JP2007012297A - Counter electrode for dye-sensitized solar cell and dye-sensitized solar cell using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a counter electrode for a dye-sensitized solar cell having a conductive polymer layer with high shock resistance and sufficiently high adhesive strength, and to provide the dye-sensitized solar cell using the counter electrode. <P>SOLUTION: The counter electrode for the dye-sensitized solar cell is comprised of a transparent conductive layer installed on plastic, and the conductive polymer layer installed on the transparent conductive layer, and the conductive polymer layer contains 1-99 wt% conductive polymer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a counter electrode for a dye-sensitized solar cell and a dye-sensitized solar cell using the counter electrode.

  The dye-sensitized solar cell has been proposed since a photoelectric conversion element using dye-sensitized semiconductor fine particles was proposed (“Nature”, Vol. 353, pages 737-740, (1991)). It is attracting attention as a new solar battery that replaces batteries. Compared to silicon-based solar cells, it is possible to reduce the manufacturing cost, and is attracting attention.

  Many dye-sensitized solar cells include a working electrode obtained by laminating a porous titanium oxide film on a transparent conductive layer on glass and adsorbing the surface with a sensitizing dye, an electrolyte, and a counter electrode. Many of the counter electrodes used in dye-sensitized solar cells that are currently known are made by carrying platinum on a transparent conductive material such as ITO glass. However, since platinum is a noble metal and expensive, it has been studied to use a cheaper conductive polymer and to carry it on a transparent conductive layer provided on a glass substrate.

Chemistry Letters 2002 1060-1061 Jornal of Photochemistry and Photobiology A: Chemistry 164 (2004) 153-157 Transactions of the Materials Resarch Society of Japan 29 [3] 1011-1015 2004 Chem Commun 2003 No21 2072-2075

  In a conventional technique, when a conductive polymer is used as a counter electrode of a dye-sensitized solar cell, a conductive polymer dispersion or a monomer dispersion thereof is placed on a transparent conductive layer on a glass substrate. A method of providing a conductive polymer layer by applying, drying or polymerizing was employed.

  However, it is necessary to use a highly polar solvent as the solvent of the dispersion liquid because the conductive polymer and its monomer are low in solubility, and the wettability to the substrate is poor. It was necessary to take a coating method. Further, when a conductive polymer layer is provided by polymerizing a conductive polymer on a substrate, sufficient adhesion may not be obtained, and peeling may be observed in the cleaning process.

  The counter electrode is used in contact with the electrolyte solution constituting the solar cell, but if the adhesion of each layer is insufficient, peeling from the transparent conductive layer occurs. Moreover, the glass used as a base material has low impact resistance, and when it is set as a solar cell, impact resistance is low.

  An object of the present invention is to solve the problems of the prior art. That is, an object of the present invention is to provide a counter electrode for a dye-sensitized solar cell and a dye-sensitized solar cell using the same provided with a conductive polymer layer that has high impact resistance and has a sufficiently high adhesive strength. Is to provide.

  That is, the present invention comprises a transparent conductive layer provided on plastic and a conductive polymer layer provided on the transparent conductive layer, and the conductive polymer layer contains 1 to 99% by weight of the conductive polymer. It is a counter electrode of the dye-sensitized solar cell characterized by containing.

  According to the present invention, it is possible to provide a counter electrode for a dye-sensitized solar cell that has high impact resistance and is bonded to a substrate with sufficiently high adhesive strength.

Hereinafter, the present invention will be described in detail.
[Plastic film]
The plastic film in the present invention is made of plastic. Plastics include polyester, polycarbonate, amorphous olefin, polyether, polyether ether ketone, polyphenylene ether, polymethacrylate, polystyrene, acrylic, polyamide, polyarylate, polysulfonic acid, polyethersulfone, polyarylene sulfide, phenol resin, Examples include urea resin, melamine resin, epoxy resin, diallyl phthalate, polyurethane, silicon resin, fluororesin, polyimide, polyetherimide, and polyamideimide. Of these, polyester is preferred.

  As polyester, aromatic polyester is used, and polyethylene naphthalene dicarboxylate and polyethylene terephthalate can be exemplified. In particular, polyethylene naphthalene dicarboxylate is preferred.

