and the oxide semiconductor can be further improved. Further, as compared with the case where C 4 exceeds 15 mM, it is possible to more sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell.
　また本発明は、透明基板及び前記透明基板上に設けられる透明導電膜を有する第１電極と、前記第１電極に対向する第２電極と、前記第１電極又は前記第２電極に設けられる酸化物半導体層と、前記第１電極及び前記第２電極の間に設けられる電解質と、前記酸化物半導体層に吸着される光増感色素とを備え、前記電解質が、上述した色素増感太陽電池用電解質である色素増感太陽電池である。 The present invention also provides a first electrode having a transparent substrate and a transparent conductive film provided on the transparent substrate, a second electrode facing the first electrode, and an oxidation provided on the first electrode or the second electrode. A dye-sensitized solar cell, comprising: an organic semiconductor layer; an electrolyte provided between the first electrode and the second electrode; and a photosensitizing dye adsorbed on the oxide semiconductor layer. It is a dye-sensitized solar cell which is an electrolyte for use.
　本発明の色素増感太陽電池によれば、電解質が、上述した色素増感太陽電池用電解質であることで、光電変換特性を十分に向上させることができる。 According to the dye-sensitized solar cell of the present invention, since the electrolyte is the above-described dye-sensitized solar cell electrolyte, the photoelectric conversion characteristics can be sufficiently improved.
　また、本発明は、ハロゲンと、ハロゲン化物塩と、塩基性物質とハロゲン化水素との塩とを含み、前記ハロゲンと前記ハロゲン化物塩とによって酸化還元対が形成された電解液を準備する電解液準備工程と、前記電解液と前記塩基性物質とを混合して色素増感太陽電池用電解質を得る塩基性物質混合工程とを含み、前記電解液準備工程において、前記ハロゲン、前記ハロゲン化物塩及び前記ハロゲン化水素が同一のハロゲン原子を有し、前記塩基性物質混合工程において、前記塩基性物質の体積モル濃度Ｃ３が、前記塩基性物質と前記ハロゲン化水素との塩の体積モル濃度Ｃ４よりも大きくなるように前記電解液と前記塩基性物質とを混合する色素増感太陽電池用電解質の製造方法である。 The present invention also provides an electrolyte for preparing an electrolytic solution containing a halogen, a halide salt, a salt of a basic substance and a hydrogen halide, wherein a redox pair is formed by the halogen and the halide salt. A liquid preparation step, and a basic substance mixing step of obtaining an electrolyte for a dye-sensitized solar cell by mixing the electrolyte and the basic substance. In the electrolyte preparation step, the halogen and the halide salt and having said hydrogen halide is the same halogen atom, in the basic material mixing step, molarity C 3 of the basic substance, molarity of the salt with the hydrogen halide and said basic substance it is the electrolyte and a manufacturing method of the basic substance and mixing the dye-sensitized solar cell electrolyte to be greater than C 4.
　本発明の色素増感太陽電池用電解質の製造方法によれば、色素増感太陽電池の光電変換特性を十分に向上させることができる色素増感太陽電池用電解質を製造することができる。 According to the method for producing an electrolyte for a dye-sensitized solar cell of the present invention, an electrolyte for a dye-sensitized solar cell that can sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell can be produced.
　上記塩基性物質混合工程においては、前記塩基性物質の体積モル濃度Ｃ３が前記塩基性物質と前記ハロゲン化水素との塩の体積モル濃度Ｃ４の３倍以上となるように前記電解液と前記塩基性物質とを混合することが好ましい。 In the above basic substance mixing step, and the electrolyte as more than three times of the basic volume mole of salt molarity C 3 material as said basic material with said hydrogen halide concentration C 4 It is preferable to mix with the basic substance.
　この場合、塩基性物質の体積モル濃度Ｃ３が、塩基性物質とハロゲン化水素との塩の体積モル濃度Ｃ４の３倍未満となるように前記電解液と前記塩基性物質とを混合する場合に比べて、得られる電解質は、色素増感太陽電池の光電変換特性をより十分に向上させることができる。 In this case, the electrolytic solution and the basic substance are mixed so that the volume molar concentration C 3 of the basic substance is less than three times the volume molar concentration C 4 of the salt of the basic substance and hydrogen halide. Compared to the case, the obtained electrolyte can more sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell.
　上記塩基性物質混合工程において、前記塩基性物質と前記ハロゲン化水素との塩の体積モル濃度Ｃ４が０．０５～１５ｍＭとなるように前記電解液と前記塩基性物質とを混合することが好ましい。 In the basic substance mixing step, be molarity C 4 of the salt with the hydrogen halide and said basic substance is mixed with the basic material and the electrolyte so that 0.05 ~ 15 mM preferable.
　この場合、Ｃ４が０．０５ｍＭ未満となるように前記電解液と前記塩基性物質とを混合する場合に比べて、塩基性物質とハロゲン化水素との塩が酸化物半導体の価電子帯の準位を上げ、色素-酸化物半導体間の電子注入効率をより向上させることができる。また、Ｃ４が１５ｍＭを超える場合に比べて、得られる電解質は、色素増感太陽電池の光電変換特性をより十分に向上させることができる。 In this case, as compared with the case where C 4 to mixing the basic material and the electrolyte to be less than 0.05 mM, a salt with a basic substance and a hydrogen halide of the valence band of the oxide semiconductor The level can be increased and the electron injection efficiency between the dye and the oxide semiconductor can be further improved. Further, as compared with the case where C 4 exceeds 15 mM, electrolyte obtained can be more sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell.
　上記色素増感太陽電池用電解質およびその製造方法においては、前記ハロゲン原子がヨウ素原子であることが好ましい。 In the dye-sensitized solar cell electrolyte and the method for producing the same, the halogen atom is preferably an iodine atom.
　この場合、電解質が、色素増感太陽電池の電解質として用いられる場合に、色素増感太陽電池に用いる光増感色素のＨＯＭＯ（結合性軌道）準位と電解質中の酸化還元対の準位が適正な位置となるため、電子注入効率をより向上させることができる。またヨウ素の還元反応が他のハロゲン種よりも優れているため、電解質が、色素増感太陽電池の電解質として用いられる場合に、光励起した光増感色素を瞬時に基底状態に戻すことができ、光増感色素による逆反応等を妨げることができる。 In this case, when the electrolyte is used as an electrolyte of a dye-sensitized solar cell, the HOMO (bonding orbital) level of the photosensitizing dye used in the dye-sensitized solar cell and the level of the redox pair in the electrolyte are Since the position is appropriate, the electron injection efficiency can be further improved. Moreover, since the reduction reaction of iodine is superior to other halogen species, when the electrolyte is used as an electrolyte of a dye-sensitized solar cell, the photosensitized photosensitizing dye can be instantaneously returned to the ground state, The reverse reaction by a photosensitizing dye etc. can be prevented.
　なお、本発明において、塩基性物質とは、ハロゲン化水素と塩を形成し得る物質を言うものとする。 In the present invention, the basic substance refers to a substance that can form a salt with hydrogen halide.
　本発明によれば、色素増感太陽電池の光電変換特性を十分に向上させることができる色素増感太陽電池用電解質および色素増感太陽電池が提供される。 According to the present invention, an electrolyte for a dye-sensitized solar cell and a dye-sensitized solar cell that can sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell are provided.
本発明の色素増感太陽電池の一実施形態を示す断面図である。It is sectional drawing which shows one Embodiment of the dye-sensitized solar cell of this invention. 本発明の色素増感太陽電池の他の実施形態を示す断面図である。It is sectional drawing which shows other embodiment of the dye-sensitized solar cell of this invention.
　以下、本発明の実施形態について図面を参照しながら詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
　＜第１実施形態＞
　まず本発明の色素増感太陽電池の第１実施形態について図１を参照しながら説明する。図１は、本発明の色素増感太陽電池の一実施形態を示す断面図である。 <First Embodiment>
First, a first embodiment of the dye-sensitized solar cell of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing an embodiment of the dye-sensitized solar cell of the present invention.
　図１に示すように、色素増感太陽電池１００は、透明導電性基板１５を有する作用極１０と、透明導電性基板１５に対向する対極２０と、透明導電性基板１５及び対極２０を連結する環状の封止部３０とを備えており、透明導電性基板１５、対極２０及び封止部３０によって形成されるセル空間には電解質４０が充填されている。 As shown in FIG. 1, the dye-sensitized solar cell 100 connects a working electrode 10 having a transparent conductive substrate 15, a counter electrode 20 facing the transparent conductive substrate 15, and the transparent conductive substrate 15 and the counter electrode 20. The cell space formed by the transparent conductive substrate 15, the counter electrode 20 and the sealing portion 30 is filled with an electrolyte 40.
　対極２０は、導電性基板２１と、導電性基板２１の作用極１０側に設けられて電解質４０の還元に寄与する触媒層２２とを備えている。本実施形態では、導電性基板２１によって第２電極が構成されている。 The counter electrode 20 includes a conductive substrate 21 and a catalyst layer 22 provided on the working electrode 10 side of the conductive substrate 21 and contributing to the reduction of the electrolyte 40. In the present embodiment, the second electrode is constituted by the conductive substrate 21.
　一方、作用極１０は、透明導電性基板１５と、透明導電性基板１５上に設けられる少なくとも１つの酸化物半導体層１３とを有している。透明導電性基板１５は、透明基板１１と、透明基板１１の上に設けられる透明導電膜１２とで構成されている。酸化物半導体層１３は、封止部３０の内側に配置されている。また酸化物半導体層１３には、光増感色素が吸着されている。本実施形態では、透明導電性基板１５によって第１電極が構成されている。 On the other hand, the working electrode 10 has a transparent conductive substrate 15 and at least one oxide semiconductor layer 13 provided on the transparent conductive substrate 15. The transparent conductive substrate 15 includes a transparent substrate 11 and a transparent conductive film 12 provided on the transparent substrate 11. The oxide semiconductor layer 13 is disposed inside the sealing portion 30. A photosensitizing dye is adsorbed on the oxide semiconductor layer 13. In the present embodiment, the first electrode is constituted by the transparent conductive substrate 15.
