JP5380617B1 - Electrolyte for dye-sensitized solar cell and dye-sensitized solar cell - Google Patents

Abstract

An object of the present invention is to provide an electrolyte for a dye-sensitized solar cell and a dye-sensitized solar cell capable of sufficiently improving the photoelectric conversion characteristics of the dye-sensitized solar cell.
SOLUTION: A halogen, a halide salt, and a hydrogen halide are included, and a redox 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. , molarity C ₁ halogens, halogenated dye-sensitized solar cell electrolyte greater than the molarity C ₂ hydrogen.
[Selection figure] None

Description

  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 Gretzell et al. In Switzerland and has attracted 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.

  In dye-sensitized solar cells, it is important to improve photoelectric conversion characteristics and durability, and various proposals focusing on electrolytes, for example, have been made.

  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.

JP 2002-289268 A

  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.

  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

  In order to solve the above-mentioned problems, the present inventor has conducted extensive studies focusing on the components of the electrolyte. As a result, the present inventor has surprisingly found that the photoelectric conversion characteristics of the dye-sensitized solar cell may be improved when the electrolyte contains hydrogen halide. Therefore, the present inventor conducted further earnest studies on the composition of the electrolyte containing hydrogen halide.

  As a result, the present inventors have found that the above problem can be solved when the electrolyte contains a halogen, a halide salt, and a hydrogen halide, and the concentration of halogen in the electrolyte is higher than the concentration of hydrogen halide, The present invention has been completed.

That is, the present invention includes a halogen, a halide salt, and a hydrogen halide, and an oxidation-reduction pair is formed by the halogen and the halide salt, and the halogen, the halide salt, and the hydrogen halide are the same. has a halogen atom, molarity C ₁ of the halogen is dye-sensitized solar cell electrolyte greater than the molarity C ₂ of the hydrogen halide.

  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.

  The 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.

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.

  In this case, the photoelectric conversion characteristics of the dye-sensitized solar cell can be particularly sufficiently improved.

In the dye-sensitized solar cell electrolyte, molarity _{C 2} of the hydrogen halide is preferably a 0.05～15MM.

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.

  In the dye-sensitized solar cell electrolyte, the halogen atom is preferably an iodine atom.

  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.

  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.

  According to the dye-sensitized solar cell of the present invention, when the electrolyte is the above-described electrolyte for a dye-sensitized solar cell, the photoelectric conversion characteristics can be sufficiently improved.

  ADVANTAGE OF THE INVENTION According to this invention, the electrolyte for dye-sensitized solar cells and dye-sensitized solar cell which can fully improve the photoelectric conversion characteristic of a dye-sensitized solar cell are provided.

It is sectional drawing which shows one Embodiment of the dye-sensitized solar cell of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an embodiment of the dye-sensitized solar cell of the present invention.

  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.

  The counter electrode 20 includes a conductive substrate 21 and a catalyst layer 22 that is provided on the side of the working electrode 10 of the conductive substrate 21 and contributes to the reduction of the electrolyte 40. In the present embodiment, the second electrode is constituted by the conductive substrate 21.

  On the other hand, the working electrode 10 includes 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.

The electrolyte 40 includes a halogen, a halide salt, and a hydrogen halide. 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. The molarity C ₁ of the halogen is larger than the molarity C ₂ hydrogen halide.

  According to the dye-sensitized solar cell 100, since the electrolyte 40 has the above configuration, the photoelectric conversion characteristics can be sufficiently improved.

  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.

(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.

  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, for example, in the range of 50 to 40,000 μm.

Examples of the material constituting the transparent conductive film 12 include 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.

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.

(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.

  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. Here, carbon nanotubes are suitably used as the carbon-based material.

(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.

(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.

  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.

  Especially, it is preferable that the halogen atom which comprises a halogen, a halide salt, and a hydrogen halide 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.

  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.

  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, dimethyl propyl 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, Examples thereof include iodide salts such as dimethylpropylimidazolium iodide, butylmethylimidazolium iodide, and methylpropylimidazolium iodide.

  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 ⁻ .

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.

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.

The value of 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 the hydrogen halide is preferably 0.05～15MM.

