WO2012086377A1

WO2012086377A1 - Dye-sensitized solar cell and dye-sensitized solar cell module, and processes for production of those

Info

Publication number: WO2012086377A1
Application number: PCT/JP2011/077613
Authority: WO
Inventors: 山中　良亮; 福井　篤; 古宮　良一
Original assignee: シャープ株式会社
Priority date: 2010-12-20
Filing date: 2011-11-30
Publication date: 2012-06-28

Abstract

Provided are: a dye-sensitized solar cell in which a FF, a short circuit current value and an open circuit voltage value can be improved effectively; and a dye-sensitized solar cell module. This dye-sensitized solar cell comprises a first electrode, a second electrode which is so arranged as to face the first electrode, a photoelectric conversion layer which is in contact with the first electrode, an auxiliary electrode which is arranged in the inside or on the second-electrode-side surface of the photoelectric conversion layer and is in contact with the first electrode, and a carrier transport material which is in contact with the photoelectric conversion layer, the auxiliary electrode and the second electrode, wherein the solar cell is characterized in that the auxiliary electrode comprises at least two materials.

Description

Dye-sensitized solar cell, dye-sensitized solar cell module and manufacturing method thereof

The present invention relates to a dye-sensitized solar cell, a dye-sensitized solar cell module, and a manufacturing method thereof.

As an alternative energy source to fossil fuels, solar cells that convert sunlight into electric power are attracting attention. Currently, solar cells in practical use include solar cells using crystalline silicon substrates and thin-film silicon solar cells. However, the former solar cell has a problem that the production cost of the silicon substrate is high, and the latter thin film silicon solar cell has a high production cost because it requires the use of various semiconductor production gases and complicated devices. There's a problem. For this reason, although efforts have been made to reduce the cost per power generation output by increasing the efficiency of photoelectric conversion in any of the solar cells, the above problem has not yet been solved.

Further, for example, in Japanese Patent Application Laid-Open No. 1-220380 (Patent Document 1), a dye-sensitized solar cell applying photoinduced electron transfer of a metal complex is proposed as a new type of solar cell. This dye-sensitized solar cell has a structure in which a photoelectric conversion layer that adsorbs a photosensitizing dye and has an absorption spectrum in the visible light region and an electrolytic solution are sandwiched between two glass substrates. The two glass substrates have a first electrode or a second electrode formed on their surfaces.

Then, when light is irradiated from the first electrode side, electrons are generated in the photoelectric conversion layer, and the generated electrons move from one first electrode to the opposing second electrode through the external electric circuit. The moved electrons are transported to ions in the electrolyte and return to the photoelectric conversion layer. Electrical energy can be extracted by such a series of electron movements.

Since the dye-sensitized solar cell described in Patent Document 1 has a structure in which an electrolytic solution is injected between the electrodes of two glass substrates, a small-area solar cell can be prototyped. It is difficult to produce a large-area solar cell. That is, when the area of one solar cell is increased, the generated current increases in proportion to the area, but the resistance in the in-plane direction of the first electrode increases, and accordingly, the internal series electric resistance as a solar cell increases. Increase. As a result, there arises a problem that the fill factor (FF) in the current-voltage characteristic during photoelectric conversion is lowered.

JP-A-2003-203681 (Patent Document 2) proposes a dye-sensitized solar cell in which a collecting electrode 103 is formed on a first electrode 102. FIG. 6A is a top view of the dye-sensitized solar cell of Patent Document 2, and FIG. 6B is a cross-sectional view of the dye-sensitized solar cell of Patent Document 2 taken along AA. is there.

In the dye-sensitized solar cell of Patent Document 2, a grid-like current collecting electrode 103 made of an alloy of gold and silver is formed on the first electrode 102 as shown in FIG. By forming the current collecting electrode 103, electric resistance can be reduced.

Japanese Patent Laid-Open No. 2000-243465 (Patent Document 3) discloses an attempt to reduce the current collecting resistance and increase the output current density per electrode unit area in FIGS. 7 (a) and 7 (b). The dye-sensitized solar cells shown have been proposed. FIG. 7A is a schematic cross-sectional view of the dye-sensitized solar cell shown in Patent Document 3, and FIG. 7B shows another form of the dye-sensitized solar cell shown in Patent Document 3. It is a schematic diagram.

In the dye-sensitized solar cell of Patent Document 3, as shown in FIG. 7A, a photoelectric conversion layer 203 is formed on the first electrode 201, and the photoelectric conversion layer 203 (that is, the photoelectric conversion layer 203) is formed. A collecting electrode 204 is formed on the surface opposite to the surface in contact with the first electrode 201. Further, as shown in FIG. 7B, the collecting electrode 204 is formed in a line shape. In this way, the short-circuit current density is improved by forming the collecting electrode 204 on the 5 cm square photoelectric conversion layer 203.