  The thickness of the plastic film in the present invention is preferably 10 to 500 μm, more preferably 20 to 400 μm, and particularly preferably 50 to 300 μm. If the thickness is less than 10 μm, handling becomes difficult and the subsequent solar cell assembly process is hindered. A thickness of more than 500 μm is not preferable because the flexibility of the dye-sensitized solar cell is lowered.

  When polyester is used as the plastic, it is preferable from the viewpoint of mechanical strength that the polyester is used as a stretched film, particularly a biaxially stretched film.

[Easily adhesive layer]
A transparent conductive layer is provided on the plastic film, but an easy-adhesion layer may be provided between the plastic film and the transparent conductive layer in order to improve the adhesion between the plastic film and the transparent conductive layer. When providing an easily bonding layer, the thickness becomes like this. Preferably it is 10-200 nm, More preferably, it is 20-150 nm. If the thickness of the easy-adhesion layer is less than 10 nm, the effect of improving the adhesion is poor, which is not preferable. If the thickness exceeds 200 nm, the easy-adhesion layer tends to cause cohesive failure and the adhesion may be lowered.

  The easy adhesion layer may be provided after the plastic film is formed, or may be provided by coating during the production process of the plastic film. The easy-adhesion layer is preferably provided by coating during the production process of the plastic film. Particularly when the plastic film is produced by being drawn, before the drawing and heat setting steps are completed in the production process of the plastic film. It is preferable to apply to.

  Here, the plastic film before crystal orientation is completed is an unstretched film, a uniaxially oriented film in which the unstretched film is oriented in either the longitudinal direction or the transverse direction, and further in two directions, the longitudinal direction and the transverse direction. And a film that has been stretched and oriented at a low magnification (a biaxially stretched film before it is finally re-stretched in the machine direction or the transverse direction to complete oriented crystallization).

  The material constituting the easy-adhesion layer is preferably a material that exhibits excellent adhesion to both the plastic film and the transparent conductive layer. Specifically, polyester resin, acrylic resin, urethane acrylic resin, silicon acrylic resin And melamine resin and polysiloxane resin. These resins may be used alone, or two or more kinds thereof may be used as a mixture, for example.

[Hard coat layer]
Furthermore, a hard coat layer may be provided between the easy-adhesion layer and the transparent conductive layer in order to improve the adhesion between the plastic film and the transparent conductive layer, particularly the durability of the adhesion.
The hard coat layer is preferably provided by a method of coating on a plastic film provided with an easy adhesion layer. The hard coat layer is preferably composed of a material that exhibits excellent adhesion to both the easy-contact layer and the transparent conductive layer. From the viewpoint of industrial productivity, thermosetting and energy ray curable resins are acrylic. A resin component such as resin, urethane resin, silicon resin, and epoxy resin, and a mixture of these with inorganic particles such as alumina, silica, and mica are preferable. The thickness of the hard coat layer is preferably 0.01 to 20 μm, more preferably 1 to 10 μm.

[Transparent conductive layer]
In the present invention, the transparent conductive layer is formed using a conductive metal oxide. Examples thereof include fluorine-doped tin oxide, indium-tin composite oxide (ITO), indium-zinc composite oxide, metal thin films (eg, platinum, gold, silver, copper, aluminum, etc.), and carbon materials. One type of transparent conductive layer may be used, or two or more types may be laminated or combined. In particular, ITO and indium-zinc composite oxide are particularly preferable because of high light transmittance and low resistance.

The surface resistance of the transparent conductive layer is preferably 100Ω / □ or less, more preferably 40Ω / □ or less. Exceeding 100Ω / □ is not preferable because the internal resistance of the solar cell increases and current does not sufficiently flow.
The thickness of the transparent conductive layer is preferably 100 to 500 nm. If it is thinner than this, the surface resistance value cannot be lowered sufficiently, and if it is thick, the transparent conductive layer is easily broken, which is not preferable.

[Conductive polymer layer]
Examples of the conductive polymer in the present invention include polythioephene, polypyrrole and polyaniline.

As the polythiophene, those represented by the following formula can be used. Polythiophene may be a copolymer or a mixture.

Moreover, what is shown to a following formula can be used as a polypyrrole. Polypyrrole may be a copolymer or a mixture.

  The weight concentration of the conductive polymer contained in the conductive polymer layer in the present invention is 1 to 99% by weight, preferably 2 to 70%. If it is less than 1% by weight, the excellent conductivity intended in the present invention cannot be obtained. When it exceeds 99% by weight, the conductive film is weak and cannot be used for a long time.

