JP6013064B2 - Dye-sensitized solar cell - Google Patents

Description

 The present invention relates to a dye-sensitized solar cell.

An important performance of a dye-sensitized solar cell is safety. In a dye-sensitized solar cell, an electrolytic solution is generally used as a charge transport layer. If the dye-sensitized solar cell is damaged, leakage of the electrolyte is assumed. Therefore, from the viewpoint of safety, it is desired that the dye-sensitized solar cell has a structure that is less likely to be damaged or a structure that prevents internal substances from leaking even if it is damaged.
In the past, many attempts have been made to solidify or quasi-solidify an electrolyte solution in order to make the dye-sensitized solar cell have a structure in which an internal substance hardly leaks even if it is damaged (for example, Patent Document 1). reference).

Japanese Patent Laid-Open No. 2003-346828

 However, when the electrolytic solution is solidified or quasi-solidified, the diffusion rate of the charge transport material contained in the electrolytic solution is lowered, and there is a problem that the conversion efficiency is lowered as compared with the liquid electrolytic solution.

 This invention is made | formed in view of the said situation, Comprising: It aims at providing the dye-sensitized solar cell which prevented the electrolyte solution from leaking outside by damage, without reducing conversion efficiency. .

The dye-sensitized solar cell of the present invention, an optical electrode having an oxide semiconductor layer which dye is supported, a counter electrode, which is disposed between the photoelectrode and the counter electrode, wherein an electrolyte, liquids or Ranaru charge A dye-sensitized solar cell including a transport layer, and a sealing material disposed between the photoelectrode and the counter electrode for sealing the charge transport layer, and in contact with the charge transport layer, A viscosity-increasing substance-containing layer containing a substance that increases the viscosity of the charge transport layer is provided in the vicinity of an interface between the sealing material, the photoelectrode, and the counter electrode, and the sealing material includes the photoelectrode and A groove-shaped first recess recessed in the thickness direction from the surface in contact and a second recess recessed in the thickness direction from the surface in contact with the counter electrode are provided, and the first recess and the second recess are provided in the first recess. The viscosity increasing substance-containing layer is provided .

The dye-sensitized solar cell of the present invention includes a photoelectrode having an oxide semiconductor layer on which a dye is supported, a counter electrode, a charge transport layer made of a liquid, including an electrolyte, disposed between the photoelectrode and the counter electrode. And a dye-sensitized solar cell that is disposed between the photoelectrode and the counter electrode and seals the charge transport layer, and when in contact with the charge transport layer, the charge transport A viscosity-increasing substance-containing layer containing a substance that increases the viscosity of the layer is provided in the vicinity of the interface between the sealing material, the photoelectrode, and the counter electrode, and the sealing material penetrates in the thickness direction. The viscosity increasing substance-containing layer is provided in the through hole.

Substances which increase the viscosity of the charge transport layer, the gelling agent der Rukoto are preferred.

 According to the present invention, since the viscosity-increasing substance-containing layer containing a substance that increases the viscosity of the charge transporting layer when in contact with the charge transporting layer is provided on at least a part of the periphery of the charge transporting layer, the charge transporting When the electrolyte that constitutes the layer leaks, the leaked electrolyte comes into contact with a substance that increases the viscosity of the electrolyte, and the electrolyte is solidified or pseudo-solidified. Leakage outside the battery can be prevented.

It is a schematic sectional drawing which shows 1st embodiment of the dye-sensitized solar cell of this invention. It is a schematic sectional drawing which shows 2nd embodiment of the dye-sensitized solar cell of this invention. It is a schematic sectional drawing which shows 3rd embodiment of the dye-sensitized solar cell of this invention. It is a schematic sectional drawing which shows 4th embodiment of the dye-sensitized solar cell of this invention. It is a schematic sectional drawing which shows 5th embodiment of the dye-sensitized solar cell of this invention.

An embodiment of the dye-sensitized solar cell of the present invention will be described.
Note that this embodiment is specifically described in order to better understand the gist of the invention, and does not limit the present invention unless otherwise specified.

<Dye-sensitized solar cell>
(First embodiment)
FIG. 1 is a schematic cross-sectional view showing a first embodiment of the dye-sensitized solar cell of the present invention.
The dye-sensitized solar cell 10 according to the present embodiment includes a photoelectrode 11, a counter electrode 12, a charge transport layer 5 including an electrolyte disposed between the photoelectrode 11 and the counter electrode 12, a photoelectrode 11, and a counter electrode 12. Between the sealing material 4 that seals the charge transport layer 5, the photoelectrode 11, the counter electrode 12, the charge transport layer 5, and the sealing material 4, It is generally composed of a viscosity increasing substance-containing layer 13 that is provided at a position where it does not overlap and contains a substance that increases the viscosity of the charge transport layer 5.
That is, the viscosity increasing substance-containing layer 13 is the outer periphery of the laminate including the photoelectrode 11, the counter electrode 12, the charge transport layer 5, and the sealing material 4, and the light receiving surface 11 a (the conductive layer of the transparent substrate 1) 2 is provided at a position that does not overlap with the surface 1a) opposite to the surface in contact with 2.