When molarity _{C 2} hydrogen halide is within the range of 0.05～15MM, _{the C 2} as compared with the case where more than 15 mM, to more sufficiently improve the photoelectric conversion characteristics of the dye-sensitized solar cell 100 Can do. The volume molar concentration _{C 2} of the hydrogen halide to be within the scope of 0.05～15MM, compared to the case _{C 2} is less than 0.05 mM, hydrogen halides 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.

C ₂ is more preferably from 0.06～14MM, further preferably 0.07～13MM.

  The electrolyte 40 may further contain an organic solvent. As an organic solvent, 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.

  The electrolyte 40 may further contain an additive. Examples of the additive include 4-t-butylpyridine, guanidinium thiocyanate, 1-methylbenzimidazole, and 1-butylbenzimidazole.

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.

(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.

  In addition, 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.

  Next, the manufacturing method of the dye-sensitized solar cell 100 described above will be described.

  First, a transparent conductive substrate 15 formed by forming a transparent conductive film 12 on one transparent substrate 11 is prepared.

As a method of forming the transparent conductive film 12, a sputtering method, a vapor deposition method, a spray pyrolysis method (SPD: Spray Pyrolysis).
Deposition) and CVD methods are used.

  Next, the oxide semiconductor layer 13 is formed over 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 includes a resin such as polyethylene glycol and a solvent such as terpineol in addition to the oxide semiconductor particles described above.

  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.

  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.

  Thus, the working electrode 10 is obtained.

  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.

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.

  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.

  Next, an annular sealing portion 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.

  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.

  Next, the counter electrode 20 is prepared and disposed so as to close the opening of the sealing portion forming body, and then 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.

  The dye-sensitized solar cell 100 is obtained as described above.

  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.

  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.

(Examples 1-4 and Comparative Examples 1-3)
<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. 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.

<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.

  Next, Z907 dye, which is a photosensitizing dye, was dissolved in a mixed solvent in which acetonitrile and t-butyl alcohol were 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.

  On the other hand, an FTO / glass substrate used for 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.

  Next, on the working electrode, an annular thermoplastic resin sheet made of high Milan (trade name, manufactured by Mitsui DuPont Polychemical Co., Ltd.), which is an ionomer, 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.

  On the other hand, the electrolyte prepared as described above was applied to the working electrode so as to cover the porous titanium oxide layer by screen printing.

  Then, the counter electrode was superposed on the working electrode so that the electrolyte was sandwiched between the working electrode and the sealing portion was heated and melted under reduced pressure (1000 Pa) to bond the counter electrode and the sealing portion.

  Thus, a dye-sensitized solar cell was obtained.

<Evaluation of characteristics>
(Photoelectric conversion characteristics)
For the dye-sensitized solar cells of Examples 1-4 and Comparative Examples 1-3 obtained as described above, the photoelectric conversion efficiency η (%) 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.

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 manufactured by Yamashita Denso Co., Ltd.) and an IV tester (MP-160 manufactured by Eiko Seiki Co., Ltd.).

  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 on the basis of Comparative Example 1 were as large as 16% or more.

  As mentioned above, according to the electrolyte for dye-sensitized solar cells of this invention, it was confirmed that the photoelectric conversion characteristic of a dye-sensitized solar cell can fully be improved.

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 ... Electrolyte 100 ... Dye-sensitized solar cell

Claims (5)

Halogen,
A halide salt;
Including 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;
An electrolyte for a dye-sensitized solar cell, wherein the halogen molar concentration C ₁ is larger than the hydrogen halide volume molar concentration C ₂ . _2. The dye-sensitized solar cell electrolyte according to claim 1, wherein the halogen molar concentration C ₁ is at least twice the volume molar concentration C ₂ of the hydrogen halide. 3. The dye-sensitized solar cell electrolyte according to claim 1, wherein a volume molar concentration C ₂ of the hydrogen halide is 0.05 to 15 mM.   The said halogen atom is an iodine atom, The electrolyte for dye-sensitized solar cells as described in any one of Claims 1-3. 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,
The dye-sensitized solar cell whose electrolyte is the electrolyte for dye-sensitized solar cells as described in any one of Claims 1-4.

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