JP2015060820A - Dye-sensitized solar cell and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dye-sensitized solar cell in which electron conductivity of an oxide semiconductor porous film is improved by a low-temperature treatment which does not deteriorate a film substrate, and to provide a method of manufacturing the same.SOLUTION: A dye-sensitized solar cell 10 comprises: an oxide semiconductor porous film 18 composed of metal oxide nanoparticles; and a sensitizing dye adsorbed on the oxide semiconductor porous film 18. An organic π-conjugated ligand is adsorbed on at least part of junctions between the metal oxide nanoparticles.

Description

 The present invention relates to a dye-sensitized solar cell and a method for producing the same.

In order to improve the photoelectric conversion efficiency of a dye-sensitized solar cell, a technique for improving the electronic conductivity of an oxide semiconductor porous film on which a dye is adsorbed has been studied.
Conventionally, in order to improve the electronic conductivity of the oxide semiconductor porous film, the metal oxide nanoparticles constituting the oxide semiconductor porous film are treated with titanium tetrachloride (TiCl ₄ ), and the metal oxide nanoparticles are bonded to each other. A method for strengthening the bonding is disclosed (for example, see Patent Document 1).
In addition, by forming a nanocomposite in which carbon nanotubes are combined as a conductive additive (a material that assists or promotes electronic conduction) on the oxide semiconductor porous film, the electronic conductivity of the oxide semiconductor porous film Has been disclosed (for example, see Patent Document 2).

JP 2006-216513 A Special table 2012-515132 gazette

However, a porous oxide semiconductor porous film made of titanium oxide, which is generally used, is baked for several hours at a high temperature (about 450 to 600 ° C.) in order to sinter titanium oxide particles with each other in the production process. There is a need.
In the methods described in Patent Documents 1 and 2, there is a problem that the oxide semiconductor porous film cannot be formed at a low temperature (150 ° C. or lower) at which the film substrate constituting the dye-sensitized solar cell does not deteriorate. .

 The present invention has been made in view of the above circumstances, a dye-sensitized solar cell capable of low-temperature treatment without deterioration of the film base material and improved in the electronic conductivity of the oxide semiconductor porous film, and It aims at providing the manufacturing method.

[1] An oxide semiconductor porous film composed of metal oxide nanoparticles, and a sensitizing dye adsorbed on the oxide semiconductor porous film, wherein the metal oxide nanoparticles are bonded to each other. A dye-sensitized solar cell, wherein an organic π-conjugated ligand is adsorbed at least partially.
[2] The organic π-conjugated ligand is selected from the group consisting of an amino group, a mercapto group, a hydroxyl group, a carboxyl group, a phosphine group, a phosphone group, a halogen group, a selenol group, a sulfide group, and a selenoether group. The dye-sensitized solar cell according to [1], wherein the dye-sensitized solar cell has seeds or two or more substituents.
[3] The dye-sensitized solar cell according to [1] or [2], wherein the organic π-conjugated ligand is phthalocyanine.
[4] The dye-sensitized solar cell according to any one of [1] to [3], wherein the metal oxide nanoparticles are titanium oxide.
[5] The dye sensitization according to the above [4], wherein the energy difference between the LUMO level of the organic π-conjugated ligand and the conductor level of the titanium oxide is 0.4 eV or less. Solar cell.
[6] The step of adsorbing the organic π-conjugated ligand on the surface of the metal oxide nanoparticles in advance and the metal oxide nanoparticles adsorbed with the organic π-conjugated ligand are 150 ° C. or lower. A step of forming an oxide semiconductor porous film comprising the metal oxide nanoparticles and the organic π-conjugated ligand at a temperature; a step of adsorbing a sensitizing dye to the oxide semiconductor porous film; Washing the oxide semiconductor porous film, and removing the organic π-conjugated ligand that is not present at the junction between the metal oxide nanoparticles. A method for producing a dye-sensitized solar cell.
[7] The dye-sensitized solar as described in [6], wherein, in the step of forming the oxide semiconductor porous film, the oxide semiconductor porous film is formed by an aerosol deposition method. Battery manufacturing method.

 According to the present invention, the organic π-conjugated ligand is adsorbed on at least a part of the junction between the metal oxide nanoparticles constituting the oxide semiconductor porous film, so that the adjacent metal oxide nanoparticles Between these, a portion where electrons move due to the organic π-conjugated ligand is formed, so that the electron conductivity of the oxide semiconductor porous film can be improved.