(Photoelectrode)
The photoelectrode 11 is composed of a transparent substrate 1, a conductive layer 2, and an oxide semiconductor layer 3 on which a dye is supported. The transparent substrate 1, the conductive layer 2, and the oxide semiconductor layer 3 are laminated in this order. ing.

 The transparent substrate 1 is not particularly limited as long as it is a substrate that transmits visible light absorbed by the sensitizing dye, and examples thereof include a glass substrate and a plastic substrate.

The glass substrate is not particularly limited, and examples thereof include soda lime glass, quartz glass, borosilicate glass, Vycor glass, alkali-free glass, blue plate glass, and white plate glass.
The plastic substrate is not particularly limited, and examples thereof include polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyacryl, polycarbonate, polyester, polyimide, polystyrene, polyvinyl chloride, and polyamide. Among these, polyester, PET, and PEN are preferable from the viewpoint of excellent heat resistance.
From the viewpoint of producing a thin, light and flexible dye-sensitized solar cell, the transparent substrate 1 is preferably a PET film or a PEN film.

The conductive layer 2 only needs to have conductivity and transmit visible light, and a known transparent conductive layer can be applied.
Examples of the material for the transparent conductive layer include metal oxides and conductive polymers.

Metal oxides include indium oxide / tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide, tin oxide, antimony-doped tin oxide (ATO), indium oxide / zinc oxide (IZO), gallium oxide / oxide Examples include zinc (GZO) and titanium oxide. Among these, ITO with high conductivity and FTO excellent in heat resistance and weather resistance are particularly preferable.
The conductive layer 2 may be either a single layer or a plurality of layers. When the conductive layer 2 has a plurality of layers, all the layers may be made of the same material, or each layer may be made of different materials.

(Oxide semiconductor layer)
The oxide semiconductor layer 3 is a porous layer (porous film) made of an oxide semiconductor carrying a sensitizing dye.
Examples of the oxide semiconductor include titanium oxide (TiO ₂ ), zinc oxide (ZnO), and strontium titanate (SrTiO ₃ ). Among these, titanium oxide is preferable because it is excellent in electron conductivity when the porous layer is formed.

The oxide semiconductor layer 3 is formed on the transparent substrate 1, and the thickness of the oxide semiconductor layer 3 is preferably 1 μm to 200 μm, preferably 2 μm to 100 μm, and preferably 5 μm to 5 μm. More preferably, it is 50 μm.
If it is at least the lower limit of the above range, the probability that the dye supported on the oxide semiconductor layer 3 absorbs light energy can be further increased, and the photoelectric conversion efficiency in the dye-sensitized solar cell 10 can be further improved. Further, when the concentration is not more than the upper limit of the above range, ions in the electrolyte (electrolyte in the solar battery cell) and the electrolyte in the oxide semiconductor layer 3 are more efficiently diffused, and the photoelectric conversion efficiency can be further improved.

The sensitizing dye is not particularly limited, and may be those used in ordinary dye-sensitized solar cells. Specifically, cis-di (thiocyanato) -bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II), cis-di (thiocyanato) -bis (2,2′-bipyridyl- 4,4′-dicarboxylic acid) ruthenium (II) bis-tetrabutylammonium salt (hereinafter abbreviated as N719), tri (thiocyanato)-(4,4 ′, 4 ′ ′-tricarboxy-2,2 ′) : Ruthenium-based dyes such as 6 ', 2''-terpyridine) ruthenium tris-tetrabutylammonium salt (black dye). In addition, coumarin dyes, polyene dyes, cyanine dyes, hemicyanine dyes, thiophene dyes, indoline dyes, xanthene dyes, carbazole dyes, perylene dyes, porphyrin dyes, phthalocyanine dyes, merocyanine dyes, Examples include various organic dyes such as catechol dyes and squarylium dyes. Furthermore, the donor-acceptor composite dye | dye etc. which combined these pigment | dyes are mentioned.
The sensitizing dye supported on the oxide semiconductor layer 3 may be one kind or two or more kinds. In the case of two or more types, the combination and ratio may be appropriately selected according to the purpose.