　上記電解質４０は、ハロゲンと、ハロゲン化物塩と、ハロゲン化水素、並びに、塩基性物質と塩基性物質及びハロゲン化水素の塩との混合物からなる群より選ばれる少なくとも１種とを含む。電解質４０においては、ハロゲンとハロゲン化物塩とによって酸化還元対が形成されている。ここで、上記ハロゲン、上記ハロゲン化物塩及び上記ハロゲン化水素は、同一のハロゲン原子を有している。そして、本実施形態では、上記ハロゲンの体積モル濃度Ｃ１は、ハロゲン化水素の体積モル濃度Ｃ２と、塩基性物質及びハロゲン化水素の塩の体積モル濃度Ｃ４との合計体積モル濃度Ｃ２０よりも大きくなっている。ここで、塩基性物質及びハロゲン化水素の塩の体積モル濃度Ｃ４は０ｍＭである。すなわち、ハロゲンの体積モル濃度Ｃ１がハロゲン化水素の体積モル濃度Ｃ２よりも大きくなっている。 The electrolyte 40 includes at least one selected from the group consisting of halogens, halide salts, hydrogen halides, and mixtures of basic substances, basic substances, and salts of hydrogen halides. In the electrolyte 40, a redox pair is formed by the halogen and the halide salt. Here, the halogen, the halide salt and the hydrogen halide have the same halogen atom. In the present embodiment, molarity C 1 of the halogen, the total molarity of the molarity C 2 hydrogen halide, the molarity C 4 salts of a basic substance and hydrogen halides C It is larger than 20 . Here, molarity C 4 salts of a basic substance and hydrogen halide is 0 mM. That is, molarity C 1 halogen is larger than the molarity C 2 hydrogen halide.
　色素増感太陽電池１００によれば、電解質４０が上記構成を有することで、光電変換特性を十分に向上させることができる。 According to the dye-sensitized solar cell 100, since the electrolyte 40 has the above configuration, the photoelectric conversion characteristics can be sufficiently improved.
　次に、作用極１０、対極２０、封止部３０、電解質４０及び光増感色素について詳細に説明する。 Next, the working electrode 10, the counter electrode 20, the sealing part 30, the electrolyte 40, and the photosensitizing dye will be described in detail.
　（作用極）
　作用極１０は、上述したように、透明導電性基板１５と、透明導電性基板１５上に設けられる少なくとも１つの酸化物半導体層１３とを有している。透明導電性基板１５は、透明基板１１と、透明基板１１の上に設けられる透明導電膜１２とで構成されている。 (Working electrode)
As described above, the working electrode 10 includes the transparent conductive substrate 15 and at least one oxide semiconductor layer 13 provided on the transparent conductive substrate 15. The transparent conductive substrate 15 includes a transparent substrate 11 and a transparent conductive film 12 provided on the transparent substrate 11.
　透明基板１１を構成する材料は、例えば透明な材料であればよく、このような透明な材料としては、例えばホウケイ酸ガラス、ソーダライムガラス、白板ガラス、石英ガラスなどのガラス、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）、ポリカーボネート（ＰＣ）、及び、ポリエーテルスルフォン（ＰＥＳ）などが挙げられる。透明基板１１の厚さは、色素増感太陽電池１００のサイズに応じて適宜決定され、特に限定されるものではないが、例えば５０～４００００μｍの範囲にすればよい。 The material which comprises the transparent substrate 11 should just be a transparent material, for example, As such a transparent material, glass, such as borosilicate glass, soda lime glass, white plate glass, quartz glass, polyethylene terephthalate (PET), for example , Polyethylene naphthalate (PEN), polycarbonate (PC), and polyethersulfone (PES). The thickness of the transparent substrate 11 is appropriately determined according to the size of the dye-sensitized solar cell 100 and is not particularly limited, but may be in the range of 50 to 40,000 μm, for example.
　透明導電膜１２を構成する材料としては、例えばスズ添加酸化インジウム（Indium－Tin－Oxide：ＩＴＯ）、酸化スズ（ＳｎＯ２）、及び、フッ素添加酸化スズ（Fluorine－doped－Tin－Oxide：ＦＴＯ）などの導電性金属酸化物が挙げられる。透明導電膜１２は、単層でも、異なる導電性金属酸化物で構成される複数の層の積層体で構成されてもよい。透明導電膜１２が単層で構成される場合、透明導電膜１２は、高い耐熱性及び耐薬品性を有することから、ＦＴＯで構成されることが好ましい。透明導電膜１２の厚さは例えば０．０１～２μｍの範囲にすればよい。 As a material constituting the transparent conductive film 12, for example, tin-doped indium oxide (Indium-Tin-Oxide: ITO), tin oxide (SnO 2 ), and fluorine-doped tin oxide (Fluorine-doped-Tin-Oxide: FTO). And conductive metal oxides such as The transparent conductive film 12 may be a single layer or a laminate of a plurality of layers made of different conductive metal oxides. When the transparent conductive film 12 is composed of a single layer, the transparent conductive film 12 is preferably composed of FTO because it has high heat resistance and chemical resistance. The thickness of the transparent conductive film 12 may be in the range of 0.01 to 2 μm, for example.
　酸化物半導体層１３は、酸化物半導体粒子で構成されている。酸化物半導体粒子は、例えば酸化チタン（ＴｉＯ２）、酸化亜鉛（ＺｎＯ）、酸化タングステン（ＷＯ３）、酸化ニオブ（Ｎｂ２Ｏ５）、チタン酸ストロンチウム（ＳｒＴｉＯ３）、酸化スズ（ＳｎＯ２）、酸化インジウム（Ｉｎ３Ｏ３）、酸化ジルコニウム（ＺｒＯ２）、酸化タリウム（Ｔａ２Ｏ５）、酸化ランタン（Ｌａ２Ｏ３）、酸化イットリウム（Ｙ２Ｏ３）、酸化ホルミウム（Ｈｏ２Ｏ３）、酸化ビスマス（Ｂｉ２Ｏ３）、酸化セリウム（ＣｅＯ２）、酸化アルミニウム（Ａｌ２Ｏ３）又はこれらの２種以上で構成される。酸化物半導体層１３の厚さは、例えば０．１～１００μｍとすればよい。 The oxide semiconductor layer 13 is composed of oxide semiconductor particles. Examples of the oxide semiconductor particles include titanium oxide (TiO 2 ), zinc oxide (ZnO), tungsten oxide (WO 3 ), niobium oxide (Nb 2 O 5 ), strontium titanate (SrTiO 3 ), and tin oxide (SnO 2 ). , Indium oxide (In 3 O 3 ), zirconium oxide (ZrO 2 ), thallium oxide (Ta 2 O 5 ), lanthanum oxide (La 2 O 3 ), yttrium oxide (Y 2 O 3 ), holmium oxide (Ho 2 O) 3 ), bismuth oxide (Bi 2 O 3 ), cerium oxide (CeO 2 ), aluminum oxide (Al 2 O 3 ), or two or more thereof. The thickness of the oxide semiconductor layer 13 may be 0.1 to 100 μm, for example.
　（対極）
　対極２０は、上述したように、導電性基板２１と、導電性基板２１のうち作用極１０側に設けられて電解質４０の還元に寄与する導電性の触媒層２２とを備えるものである。 (Counter electrode)
As described above, the counter electrode 20 includes the conductive substrate 21 and the conductive catalyst layer 22 provided on the working electrode 10 side of the conductive substrate 21 and contributing to the reduction of the electrolyte 40.
　導電性基板２１は、例えばチタン、ニッケル、白金、モリブデン、タングステン、アルミニウム、ステンレス等の耐食性の金属材料や、上述した透明基板１１にＩＴＯ、ＦＴＯ等の導電性酸化物からなる膜を形成したもので構成される。導電性基板２１の厚さは、色素増感太陽電池１００のサイズに応じて適宜決定され、特に限定されるものではないが、例えば０．００５～４ｍｍとすればよい。 The conductive substrate 21 is, for example, a corrosion-resistant metal material such as titanium, nickel, platinum, molybdenum, tungsten, aluminum, or stainless steel, or a film made of a conductive oxide such as ITO or FTO on the transparent substrate 11 described above. Consists of. The thickness of the conductive substrate 21 is appropriately determined according to the size of the dye-sensitized solar cell 100 and is not particularly limited, but may be, for example, 0.005 to 4 mm.
　触媒層２２は、白金、炭素系材料又は導電性高分子などから構成される。ここで、炭素系材料としては、カーボンナノチューブが好適に用いられる。 The catalyst layer 22 is composed of platinum, a carbon-based material, a conductive polymer, or the like. Here, carbon nanotubes are suitably used as the carbon-based material.
　（封止部）
　封止部３０としては、例えば変性ポリオレフィン樹脂、ビニルアルコール重合体などの熱可塑性樹脂、及び、紫外線硬化樹脂などの樹脂が挙げられる。変性ポリオレフィン樹脂としては、例えばアイオノマー、エチレン－ビニル酢酸無水物共重合体、エチレン－メタクリル酸共重合体およびエチレン－ビニルアルコール共重合体が挙げられる。これらの樹脂は単独で又は２種以上を組み合せて用いることができる。 (Sealing part)
Examples of the sealing portion 30 include thermoplastic resins such as modified polyolefin resins and vinyl alcohol polymers, and resins such as ultraviolet curable resins. Examples of modified polyolefin resins include ionomers, ethylene-vinyl acetic anhydride copolymers, ethylene-methacrylic acid copolymers, and ethylene-vinyl alcohol copolymers. These resins can be used alone or in combination of two or more.
　（電解質）
　電解質４０は、上述したように、ハロゲンと、ハロゲン化物塩と、ハロゲン化水素と、を含んでいる。そして、電解質４０においては、ハロゲンとハロゲン化物塩とによって酸化還元対が形成されている。また上記ハロゲン、上記ハロゲン化物塩及び上記ハロゲン化水素は同一のハロゲン原子を有している。そして、上記ハロゲンの体積モル濃度Ｃ１が、上記ハロゲン化水素の体積モル濃度Ｃ２よりも大きくなっている、すなわちＣ１／Ｃ２の値が１より大きくなっている。 (Electrolytes)
As described above, the electrolyte 40 contains halogen, a halide salt, and hydrogen halide. In the electrolyte 40, a redox pair is formed by the halogen and the halide salt. The halogen, the halide salt and the hydrogen halide have the same halogen atom. The volume molar concentration C 1 of the halogen is larger than the volume molar concentration C 2 of the hydrogen halide, that is, the value of C 1 / C 2 is larger than 1.