It is a schematic sectional drawing which shows the dye-sensitized solar cell of this embodiment. It is the schematic diagram which expanded a part of FIG. It is a schematic block diagram which shows an example of an aerosol deposition apparatus. It is a graph which shows the measurement result of the light absorbency of a semiconductor electrode in Experimental Examples 1-3. It is a graph which shows the result of having measured the visible light transmittance | permeability of the semiconductor electrode in Experimental Examples 4-6. In Experimental Examples 7-9, it is a graph which shows the result of having measured the series resistance value of the dye-sensitized solar cell.

Embodiments of the dye-sensitized solar cell and the method for producing the same 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>
The dye-sensitized solar cell of the present embodiment includes an oxide semiconductor porous film composed of metal oxide nanoparticles, and a sensitizing dye adsorbed on the oxide semiconductor porous film. The organic π-conjugated ligand is adsorbed on at least a part of the joint between the particles.

FIG. 1 is a schematic cross-sectional view showing the dye-sensitized solar cell of the present embodiment. FIG. 2 is a schematic diagram enlarging a part of FIG.
The dye-sensitized solar cell 10 according to the present embodiment is roughly configured by a semiconductor electrode 11, a counter electrode 12, an electrolyte 13, and a sealing material 14.
The semiconductor electrode 11 includes a base material 16, a transparent conductive film 17 stacked on the base material 16, and an oxide semiconductor porous film 18 stacked on the transparent conductive film 17.
A well-known sensitizing dye is adsorbed on the surface of the oxide semiconductor porous film 18 in contact with the electrolyte 13 including the porous interior.
The counter electrode 12 includes a base material 20, a counter conductive film 21 stacked on the base material 20, and a catalyst layer 22 stacked on the counter conductive film 21.
The sealing material 14 surrounds the oxide semiconductor porous film 18 and is provided to form a solar cell power generation unit including the semiconductor electrode 11, the counter electrode 12, and the electrolyte 13. That is, a gap is formed between the semiconductor electrode 11 and the counter electrode 12 by the sealing material 14, and the electrolyte 13 is sealed in the gap.

As shown in FIG. 2, the oxide semiconductor porous film 18 is composed of a large number of metal oxide nanoparticles 31, and an organic π-conjugated ligand is formed at least at a part of the junction between the metal oxide nanoparticles 31. 32 is adsorbed.
Here, the organic π-conjugated ligand 32 is adsorbed on the joint between the metal oxide nanoparticles 31, as shown in FIG. 2, at least one of the joints between the metal oxide nanoparticles 31. This means that the organic π-conjugated ligand 32 is present in the part. That is, it means that at least a part of the adjacent metal oxide nanoparticles 31, 31 are bonded via the organic π-conjugated ligand 32.

The organic π-conjugated ligand 32 is one selected from the group consisting of an amino group, a mercapto group, a hydroxyl group, a carboxyl group, a phosphine group, a phosphone group, a halogen group, a selenol group, a sulfide group, and a selenoether group. Those having two or more kinds of substituents are used.
Examples of such an organic π-conjugated ligand 32 include phthalocyanine.
Further, as the organic π-conjugated ligand 32, porphyrin may be used.
Among these organic π-conjugated ligands 32, the phthalocyanine represented by the following formula (1) is obtained from the point that the LUMO level energy is −4.06 eV and the HOMO level energy is −6.34 eV. preferable.

 As the metal oxide nanoparticles 31 constituting the oxide semiconductor porous film 18, conventionally known materials can be applied as long as they can adsorb sensitizing dyes. Examples of the metal oxide nanoparticles 31 include titanium oxide, zinc oxide, strontium titanate, and the like. Among these metal oxide nanoparticles 31, titanium oxide is preferable because the energy difference between the LUMO level of the organic π-conjugated ligand and the conductor level of titanium oxide is 0.4 eV or less. Since the energy difference between the LUMO level of the organic π-conjugated ligand and the conductor level of titanium oxide is 0.4 eV or less, the adjacent metal oxide nanostructures are connected via the organic π-conjugated ligand 32. The electron conductivity of the particles 31, 31 is improved.

The crystal form of titanium oxide may be any of anatase type, rutile type and brookite type.
The shape of titanium oxide is not particularly limited, and examples thereof include a spherical shape or a similar shape thereof, a regular octahedral shape or a similar shape thereof, a star shape or a similar shape thereof, a needle shape, a plate shape, and a fiber shape.