  The conductive polymer layer preferably further contains at least one element selected from the group consisting of silicon, titanium and boron. These elements are preferably contained in a total of 0.01 to 40% by weight. If it is less than 0.01% by weight, the desired adhesion cannot be obtained, and if it exceeds 40% by weight, the conductivity is undesirably lowered.

  The conductive polymer layer is, for example, 1) a method of removing a solvent by applying a dispersion containing a conductive polymer to a transparent conductive layer on a plastic film, and 2) a dispersion containing a monomer of a conductive polymer and a polymerization catalyst. Can be formed by applying polymerization to a transparent conductive layer on a plastic film and then proceeding with polymerization to finally remove the solvent.

  As the solvent used in the above 1) and 2), a solvent that sufficiently disperses the conductive polymer, the monomer, the polymerization catalyst, and the like and does not dissolve or erode the plastic film is used. Suitable solvents include, for example, water, methanol, ethanol, propanol, isopropanol, butanol, 2-butanol, t-butanol, ethylene glycol, diethylene glycol, and other protic solvents, acetonitrile, propylonitrile, 3-methoxypropylonitrile, butyronitrile. Nitrile solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, hexamethylphosphoramide, 1,3-dimethylimidazolidinone, tetramethylurea, 1,3-dipyropyr Aprotic polar solvents such as imidazolidinone, N-methylcaprolactam, dimethyl sulfoxide, dimethyl sulfone, tetramethyl sulfone, methylene chloride, chloroform, tetrachloroethane, etc. Halogen solvents may be used tetrahydrofuran. These solvents may be used alone or as a mixture.

  In the above 1), a dispersant may be used for improving dispersibility, if necessary. Examples of the dispersant include sulfonic acid compounds or polymers. The addition amount is 0.01 to 5 times mol, preferably 0.5 to 3 times mol per number of repeating units of the conductive polymer. If the amount is less than 0.01 moles, the dispersibility is not sufficiently improved, and if it exceeds 5 moles, the internal resistance is increased and the function as a conductive polymer cannot be exhibited.

  Examples of the polymerization catalyst in 2) include iron chloride, iron organic sulfonate, and hydrates thereof. The amount of the catalyst added is, for example, 0.1 to 5 times mol, preferably 0.5 to 3 times mol for the monomer in order to sufficiently proceed the reaction. If it is less than 0.1 times, the reaction does not proceed sufficiently. This is not preferable, and if it exceeds 5 times, it is excessively large and not industrially preferable.

  In the above 2), a polymerization controller may be added to improve the film forming property. Examples of the control agent include imidazole and aromatic oxysulfonic acid. The addition amount of the control agent is, for example, 9 times mol or less, preferably 5 times mol or less with respect to the monomer in order to sufficiently advance the polymerization reaction while increasing the film-forming property. If it exceeds 9 moles, the polymerization reaction does not proceed sufficiently, which is not preferable.

  In the present invention, the conductive polymer layer contains, in addition to the conductive polymer, a component for fixing the conductive polymer to the substrate. The weight fraction of the component to be fixed in the conductive polymer layer is preferably 0.1 to 60% by weight. When it is less than 0.1%, particularly when an electrolyte is used as a solution when assembled into a solar cell, peeling from the transparent conductive layer cannot be sufficiently suppressed, which is not preferable. If it exceeds 60%, it is not preferable because excellent conductivity cannot be obtained.

  Examples of the component to be fixed include resin components such as acrylic resin, urethane resin, silicon resin, epoxy resin and styrene resin, modified resin containing a substituent such as a metal alkoxy group / hydroxyl group, a resin containing a metal oxide in the skeleton, and a silane cup A metal oxide using a ring agent, a mixture thereof, or a composition containing a mixture of these resin components with inorganic particles such as alumina, silica, and mica can be used.

In particular, a resin in which a part of the resin component is substituted with a metal or a metal oxide is preferable because it has high adhesion to a base material and high resistance to an electrolytic solution used when a solar cell is assembled.
Examples of the general formula of those used as the fixing component include the following metal-alkoxy compounds.