　電解質４０において、ハロゲン、ハロゲン化物塩及びハロゲン化水素を構成するハロゲン原子としては、例えば臭素原子、ヨウ素原子などが挙げられる。 In the electrolyte 40, examples of the halogen atom constituting the halogen, halide salt and hydrogen halide include a bromine atom and an iodine atom.
　中でも、ハロゲン、ハロゲン化物塩及びハロゲン化水素を構成するハロゲン原子は、ヨウ素原子であることが好ましい。すなわち、ハロゲンがヨウ素であり、ハロゲン化物質塩がヨウ化物塩であり、ハロゲン化水素がヨウ化水素であることが好ましい。 Among them, the halogen atom constituting the halogen, halide salt and hydrogen halide is preferably an iodine atom. That is, it is preferable that the halogen is iodine, the halide salt is an iodide salt, and the hydrogen halide is hydrogen iodide.
　この場合、色素増感太陽電池１００に用いる光増感色素のＨＯＭＯ（結合性軌道）準位と電解質中のレドックス準位が適正な位置となるため、電子注入効率がより向上する。またヨウ素の還元反応が他のハロゲン種よりも優れているため、光励起した光増感色素を瞬時に基底状態に戻すことができ、光増感色素による逆反応等を妨げることができる。 In this case, since the HOMO (bonding orbital) level of the photosensitizing dye used in the dye-sensitized solar cell 100 and the redox level in the electrolyte are in proper positions, the electron injection efficiency is further improved. In addition, since the iodine reduction reaction is superior to other halogen species, the photosensitized photosensitizing dye can be instantaneously returned to the ground state, and the reverse reaction by the photosensitizing dye can be prevented.
　電解質４０に含まれるハロゲン化物塩としては、例えば、臭化リチウム、臭化ナトリウム、臭化カリウム、テトラメチルアンモニウムブロマイド、テトラエチルアンモニウムブロマイド、テトラブチルアンモニウムブロマイド、テトラヘキシルアンモニウムブロマイド、１－ヘキシル－３－メチルイミダゾリウムブロマイド、１－エチル－３－プロピルイミダゾリウムブロマイド、ジメチルイミダゾリウムブロマイド、エチルメチルイミダゾリウムブロマイド、ジメチルプロピルイミダゾリウムブロマイド、ブチルメチルイミダゾリウムブロマイド、メチルプロピルイミダゾリウムブロマイドなどの臭化物塩、ヨウ化リチウム、ヨウ化ナトリウム、ヨウ化カリウム、テトラメチルアンモニウムヨーダイド、テトラエチルアンモニウムヨーダイド、テトラブチルアンモニウムヨーダイド、テトラヘキシルアンモニウムヨーダイド、１－ヘキシル－３－メチルイミダゾリウムヨーダイド、１－エチル－３－プロピルイミダゾリウムヨーダイド、ジメチルイミダゾリウムヨーダイド、エチルメチルイミダゾリウムヨーダイド、ジメチルプロピルイミダゾリウムヨーダイド、ブチルメチルイミダゾリウムヨーダイド、又は、メチルプロピルイミダゾリウムヨーダイドなどのヨウ化物塩が挙げられる。 Examples of the halide salt contained in the electrolyte 40 include lithium bromide, sodium bromide, potassium bromide, tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, tetrahexylammonium bromide, 1-hexyl-3- Bromide salts such as methyl imidazolium bromide, 1-ethyl-3-propyl imidazolium bromide, dimethyl imidazolium bromide, ethyl methyl imidazolium bromide, dimethylpropyl imidazolium bromide, butyl methyl imidazolium bromide, methyl propyl imidazolium bromide, iodine Lithium iodide, sodium iodide, potassium iodide, tetramethylammonium iodide, tetraethylammonium iodide , Tetrabutylammonium iodide, tetrahexylammonium iodide, 1-hexyl-3-methylimidazolium iodide, 1-ethyl-3-propylimidazolium iodide, dimethylimidazolium iodide, ethylmethylimidazolium iodide And iodide salts such as dimethylpropylimidazolium iodide, butylmethylimidazolium iodide, and methylpropylimidazolium iodide.
　また、電解質４０に含まれるハロゲン化水素としては、例えば臭化水素、ヨウ化水素などが挙げられる。 Also, examples of the hydrogen halide contained in the electrolyte 40 include hydrogen bromide and hydrogen iodide.
　ハロゲンとハロゲン化塩とによって形成される酸化還元対としては、ハロゲン化物イオンとポリハロゲン化物イオンの組合せ等が挙げられる。具体的には、Ｉ－／Ｉ３ －やＢｒ－／Ｂｒ３ －などが挙げられる。 Examples of the redox pair formed by halogen and a halide salt include combinations of halide ions and polyhalide ions. Specific examples include I − / I 3 — and Br − / Br 3 — .
　電解質４０においては、ハロゲンの体積モル濃度Ｃ１がハロゲン化水素の体積モル濃度Ｃ２の２倍以上、すなわちＣ１／Ｃ２の値は２以上であることであることが好ましい。 In the electrolyte 40, molarity C 1 halogen twice more molarity C 2 hydrogen halide, that is, the value of C 1 / C 2 is preferably by 2 or more.
　この場合、Ｃ１／Ｃ２の値が２未満である場合に比べて、色素増感太陽電池１００の光電変換特性を特に十分に向上させることができる。 In this case, as compared with the case where the value of C 1 / C 2 is less than 2, it is particularly well improve the photoelectric conversion characteristics of the dye-sensitized solar cell 100.
　Ｃ１／Ｃ２の値は２．５～３００であることがより好ましく、１０～２５０であることがさらに好ましい。 The value of C 1 / C 2 is more preferably 2.5 to 300, and further preferably 10 to 250.
　ハロゲンの体積モル濃度Ｃ１は、上述したように、ハロゲン化水素の体積モル濃度Ｃ２より大きければよい。 Molarity C 1 halogen, as described above, may be greater than the volume molar concentration C 2 of the hydrogen halide.
　また、ハロゲン化水素の体積モル濃度Ｃ２は０．０５～１５ｍＭであることが好ましい。 The volume molar concentration C 2 of hydrogen halide is preferably 0.05 to 15 mM.
　ハロゲン化水素の体積モル濃度Ｃ２が０．０５～１５ｍＭの範囲内にあると、Ｃ２が１５ｍＭを超える場合に比べて、色素増感太陽電池１００の光電変換特性をより十分に向上させることができる。また、ハロゲン化水素の体積モル濃度Ｃ２が０．０５～１５ｍＭの範囲内にあると、Ｃ２が０．０５ｍＭ未満である場合に比べて、ハロゲン化水素が酸化物半導体の価電子帯の準位を上げ、色素-酸化物半導体間の電子注入効率をより向上させることができる。 When the volume molar concentration C 2 of hydrogen halide is in the range of 0.05 to 15 mM, the photoelectric conversion characteristics of the dye-sensitized solar cell 100 can be more sufficiently improved than when C 2 exceeds 15 mM. Can do. Further, when the volume molar concentration C 2 of hydrogen halide is in the range of 0.05 to 15 mM, the hydrogen halide is in the valence band of the oxide semiconductor as compared with the case where C 2 is less than 0.05 mM. The level can be increased and the electron injection efficiency between the dye and the oxide semiconductor can be further improved.
　Ｃ２は０．０６～１４ｍＭであることがより好ましく、０．０７～１３ｍＭであることがさらに好ましい。 C 2 is more preferably 0.06 to 14 mM, and further preferably 0.07 to 13 mM.
　電解質４０は、さらに有機溶媒を含んでいてもよい。有機溶媒としては、アセトニトリル、メトキシアセトニトリル、メトキシプロピオニトリル、プロピオニトリル、エチレンカーボネート、プロピレンカーボネート、ジエチルカーボネート、γ－ブチロラクトン、バレロニトリル、ピバロニトリル、グルタロニトリル、メタクリロニトリル、イソブチロニトリル、フェニルアセトニトリル、アクリロニトリル、スクシノニトリル、オキサロニトリル、ペンタニトリル、アジポニトリルなどを用いることができる。これらは１種類を単独で用いても、２種類以上を組み合わせて用いてもよい。 Electrolyte 40 may further contain an organic solvent. Examples of organic solvents include acetonitrile, methoxyacetonitrile, methoxypropionitrile, propionitrile, ethylene carbonate, propylene carbonate, diethyl carbonate, γ-butyrolactone, valeronitrile, pivalonitrile, glutaronitrile, methacrylonitrile, isobutyronitrile, Phenylacetonitrile, acrylonitrile, succinonitrile, oxalonitrile, pentanitrile, adiponitrile and the like can be used. These may be used alone or in combination of two or more.
　また電解質４０は、さらに添加剤を含んでもよい。添加剤としては、４－ｔ－ブチルピリジン、グアニジウムチオシアネート、１－メチルベンゾイミダゾール、１-ブチルベンゾイミダゾールなどが挙げられる。 The electrolyte 40 may further contain an additive. Examples of the additive include 4-t-butylpyridine, guanidinium thiocyanate, 1-methylbenzimidazole, and 1-butylbenzimidazole.
　さらに電解質４０としては、上記電解質にＳｉＯ２、ＴｉＯ２、カーボンナノチューブなどのナノ粒子を混練してゲル様となった擬固体電解質であるナノコンポジットゲル電解質を用いてもよく、また、ポリフッ化ビニリデン、ポリエチレンオキサイド誘導体、アミノ酸誘導体などの有機系ゲル化剤を用いてゲル化した電解質を用いてもよい。 Further, as the electrolyte 40, a nano-composite gel electrolyte, which is a pseudo-solid electrolyte formed by kneading nanoparticles such as SiO 2 , TiO 2 , carbon nanotubes, etc. into the electrolyte, may be used, and polyvinylidene fluoride may be used. Alternatively, an electrolyte gelled with an organic gelling agent such as a polyethylene oxide derivative or an amino acid derivative may be used.