 The particle size of the metal oxide nanoparticles 31 is not particularly limited, but is preferably 5 nm to 500 nm, and more preferably 10 nm to 200 nm.

 The organic π-conjugated ligand such as phthalocyanine may be used as a dye, but the sensitizing dye adsorbed on the oxide semiconductor porous film 18 is not an organic π-conjugated ligand such as phthalocyanine. Is used. Examples of such a sensitizing dye include organic dyes such as a ruthenium complex, cyanine and chlorophyll. A ruthenium complex is suitable as the sensitizing dye because it has a wide absorption wavelength range, has a long photoexcitation lifetime, and stabilizes the electrons transferred to the porous oxide semiconductor film 18. Examples of the ruthenium complex include 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 referred to as N719) and the like.

As the electrolyte 13, for example, an electrolytic solution used in a conventionally known dye-sensitized solar cell can be applied. As an electrolytic solution for a dye-sensitized solar cell, a solution obtained by dissolving a redox couple (electrolyte) in a solvent is generally used.
An organic solvent can be used as a component of the electrolyte 13. Examples of the organic solvent include alcohols, nitriles, ethers, esters, ketones, hydrocarbons, halogenated hydrocarbons, and the like.

As the alcohols, the skeleton of the chemical structure may be linear, branched or cyclic, and may be any of monohydric alcohol and polyhydric alcohol, such as methanol, ethanol, 1-propanol, 2-propanol 1-butanol, 2-methyl-1-propanol (isobutanol), 2-butanol, 2-methyl-2-propanol (tert-butanol), ethylene glycol and the like.
Examples of nitriles include acetonitrile and propionitrile.
As ethers, the skeleton of the chemical structure may be linear, branched or cyclic, and examples thereof include dimethyl ether, diethyl ether, ethyl methyl ether, and tetrahydrofuran.

Examples of the esters include ethyl acetate, propyl acetate, butyl acetate and the like.
Examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, and γ-butyrolactone.
As the hydrocarbons, the skeleton of the chemical structure may be linear, branched or cyclic, and may be any of aliphatic hydrocarbons and aromatic hydrocarbons, such as pentane, hexane, heptane, Examples include octane, cyclohexane, toluene, and xylene.
Examples of halogenated hydrocarbons include methylene chloride and chloroform.

As the redox couple dissolved in the electrolyte 13, a conventionally known redox couple can be applied.
Examples of the redox pair include a combination of iodine molecules and iodides, or a combination of bromine molecules and bromine compounds.
Preferred examples of the iodide include metal iodides such as sodium iodide (NaI) and potassium iodide (KI), or iodine salts such as tetraalkylammonium iodide, pyridinium iodide, imidazolium iodide, and the like. As mentioned.
Preferable examples of the bromide include metal bromides such as sodium bromide (NaBr) and potassium bromide (KBr), and bromine salts such as tetraalkylammonium bromide, pyridinium bromide, and imidazolium bromide.

The material of the base materials 16 and 20 constituting the semiconductor electrode 11 and the counter electrode 12 is not particularly limited, and may be any of glass, resin, and metal. A transparent conductive film or a counter conductive film may be formed on the adhesion surface of the substrate to which the curable resin composition adheres.
As the glass, those having visible light permeability are preferable, and examples thereof include soda lime glass, quartz glass, borosilicate glass, Vycor glass, alkali-free glass, blue plate glass, and white plate glass.
As the resin (plastic), those having visible light permeability are preferable, and examples thereof include polyacryl, polycarbonate, polyester, polyimide, polystyrene, polyvinyl chloride, and polyamide. Among these, polyesters, particularly polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are produced and used in large quantities as transparent heat-resistant films.
From the viewpoint of producing a thin and light flexible dye-sensitized solar cell, the base materials 16 and 20 are preferably plastic transparent base materials, and more preferably PET films or PEN films.

The transparent conductive film 17 and the counter conductive film 21 are not particularly limited, but a conductive film used in a conventionally known dye-sensitized solar cell is applicable, for example, a thin film made of a metal oxide Is mentioned.
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 Zinc (GZO), titanium oxide, etc. are mentioned. Among these, ITO with low specific resistance and high electrical conductivity, and FTO excellent in heat resistance and weather resistance are particularly preferable.

 As the material constituting the catalyst layer 22, conventionally known materials can be applied, and examples thereof include carbons such as platinum and carbon nanotubes, and conductive polymers (PEDOT / PSS etc.).