Japanese Patent Laid-Open No. 1-220380 JP 2003-203681 A JP 2000-243465 A

However, the dye-sensitized solar cell of Patent Document 3 has a problem that depending on the material of the current collecting electrode 204, the leakage current from the current collecting electrode 204 becomes large and the open circuit voltage decreases, resulting in an improvement in conversion efficiency. I found out there was a problem.

The present invention has been made in view of the above-described situation, and an object of the present invention is to provide a dye-sensitized solar cell and a dye that can effectively improve the FF, the short-circuit current value, and the open-circuit voltage value. It is to provide a sensitized solar cell module.

The dye-sensitized solar cell of the present invention includes a first electrode, a second electrode provided to face the first electrode, a photoelectric conversion layer in contact with the first electrode, and within the photoelectric conversion layer or photoelectric conversion. An auxiliary electrode provided on the surface of the layer on the second electrode side and in contact with the first electrode; a photoelectric conversion layer, the auxiliary electrode, and a carrier transporting material in contact with the second electrode; Including material.

The coating material preferably contains an organic substance. The metal is preferably titanium. The coating material preferably has a laminated structure of a metal oxide and an organic substance. The film thickness of the photoelectric conversion layer is preferably 8 μm or less. The dye-sensitized solar cell of the present invention preferably has a structure in which two or more photoelectric conversion layers and auxiliary electrodes are alternately laminated.

The coating material preferably has a laminated structure of a metal oxide and an organic substance constituting the auxiliary electrode. The film thickness of the photoelectric conversion layer is preferably 8 μm or less. It is preferable that the photoelectric conversion layer and the auxiliary electrode have a structure in which they are alternately stacked.

A dye-sensitized solar cell module of the present invention is a module in which a plurality of the above-described dye-sensitized solar cells are connected, and the first electrode of one dye-sensitized solar cell of the adjacent dye-sensitized solar cells and the other The second electrode of the dye-sensitized solar cell is connected in series.

A dye-sensitized solar cell module according to the present invention is obtained by connecting a plurality of the above-described dye-sensitized solar cells, the auxiliary electrode of one dye-sensitized solar cell of the adjacent dye-sensitized solar cell, and the other dye The second electrode of the sensitized solar cell is connected in series.

A method for manufacturing the above dye-sensitized solar cell module, wherein an auxiliary electrode of one dye-sensitized solar cell of adjacent dye-sensitized solar cells and a second electrode of the other dye-sensitized solar cell are connected in series And a step of forming a coating material on the surface of the auxiliary electrode in this order.

According to the present invention, it is possible to effectively improve the FF, the short-circuit current value, and the open-circuit voltage value, and provide a dye-sensitized solar cell and a dye-sensitized solar cell module with high conversion efficiency.

It is sectional drawing which shows typically an example of the structure of the dye-sensitized solar cell of this invention. It is sectional drawing which shows typically an example of the structure of the dye-sensitized solar cell of this invention. It is sectional drawing which shows typically an example of the structure of the dye-sensitized solar cell module of this invention. It is sectional drawing which shows typically an example of the structure of the dye-sensitized solar cell module of this invention. It is a graph which shows the relationship between the film thickness of a porous semiconductor at the time of forming an auxiliary electrode on the porous semiconductor consisting of a titanium oxide, and a short circuit current. (A) is a top view of the dye-sensitized solar cell module disclosed in Patent Document 2, and (b) is a cross-sectional view when the dye-sensitized solar cell module of (a) is cut along AA. is there. (A) is typical sectional drawing of the dye-sensitized solar cell shown by patent document 3, (b) is a schematic diagram of another form of the dye-sensitized solar cell shown by patent document 3. FIG. .

Hereinafter, the dye-sensitized solar cell and the dye-sensitized solar cell module according to the present invention will be described with reference to the drawings. The following embodiment is an example, and various embodiments can be implemented within the scope of the present invention. In the drawings of the present invention, the same reference numerals represent the same or corresponding parts.

<Dye-sensitized solar cell>
FIG. 1 is a cross-sectional view schematically showing an example of the structure of the dye-sensitized solar cell of the present invention. As shown in FIG. 1, the dye-sensitized solar cell 100 of the present embodiment is obtained by fixing a support body 1 and a cover body 7 with a sealing material 8, and is formed on the support body 1. A first electrode 2; a photoelectric conversion layer 3 formed on the first electrode 2; an auxiliary electrode 4 formed on the photoelectric conversion layer 3; and a first electrode provided in contact with or apart from the cover body 7. Two electrodes 9, a carrier transport material between the support 1 and the cover body 7, the photoelectric conversion layer 3, the auxiliary electrode 4, and the second electrode 9 are in contact with the carrier transport material 6, and the auxiliary electrode 4 is Contains two or more materials. As described above, when the auxiliary electrode 4 includes two or more kinds of materials, the leakage current from the auxiliary electrode 4 can be reduced, the reduction in the open-circuit voltage can be reduced, and the conversion efficiency can be improved. Below, each part which comprises the dye-sensitized solar cell 100 is demonstrated.