　（光増感色素）
　光増感色素としては、例えばビピリジン構造、ターピリジン構造などを含む配位子を有するルテニウム錯体や、ポルフィリン、エオシン、ローダミン、メロシアニンなどの有機色素が挙げられる。中でも、ターピリジン構造を含む配位子を有するルテニウム錯体が好ましい。この場合、色素増感太陽電池１００の光電変換特性をより向上させることができる。 (Photosensitizing dye)
Examples of the photosensitizing dye include a ruthenium complex having a ligand containing a bipyridine structure, a terpyridine structure, and the like, and organic dyes such as porphyrin, eosin, rhodamine, and merocyanine. Among these, a ruthenium complex having a ligand containing a terpyridine structure is preferable. In this case, the photoelectric conversion characteristics of the dye-sensitized solar cell 100 can be further improved.
　なお、色素増感太陽電池１００が屋内や低照度（１０～１００００ｌｕｘ）の環境下において使用される場合には、光増感色素として、ビピリジン構造を含む配位子を有するルテニウム錯体を用いることが好ましい。 When the dye-sensitized solar cell 100 is used indoors or in an environment with low illuminance (10 to 10,000 lux), a ruthenium complex having a ligand containing a bipyridine structure may be used as the photosensitizing dye. preferable.
　次に、上述した色素増感太陽電池１００の製造方法について説明する。 Next, a method for manufacturing the above-described dye-sensitized solar cell 100 will be described.
　まず１つの透明基板１１の上に、透明導電膜１２を形成してなる透明導電性基板１５を用意する。 First, a transparent conductive substrate 15 formed by forming a transparent conductive film 12 on one transparent substrate 11 is prepared.
　透明導電膜１２の形成方法としては、スパッタリング法、蒸着法、スプレー熱分解法（ＳＰＤ：Spray Pyrolysis Deposition）及びＣＶＤ法などが用いられる。 As a method for forming the transparent conductive film 12, a sputtering method, a vapor deposition method, a spray pyrolysis method (SPD), a CVD method, or the like is used.
　次に、透明導電膜１２の上に、酸化物半導体層１３を形成する。酸化物半導体層１３は、酸化物半導体粒子を含む多孔質酸化物半導体層形成用ペーストを印刷した後、焼成して形成する。 Next, an oxide semiconductor layer 13 is formed on the transparent conductive film 12. The oxide semiconductor layer 13 is formed by printing a porous oxide semiconductor layer forming paste containing oxide semiconductor particles, followed by firing.
　酸化物半導体層形成用ペーストは、上述した酸化物半導体粒子のほか、ポリエチレングリコールなどの樹脂及び、テレピネオールなどの溶媒を含む。 The oxide semiconductor layer forming paste contains a resin such as polyethylene glycol and a solvent such as terpineol in addition to the oxide semiconductor particles described above.
　酸化物半導体層形成用ペーストの印刷方法としては、例えばスクリーン印刷法、ドクターブレード法、又は、バーコート法などを用いることができる。 As a method for printing the oxide semiconductor layer forming paste, for example, a screen printing method, a doctor blade method, a bar coating method, or the like can be used.
　焼成温度は酸化物半導体粒子の材質により異なるが、通常は３５０～６００℃であり、焼成時間も、酸化物半導体粒子の材質により異なるが、通常は１～５時間である。 The firing temperature varies depending on the material of the oxide semiconductor particles, but is usually 350 to 600 ° C., and the firing time also varies depending on the material of the oxide semiconductor particles, but is usually 1 to 5 hours.
　こうして作用極１０が得られる。 Thus, the working electrode 10 is obtained.
　次に、作用極１０の酸化物半導体層１３の表面に光増感色素を吸着させる。このためには、作用極１０を、光増感色素を含有する溶液の中に浸漬させ、その光増感色素を酸化物半導体層１３に吸着させた後に上記溶液の溶媒成分で余分な光増感色素を洗い流し、乾燥させることで、光増感色素を酸化物半導体層１３に吸着させればよい。但し、光増感色素を含有する溶液を酸化物半導体層１３に塗布した後、乾燥させることによって光増感色素を酸化物半導体層１３に吸着させてもよい。 Next, a photosensitizing dye is adsorbed on the surface of the oxide semiconductor layer 13 of the working electrode 10. For this purpose, the working electrode 10 is immersed in a solution containing a photosensitizing dye, the photosensitizing dye is adsorbed on the oxide semiconductor layer 13, and then the excess photosensitizer is added with the solvent component of the solution. The photosensitizing dye may be adsorbed to the oxide semiconductor layer 13 by washing away the dye and drying it. However, the photosensitizing dye may be adsorbed to the oxide semiconductor layer 13 by applying a solution containing the photosensitizing dye to the oxide semiconductor layer 13 and then drying the solution.
　次に、電解質４０を用意する。電解質４０は、上述したハロゲン、ハロゲン化物塩及びハロゲン化水素を含み、Ｃ１／Ｃ２の値が１より大きくなるように調製することによって得られる。このとき、電解質４０においては、ハロゲンとハロゲン化物塩とによって酸化還元対が形成される。 Next, the electrolyte 40 is prepared. The electrolyte 40 contains the halogen, halide salt, and hydrogen halide described above, and is obtained by adjusting the C 1 / C 2 value to be greater than 1. At this time, in the electrolyte 40, a redox pair is formed by the halogen and the halide salt.
　そして、酸化物半導体層１３の上に、電解質４０を配置する。電解質４０は、例えばスクリーン印刷等の印刷法によって配置することが可能である。 Then, the electrolyte 40 is disposed on the oxide semiconductor layer 13. The electrolyte 40 can be disposed by a printing method such as screen printing.
　次に、環状の封止部形成体を準備する。封止部形成体は、例えば封止用樹脂フィルムを用意し、その封止用樹脂フィルムに１つの四角形状の開口を形成することによって得ることができる。 Next, an annular sealing part forming body is prepared. The sealing part forming body can be obtained, for example, by preparing a sealing resin film and forming one rectangular opening in the sealing resin film.
　そして、この封止部形成体を、作用極１０の上に接着させる。このとき、封止部形成体の作用極１０への接着は、例えば封止部形成体を加熱溶融させることによって行うことができる。 Then, the sealing portion forming body is bonded onto the working electrode 10. At this time, adhesion of the sealing portion forming body to the working electrode 10 can be performed by, for example, heating and melting the sealing portion forming body.
　次に、対極２０を用意し、封止部形成体の開口を塞ぐように配置した後、封止部形成体と貼り合わせる。このとき、対極２０にも予め封止部形成体を接着させておき、この封止部形成体を作用極１０側の封止部形成体と貼り合せてもよい。対極２０の封止部形成体への貼合せは、大気圧下で行っても減圧下で行ってもよいが、減圧下で行うことが好ましい。 Next, after preparing the counter electrode 20 and arranging it so as to close the opening of the sealing portion forming body, it is bonded to the sealing portion forming body. At this time, the sealing portion forming body may be bonded to the counter electrode 20 in advance, and the sealing portion forming body may be bonded to the sealing portion forming body on the working electrode 10 side. Lamination of the counter electrode 20 to the sealing portion forming body may be performed under atmospheric pressure or under reduced pressure, but is preferably performed under reduced pressure.
　以上のようにして色素増感太陽電池１００が得られる。 The dye-sensitized solar cell 100 is obtained as described above.
　＜第２実施形態＞
　まず本発明の色素増感太陽電池の第２実施形態について図２を参照しながら説明する。図２は、本発明の色素増感太陽電池の第２実施形態を示す断面図である。 Second Embodiment
First, a second embodiment of the dye-sensitized solar cell of the present invention will be described with reference to FIG. FIG. 2 is a cross-sectional view showing a second embodiment of the dye-sensitized solar cell of the present invention.
　図２に示すように、本実施形態の色素増感太陽電池２００は、電解質４０に代えて電解質２４０を用いる点で第１実施形態の色素増感太陽電池１００と相違する。 As shown in FIG. 2, the dye-sensitized solar cell 200 of the present embodiment is different from the dye-sensitized solar cell 100 of the first embodiment in that an electrolyte 240 is used instead of the electrolyte 40.
　上記電解質２４０は、ハロゲンと、ハロゲン化物塩と、塩基性物質と、該塩基性物質とハロゲン化水素との塩とを含む。電解質２４０においては、ハロゲンとハロゲン化物塩とによって酸化還元対が形成されている。ここで、上記ハロゲン、上記ハロゲン化物塩及び上記ハロゲン化水素は同一のハロゲン原子を有している。そして、本実施形態では、塩基性物質の体積モル濃度Ｃ３が、ハロゲン化水素の体積モル濃度Ｃ２と、塩基性物質及びハロゲン化水素の塩の体積モル濃度Ｃ４との合計体積モル濃度Ｃ２０より大きくなっている。ここで、ハロゲン化水素の体積モル濃度Ｃ２が０ｍＭとなっている。すなわち、上記塩基性物質の体積モル濃度Ｃ３は、上記塩基性物質と上記ハロゲン化水素との塩の体積モル濃度Ｃ４よりも大きくなっている。すなわちＣ３／Ｃ４の値が１より大きくなっている。 The electrolyte 240 includes a halogen, a halide salt, a basic substance, and a salt of the basic substance and hydrogen halide. In the electrolyte 240, a redox pair is formed by halogen and a halide salt. Here, the halogen, the halide salt and the hydrogen halide have the same halogen atom. In the present embodiment, the total molarity of molarity C 3 of the basic substance, the molarity C 2 hydrogen halide, the molarity C 4 salts of a basic substance and a hydrogen halide It is greater than C 20. Here, molarity C 2 hydrogen halide is in the 0 mM. That is, molarity C 3 of the basic substance is greater than the molarity C 4 of the salt with the basic substance and the hydrogen halide. That is, the value of C 3 / C 4 is larger than 1.
　電解質２４０において、ハロゲン、ハロゲン化物塩及びハロゲン化水素が有するハロゲン原子としては、例えば臭素原子、ヨウ素原子などが挙げられる。 In the electrolyte 240, examples of the halogen atom contained in the halogen, halide salt, and hydrogen halide include a bromine atom and an iodine atom.
　中でも、ハロゲン、ハロゲン化物塩及びハロゲン化水素が有するハロゲン原子は、ヨウ素原子であることが好ましい。すなわち、ハロゲンがヨウ素であり、ハロゲン化物塩がヨウ化物塩であり、ハロゲン化水素がヨウ化水素であることが好ましい。 Especially, it is preferable that the halogen atom which a halogen, a halide salt, and a hydrogen halide have is an iodine atom. That is, it is preferable that the halogen is iodine, the halide salt is an iodide salt, and the hydrogen halide is hydrogen iodide.