 As the material of the sealing material 14, for example, an ultraviolet curable resin, a thermosetting resin, a resin containing an ultraviolet curable resin and a thermosetting resin, etc. temporarily has fluidity and is solidified by an appropriate treatment. A resin material or the like to be used is used.

 According to the dye-sensitized solar cell 10 of the present embodiment, since the organic π-conjugated ligand 32 is interposed in at least a part of the joint portion between the metal oxide nanoparticles 31, the adjacent metal oxide nanoparticle Since a portion where electrons move due to the organic π-conjugated ligand 32 is formed between the particles 31 and 31, the electron conductivity of the oxide semiconductor porous film 18 can be improved.

<Method for producing dye-sensitized solar cell>
The method for producing a dye-sensitized solar cell according to the present embodiment includes a step of adsorbing an organic π-conjugated ligand on the surface of a metal oxide nanoparticle in advance, and a metal oxide having an organic π-conjugated ligand adsorbed. A process of forming a porous oxide semiconductor film composed of metal oxide nanoparticles and an organic π-conjugated ligand at a temperature of 150 ° C. or lower using nanoparticles, and sensitizing the porous oxide semiconductor film A step of adsorbing a dye, and a step of washing the oxide semiconductor porous membrane to remove an organic π-conjugated ligand that does not intervene at the junction between metal oxide nanoparticles. It is a method to have.
In addition, each said process is performed in the order described.

In the step of adsorbing the organic π-conjugated ligand to the surface of the metal oxide nanoparticles in advance, first, an organic π-conjugated ligand such as phthalocyanine is dissolved in an alcohol such as ethanol to obtain an organic π-conjugated system. A solution containing the ligand is prepared.
Next, the metal oxide nanoparticles are immersed in the solution, and the organic π-conjugated ligand is adsorbed on the surface of the metal oxide nanoparticles.
Next, after immersing the metal oxide nanoparticles in the solution for a predetermined time, the metal oxide nanoparticles having the organic π-conjugated ligand adsorbed are recovered from the solution.

 In the step of forming the oxide semiconductor porous film, the method of forming the oxide semiconductor porous film is not particularly limited. For example, the transparent film formed on one surface of the substrate constituting the semiconductor electrode A method of applying a paste containing metal oxide nanoparticles adsorbing an organic π-conjugated ligand on a conductive film by a printing method, or a transparent conductive film formed on one surface of a substrate constituting a semiconductor electrode An example is a method of spraying metal oxide nanoparticles on which an organic π-conjugated ligand is adsorbed.

 When forming an oxide semiconductor porous film by a printing method, a paste containing metal oxide nanoparticles adsorbing an organic π-conjugated ligand was applied to form a coating film on a transparent conductive film Thereafter, the coating film is baked at a temperature equal to or lower than the temperature at which the substrate does not deteriorate to form an oxide semiconductor porous film. The temperature below the temperature at which the base material does not deteriorate is a temperature of 150 ° C. or below when the base material is a plastic transparent base material.

 As a method for spraying metal oxide nanoparticles (hereinafter abbreviated as “spraying method”), a known method is used. For example, a thermal spraying method, a cold spray method, an aerosol deposition method (hereinafter referred to as “AD method”). For example).).

 The thermal spraying method means that a thermal spray material (in this embodiment, a metal oxide nanoparticle adsorbing an organic π-conjugated ligand) is heated and sprayed on a base material, and a thin film (in this embodiment, This is a technique for forming an oxide semiconductor porous film. A combustion flame or plasma is used as a heat source for heating the thermal spray material, and the thermal spray material made into droplets or fine particles by these heats is sprayed onto the substrate by a high-speed gas flow or the like. A thin film is formed by the sprayed material in the form of droplets or fine particles solidifying and adhering on the substrate.

 The cold spray method is a method in which a powder material (in this embodiment, a metal oxide nanoparticle adsorbed with an organic π-conjugated ligand) is collided with a base material in a solid state at a melting temperature or lower, and then on the base material. In this technique, a thin film (in this embodiment, an oxide semiconductor porous film) is formed.