(Counter electrode)
The counter electrode 12 includes a substrate 7, a conductive layer 6, and a catalyst layer 8, and the substrate 7, the conductive layer 6, and the catalyst layer 8 are laminated in this order.
The substrate 7 and the conductive layer 6 may be either opaque or transparent, but are preferably transparent. Specifically, what was illustrated as a material of the above-mentioned photoelectrode 11 is applicable similarly. Among them, polyethylene naphthalate (PEN) is preferable as the material of the substrate 7, and indium oxide / tin oxide (ITO) is preferable as the material of the conductive layer 6.

The catalyst layer 8 is provided on the conductive layer 6 in a region in contact with the charge transport layer 5.
The catalyst layer 8 is a layer made of a binder resin containing a carbon material such as acetylene black or ketjen black.
By disposing the catalyst layer 8 on the surface of the counter electrode 12, it is possible to promote electron exchange with the electrolyte.
The thickness of the catalyst layer 8 is not particularly limited, and can be, for example, 0.1 μm to 10 μm.

(Charge transport layer)
The charge transport layer 5 includes at least an electrolyte. The charge transport layer 5 may or may not contain a solvent. Moreover, the gelatinizer etc. may be included as needed. The state of the charge transport layer 5 may be any of liquid, gel, and solid.

(solvent)
The solvent is not particularly limited as long as it can dissolve the electrolyte, and examples thereof include carbonate compounds such as ethylene carbonate and propylene carbonate, and nitrile compounds such as acetonitrile and methoxypropionitrile. A nitrile compound is preferable because it can dissolve an electrolyte composed of iodine and an iodide salt and is excellent in ionic conductivity.
Moreover, you may use an ionic liquid as a main component or additive of a solvent. Examples of the ionic liquid include a room temperature molten salt containing t-butylpyridine, a room temperature molten salt containing methylpropylimidazolium, dimethylpropylimidazolium, a guanidinium thiocyanate, an N-alkylbenzimidazole, and the like. Etc.

(Gelling agent)
Examples of the gelling agent include a high molecular gelling agent and a low molecular gelling agent. Among these, a low-molecular gelling agent that has a low viscosity at the sol-gel transition point or higher and that can provide an electrolyte with high fluidity is preferable. Here, the low molecular weight gelling agent refers to a gelling agent having a molecular weight of 1000 or less.

As the low-molecular gelling agent, various known ones can be used. For example, fatty acids such as 12-hydroxystearic acid, dibenzylidene sorbitol (trade name “Gelol D” manufactured by Shin Nippon Rika Co., Ltd.), etc. Sugar derivatives, hydrocarbons such as hexatriacontane, and other amides.
The concentration of the low-molecular gelling agent and the high-molecular gelling agent is appropriately adjusted according to the type of gelling agent used and other components (electrolyte, solvent, etc.) contained in the charge transport layer.

(Electrolytes)
As the electrolyte contained in the charge transport layer 5, those used in conventionally known dye-sensitized solar cells can be applied.
As the electrolyte, a combination of iodine molecule (I ₂ ) and iodide or a combination of bromine molecule (Br ₂ ) and bromine compound is preferably used.
Examples of the iodide include metal iodides such as lithium iodide (LiI), sodium iodide (NaI), and potassium iodide (KI), or tetraalkylammonium iodide, pyridinium iodide, imidazolium iodide, and the like. Iodine salts are preferred.
Examples of bromides include metal bromides such as lithium bromide (LiBr), sodium bromide (NaBr), and potassium bromide (KBr), or bromine salts such as tetraalkylammonium bromide, pyridinium bromide, and imidazolium bromide. It is mentioned as a suitable thing.
Among these electrolytes, a redox pair in which iodine molecules and LiI or iodine molecules and imidazolium iodide are combined is preferable.

The hydrogen atom bonded to the pyridinium ring and the imidazole ring constituting the pyridinium iodide and imidazolium iodide may be substituted with an alkyl group. Specific examples include 1-butyl-4-methylpyridinium iodide and 1-methyl-3-propylimidazolium iodide. When these iodide salts are used, N-methylbenzimidazole or the like may be used as an additive.
Moreover, the electrolyte may be used individually by 1 type, and multiple types may be mixed and used for it.

The electrolyte (redox pair) is composed of a combination of oxidized ionic species (oxidized species), substances that cause an equilibrium reaction with oxidized and reduced species (equilibrium reactive species), and reduced ionic species (reduced species). Are preferred. For example, an electrolyte composed of a combination of iodine ion (I ⁻ ) / iodine molecule (I ₂ ) / triiodide ion (I ₃ ⁻ ), bromine ion (Br ⁻ ) / bromine molecule (Br ₂ ) / tribromide ion An electrolyte composed of a combination of (Br ₃ ⁻ ) is mentioned. Among these, iodine ion (I ⁻ ) / iodine molecule (I ₂ ) / triiodide ion (I ₃ ⁻ ) having a redox potential at a suitable height relative to commonly used dyes. A combination of electrolytes is preferred. The iodine molecule (I ₂ ) that is an equilibrium reactive species reacts with iodine ions (I ⁻ ) that are reducing species to generate triiodide ions (I ₃ ⁻ ) that are oxidizing species. That is, iodine molecules cause an equilibrium reaction with triiodide ions and iodine ions.
In addition, thiocyanate (SCN ⁻ / (SCN) ₃ ⁻ ), metal (Co (II) / Co (III), Cu (I) / Cu (II), etc.) electrolytes can be used.