ここでＭｅは珪素・チタンもしくはホウ素であり、珪素及びチタンの場合Ｘは１〜４でありホウ素の場合は１〜３である。
Ｒ^５としては、下記の置換基を例示することができる。

ここでｍは１〜３０である。Ｒ^５はＸが２もしくは１の時、同一の置換基もしくは異なる置換基であっても良い。
Ｒ^６は炭素数１〜２２の炭化水素基もしくは炭素数１〜１８のエステル基または水素である。

Here, Me is silicon / titanium or boron, and X is 1 to 4 in the case of silicon and titanium, and 1 to 3 in the case of boron.
Examples of R ⁵ include the following substituents.

Here, m is 1-30. R ⁵ may be the same or different substituent when X is 2 or 1.
R ⁶ is a hydrocarbon group having 1 to 22 carbon atoms, an ester group having 1 to 18 carbon atoms, or hydrogen.

These fixing agents may be used alone or in combination of two or more.
In particular, in order to improve the adhesion to the substrate and the film quality of the conductive polymer layer, X may contain 2 to 3, and R ⁵ may contain an epoxy group, a methacryl group, an amino group, a cyano group, a thiol group, or the like. preferable.
Specifically, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane silane, γ-glycidoxypropylmethyldiethoxysilane, 2- (3,4-epoxycyclohexylethyltrimethoxysilane) ) Tetraethoxysilane, 3- (trimethoxysilyl) propyl ester acrylic acid, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxy Silane, phenyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyldimethylmethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, 3-amino Propyldimethylethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-cyanoethylmethyldimethoxysilane, 3-cyanoethyltrimethoxysilane, 3-cyanomethyltrimethoxysilane, 3-cyanopropyltrimethoxysilane, 3-cyanopropyltriethoxy Silane, 3-mercaptopropyltrimethoxysilane, tetraisopropoxy titanium, tetrapropoxy titanium, tetra n-butoxy titanium, triisopropoxide chloro titanium, tetraethoxy titanium, titanium hydroxide trimethoxyborane, triethoxyborane, tri n -Butylborane, triisopropoxyborane, etc. can be mentioned.

  The dispersion 1) containing the conductive polymer 2 and the fixing agent 1) above and the dispersion containing the monomer and the fixing agent on the transparent conductive layer is applied by spin coating, casting, spray coating, dip coating, roll coating. And a known coating method such as bead coating.

  After the application, the target conductive polymer film can be formed by removing the solvent by heating and, if necessary, reducing the pressure. The temperature at this time is equal to or higher than the temperature at which the solvent volatilizes in the case of 1), and is equal to or higher than the temperature at which the polymerization proceeds and the solvent volatilizes in the case of 2).

  In the case of 2), it is preferable to remove excess polymerization catalyst after polymerization. An example of the removal method is washing. As the solvent for washing, a solvent that dissolves the polymerization catalyst and does not dissolve the conductive polymer may be used. Preferably, water, methanol, ethanol and isopropanol can be used. Moreover, it is preferable to dry after washing. The drying temperature may be lower than the temperature at which the plastic substrate and the conductive polymer are not deteriorated.

  The thickness of the conductive polymer layer thus obtained is preferably 0.1 to 500 nm, more preferably 1 to 200 nm. If it is less than 0.1 nm, it is not preferable because the intended delivery of electrons becomes insufficient. If it exceeds 500 nm, peeling of the film or the like becomes a problem, which is not preferable.

[Preparation of dye-sensitized solar cell]
In order to produce a dye-sensitized solar cell using the counter electrode of the solar cell of the present invention, a known method can be used. Specifically, for example, it can be created by the following method.
(1) Creation of porous semiconductor A porous semiconductor layer is formed on the transparent conductive layer of the counter electrode of the solar cell of the present invention. The porous semiconductor layer is formed by applying a dispersion of titanium oxide crystal fine particles dispersed in a solvent such as water or alcohol on the transparent conductive layer of the electrode by spin coating, casting, spray coating, dip coating, roll coating, or beading. It can apply by apply | coating by well-known methods, such as a coating, and removing a solvent.

  In addition, for forming the porous semiconductor layer, a method of supporting a thin film of particles by electrodeposition may be used. That is, the semiconductor fine particles are added to an appropriate low-conductivity solvent such as pure water, polar organic solvents such as alcohol, acetonitrile and THF, nonpolar organic solvents such as hexane and chloroform, or a mixed solvent thereof, so that there is no aggregation. The conductive resin sheet electrode to be electrodeposited and the counter electrode are made to face each other in parallel at a constant interval, the dispersion liquid is injected into the gap, and a DC voltage is applied between the electrodes. By selecting the concentration of the dispersion and the electrode spacing, a porous semiconductor layer that is an electrodeposition film having a constant and uniform thickness can be formed on the substrate electrode.