With the AD method, raw material particles (in this embodiment, metal oxide nanoparticles adsorbed with an organic π-conjugated ligand) are subsonic-speeded by a carrier gas composed of an inert gas such as helium, argon, or nitrogen. It is a technique of accelerating to a supersonic speed, spraying raw material particles on a base material at high speed, joining the raw material particles and the base material, or the raw material particles to form a thin film on the base material.
At least part of the raw material particles that collide with the surface of the base material bite into the surface of the base material and are not easily peeled off. Furthermore, by continuing the spraying, another fine particle collides with the raw material particles that have digged into the surface of the base material, and a new surface is formed on the surface of the raw material particles due to the collision between the raw material particles. The raw material particles are joined to each other on the new surface. In the collision between the raw material particles, a temperature rise that causes the raw material particles to melt hardly occurs, and therefore, a grain boundary layer made of vitreous substantially does not exist at the interface where the raw material particles are joined to each other. And by continuing spraying of raw material particles, many raw material particles are gradually joined to the base material surface, and a thin film is formed. Since the formed thin film has sufficient strength, baking by baking is unnecessary.

As the AD method, for example, the ultrafine particle beam deposition method disclosed in “International Publication No. WO01 / 27348A1 pamphlet” and the brittle material ultrafine particle low temperature molding method disclosed in “Patent No. 32655481” are used. .
In these known AD methods, it is important that the raw material particles are pre-treated with a ball mill or the like so as to preliminarily apply an internal strain to the raw material particles to determine whether or not cracks will occur. By adding this internal strain, the sprayed fine particles can be easily crushed or deformed when colliding with the base material or the already deposited raw material particles, and as a result, a denser film can be formed. , And.

In forming a thin film using the AD method, an aerosol deposition apparatus (hereinafter abbreviated as “AD apparatus”) is used.
In the present embodiment, for example, an AD device 40 shown in FIG. 3 is used.
The AD apparatus 40 includes a film forming chamber 41 for accommodating a base material 61 and forming a transparent conductive layer and a photoelectric conversion layer on one surface 61a thereof.
In the film forming chamber 41, a stage 42 having an arrangement surface 42a for arranging the base material 41 is provided. The stage 42 is movable in the horizontal direction with the base material 61 disposed.
A vacuum pump 43 is connected to the film forming chamber 41. The vacuum pump 43 creates a negative pressure in the film forming chamber 41.

Further, a nozzle 44 having a rectangular opening 44 a is disposed in the film forming chamber 41. The nozzle 44 is disposed such that the opening 44 a faces the arrangement surface 42 a of the stage 42, that is, one surface 61 a of the substrate 61 arranged on the arrangement surface 42 a of the stage 42.
The nozzle 44 is connected to the gas cylinder 46 through the transport pipe 45.
A mass flow controller 47, an aerosol generator 48, a crusher 49, and a classifier 50 are provided in the middle of the transport pipe 45 in order from the gas cylinder 46 side.

In the AD device 40, the carrier gas is supplied from the gas cylinder 46 to the carrier pipe 45, and the flow rate of the carrier gas is adjusted by the mass flow controller 47.
The raw material particles for spraying are loaded into the aerosol generator 48, the raw material particles are dispersed in the carrier gas flowing in the carrier pipe 45, and the raw material particles are conveyed to the crusher 49 and the classifier 50. Then, the aerosol 71 containing the raw material particles is sprayed from the nozzle 44 onto the one surface 61 a of the substrate 61 at a subsonic to supersonic spraying speed.

Here, the details of the film forming process using the AD apparatus 40 will be described.
First, the base material 61 is arranged on the arrangement surface 42 a of the stage 42 in the film forming chamber 41.
Next, the inside of the film forming chamber 41 is set to a negative pressure by the vacuum pump 43.
Next, a carrier gas is supplied from the gas cylinder 46 into the film forming chamber 41 through the carrier pipe 45, and the inside of the film forming chamber 41 is set to a carrier gas atmosphere.

Next, the aerosol 71 containing the raw material particles is sprayed from the nozzle 44 onto the one surface 61a of the substrate 61 at a subsonic to supersonic injection speed, and a thin film (in this embodiment) is applied to the one surface 61a of the substrate 61. , A composite film composed of metal oxide nanoparticles adsorbed with an organic π-conjugated ligand).
In order to form a thin film, the raw material particles loaded in the aerosol generator 48 are dispersed in a carrier gas flowing in the carrier tube 45 and conveyed to the crusher 49 and the classifier 50. Then, the aerosol 71 containing the raw material particles is sprayed from the opening 44 a of the nozzle 44 to the one surface 61 a of the substrate 61. At this time, in order to adjust the thickness of the thin film, the number of reciprocations of the stage 42 may be adjusted as appropriate.