When a combination of iodine ion (I ⁻ ), iodine molecule (I ₂ ), and triiodide ion (I ₃ ⁻ ) is used as the electrolyte (redox pair), the mixing ratio is added to the electrolyte. It can be determined by the ratio of iodide ion (I ⁻ ) and iodine (I ₂ ). It can be considered that iodine reacts with iodide ions and becomes almost quantitatively triiodide ions (I ₃ ⁻ ).
In addition, when an ionic liquid or the like containing triiodide ions or iodide ions is added to the electrolyte, the mixing ratio is also taken into consideration.

The concentration of a salt containing a reducing species such as an iodide salt containing iodine ion (I ⁻ ) in the electrolyte in the charge transport layer 5 is preferably 0.1 to 10 mol / L (hereinafter, this unit is described as M) And more preferably 0.5 to 5 mol / L. If it is at least the lower limit of the above range, the oxidation-reduction reaction can be carried out sufficiently. The performance fall by a reverse electron transfer reaction can fully be suppressed as it is below the upper limit of the said range. A preferable iodine concentration when adding iodine (I ₂ ) to the charge transport layer 5 is 0.001 to 1 mol / L.

(Encapsulant)
The sealing material 4 is not particularly limited as long as it is made of a material capable of sealing the charge transport layer 5 disposed between the photoelectrode 11 and the counter electrode 12. Examples thereof include a sealing material made of a material such as a curable resin, a thermosetting resin, or a thermoplastic resin.
Examples of a method for forming the sealing material 4 include a method in which a solution containing the above resin is applied to a predetermined portion of the photoelectrode 11 or the counter electrode 12 and cured. As another method, there is also a method in which a member obtained by molding the previously cured resin into a predetermined size is prepared as the sealing material 4, and this is disposed between the photoelectrode 11 and the counter electrode 12 for adhesion. It can be illustrated.

 Although the thickness of the sealing material 4 is not particularly limited, the thickness is appropriately adjusted so that the photoelectrode 11 and the counter electrode 12 are separated from each other with a predetermined interval and the charge transport layer 5 is required. .

(Viscosity increasing substance-containing layer)
The viscosity-increasing substance-containing layer 13 is a layer containing a substance that increases the viscosity of the electrolytic solution when it comes into contact with the electrolytic solution constituting the charge transport layer 5. Increasing the viscosity of the electrolytic solution means solidifying or quasi-solidifying the electrolytic solution.
The viscosity increasing substance-containing layer 13 is provided on the outer periphery of the laminate including the photoelectrode 11, the counter electrode 12, the charge transport layer 5, and the sealing material 4 and at a position that does not overlap the light receiving surface. When peeling at the interface between the photoelectrode 11 and the sealing material 4 and peeling at the interface between the counter electrode 12 and the sealing material 4 occur, or when the photoelectrode 11 or the counter electrode 12 is damaged and cracks occur, Since the electrolyte constituting the charge transport layer 5 often leaks to the outside from the peeled portions or cracks, the viscosity increasing substance-containing layer 13 is composed of the photoelectrode 11, the counter electrode 12, the charge transport layer 5, and the sealing material. 4 is preferably provided on the outer periphery of the laminate including 4.

 Examples of the substance that increases the viscosity of the electrolytic solution include a low molecular gelling agent. As the low-molecular gelling agent, various known ones can be used. For example, fatty acids such as 12-hydroxystearic acid, dibenzylidene sorbitol (trade name “Gelol D” manufactured by Shin Nippon Rika Co., Ltd.), etc. Sugar derivatives, hydrocarbons such as hexatriacontane, and other amides.

 As a method for forming the viscosity increasing substance-containing layer 13, for example, a dispersion solution in which a low molecular gelling agent is dispersed is applied onto a film, and the solvent is dried to form a layer composed of the low molecular gelling agent. Forming a viscosity increasing substance-containing layer 13 between the solar battery cell and the film by surrounding the outer periphery of the laminate including the photoelectrode 11, the counter electrode 12, the charge transport layer 5 and the encapsulant 4 with a film, surface Including a viscosity increasing substance between the solar cell and the film by surrounding the outer periphery of the laminate including the photoelectrode 11, the counter electrode 12, the charge transport layer 5 and the sealing material 4 with a film coated with a low molecular gelling agent A method of forming the layer 13, and a bag-like container containing a dispersion solution in which a low-molecular gelling agent is dispersed surrounds the outer periphery of the laminate including the photoelectrode 11, the counter electrode 12, the charge transport layer 5, and the sealing material 4. The solar cells and A method in which forming a viscosity increasing material-containing layer 13 between the Lum thereof.