  The coated porous semiconductor layer may be further subjected to a high temperature treatment in order to enhance the electronic contact between the semiconductor particles and improve the adhesion to the support. In addition, the semiconductor particles are irradiated with ultraviolet light or the like that the particles strongly absorb, the microwave layer is irradiated to heat the fine particle layer, and the amorphous component of the semiconductor particles is added to form a physical bond between the fine particles. Processing such as strengthening may be performed.

(2) Production of working electrode A dye is adsorbed to the porous semiconductor layer produced in (1) above. Examples of the dye include a dye having a characteristic of absorbing light in the visible light region and the infrared light region, for example, an organometallic complex dye represented by a ruthenium bipyridine complex (ruthenium complex), a cyanine dye, a coumarin dye, and a xanthene. System dyes and porphyrin dyes can be used. These are dissolved in a solvent such as alcohol or toluene to prepare a dye solution, and the porous semiconductor layer is immersed, or sprayed or applied to the porous semiconductor layer.

(3) Seal The working electrode prepared in the above (2) and the counter electrode of the solar cell of the present invention are overlapped with a thermocompression-bonding polyethylene film frame spacer (thickness 20 μm) sandwiched, and the spacer portion is heated. Crimp both electrodes. Further, the edge portion is sealed with an epoxy resin adhesive.

  Through a small hole for electrolyte injection provided in advance in the corner of the sheet, an aqueous electrolyte solution containing lithium iodide and iodine (molar ratio 3: 2) and 3% by weight of nylon beads having an average particle diameter of 20 μm as a spacer is injected. Thoroughly deaerate the inside and finally seal the small holes with an epoxy resin adhesive.

Next, the present invention will be described in more detail with reference to examples. In addition, each characteristic value in an example was measured with the following method.
(1) Film thickness Using a micrometer (K-402B type manufactured by Anritsu Co., Ltd.), the film thickness is measured at 10 cm intervals in the continuous film-forming direction and the width direction of the film, and the film thickness is measured at a total of 300 locations. did. The average value of the film thicknesses of the obtained 300 locations was calculated and used as the film thickness.
(2) Surface resistance value Any five points were measured using a 4-probe type surface resistivity measuring device (Made by Mitsubishi Chemical Corporation, Loresta GP), and the average value was used as a representative value.
(3) IV characteristics (photocurrent-voltage characteristics)
A dye-sensitized solar cell having a size of 100 mm 2 was formed, and the photovoltaic power generation efficiency was calculated by the following method. Using a solar simulator (PEC-L10) manufactured by Pexel Technologies, simulated sunlight having an incident light intensity of 100 mW / cm 2 was measured in an atmosphere at a temperature of 25 ° C. and a humidity of 50%. Using a current-voltage measuring device (PECK 2400), the DC voltage applied to the system is scanned at a constant speed of 10 mV / sec, and the photocurrent output from the device is measured to measure the photocurrent-voltage characteristics. Photovoltaic efficiency was calculated.

[Example 1]
<Creation of easy-adhesion layer composition (Coating A)>
66 parts of dimethyl 2,6-naphthalenedicarboxylate, 47 parts of dimethyl isophthalate, 8 parts of dimethyl 5-sodium sulfoisophthalate, 54 parts of ethylene glycol and 62 parts of diethylene glycol were charged into the reactor, and 0.05 parts of tetrabutoxy titanium Was added and heated under a nitrogen atmosphere while controlling the temperature at 230 ° C., and the produced methanol was distilled off to conduct a transesterification reaction. Subsequently, the temperature of the reaction system was gradually raised to 255 ° C., and the pressure inside the system was reduced to 1 mmHg to carry out a polycondensation reaction to obtain a polyester. 25 parts of this polyester was dissolved in 75 parts of tetrahydrofuran, and 75 parts of water was dropped into the resulting solution under high-speed stirring at 10,000 rpm to obtain a milky white dispersion. Then, this dispersion was subjected to a reduced pressure of 20 mmHg. Distillation was performed, and tetrahydrofuran was distilled off to obtain an aqueous dispersion of polyester having a solid content of 25% by weight.