In the present embodiment, the raw material particles are preferably sprayed in a room temperature environment.
Here, normal temperature refers to a temperature sufficiently lower than the melting point of the raw material particles, and is substantially 200 ° C. or lower.
The temperature of the normal temperature environment is preferably equal to or lower than the melting point of the substrate 61. In particular, when the substrate 61 is made of a resin, the temperature in the normal temperature environment is preferably lower than the glass transition temperature of the substrate 61.

 In the step of adsorbing the sensitizing dye to the oxide semiconductor porous film, after forming the oxide semiconductor porous film, the oxide semiconductor porous film is immersed in a sensitizing dye solution in which the sensitizing dye is dissolved in a solvent, A sensitizing dye is supported on the oxide semiconductor porous film. The method for supporting the sensitizing dye on the oxide semiconductor porous film is not limited to the above, and the oxide semiconductor porous film is continuously charged, immersed, and pulled up while moving the oxide semiconductor porous film into the sensitizing dye solution. Methods are also adopted.

In the step of cleaning the oxide semiconductor porous membrane, after the sensitizing dye is adsorbed to the oxide semiconductor porous membrane, the oxide semiconductor porous membrane is washed with a solvent, and the organic π-conjugated ligand The thing which is not interposed in the junction part of metal oxide nanoparticles is removed.
Although it does not specifically limit as a solvent used for washing | cleaning of an oxide semiconductor porous film, For example, water, alcohol, etc. are mentioned.

 Step of adsorbing organic π-conjugated ligand on the surface of metal oxide nanoparticles described above, step of forming oxide semiconductor porous membrane, step of adsorbing sensitizing dye to oxide semiconductor porous membrane, oxidation A semiconductor electrode can be obtained through a step of cleaning the porous semiconductor porous membrane.

A counter electrode is produced separately from the semiconductor electrode.
A counter conductive film made of ITO, zinc oxide, platinum, or the like is formed on one surface of a substrate similar to that constituting the semiconductor electrode by sputtering, printing, spraying, or the like.
Further, a carbon paste or the like is formed on the surface of the counter conductive film (the surface opposite to the surface in contact with the base material in the counter conductive film) to form a catalyst layer.

 Next, an uncured sealing material is arranged in a frame shape having a predetermined width dimension on the outer peripheral portion of the surface of the semiconductor electrode facing the counter electrode, and the oxide semiconductor porous film is formed by the sealing material. Go.

 Next, the semiconductor electrode and the counter electrode are arranged to face each other, and the outer peripheral portions of the respective electrodes are bonded to each other through a sealing material to seal the semiconductor electrode and the counter electrode.

 Next, the sealing material is cured by heating, ultraviolet irradiation, or the like, and the semiconductor electrode and the counter electrode are bonded.

 Next, the liquid injection hole reaching the gap (internal space) between the semiconductor electrode and the counter electrode from the outside is removed by pulling out the liquid injection hole forming member previously protruded from the outer peripheral wall portion of the substrate of the counter electrode. Form.

 Next, the joined body formed by laminating the semiconductor electrode and the counter electrode is placed in a reduced-pressure atmosphere, the injection hole is immersed in a container (not shown) holding the electrolytic solution, and the electrolytic solution is removed by vacuuming. Inject more to fill the interior space.

After injecting the electrolytic solution, the injection hole is closed with an adhesive or the like to seal the internal space.
As described above, the semiconductor electrode and the counter electrode are disposed to be opposed to each other with a predetermined gap and bonded via the sealing material, and the gap between the electrodes is filled with the electrolyte solution. A solar cell is obtained.

 According to the method for producing a dye-sensitized solar cell of the present embodiment, the metal oxide nanoparticles having the organic π-conjugated ligand adsorbed in advance at a temperature of 150 ° C. or less and Since an oxide semiconductor porous film made of an organic π-conjugated ligand is formed, it can be applied to the production of a dye-sensitized solar cell using a resin substrate (film substrate). In addition, according to the method for manufacturing a dye-sensitized solar cell of the present embodiment, it can be applied to a method for manufacturing a dye-sensitized solar cell that does not include a heat treatment step and that uses a film forming method such as an aerosol deposition method. it can.

 Hereinafter, the present invention will be described more specifically with experimental examples, but the present invention is not limited to the following experimental examples.