 The thickness of the viscosity increasing substance-containing layer 13 is not particularly limited, but is appropriately adjusted according to the amount of the electrolyte solution constituting the charge transport layer 5.

 According to the dye-sensitized solar cell 10 of the present embodiment, the viscosity increasing substance-containing layer 13 is an outer periphery of a laminate including the photoelectrode 11, the counter electrode 12, the charge transport layer 5, and the sealing material 4, and the photoelectrode 11 is provided at a position that does not overlap the light receiving surface 11a, and peeling at the interface between the photoelectrode 11 and the sealing material 4 or peeling at the interface between the counter electrode 12 and the sealing material 4 occurs. When the electrolytic solution constituting the charge transport layer 5 leaks along the interface, or the photoelectrode 11 or the counter electrode 12 is damaged and cracks are generated, and the charge transport layer 5 is removed from the cracks. When the constituting electrolyte solution leaks, the electrolyte solution is brought into contact with the low-molecular gelling agent contained in the viscosity increasing substance-containing layer 13 to solidify or quasi-solidify the electrolyte solution, so that the electrolyte solution is a dye-sensitized solar cell. 10 can be prevented from leaking outside. Further, by providing the viscosity increasing substance-containing layer 13, it is not necessary to solidify or quasi-solidify the charge transport layer 5 in order to prevent leakage of the electrolytic solution, thereby reducing the conversion efficiency of the dye-sensitized solar cell 10. There is nothing to do.

(Second embodiment)
FIG. 2 is a schematic cross-sectional view showing a second embodiment of the dye-sensitized solar cell of the present invention.
In FIG. 2, the same components as those in the dye-sensitized solar cell 10 shown in FIG.
The difference between the dye-sensitized solar cell 20 of the present embodiment and the dye-sensitized solar cell 10 described above is that the viscosity-increased substance-containing layer 21 surrounds the side surfaces of the photoelectrode 11, the counter electrode 12, and the sealing material 4. It is a point that is arranged.

 The thickness of the viscosity increasing substance-containing layer 21 is not particularly limited, but is appropriately adjusted according to the amount of the electrolytic solution constituting the charge transport layer 5.

 As the substance for increasing the viscosity of the electrolytic solution constituting the viscosity increasing substance-containing layer 21, the same substance as in the first embodiment described above is used.

 According to the dye-sensitized solar cell 20 of the present embodiment, since the viscosity increasing substance-containing layer 21 is disposed so as to surround the side surfaces of the photoelectrode 11, the counter electrode 12, and the sealing material 4, the photoelectrode 11 and the sealing layer are sealed. When peeling at the interface of the material 4 or peeling at the interface between the counter electrode 12 and the sealing material 4 occurs and the electrolyte solution constituting the charge transport layer 5 leaks from the peeled portion along the interface, The electrolyte solution and the low-molecular gelling agent contained in the viscosity increasing substance-containing layer 21 come into contact with each other to solidify or quasi-solidify the electrolyte solution, thereby preventing the electrolyte solution from leaking outside the dye-sensitized solar cell 20. it can. In addition, by providing the viscosity increasing substance-containing layer 21, it is not necessary to solidify or quasi-solidify the charge transport layer 5 in order to prevent leakage of the electrolyte solution, thereby reducing the conversion efficiency of the dye-sensitized solar cell 20. There is nothing to do.

(Third embodiment)
FIG. 3 is a schematic cross-sectional view showing a third embodiment of the dye-sensitized solar cell of the present invention.
In FIG. 3, the same components as those of the dye-sensitized solar cell 10 shown in FIG.
The difference between the dye-sensitized solar cell 30 of the present embodiment and the above-described dye-sensitized solar cell 10 is that the encapsulant 4 has a groove-like recess 4a that is recessed in the thickness direction from the surface in contact with the photoelectrode 11. A recess 4b that is recessed in the thickness direction from the surface in contact with the counter electrode 12 is provided, and a viscosity-increasing substance-containing layer 31 that contains a substance that increases the viscosity of the charge transport layer 5 is provided in the recesses 4a and 4b. Is a point. That is, the viscosity increasing substance-containing layer 31 is formed of a substance that increases the viscosity of the electrolytic solution filled in the recesses 4 a and 4 b of the sealing material 4.