  Next, 3 parts of sodium lauryl sulfonate as a surfactant and 181 parts of ion-exchanged water are charged into a four-necked flask and the temperature is raised to 60 ° C. in a nitrogen stream, and then 0.5% ammonium persulfate is used as a polymerization initiator. Part, 0.2 part of sodium hydrogen nitrite is added, and further monomers 30.1 parts of methyl methacrylate, 21.9 parts of 2-isopropenyl-2-oxazoline, polyethylene oxide (n = 10) methacrylic acid A mixture of 39.4 parts and 8.6 parts of acrylamide was added dropwise over 3 hours while adjusting the liquid temperature to 60 to 70 ° C. After completion of dropping, the reaction was continued with stirring while maintaining the same temperature range for 2 hours, and then cooled to obtain an acrylic aqueous dispersion having a solid content of 35% by weight.

On the other hand, 0.2% by weight of silica filler (average particle size: 100 nm) (trade name Snowtex ZL manufactured by Nissan Chemical Co., Ltd.), polyoxyethylene (n = 7) lauryl ether (Sanyo Chemical Co., Ltd.) as a wetting agent An aqueous solution containing 0.3% by weight of the trade name NAROACTY N-70) was prepared.
A coating agent A was prepared by mixing 8 parts by weight of the polyester aqueous dispersion, 7 parts by weight of the acrylic water dispersion and 85 parts by weight of the aqueous solution.

<Creation of plastic film>
Polyethylene-2,6-naphthalene dicarboxylate pellets having an intrinsic viscosity of 0.63 and containing substantially no particles are dried at 170 ° C. for 6 hours, then fed to an extruder hopper, and melted at a melting temperature of 305 ° C. Then, it was filtered through a stainless steel fine wire filter having an average opening of 17 μm, extruded through a 3 mm slit die on a rotary cooling drum having a surface temperature of 60 ° C., and rapidly cooled to obtain an unstretched film. The unstretched film thus obtained was preheated at 120 ° C., and further heated by an IR heater at 850 ° C. from above 15 mm between low-speed and high-speed rolls and stretched 3.1 times in the longitudinal direction. The following coating agent A was applied on one side of the film after the longitudinal stretching with a roll coater so that the coating thickness after drying was 0.25 μm, thereby forming an easy-contact layer.

  Subsequently, it was supplied to the tenter and laterally at 140 ° C. 3. Stretched 3 times. The obtained biaxially oriented film was heat-fixed at a temperature of 245 ° C. for 5 seconds to form a film having an intrinsic viscosity of 0.58 dl / g and a thickness of 125 μm, and then the film was suspended, with a relaxation rate of 0.7%, It was heat relaxed at a temperature of 205 ° C. to obtain a plastic film.

<Formation of hard coat layer>
Using the obtained plastic film, a UV curable hard coat agent (Desolite R7501 manufactured by JSR) was applied to the easy-contact layer side so as to have a thickness of about 5 μm, and UV cured to form a hard coat layer.

<Transparent conductive layer formation>
On the surface on which the hard coat layer was formed, a transparent conductive layer made of ITO having a film thickness of 400 nm was formed by a direct current magnetron sputtering method using an ITO target (tin concentration is 10% by weight in terms of tin dioxide). Formation of the transparent conductive layer by sputtering is performed by evacuating the chamber to 5 × 10 −4 Pa before plasma discharge, and then introducing a mixed gas of argon and oxygen (oxygen concentration is 0.5% by volume) into the chamber. The pressure was 0.3 Pa, and 1000 W was applied to the ITO target. The surface resistance value of the transparent conductive layer was 15Ω / □, and the surface energy was 30.0 mN / m.

<Counter electrode formation>
1.3 g of 3,4-ethylenedioxythiophene (Baytron M V2 manufactured by Starck), 27.6 g of toluenesulfonic acid-n-butanol 40% solution (Baytron CB 40 manufactured by Bayer), imidazole (Wako Pure Chemical Industries, Ltd.) 0.9), 10 g of 10% aqueous solution of 5,4-epoxypentyltrimethoxysilane (manufactured by GE Toshiba Silicone) and 10 g of n-butanol were mixed to obtain a dispersion. This was applied to the surface of the transparent conductive layer and then dried at 110 ° C. for 10 minutes. Then, after thoroughly washing in water, the conductive polymer layer containing 18.9% of the conductive polymer and 10.7% of the fixing component concentration was formed on the transparent conductive layer by drying at 110 ° C. for 5 minutes. No peeling or the like was observed.