　この場合、色素増感太陽電池２００に用いる光増感色素のＨＯＭＯ（結合性軌道）準位と電解質中のレドックス準位が適正な位置となるため、電子注入効率がより向上する。またヨウ素の還元反応が他のハロゲン種よりも優れているため、電解質２４０は、光励起した光増感色素を瞬時に基底状態に戻すことができ、光増感色素による逆反応等を妨げることができる。 In this case, since the HOMO (bonding orbital) level of the photosensitizing dye used in the dye-sensitized solar cell 200 and the redox level in the electrolyte are in proper positions, the electron injection efficiency is further improved. In addition, since the reduction reaction of iodine is superior to other halogen species, the electrolyte 240 can instantaneously return the photosensitized photosensitizing dye to the ground state, and hinder the reverse reaction by the photosensitizing dye. it can.
　塩基性物質としては、具体的には、例えば水酸化リチウム、水酸化ナトリウム、水酸化カリウム、テトラメチルアミン、テトラエチルアミン、テトラブチルアミン、テトラヘキシルアミン、１－ヘキシル－３－メチルイミダゾール、１－エチル－３－プロピルイミダゾール、ジメチルイミダゾール、エチルメチルイミダゾール、ジメチルプロピルイミダゾール、ブチルメチルイミダゾール、メチルプロピルイミダゾール、メチルベンゾイミダゾール、ブチルベンゾイミダゾール、ｔ－ブチルピリジン、グアニジウムチオシアネートなどが好適に用いられる。塩基性物質は１種類を単独で用いても、２種類以上を組み合わせて用いてもよい。 Specific examples of the basic substance include lithium hydroxide, sodium hydroxide, potassium hydroxide, tetramethylamine, tetraethylamine, tetrabutylamine, tetrahexylamine, 1-hexyl-3-methylimidazole, and 1-ethyl. -3-Propylimidazole, dimethylimidazole, ethylmethylimidazole, dimethylpropylimidazole, butylmethylimidazole, methylpropylimidazole, methylbenzimidazole, butylbenzimidazole, t-butylpyridine, guanidinium thiocyanate and the like are preferably used. A basic substance may be used individually by 1 type, or may be used in combination of 2 or more types.
　電解質２４０においては、塩基性物質の体積モル濃度Ｃ３が、塩基性物質とハロゲン化水素との塩の体積モル濃度Ｃ４の３倍以上、すなわちＣ３／Ｃ４の値が３以上であることが好ましい。 In the electrolyte 240, molarity C 3 of the basic substance is a basic substance and more than three times the molarity C 4 of the salts with hydrogen halides, i.e. the value of C 3 / C 4 is 3 or more It is preferable.
　この場合、Ｃ３／Ｃ４の値が３未満である場合に比べて、色素増感太陽電池２００の光電変換特性を特に十分に向上させることができる。 In this case, compared with the case where the value of C 3 / C 4 is less than 3, the photoelectric conversion characteristics of the dye-sensitized solar cell 200 can be particularly sufficiently improved.
　Ｃ３／Ｃ４値は３～１０００であることがより好ましく、７～９００であることがさらに好ましい。 The C 3 / C 4 value is more preferably 3 to 1000, and even more preferably 7 to 900.
　塩基性物質の体積モル濃度Ｃ３は、上述したように、塩基性物質とハロゲン化水素との塩の体積モル濃度Ｃ４より大きければよい。 The volume molar concentration C 3 of the basic substance may be larger than the volume molar concentration C 4 of the salt of the basic substance and hydrogen halide as described above.
　また、塩基性物質とハロゲン化水素との塩の体積モル濃度Ｃ４は０．０５～１５ｍＭであることが好ましい。 Further, the volume molar concentration C 4 of the salt of the basic substance and the hydrogen halide is preferably 0.05 to 15 mM.
　Ｃ４が０．０５～１５ｍＭの範囲内にあると、Ｃ４が１５ｍＭを超える場合に比べて、電解質４は、色素増感太陽電池２００の光電変換特性をより十分に向上させることができる。また、Ｃ４が０．０５～１５ｍＭの範囲内にあると、Ｃ４が０．０５ｍＭ未満である場合に比べて、塩基性物質とハロゲン化水素との塩が酸化物半導体の価電子帯の準位を上げ、色素-酸化物半導体間の電子注入効率をより向上させることができる。 When C 4 is in the range of 0.05 to 15 mM, the electrolyte 4 can sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell 200 as compared with the case where C 4 exceeds 15 mM. In addition, when C 4 is in the range of 0.05 to 15 mM, the salt of the basic substance and the hydrogen halide is in the valence band of the oxide semiconductor as compared to the case where C 4 is less than 0.05 mM. The level can be increased and the electron injection efficiency between the dye and the oxide semiconductor can be further improved.
　Ｃ４は０．０６～１４ｍＭであることがより好ましく、０．０７～１３ｍＭであることがさらに好ましい。 C 4 is more preferably 0.06 to 14 mM, and further preferably 0.07 to 13 mM.
　色素増感太陽電池２００の製造方法は、電解質４０の代わりに、電解質２４０を用いる点で色素増感太陽電池１００の製造方法と相違する。 The method for manufacturing the dye-sensitized solar cell 200 is different from the method for manufacturing the dye-sensitized solar cell 100 in that the electrolyte 240 is used instead of the electrolyte 40.
　ここで、電解質２４０の製造方法について説明する。 Here, a manufacturing method of the electrolyte 240 will be described.
　電解質２４０は、ハロゲンと、ハロゲン化物塩と、塩基性物質とハロゲン化水素との塩とを含み、ハロゲンとハロゲン化物塩とによって酸化還元対が形成された電解液を準備する電解液準備工程と、電解液と塩基性物質とを混合して電解質２４０を得る塩基性物質混合工程とを含む方法により製造される。このとき、電解液準備工程においては、ハロゲン、ハロゲン化物塩及びハロゲン化水素が同一のハロゲン原子を有するようにする。また塩基性物質混合工程においては、塩基性物質の体積モル濃度Ｃ３が、塩基性物質とハロゲン化水素との塩の体積モル濃度Ｃ４よりも大きくなるように電解液と塩基性物質とを混合する。 The electrolyte 240 includes a halogen, a halide salt, a salt of a basic substance and a hydrogen halide, and an electrolyte solution preparing step of preparing an electrolyte solution in which a redox pair is formed by the halogen and the halide salt. And a basic substance mixing step of mixing the electrolytic solution and the basic substance to obtain the electrolyte 240. At this time, in the electrolytic solution preparation step, the halogen, halide salt, and hydrogen halide have the same halogen atom. In the basic substance mixing step, the electrolytic solution and the basic substance are mixed so that the volume molar concentration C 3 of the basic substance is larger than the volume molar concentration C 4 of the salt of the basic substance and hydrogen halide. Mix.
　以下、上記電解液準備工程及び塩基性物質混合工程について具体的に説明する。 Hereinafter, the electrolytic solution preparation step and the basic substance mixing step will be specifically described.
　（電解液準備工程）
　まず、例えば上述した有機溶媒に、ハロゲンと、ハロゲン化物塩とを溶解させて、ハロゲンとハロゲン化物塩とによって形成された酸化還元対を含む溶液を調製する。 (Electrolyte preparation process)
First, for example, a halogen and a halide salt are dissolved in the organic solvent described above to prepare a solution containing a redox pair formed by the halogen and the halide salt.
　次に、上述した塩基性物質とハロゲン化水素との塩を、上記の酸化還元対を含む溶液に溶解させる。 Next, the above-mentioned salt of the basic substance and hydrogen halide is dissolved in the solution containing the above redox couple.
　こうして、ハロゲンとハロゲン化物塩とによって形成された酸化還元対を含む電解液が得られる。 Thus, an electrolytic solution containing a redox couple formed by halogen and a halide salt is obtained.
　（塩基性物質混合工程）
　次に、上記のようにして製造された電解液と上述した塩基性物質とを混合する。ここで、塩基性物質は、Ｃ３／Ｃ４の値が１より大きくなるように混合する。 (Basic substance mixing process)
Next, the electrolytic solution manufactured as described above and the basic substance described above are mixed. Here, the basic substance is mixed so that the value of C 3 / C 4 is larger than 1.
　こうして電解質２４０が得られる。上記の電解質２４０の製造方法によれば、得られる電解質２４０は、色素増感太陽電池２００の光電変換特性を十分に向上させることができる。 Thus, the electrolyte 240 is obtained. According to the manufacturing method of the electrolyte 240 described above, the obtained electrolyte 240 can sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell 200.
　上記塩基性物質混合工程においては、塩基性物質の体積モル濃度Ｃ３が、塩基性物質とハロゲン化水素との塩の体積モル濃度Ｃ４の３倍以上となるように電解液と塩基性物質とを混合することが好ましい。 In the above basic substance mixing step, basic molarity C 3 substances, electrolyte and the basic substance so that the basic substance and 3 times more salt molarity C 4 of the hydrogen halide Are preferably mixed.
　この場合、こうして得られる電解質２４０によって、色素増感太陽電池２００の光電変換特性をより十分に向上させることができる。 In this case, the photoelectric conversion characteristics of the dye-sensitized solar cell 200 can be more sufficiently improved by the electrolyte 240 thus obtained.
　ここで、Ｃ３／Ｃ４の値が３～１０００となるように電解液と塩基性物質とを混合することがより好ましく、７～９００となるように電解液と塩基性物質とを混合することがさらに好ましい。 Here, it is more preferable to mix the electrolytic solution and the basic substance so that the value of C 3 / C 4 is 3 to 1000, and the electrolytic solution and the basic substance are mixed so as to be 7 to 900. More preferably.
　また、塩基性物質とハロゲン化水素との塩の体積モル濃度Ｃ４が０．０５～１５ｍＭとなるように電解液と塩基性物質とを混合することが好ましい。 Further, it is preferred that molarity C 4 of salt with a basic substance and hydrogen halide is mixed with the electrolytic solution and the basic substance so that 0.05 ~ 15 mM.