The shape and size (depth, area in plan view) of the recesses 4 a and 4 b formed in the sealing material 4 are not particularly limited, but are appropriately determined according to the amount of the electrolyte solution constituting the charge transport layer 5. Adjusted.
Further, the recesses 4 a and 4 b may have two or more groove shapes formed at intervals along the width direction of the sealing material 4.

 As the substance for increasing the viscosity of the electrolytic solution constituting the viscosity increasing substance-containing layer 31, the same one as in the first embodiment described above is used.

 According to the dye-sensitized solar cell 30 of the present embodiment, the sealing material 4 is provided with the viscosity increasing substance-containing layer 31 in the groove-shaped recess 4a that is recessed in the thickness direction from the surface in contact with the photoelectrode 11. Since the viscosity increasing substance-containing layer 31 is provided in the concave portion 4 b that is recessed in the thickness direction from the surface in contact with the counter electrode 12, peeling at the interface between the photoelectrode 11 and the sealing material 4, and the counter electrode 12 and the sealing material 4 When peeling occurs at the interface and the electrolyte solution constituting the charge transport layer 5 leaks along the interface from the peeled portion, the low molecular gelation contained in the electrolyte solution and the viscosity increasing substance-containing layer 31 Since the agent comes into contact and solidifies or quasi-solidifies the electrolytic solution, the electrolytic solution can be prevented from leaking outside the dye-sensitized solar cell 30. In addition, by providing the viscosity increasing substance-containing layer 31, it is not necessary to solidify or quasi-solidify the charge transport layer 5 in order to prevent leakage of the electrolytic solution, thereby reducing the conversion efficiency of the dye-sensitized solar cell 30. There is nothing to do.

(Fourth embodiment)
FIG. 4 is a schematic cross-sectional view showing a fourth embodiment of the dye-sensitized solar cell of the present invention.
In FIG. 4, the same components as those of the dye-sensitized solar cell 10 shown in FIG.
The dye-sensitized solar cell 40 of the present embodiment is different from the dye-sensitized solar cell 10 described above in that the sealing material 4 is provided with a through-hole 4c penetrating in the thickness direction, and inside the through-hole 4c. 3 is provided with a viscosity increasing substance-containing layer 41 that contains a substance that increases the viscosity of the charge transport layer 5. That is, the viscosity increasing substance-containing layer 41 is formed of a substance that increases the viscosity of the electrolytic solution filled in the through hole 4 c of the sealing material 4.

The shape and size (width) of the through-hole 4 c formed in the sealing material 4 are not particularly limited, but are appropriately adjusted according to the amount of the electrolytic solution constituting the charge transport layer 5.
Further, the through holes 4 c may be two or more through holes formed at intervals along the width direction of the sealing material 4.

 As the substance for increasing the viscosity of the electrolytic solution constituting the viscosity increasing substance-containing layer 41, the same substances as those in the first embodiment described above are used.

 According to the dye-sensitized solar cell 40 of the present embodiment, the sealing material 4 is provided with the viscosity increasing substance-containing layer 41 in the through-hole 4c penetrating in the thickness direction. Separation at the interface of the sealing material 4 or separation at the interface between the counter electrode 12 and the sealing material 4 occurred, and the electrolyte constituting the charge transport layer 5 leaked along the interface from the peeled portion. In this case, the electrolyte solution and the low-molecular gelling agent contained in the viscosity increasing substance-containing layer 41 come into contact with each other to solidify or quasi-solidify the electrolyte solution, so that the electrolyte solution leaks to the outside of the dye-sensitized solar cell 40. Can be prevented. Further, by providing the viscosity increasing substance-containing layer 41, it is not necessary to solidify or quasi-solidify the charge transport layer 5 in order to prevent leakage of the electrolytic solution, thereby reducing the conversion efficiency of the dye-sensitized solar cell 40. There is nothing to do.

(Fifth embodiment)
FIG. 5 is a schematic cross-sectional view showing a fifth embodiment of the dye-sensitized solar cell of the present invention.
In FIG. 5, the same components as those of the dye-sensitized solar cell 10 shown in FIG.
The difference between the dye-sensitized solar cell 50 of the present embodiment and the above-described dye-sensitized solar cell 10 is that the viscosity increasing substance-containing layer is formed on the surface of the transparent substrate 1 opposite to the surface in contact with the conductive layer 2. 51 is provided.

 The thickness of the viscosity increasing substance-containing layer 51 is not particularly limited, but is appropriately adjusted according to the amount of the electrolytic solution constituting the charge transport layer 5.

 As the substance for increasing the viscosity of the electrolytic solution constituting the viscosity increasing substance-containing layer 51, the same one as in the first embodiment described above is used.