[Experimental Example 1]
Using a glass substrate (manufactured by Nippon Sheet Glass Co., Ltd.) equipped with FTO as a transparent conductive layer on the surface, using a Ti-Nanoxide T / SP paste (manufactured by Solaronics) on the transparent conductive layer, by a coating method, A titanium oxide film having a thickness of 6 μm was formed and then baked at 500 ° C. for 2 hours to form a titanium oxide porous film.
Next, a 0.1 mM ethanol solution of phthalocyanine was prepared, and the titanium oxide porous membrane was immersed in the ethanol solution for 24 hours.
Then, the titanium oxide porous membrane was washed with pure water to remove phthalocyanine that was not adsorbed on the titanium oxide porous membrane, and the semiconductor electrode of Experimental Example 1 was obtained.
In order to quantitatively evaluate the amount of phthalocyanine adsorbed on the porous titanium oxide film, the semiconductor electrode was subjected to spectroscopic measurement. In the spectroscopic measurement of the semiconductor electrode, the absorbance was measured by irradiating the portion where the titanium oxide porous film was formed with light having a wavelength of 500 nm to 700 nm in the thickness direction of the semiconductor electrode. The measurement results of absorbance are shown in FIG.

[Experiment 2]
The semiconductor electrode of Experimental Example 2 was the same as Experimental Example 1 except that the titanium oxide porous film was immersed in a 0.1 mM ethanol solution of phthalocyanine for 24 hours and then the titanium oxide porous film was not washed with pure water. Got.
The obtained semiconductor electrode was subjected to spectroscopic measurement in the same manner as in Experimental Example 1. The measurement results of absorbance are shown in FIG.

[Experiment 3]
In the same manner as in Experimental Example 1, a porous titanium oxide film was formed on the transparent conductive layer of the glass substrate to obtain the semiconductor electrode of Experimental Example 3.
The obtained semiconductor electrode was subjected to spectroscopic measurement in the same manner as in Experimental Example 1. The measurement results of absorbance are shown in FIG.

From the results shown in FIG. 4, in Experimental Example 2, phthalocyanine was adsorbed on the porous titanium oxide film and was not washed with pure water, so light absorption due to phthalocyanine was observed around 650 nm.
On the other hand, in Experimental Example 1, since phthalocyanine was adsorbed on the titanium oxide porous film and washed with pure water, no light absorption due to phthalocyanine was observed in the vicinity of 650 nm as in Experimental Example 2. . Even in Experimental Example 3, since no light absorption due to phthalocyanine is observed, the amount (adsorption amount) of phthalocyanine adsorbed on the titanium oxide porous film in Experimental Example 1 is considered to be very small. Specifically, while the adsorption amount of phthalocyanine in Experimental Example 2 is 1.15 × 10 ⁻⁹ mol / cm ² , the adsorption amount of phthalocyanine in Experimental Example 1 is 1/10 or less of Experimental Example 2. 1 × 10 ⁻¹⁰ mol / cm ² or less.

[Experimental Example 4]
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.
The semiconductor electrode produced in Experimental Example 1 was immersed in this N719 dye solution for 24 hours to obtain the semiconductor electrode of Experimental Example 4.
With respect to the obtained semiconductor electrode, the visible light transmittance was measured using a transmittance photometer with an integrating sphere. Normally, “visible light” means light having a wavelength of 360 to 830 nm. The measurement result of the visible light transmittance is shown in FIG.

[Experimental Example 5]
A semiconductor electrode of Experimental Example 5 was obtained in the same manner as Experimental Example 4 except that the semiconductor electrode produced in Experimental Example 2 was used.
With respect to the obtained semiconductor electrode, the visible light transmittance was measured in the same manner as in Experimental Example 4. The measurement result of the visible light transmittance is shown in FIG.

[Experimental Example 6]
A semiconductor electrode of Experimental Example 6 was obtained in the same manner as in Experimental Example 4 except that the semiconductor electrode manufactured in Experimental Example 3 was used.
With respect to the obtained semiconductor electrode, the visible light transmittance was measured in the same manner as in Experimental Example 4. The measurement result of the visible light transmittance is shown in FIG.

 From the results of FIG. 5, it was found that when the visible light transmittances of the semiconductor electrodes of Experimental Examples 4 to 6 were compared, the visible light transmittance was not affected by the presence or absence of phthalocyanine adsorption. That is, it is considered that the visible light transmittances of the semiconductor electrodes of Experimental Examples 4 to 6 are affected by the absorption of the dye N719 but are not affected by the absorption of phthalocyanine.