　Ｃ４が０．０５～１５ｍＭの範囲内にあると、Ｃ４が１５ｍＭを超える場合に比べて、電解質２４０は、色素増感太陽電池２００の光電変換特性をより十分に向上させることができる。また、Ｃ４が０．０５～１５ｍＭの範囲内にあると、Ｃ４が０．０５ｍＭ未満である場合に比べて、塩基性物質とハロゲン化水素との塩が酸化物半導体の価電子帯の準位を上げ、色素-酸化物半導体間の電子注入効率をより向上させることができる。 When C 4 is in the range of 0.05 to 15 mM, the electrolyte 240 can sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell 200 as compared with the case where C 4 exceeds 15 mM. In addition, when C 4 is in the range of 0.05 to 15 mM, the salt of the basic substance and the hydrogen halide is in the valence band of the oxide semiconductor as compared to the case where C 4 is less than 0.05 mM. The level can be increased and the electron injection efficiency between the dye and the oxide semiconductor can be further improved.
　このとき、Ｃ４は０．０６～１４ｍＭとなるように電解液と塩基性物質とを混合することがより好ましく、０．０７～１３ｍＭとなるように電解液と塩基性物質とを混合することがさらに好ましい。 At this time, it is more preferable to mix the electrolyte and the basic substance so that C 4 is 0.06 to 14 mM, and the electrolyte and the basic substance are mixed so that C 4 is 0.07 to 13 mM. Is more preferable.
　本発明は、上記実施形態に限定されるものではない。例えば上記実施形態では、透明導電性基板１５上に多孔質酸化物半導体層１３が設けられ、こちら側から受光する構造となっているが、多孔質酸化物半導体層１３が形成される基材に不透明な材料（例えば金属基板）を用い、対極２０を形成する基材に透明な材料を用いて対極側から受光する構造をとっても構わず、さらに、両面から受光する構造としても構わない。 The present invention is not limited to the above embodiment. For example, in the above embodiment, the porous oxide semiconductor layer 13 is provided on the transparent conductive substrate 15 to receive light from this side, but the base material on which the porous oxide semiconductor layer 13 is formed is provided. An opaque material (for example, a metal substrate) may be used, a transparent material may be used for the base material on which the counter electrode 20 is formed, and a structure for receiving light from the counter electrode side may be used.
　以下、本発明の内容を、実施例を挙げてより具体的に説明するが、本発明は下記の実施例に限定されるものではない。 Hereinafter, the content of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.
　（実施例１～４及び比較例１～３）
＜色素増感太陽電池用電解質の調製＞
　ジメチルプロピルイミダゾリウムヨーダイド（ＤＭＰＩｍＩ）３．１ｇ及び３－メトキシプロピオニトリル２０ｍＬの混合物に、１－メチルベンゾイミダゾール０．２ｇ、グアニジウムチオシアネート（ＧｕＳＣＮ）０．２ｇ、ヨウ素及びヨウ化水素を添加し、色素増感太陽電池用電解質を調製した。このとき、ヨウ素については、電解質中のヨウ素の体積モル濃度Ｃ１が３０ｍＭとなるように、ヨウ化水素については、電解質中の体積モル濃度Ｃ２が表１に記載された体積モル濃度になるように添加した。ここで、ヨウ素の体積モル濃度Ｃ１は紫外可視（UV-vis）分光光度計を用いた吸光光度法により、ヨウ化水素の体積モル濃度は水酸化カリウムを用いた中和滴定により定量した。また塩の体積モル濃度Ｃ４は、表１に記載されているように０ｍＭとした。こうして、色素増感太陽電池用電解質を調製した。この電解質においては、ヨウ素とヨウ化水素とによって酸化還元対が形成されていた。 (Examples 1 to 4 and Comparative Examples 1 to 3)
<Preparation of electrolyte for dye-sensitized solar cell>
To a mixture of 3.1 g of dimethylpropylimidazolium iodide (DMPImI) and 20 mL of 3-methoxypropionitrile, 0.2 g of 1-methylbenzimidazole, 0.2 g of guanidinium thiocyanate (GuSCN), iodine and hydrogen iodide were added. This was added to prepare a dye-sensitized solar cell electrolyte. At this time, for the iodine, as molarity C 1 of iodine in the electrolyte is 30 mM, for hydrogen iodide, molarity C 2 in the electrolyte is molarity listed in Table 1 Was added as follows. Here, molarity C 1 iodine by ultraviolet-visible (UV-vis) absorption spectroscopy using a spectrophotometer, molarity of hydrogen iodide was determined by neutralization titration with potassium hydroxide. The salt molar concentration C 4 was 0 mM as described in Table 1. Thus, an electrolyte for a dye-sensitized solar cell was prepared. In this electrolyte, an oxidation-reduction pair was formed by iodine and hydrogen iodide.
　＜色素増感太陽電池の作製＞
　はじめに、ガラス基板上にＦＴＯ膜が形成されたＦＴＯ／ガラス基板を準備した。そして、このＦＴＯ／ガラス基板を洗浄し、この基板にＵＶ－Ｏ３処理を行い、その基板上にスクリーン印刷により、酸化チタンを含有する酸化チタンナノ粒子ペーストを塗布し、５０×５０ｍｍの膜を作製し、１５０℃で１０分間乾燥させた。こうして、未焼成基板を得た。その後、この未焼成基板をオーブンに入れて酸化チタンナノ粒子ペーストを５００℃で１時間焼成し、ＦＴＯ膜上に、厚さ１４μｍの多孔質酸化チタン層を形成し、作用極を得た。 <Preparation of dye-sensitized solar cell>
First, an FTO / glass substrate having an FTO film formed on a glass substrate was prepared. Then, this FTO / glass substrate is cleaned, this substrate is subjected to UV-O 3 treatment, and a titanium oxide nanoparticle paste containing titanium oxide is applied onto the substrate by screen printing to produce a 50 × 50 mm film. And dried at 150 ° C. for 10 minutes. Thus, an unfired substrate was obtained. Thereafter, this unfired substrate was put in an oven, and the titanium oxide nanoparticle paste was fired at 500 ° C. for 1 hour to form a porous titanium oxide layer having a thickness of 14 μm on the FTO film, thereby obtaining a working electrode.
　次に、光増感色素であるＺ９０７色素を、アセトニトリルとｔ－ブチルアルコールとを１：１（体積比）で混合した混合溶媒中に溶かして色素溶液を作製した。そして、この色素溶液中に上記作用極を２４時間浸漬させ、多孔質酸化チタン層に光増感色素を担持させた。 Next, the photosensitizing dye Z907 dye was dissolved in a mixed solvent of acetonitrile and t-butyl alcohol mixed at 1: 1 (volume ratio) to prepare a dye solution. Then, the working electrode was immersed in this dye solution for 24 hours, and the photosensitizing dye was supported on the porous titanium oxide layer.
　一方、作用極の作製で使用したＦＴＯ／ガラス基板を用意し、この基板上にスパッタリング法によってＰｔを堆積させた。こうして対極を得た。 On the other hand, the FTO / glass substrate used in the production of the working electrode was prepared, and Pt was deposited on this substrate by a sputtering method. In this way, a counter electrode was obtained.
　次に、作用極の上に、アイオノマーであるハイミラン（商品名、三井・デュポンポリケミカル社製）からなる環状の熱可塑性樹脂シートを配置した。このとき、環状の熱可塑性樹脂シートの内側に、多孔質酸化チタン層が配置されるようにした。そして、熱可塑性樹脂シートを１８０℃で５分間加熱し溶融させて作用極に接着させた。 Next, on the working electrode, an annular thermoplastic resin sheet made of ionomer Himiran (trade name, manufactured by Mitsui DuPont Polychemical Co., Ltd.) was placed. At this time, the porous titanium oxide layer was arranged inside the annular thermoplastic resin sheet. The thermoplastic resin sheet was heated and melted at 180 ° C. for 5 minutes to adhere to the working electrode.
　他方、上記のようにして調製した電解質をスクリーン印刷法によって、作用極に多孔質酸化チタン層を覆うように塗布した。 On the other hand, the electrolyte prepared as described above was applied by screen printing so as to cover the porous titanium oxide layer on the working electrode.
　そして作用極に対し、対極を、作用極との間に電解質を挟むように重ね合わせ、封止部を減圧下（１０００Ｐａ）で加熱溶融することによって対極と封止部とを接着させた。 Then, the counter electrode was superposed on the working electrode so that the electrolyte was sandwiched between the working electrode and the sealed portion was heated and melted under reduced pressure (1000 Pa) to adhere the counter electrode and the sealed portion.
　こうして色素増感太陽電池を得た。 Thus, a dye-sensitized solar cell was obtained.
　（実施例５～２４及び比較例４～１８）
＜色素増感太陽電池用電解質の調製＞
　ジメチルプロピルイミダゾリウムヨーダイド（ＤＭＰＩｍＩ）３．１ｇ及び３－メトキシプロピオニトリル２０ｍＬの混合物に、下記表２～６に示す塩基性物質とヨウ化水素との塩を溶解させ、電解液を調製した。そして、上記のようにして得られた電解液に、下記表２～６に示す塩基性物質を溶解させ、色素増感太陽電池用電解質を調製した。ここで、表２に記載の「ＮＭＢＩｍ」はメチルベンゾイミダゾールを表し、表３に記載の「ＮＢＢ」はブチルベンゾイミダゾールを表し、「ＴＢＰ」はｔ－ブチルピリジンを表し、「ＧｕＳＣＮ」はグアニジウムチオシアネートを表す。また塩基性物質とヨウ化水素との塩については、電解質中の体積モル濃度Ｃ４が、表２～６に「塩の濃度Ｃ４」として記載された体積モル濃度になるように上記混合物に溶解させた。ここで、塩基性物質とヨウ化水素との塩の体積モル濃度Ｃ４は定量滴定法により定量した。また得られた電解質においては、ヨウ素とヨウ化水素とによって酸化還元対が形成されていた。 (Examples 5 to 24 and Comparative Examples 4 to 18)
<Preparation of electrolyte for dye-sensitized solar cell>
Salts of basic substances and hydrogen iodide shown in Tables 2 to 6 below were dissolved in a mixture of 3.1 g of dimethylpropylimidazolium iodide (DMPImI) and 20 mL of 3-methoxypropionitrile to prepare an electrolytic solution. . Then, basic substances shown in Tables 2 to 6 below were dissolved in the electrolytic solution obtained as described above to prepare a dye-sensitized solar cell electrolyte. Here, “NMBIm” described in Table 2 represents methylbenzimidazole, “NBB” described in Table 3 represents butylbenzimidazole, “TBP” represents t-butylpyridine, and “GuSCN” represents guani Represents thiocyanate. For the salt of the basic substance and hydrogen iodide, the volume molar concentration C 4 in the electrolyte is adjusted to the volume molar concentration described as “salt concentration C 4 ” in Tables 2 to 6 in the above mixture. Dissolved. Here, the volume molar concentration C 4 of the salt of the basic substance and hydrogen iodide was quantified by a quantitative titration method. In the obtained electrolyte, an oxidation-reduction pair was formed by iodine and hydrogen iodide.