<Porous semiconductor layer formation>
After thoroughly stirring the titanium oxide dispersion PECC01 manufactured by Pexel Technologies, it was applied onto the transparent conductive layer using a 100 μm doctor blade. Thereafter, the porous semiconductor layer was formed by drying in the atmosphere at 150 ° C. for 5 minutes.

<Creation of dye-sensitized solar cell>
The film having the porous semiconductor layer was immersed in a 300 μM ethanol solution of ruthenium complex (Ru535bisTBA, manufactured by Solaronix) for 24 hours, and the ruthenium complex was adsorbed on the surface of the photoworking electrode to prepare a working electrode. The working electrode and the counter electrode are overlapped via a thermocompression-resistant polyethylene film frame spacer (thickness 20 μm), the spacer portion is heated to 120 ° C., and both electrodes are pressure-bonded. Further, the edge portion is sealed with an epoxy resin adhesive. After injecting an electrolyte solution (3-methoxypropionitrile solution containing 0.5% lithium iodide, 0.05M iodine, 0.5M tert-butylpyridine, 3% by weight of nylon beads having an average particle size of 20 μm) And sealed with an epoxy adhesive.

As a result of measuring IV characteristics (effective area 100 mm ² ) of the completed dye-sensitized solar cell, the open circuit voltage, short circuit current density, and fill factor were 0.73 V, 3.9 mA / cm ² , 0, respectively. As a result, the photovoltaic power generation efficiency was 1.7%.

[Example 2]
A polyester film was prepared in the same manner as in Example 1 to form a hard coat, a transparent conductive layer, and a porous semiconductor layer. When preparing the counter electrode, the same procedure was carried out except that 5 g of a 10% aqueous solution of γ-glycidoxypropyltrimethoxysilane (manufactured by Toshiba Silicone) was used as a fixing component. As the conductive polymer contained in the conductive polymer layer on the counter electrode, a conductive polymer layer containing 20.2% conductive polymer and 5.7% fixing component was formed. No peeling or the like was observed.

As a result of measuring the IV characteristics (effective area 100 mm ² ) of the dye-sensitized solar cell prepared using the same method as in Example 1, the open circuit voltage, the short-circuit current density, and the fill factor were each set to 0. 70 V, 4.2 mA / cm ² , and 0.54. As a result, the photovoltaic generation efficiency was 1.6%.

[Example 3]
A polyester film was prepared in the same manner as in Example 1 to form a hard coat, a transparent conductive layer, and a porous semiconductor layer. When creating the counter electrode, the same procedure was carried out except that 2.5 g of a 10% aqueous solution of 5,4-epoxypentyltrimethoxysilane (manufactured by Toshiba Silicone) was used as the fixing component. The conductive polymer contained in the conductive polymer layer on the counter electrode was a conductive polymer layer containing 21.0% conductive polymer and 3.0% anchoring component concentration. No peeling or the like was observed.

As a result of measuring the IV characteristics (effective area 100 mm ² ) of the dye-sensitized solar cell prepared using the same method as in Example 1, the open circuit voltage, the short-circuit current density, and the fill factor were each set to 0. 70 V, 4.2 mA / cm ² , and 0.54. As a result, the photovoltaic generation efficiency was 1.6%.

[Comparative Example 1]
A polyester film was prepared in the same manner as in Example 1 to form a hard coat, a transparent conductive layer, and a porous semiconductor layer. When creating the counter electrode, the same method was carried out except that the fixing component was not used. The obtained conductive polymer layer was peeled off due to poor adhesion to the surface of the transparent conductive layer.

  The counter electrode for a dye-sensitized solar cell of the present invention can be used as a counter electrode used for a dye-sensitized solar cell, that is, the other electrode used as a pair with one working electrode.

Claims (3)

  It consists of a transparent conductive layer provided on plastic and a conductive polymer layer provided on the transparent conductive layer, and the conductive polymer layer contains 1 to 99% by weight of a conductive polymer. The counter electrode of the dye-sensitized solar cell.   The counter electrode of the dye-sensitized solar cell according to claim 1, wherein the conductive polymer layer contains 1 to 99% by weight of the conductive polymer and 0.1 to 60% of a component for fixing the conductive polymer.   The counter electrode of the dye-sensitized solar cell according to claim 1, wherein the conductive polymer layer further contains at least one element selected from the group consisting of silicon, titanium and boron.