 According to the dye-sensitized solar cell 50 of the present embodiment, the viscosity increasing substance-containing layer 51 is provided on the surface opposite to the surface in contact with the conductive layer 2 of the transparent substrate 1. When the cross section of the solar cell 50 is broken due to a sharp cross-section, and the electrolytic solution constituting the charge transport layer 5 leaks from the damaged portion, the low molecular gelation contained in the electrolytic solution and the viscosity increasing substance-containing layer 51 Since the agent contacts and solidifies or quasi-solidifies the electrolytic solution, the electrolytic solution can be prevented from leaking outside the dye-sensitized solar cell 50. Further, by providing the viscosity increasing substance-containing layer 51, it is not necessary to solidify or quasi-solidify the charge transport layer 5 in order to prevent leakage of the electrolytic solution, thereby reducing the conversion efficiency of the dye-sensitized solar cell 50. There is nothing to do.

 EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to a following example.

[Example 1]
(Photoelectrode production)
As the transparent substrate, a PEN substrate (ITO-PEN substrate, sheet resistance 15 Ω / cm ² , manufactured by Pexel) on which a conductive layer made of ITO was previously formed on one surface was used.
On the PEN substrate, a low-temperature baked titanium oxide (TiO ₂ ) paste (manufactured by Pexel) was applied by a doctor blade method, and heated and baked at 150 ° C. for 30 minutes in an air atmosphere to obtain a film thickness of 10 μm. An oxide semiconductor layer was formed.
Next, an N719 dye solution in which a dye N719 was dissolved in a mixed solvent of acetonitrile / tert-butanol (1/1, volume ratio) to a concentration of 0.3 mM was prepared.
Next, the substrate on which the oxide semiconductor layer was formed was immersed in the N719 dye solution for 20 hours to produce a photoelectrode.

(Counter electrode fabrication)
As the substrate, a PEN substrate (ITO-PEN substrate, sheet resistance 15 Ω / cm ² , manufactured by Pexel) on which a conductive layer made of ITO was previously formed on one surface was used.
Next, a carbon paste was applied onto the conductive layer by a screen printing method, and heated and fired at 120 ° C. for 20 minutes in an air atmosphere to form a catalyst layer having a thickness of 8 μm.

(Sealing)
After the photoelectrode and the counter electrode substrate are opposed to each other through a 50 μm-thick sealing material (High Milan), a 30 μm-thick nonwoven fabric (separator), and a 50 μm-thick sealing material (High Milan) laminated in this order. The photoelectrode and the counter electrode substrate were bonded together by hot pressing.
Next, an electrolytic solution (1.0 M 1-methyl-3-propylimidazolium iodide, 0.005 M iodine, 0.1 M guanidine thiocyanate, methoxyprote) was passed through a through-hole previously provided in a part of the counter electrode substrate. Pionitrile electrolyte solution) was injected, and finally the through hole was sealed with a photocurable resin.

(laminate)
12-hydroxystearic acid was coated on one surface of a 50 μm thick PEN substrate, and 12-hydroxystearic acid was coated on the outer side of the counter electrode substrate side of the laminate composed of a photoelectrode, a counter electrode substrate and a sealing material. The PEN substrate was placed so that the side was the counter electrode side, the PEN substrate of 50 μm was placed on the photoelectrode side of the laminate, and the laminate was laminated to obtain the dye-sensitized solar cell of Example 1 .

[Example 2]
(Photoelectrode production)
A photoelectrode was prepared in the same manner as in Example 1.

(Counter electrode fabrication)
A counter electrode substrate was produced in the same manner as in Example 1.

(Sealing)
12-Hydroxystearic acid was covered with a mask at a distance from the outer peripheral portion of the oxide semiconductor layer of the photoelectrode and the outer peripheral portion of the catalyst layer of the counter electrode substrate. After making this photoelectrode and counter electrode face each other through a laminate of a 50 μm-thick sealing material (High Milan), a 30 μm-thick nonwoven fabric (Separator), and a 50 μm-thick sealing material (High Milan) in this order The photoelectrode and the counter electrode substrate were bonded together by hot pressing. At this time, the sealing material was disposed so as to cover 12-hydroxystearic acid.
Next, an electrolytic solution (1.0 M 1-methyl-3-propylimidazolium iodide, 0.005 M iodine, 0.1 M guanidine thiocyanate, methoxyprote) was passed through a through-hole previously provided in a part of the counter electrode substrate. Pionitrile electrolyte solution) was injected, and finally the through-hole was sealed with a photocurable resin to obtain a dye-sensitized solar cell of Example 2.

[Example 3]
(Photoelectrode production)
A photoelectrode was prepared in the same manner as in Example 1.

(Counter electrode fabrication)
A counter electrode substrate was produced in the same manner as in Example 1.