　さらに、電解液に塩基性物質を溶解させる際には、電解質中の塩基性物質の体積モル濃度Ｃ３が、１００ｍＭになるようにした。ここで、表６の実施例２０～２４及び比較例１６～１８については、ＮＭＢＩｍの体積モル濃度が５０ｍＭに、ＧｕＳＣＮの体積モル濃度が５０ｍＭになるように調製した。塩基性物質の体積モル濃度Ｃ３は定量滴定法により定量した。また、電解質中のヨウ化水素の体積モル濃度Ｃ２は０ｍＭであった。ヨウ化水素の体積モル濃度は水酸化カリウムを用いた中和滴定により定量した。 Moreover, when dissolving the basic substance in the electrolyte solution, the molarity C 3 of the basic substance in the electrolyte, was set to 100 mM. Here, Examples 20 to 24 and Comparative Examples 16 to 18 shown in Table 6 were prepared so that the NMBIm had a molar molar concentration of 50 mM and the GuSCN had a molar molar concentration of 50 mM. Molarity C 3 of the basic substance was quantified by quantitative titration. The volume molar concentration C 2 of the hydrogen iodide in the electrolyte was 0 mM. The volume molar concentration of hydrogen iodide was determined by neutralization titration with potassium hydroxide.
　＜色素増感太陽電池の作製＞
　はじめに、ガラス基板上にＦＴＯ膜が形成されたＦＴＯ／ガラス基板を準備した。そして、このＦＴＯ／ガラス基板を洗浄し、この基板にＵＶ－Ｏ３処理を行い、その基板上にスクリーン印刷により、酸化チタンを含有する酸化チタンナノ粒子ペーストを塗布し、５０×５０ｍｍの膜を作製し、１５０℃で１０分間乾燥させた。こうして、未焼成基板を得た。その後、この未焼成基板をオーブンに入れて酸化チタンナノ粒子ペーストを５００℃で１時間焼成し、ＦＴＯ膜上に、厚さ１４μｍの多孔質酸化チタン層を形成し、作用極を得た。 <Preparation of dye-sensitized solar cell>
First, an FTO / glass substrate having an FTO film formed on a glass substrate was prepared. Then, this FTO / glass substrate is cleaned, this substrate is subjected to UV-O 3 treatment, and a titanium oxide nanoparticle paste containing titanium oxide is applied onto the substrate by screen printing to produce a 50 × 50 mm film. And dried at 150 ° C. for 10 minutes. Thus, an unfired substrate was obtained. Thereafter, this unfired substrate was put in an oven, and the titanium oxide nanoparticle paste was fired at 500 ° C. for 1 hour to form a porous titanium oxide layer having a thickness of 14 μm on the FTO film, thereby obtaining a working electrode.
　次に、光増感色素であるＺ９０７色素を、アセトニトリルとｔ－ブチルアルコールとを１：１（体積比）で混合した混合溶媒中に溶かして色素溶液を作製した。そして、この色素溶液中に上記作用極を２４時間浸漬させ、多孔質酸化チタン層に光増感色素を担持させた。 Next, the photosensitizing dye Z907 dye was dissolved in a mixed solvent of acetonitrile and t-butyl alcohol mixed at 1: 1 (volume ratio) to prepare a dye solution. Then, the working electrode was immersed in this dye solution for 24 hours, and the photosensitizing dye was supported on the porous titanium oxide layer.
　一方、作用極の作製で使用したＦＴＯ／ガラス基板を用意し、この基板上にスパッタリング法によってＰｔを堆積させた。こうして対極を得た。 On the other hand, the FTO / glass substrate used in the production of the working electrode was prepared, and Pt was deposited on this substrate by a sputtering method. In this way, a counter electrode was obtained.
　次に、作用極の上に、アイオノマーであるハイミラン（商品名、三井・デュポンポリケミカル社製）からなる環状の熱可塑性樹脂シートを配置した。このとき、環状の熱可塑性樹脂シートの内側に、多孔質酸化チタン層が配置されるようにした。そして、熱可塑性樹脂シートを１８０℃で５分間加熱し溶融させて作用極に接着させた。 Next, on the working electrode, an annular thermoplastic resin sheet made of ionomer Himiran (trade name, manufactured by Mitsui DuPont Polychemical Co., Ltd.) was placed. At this time, the porous titanium oxide layer was arranged inside the annular thermoplastic resin sheet. The thermoplastic resin sheet was heated and melted at 180 ° C. for 5 minutes to adhere to the working electrode.
　他方、上記のようにして調製した電解質をスクリーン印刷法によって、作用極に多孔質酸化チタン層を覆うように塗布した。 On the other hand, the electrolyte prepared as described above was applied by screen printing so as to cover the porous titanium oxide layer on the working electrode.
　そして作用極に対し、対極を、作用極との間に電解質を挟むように重ね合わせ、封止部を減圧下（１０００Ｐａ）で加熱溶融することによって対極と封止部とを接着させた。 Then, the counter electrode was superposed on the working electrode so that the electrolyte was sandwiched between the working electrode and the sealed portion was heated and melted under reduced pressure (1000 Pa) to adhere the counter electrode and the sealed portion.
　こうして色素増感太陽電池を得た。 Thus, a dye-sensitized solar cell was obtained.
　＜特性の評価＞
（光電変換特性）
　上記のようにして得られた上記実施例１～４及び比較例１～３の色素増感太陽電池について、光電変換効率η（％）を測定した。そして、比較例１を基準として、下記式に基づいて光電変換効率ηの増大率を算出した。結果を表１に示す。 <Evaluation of characteristics>
(Photoelectric conversion characteristics)
The photoelectric conversion efficiency η (%) of the dye-sensitized solar cells of Examples 1 to 4 and Comparative Examples 1 to 3 obtained as described above was measured. And the increase rate of photoelectric conversion efficiency (eta) was computed based on the following formula on the basis of the comparative example 1. FIG. The results are shown in Table 1.
　また上記のようにして得られた上記実施例５～２４及び比較例４～１８の色素増感太陽電池について、光電変換効率η（％）を測定した。そして、塩基性物質としてＮＭＢＩｍを用いた実施例５～８及び比較例４～６については比較例４を基準比較例として、塩基性物質としてＮＢＢを用いた実施例９～１２及び比較例７～９については比較例７を基準比較例として、塩基性物質としてＴＢＰを用いた実施例１３～１６及び比較例１０～１２ついては比較例１０を基準比較例として、塩基性物質としてＧｕＳＣＮを用いた実施例１７～２０及び比較例１３～１５については比較例１３を基準比較例として、塩基性物質としてＮＭＢＩｍ及びＧｕＳＣＮを用いた実施例２１～２４及び比較例１６～１８については比較例１６を基準比較例として、下記式に基づいて光電変換効率ηの増大率を算出した。結果を表２～６に示す。
 
光電変換効率の増大率（％）＝１００×（実施例又は比較例の光電変換効率－比較例１の光電変換効率）／比較例１の光電変換効率
 
このとき、光電変換効率の測定は、Ｘｅランプソーラーシミュレータ（山下電装社製ＹＳＳ－１５０）とＩＶテスタ（英光精機社製ＭＰ－１６０）を使用して行った。
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000006
 The photoelectric conversion efficiency η (%) of the dye-sensitized solar cells of Examples 5 to 24 and Comparative Examples 4 to 18 obtained as described above was measured. For Examples 5 to 8 and Comparative Examples 4 to 6 using NMBIm as a basic substance, Comparative Example 4 was used as a reference comparative example, and Examples 9 to 12 and Comparative Examples 7 to 7 using NBB as a basic substance were used. For Example 9, Comparative Example 7 was used as a standard comparative example, and Examples 13 to 16 and Comparative Examples 10 to 12 using TBP as a basic substance were used as Comparative Examples 10 and GuSCN was used as a basic substance. For Examples 17 to 20 and Comparative Examples 13 to 15, Comparative Example 13 was used as a reference comparative example, and for Examples 21 to 24 and Comparative Examples 16 to 18 using NMBIm and GuSCN as basic substances, Comparative Example 16 was used as a reference comparison. As an example, the rate of increase in photoelectric conversion efficiency η was calculated based on the following formula. The results are shown in Tables 2-6.

Rate of increase in photoelectric conversion efficiency (%) = 100 × (photoelectric conversion efficiency of example or comparative example−photoelectric conversion efficiency of comparative example 1) / photoelectric conversion efficiency of comparative example 1
At this time, the photoelectric conversion efficiency was measured using a Xe lamp solar simulator (YSS-150, Yamashita Denso Co., Ltd.) and an IV tester (MP-160, Eiko Seiki Co., Ltd.).
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000006
　表１に示す結果より、比較例１を基準とした実施例１～４の色素増感太陽電池の光電変換効率は、１６％以上と非常に大きくなることがわかった。 From the results shown in Table 1, it was found that the photoelectric conversion efficiencies of the dye-sensitized solar cells of Examples 1 to 4 based on Comparative Example 1 were as high as 16% or more.
　表２～６に示す結果より、基準比較例を基準とした実施例５～２４の色素増感太陽電池の光電変換効率の増大率は、５％以上と十分に大きくなることがわかった。 From the results shown in Tables 2 to 6, it was found that the increase rate of the photoelectric conversion efficiency of the dye-sensitized solar cells of Examples 5 to 24 based on the reference comparative example was sufficiently large as 5% or more.
　以上より、本発明の色素増感太陽電池用電解質によれば、色素増感太陽電池の光電変換特性を十分に向上させることができることが確認された。 From the above, it was confirmed that the photoelectric conversion characteristics of the dye-sensitized solar cell can be sufficiently improved according to the dye-sensitized solar cell electrolyte of the present invention.