[Experimental Example 7]
As a counter electrode, a glass substrate formed by laminating ITO, chromium, and platinum in this order was used.
This counter electrode and the semiconductor electrode of Experimental Example 1 were overlapped and clipped via a resin gasket (separator) having a thickness of 30 μm, and iodine: 0.05M, lithium iodide: 0.1M, 1-propyl-2,3-dimethylimidazolium iodide (DMPImI): 0.1M, tert-butylpyridine: A dye-sensitized solar cell of Experimental Example 7 by injecting an electrolyte solution of 0.6M acetonitrile solvent Got.
A voltage was applied in the dark state to the obtained dye-sensitized solar cell to measure the current, and the series resistance value (Ω) of the dye-sensitized solar cell was measured. The measurement result of the series resistance value is shown in FIG.

[Experimental Example 8]
A dye-sensitized solar cell of Experimental Example 8 was obtained in the same manner as Experimental Example 7 except that the semiconductor electrode prepared in Experimental Example 2 was used.
For the obtained dye-sensitized solar cell, the series resistance value was measured in the same manner as in Experimental Example 7. The measurement result of the series resistance value is shown in FIG.

[Experimental Example 9]
A dye-sensitized solar cell of Experimental Example 9 was obtained in the same manner as Experimental Example 7 except that the semiconductor electrode prepared in Experimental Example 3 was used.
For the obtained dye-sensitized solar cell, the series resistance value was measured in the same manner as in Experimental Example 7. The measurement result of the series resistance value is shown in FIG.

From the results shown in FIG. 6, the dye-sensitized solar was obtained when the semiconductor electrode with the phthalocyanine adsorbed in Experimental Examples 7 and 8 was used rather than the semiconductor electrode with no phthalocyanine adsorbed in Experimental Example 9. It has been found that the series resistance value of the battery decreases.
Further, comparing Experimental Example 7 and Experimental Example 8, the series resistance value of the dye-sensitized solar cell of Experimental Example 7 is higher. After adsorbing phthalocyanine, the titanium oxide porous film is washed with pure water. Therefore, it is considered that a part of the phthalocyanine contributing to the improvement of the electron conductivity has been removed.

DESCRIPTION OF SYMBOLS 10 ... Dye-sensitized solar cell, 11 ... Semiconductor electrode, 12 ... Counter electrode, 13 ... Electrolyte, 14 ... Sealing material, 16 ... Base material, 17 ... Transparent Conductive film, 18 ... porous oxide semiconductor film, 20 ... base material, 21 ... opposing conductive film, 22 ... catalyst layer, 31 ... metal oxide nanoparticles, 32 ... Organic π-conjugated ligand.

Claims (7)

An oxide semiconductor porous film composed of metal oxide nanoparticles, and a sensitizing dye adsorbed on the oxide semiconductor porous film,
A dye-sensitized solar cell, wherein an organic π-conjugated ligand is adsorbed on at least a part of a junction between the metal oxide nanoparticles.  The organic π-conjugated ligand is one or two selected from the group consisting of amino group, mercapto group, hydroxyl group, carboxyl group, phosphine group, phosphone group, halogen group, selenol group, sulfide group, and selenoether group. The dye-sensitized solar cell according to claim 1, wherein the dye-sensitized solar cell has one or more kinds of substituents.  The dye-sensitized solar cell according to claim 1 or 2, wherein the organic π-conjugated ligand is phthalocyanine.  The dye-sensitized solar cell according to any one of claims 1 to 3, wherein the metal oxide nanoparticles are titanium oxide.  5. The dye-sensitized solar cell according to claim 4, wherein an energy difference between the LUMO level of the organic π-conjugated ligand and the conductor level of the titanium oxide is 0.4 eV or less. A step of adsorbing an organic π-conjugated ligand to the surface of the metal oxide nanoparticles in advance;
A porous oxide semiconductor comprising the metal oxide nanoparticle and the organic π-conjugated ligand at a temperature of 150 ° C. or lower using the metal oxide nanoparticle adsorbed with the organic π-conjugated ligand. Forming a film;
Adsorbing a sensitizing dye to the oxide semiconductor porous membrane;
Washing the oxide semiconductor porous film, and removing the organic π-conjugated ligand that is not present at the junction between the metal oxide nanoparticles. A method for producing a dye-sensitized solar cell.  The method for producing a dye-sensitized solar cell according to claim 6, wherein, in the step of forming the oxide semiconductor porous film, the oxide semiconductor porous film is formed by an aerosol deposition method. .

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