(Sealing)
A sealing material (hylamin) having a thickness of 50 μm, which was previously formed into a double frame shape, was disposed on each of the outer peripheral portion of the oxide semiconductor layer of the photoelectrode and the outer peripheral portion of the catalyst layer of the counter electrode substrate. From above, 12-hydroxystearic acid was applied to the middle part of each double frame using a mask. Such a laminate and a counter electrode are made to face each other through a non-woven fabric (separator) having a thickness of 30 μm and a sealing material (hylamin) formed so as to have a double frame shape having a thickness of 50 μm. By carrying out, the photoelectrode and the counter electrode substrate were bonded together.
Next, an electrolytic solution (1.0 M 1-methyl-3-propylimidazolium iodide, 0.005 M iodine, 0.1 M guanidine thiocyanate, methoxyprote) was passed through a through-hole previously provided in a part of the counter electrode substrate. Pionitrile electrolyte solution) was injected, and finally the through-hole was sealed with a photocurable resin to obtain a dye-sensitized solar cell of Example 3.

[Comparative example]
The dye-sensitized solar cell of the comparative example was manufactured in the same manner as in the example except that the side surface of the laminate composed of the photoelectrode, the counter electrode substrate and the sealing material was not surrounded by the PEN substrate coated with 12-hydroxystearic acid. Obtained.

[Evaluation]
(1) Output measurement The output was measured about the dye-sensitized solar cell of Examples 1-3 and a comparative example.
The output of the dye-sensitized solar cell was obtained by using a Xe lamp as a light source, irradiating the dye-sensitized solar cell with simulated sunlight, and measuring the current at each voltage. In addition, the intensity | strength of the pseudo sunlight from a Xe lamp was 100 W / cm < ² >.
As a result of the measurement, the output is 2.1 W / cm ² of the dye-sensitized solar cell of Example 1, the output is 2.3 W / cm ^2, the dye-sensitized solar Example 3 of the dye-sensitized solar cell of Example 2 The output of the battery was 2.2 W / cm ² . On the other hand, the output of the dye-sensitized solar cell of the comparative example was 2.1 W / cm ² .

(2) Dispersion state of electrolyte solution Moreover, the dye-sensitized solar cell of Examples 1-3 and the comparative example was physically fractured using a cutter, and the dispersion state of the electrolyte solution was visually confirmed.
As a result, in the dye-sensitized solar cell of the comparative example, leakage of the electrolytic solution after breakage was significant.
On the other hand, in the dye-sensitized solar cells of Examples 1 to 3, the electrolyte solution leaked after rupture, but the amount of electrolyte solution leaked was smaller than that of the comparative example. In addition, in the dye-sensitized solar cells of Examples 1 to 3, the amount of leakage of the electrolytic solution was small, but in Example 1, the amount of leakage of the electrolytic solution was particularly small.

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate, 2 ... Conductive layer, 3 ... Oxide semiconductor layer, 4 ... Sealing material, 5 ... Charge transport layer, 6 ... Conductive layer, 7 ... Substrate, 10, 20, 30, 40, 50 ... Dye-sensitized solar cell, 11 ... Photoelectrode, 12 ... Counter electrode, 13, 21, 31, 41, 51 ... Viscosity increasing substance-containing layer .

Claims (3)

Dye is disposed between the photoelectrode having an oxide semiconductor layer supported, counter electrode, and the photoelectrode and the counter electrode, wherein an electrolyte, liquids or Ranaru charge transport layer, and wherein said photoelectrode A dye-sensitized solar cell provided with a sealing material that seals the charge transport layer, disposed between counter electrodes,
When in contact with the charge transport layer, a viscosity increasing substance-containing layer containing a substance that increases the viscosity of the charge transport layer is provided in the vicinity of the interface between the sealing material, the photoelectrode and the counter electrode ,
The sealing material is provided with a groove-shaped first recess recessed in the thickness direction from the surface in contact with the photoelectrode, and a second recess recessed in the thickness direction from the surface in contact with the counter electrode. The dye-sensitized solar cell , wherein the viscosity-increasing substance-containing layer is provided in one concave portion and the second concave portion . A photoelectrode having a dye-supported oxide semiconductor layer, a counter electrode, a charge transport layer comprising an electrolyte and disposed between the photoelectrode and the counter electrode, and the photoelectrode and the counter electrode A dye-sensitized solar cell provided with a sealing material disposed between and encapsulating the charge transport layer,
When in contact with the charge transport layer, a viscosity increasing substance-containing layer containing a substance that increases the viscosity of the charge transport layer is provided in the vicinity of the interface between the sealing material, the photoelectrode and the counter electrode,
Wherein the sealing material has a through hole is provided, the color Motozo sensitized solar cell you wherein viscosity-increasing substances containing layer is provided in the through hole penetrating in the thickness direction. The dye-sensitized solar cell according to claim 1 or 2 , wherein the substance that increases the viscosity of the charge transport layer is a gelling agent.

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