　１１…透明基板
　１２…透明導電膜
　１３…酸化物半導体層
　１５…透明導電性基板（第１電極）
　２０…対極（第２電極）
　４０，２４０…電解質
　１００，２００…色素増感太陽電池 DESCRIPTION OF SYMBOLS 11 ... Transparent substrate 12 ... Transparent electrically conductive film 13 ... Oxide semiconductor layer 15 ... Transparent conductive substrate (1st electrode)
20 ... Counter electrode (second electrode)
40, 240 ... electrolyte 100, 200 ... dye-sensitized solar cell

Claims (14)

  1. 　ハロゲンと、
    　ハロゲン化物塩と、
    　ハロゲン化水素、並びに、塩基性物質と前記塩基性物質及びハロゲン化水素の塩との混合物からなる群より選ばれる少なくとも１種とを含み、
    　前記ハロゲンと前記ハロゲン化物塩とによって酸化還元対が形成され、
    　前記ハロゲン、前記ハロゲン化物塩、及び前記ハロゲン化水素が同一のハロゲン原子を有し、
    　前記ハロゲンの体積モル濃度Ｃ１又は前記塩基性物質の体積モル濃度Ｃ３が、前記ハロゲン化水素の体積モル濃度Ｃ２と、前記塩基性物質及び前記ハロゲン化水素の塩の体積モル濃度Ｃ４との合計体積モル濃度Ｃ２０より大きい色素増感太陽電池用電解質。     Halogen,
    A halide salt;
    Hydrogen halide, and at least one selected from the group consisting of a basic substance and a mixture of the basic substance and a salt of hydrogen halide,
    A redox pair is formed by the halogen and the halide salt,
    The halogen, the halide salt, and the hydrogen halide have the same halogen atom;
    The volume molar concentration C 1 of the halogen or the volume molar concentration C 3 of the basic substance is the volume molar concentration C 2 of the hydrogen halide, and the volume molar concentration C 4 of the basic substance and the salt of the hydrogen halide. total molarity C 20 greater than the dye-sensitized solar cell electrolyte with.
  2. 　前記ハロゲンと、
    　前記ハロゲン化物塩と、
    　前記ハロゲン化水素とを含み、
    　前記ハロゲンの体積モル濃度Ｃ１が、前記ハロゲン化水素の体積モル濃度Ｃ２と、前記塩基性物質及び前記ハロゲン化水素の塩の体積モル濃度Ｃ４との合計体積モル濃度Ｃ２０より大きく、
    　前記塩基性物質及び前記ハロゲン化水素の塩の体積モル濃度Ｃ４が０ｍＭである請求項１に記載の色素増感太陽電池用電解質。     The halogen;
    The halide salt;
    Including the hydrogen halide,
    Molarity C 1 of the halogen, the molarity C 2 of the hydrogen halide, larger than the total molarity C 20 with molarity C 4 salts of said basic material and the hydrogen halide,
    2. The dye-sensitized solar cell electrolyte according to claim 1, wherein a volume molar concentration C 4 of the basic substance and the hydrogen halide salt is 0 mM.
  3. 　前記ハロゲンの体積モル濃度Ｃ１が、前記ハロゲン化水素の体積モル濃度Ｃ２の２倍以上である請求項２に記載の色素増感太陽電池用電解質。 3. The dye-sensitized solar cell electrolyte according to claim 2, wherein the volume molar concentration C 1 of the halogen is at least twice the volume molar concentration C 2 of the hydrogen halide.
  4. 　前記ハロゲン化水素の体積モル濃度Ｃ２が０．０５～１５ｍＭである請求項２又は３に記載の色素増感太陽電池用電解質。 4. The dye-sensitized solar cell electrolyte according to claim 2 , wherein the hydrogen halide has a volume molar concentration C 2 of 0.05 to 15 mM.
  5. 　前記ハロゲン原子がヨウ素原子である請求項２～４のいずれか一項に記載の色素増感太陽電池用電解質。 The dye-sensitized solar cell electrolyte according to any one of claims 2 to 4, wherein the halogen atom is an iodine atom.
  6. 　前記ハロゲンと、
    　前記ハロゲン化物塩と、
    　前記塩基性物質と、
    　前記塩基性物質と前記ハロゲン化水素との塩とを含み、
    　前記塩基性物質の体積モル濃度Ｃ３が、前記ハロゲン化水素の体積モル濃度Ｃ２と、前記塩基性物質及び前記ハロゲン化水素の塩の体積モル濃度Ｃ４との合計体積モル濃度Ｃ２０より大きく、
    　前記ハロゲン化水素の体積モル濃度Ｃ２が０ｍＭである請求項１に記載の色素増感太陽電池用電解質。     The halogen;
    The halide salt;
    The basic substance;
    A salt of the basic substance and the hydrogen halide,
    Is molarity C 3 of the basic material, the molarity C 2 of the hydrogen halide, than the total molarity C 20 with molarity C 4 salts of said basic material and the hydrogen halide big,
    2. The dye-sensitized solar cell electrolyte according to claim 1, wherein a volume molar concentration C 2 of the hydrogen halide is 0 mM.
  7. 　前記塩基性物質の体積モル濃度Ｃ３が、前記塩基性物質と前記ハロゲン化水素との塩の体積モル濃度Ｃ４の３倍以上である請求項６に記載の色素増感太陽電池用電解質。 The molarity C 3 of the basic substance, the basic substance and a dye-sensitized solar cell electrolyte according to claim 6, wherein at least three times of the halogenated volume mole of the salt with hydrogen concentration C 4.
  8. 　前記塩基性物質と前記ハロゲン化水素との塩の体積モル濃度Ｃ４が０．０５～１５ｍＭである請求項６又は７に記載の色素増感太陽電池用電解質。 The dye-sensitized solar cell electrolyte according to claim 6 or 7, wherein a volume molar concentration C 4 of the salt of the basic substance and the hydrogen halide is 0.05 to 15 mM.
  9. 　前記ハロゲン原子がヨウ素原子である請求項６～８のいずれか一項に記載の色素増感太陽電池用電解質。 The dye-sensitized solar cell electrolyte according to any one of claims 6 to 8, wherein the halogen atom is an iodine atom.
  10. 　透明基板及び前記透明基板上に設けられる透明導電膜を有する第１電極と、
    　前記第１電極に対向する第２電極と、
    　前記第１電極又は前記第２電極に設けられる酸化物半導体層と、
    　前記第１電極及び前記第２電極の間に設けられる電解質と、
    　前記酸化物半導体層に吸着される光増感色素とを備え、
    　前記電解質が、請求項１～９のいずれか一項に記載の色素増感太陽電池用電解質である色素増感太陽電池。     A first electrode having a transparent substrate and a transparent conductive film provided on the transparent substrate;
    A second electrode facing the first electrode;
    An oxide semiconductor layer provided on the first electrode or the second electrode;
    An electrolyte provided between the first electrode and the second electrode;
    A photosensitizing dye adsorbed on the oxide semiconductor layer,
    A dye-sensitized solar cell, wherein the electrolyte is an electrolyte for a dye-sensitized solar cell according to any one of claims 1 to 9.
  11. 　ハロゲンと、ハロゲン化物塩と、塩基性物質とハロゲン化水素との塩とを含み、前記ハロゲンと前記ハロゲン化物塩とによって酸化還元対が形成された電解液を準備する電解液準備工程と、
    　前記電解液と前記塩基性物質とを混合して色素増感太陽電池用電解質を得る塩基性物質混合工程とを含み、
    　前記電解液準備工程において、前記ハロゲン、前記ハロゲン化物塩及び前記ハロゲン化水素が同一のハロゲン原子を有し、
    　前記塩基性物質混合工程において、前記塩基性物質の体積モル濃度Ｃ３が、前記塩基性物質と前記ハロゲン化水素との塩の体積モル濃度Ｃ４よりも大きくなるように前記電解液と前記塩基性物質とを混合する、色素増感太陽電池用電解質の製造方法。     An electrolyte solution preparing step of preparing an electrolyte solution containing a halogen, a halide salt, and a salt of a basic substance and a hydrogen halide, wherein a redox pair is formed by the halogen and the halide salt;
    A basic substance mixing step of obtaining the dye-sensitized solar cell electrolyte by mixing the electrolytic solution and the basic substance,
    In the electrolyte solution preparation step, the halogen, the halide salt, and the hydrogen halide have the same halogen atom,
    In the basic substance mixing step, the electrolytic solution and the base are adjusted so that the molar molar concentration C 3 of the basic substance is larger than the molar molar concentration C 4 of the salt of the basic substance and the hydrogen halide. The manufacturing method of the electrolyte for dye-sensitized solar cells which mixes a luminescent substance.
  12. 　前記塩基性物質混合工程において、前記塩基性物質の体積モル濃度Ｃ３が、前記塩基性物質と前記ハロゲン化水素との塩の体積モル濃度Ｃ４の３倍以上となるように前記電解液と前記塩基性物質とを混合する請求項１１に記載の色素増感太陽電池用電解質の製造方法。 In the basic material mixing step, molarity C 3 of the basic substance, and the electrolyte so that more than three times the molarity C 4 of the salt with the basic substance and the hydrogen halide The manufacturing method of the electrolyte for dye-sensitized solar cells of Claim 11 which mixes the said basic substance.
  13. 　前記塩基性物質混合工程において、前記色素増感太陽電池用電解質中の前記塩基性物質と前記ハロゲン化水素との塩の体積モル濃度Ｃ４が０．０５～１５ｍＭとなるように前記電解液と前記塩基性物質とを混合する請求項１１又は１２に記載の色素増感太陽電池用電解質の製造方法。 In the basic substance mixing step, the electrolyte solution is adjusted so that the volume molar concentration C 4 of the salt of the basic substance and the hydrogen halide in the dye-sensitized solar cell electrolyte is 0.05 to 15 mM. The method for producing an electrolyte for a dye-sensitized solar cell according to claim 11 or 12, wherein the basic substance is mixed.
  14. 　前記ハロゲン原子がヨウ素原子である請求項１１～１３のいずれか一項に記載の色素増感太陽電池用電解質の製造方法。 The method for producing an electrolyte for a dye-sensitized solar cell according to any one of claims 11 to 13, wherein the halogen atom is an iodine atom.
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