≪Support body≫
In the present embodiment, at least the portion of the support 1 that becomes the light receiving surface is made of a light transmissive material. However, any material can be used as long as it is a material that substantially transmits light having a wavelength that has an effective sensitivity to the dye described later, and is not necessarily transparent to light in all wavelength regions. The thickness of the support 1 is preferably about 0.2 to 5 mm.

The material constituting the support 1 is not particularly limited as long as it is generally a material that can be used for solar cells. For example, glass substrates such as soda glass, fused quartz glass, and crystal quartz glass, and flexible films A heat-resistant resin plate such as can be used. Examples of such flexible films include tetraacetyl cellulose (TAC), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polycarbonate (PC), polyarylate (PA), polyether imide (PEI), phenoxy resin, Examples include Teflon (registered trademark).

When another member is formed on the support 1 with heating, that is, for example, when a photoelectric conversion layer made of a porous semiconductor is formed on the support 1 with heating at about 250 ° C., the support 1 It is particularly preferable to use Teflon (registered trademark) having heat resistance of 250 ° C. or higher as a material constituting the material. Moreover, the support body 1 can be utilized as a base | substrate when attaching to another structure. That is, the peripheral part of the support body 1 such as a glass substrate can be easily attached to another structure using a metal processed part and a screw.

≪First electrode≫
In the present embodiment, the first electrode 2 has conductivity and is made of a light transmissive material. However, any material can be used as long as it can substantially transmit light having a wavelength having an effective sensitivity to the dye described later, and it is not necessarily required to be transparent to light in all wavelength regions. Examples of the material constituting the first electrode 2 include indium tin composite oxide (ITO), tin oxide (SnO ₂ ), tin oxide doped with fluorine (FTO), and zinc oxide (ZnO). Metals that are not corrosive to the electrolytic solution, such as titanium, nickel, and tantalum, can also be used.

The first electrode 2 can be formed on the support 1 by a known method such as a sputtering method or a spray method. The film thickness of the first electrode 2 is preferably about 0.02 to 5 μm, and the film resistance is preferably as low as possible, more preferably 40Ω / sq or less.

When using soda-lime float glass as the support 1, it is particularly preferable to use a soda-lime float glass formed on the support 1 as the first electrode 2, and a commercially available support 1 with the first electrode 2 is used. May be.

≪Photoelectric conversion layer≫
In the present embodiment, the photoelectric conversion layer 3 is made of a porous semiconductor that has adsorbed a dye. Below, the porous semiconductor and pigment | dye which comprise the photoelectric converting layer 3 are demonstrated.

(Porous semiconductor)
The kind of the porous semiconductor constituting the photoelectric conversion layer 3 is not particularly limited as long as it is generally used for a photoelectric conversion material. For example, titanium oxide, zinc oxide, tin oxide, iron oxide, niobium oxide, cerium oxide are used. Semiconductors such as tungsten oxide, barium titanate, strontium titanate, cadmium sulfide, lead sulfide, zinc sulfide, indium phosphide, copper-indium sulfide (CuInS ₂ ), CuAlO ₂ , SrCu ₂ O ₂ and combinations thereof Can be used. Among these, it is particularly preferable to use titanium oxide from the viewpoint of stability and safety.

Titanium oxides suitably used for porous semiconductors include various narrowly defined titanium oxides such as anatase type titanium oxide, rutile type titanium oxide, amorphous titanium oxide, metatitanic acid, orthotitanic acid, titanium hydroxide, and hydrous titanium oxide. These may be used alone or in combination. The two types of crystalline titanium oxide, anatase type and rutile type, can be in any form depending on the production method and thermal history, but the porous semiconductor preferably has a high content of anatase type titanium oxide, 80 More preferably, it contains at least% anatase-type titanium oxide.

The porous semiconductor may be formed of either a single crystal or a polycrystal, but is preferably a polycrystal from the viewpoints of stability, ease of crystal growth, manufacturing cost, and the like. The porous semiconductor is preferably composed of nanoscale to microscale semiconductor fine particles, and more preferably composed of titanium oxide. Such fine particles of titanium oxide can be produced by a known method such as a gas phase method or a liquid phase method (hydrothermal synthesis method, sulfuric acid method). Alternatively, a porous semiconductor may be formed by high-temperature hydrolysis of a chloride developed by Degussa.

Further, as the semiconductor fine particles constituting the porous semiconductor, semiconductor compounds having the same composition may be used, or two or more kinds of semiconductor compounds having different compositions may be mixed and used. As the particle size of the semiconductor fine particles, those having an average particle size of about 100 to 500 nm may be used, those having an average particle size of about 5 nm to 50 nm may be used, or these semiconductor fine particles may be mixed. You may use what you did. Semiconductor fine particles having a particle size of about 100 to 500 nm scatter incident light and contribute to an improvement in light capture rate. Semiconductor fine particles having an average particle size of about 5 nm to 50 nm can increase the adsorption point by increasing the adsorption point. It is thought that it contributes to the improvement.

When a porous semiconductor is formed by mixing two or more types of semiconductor fine particles having different particle sizes, the average particle size of the semiconductor fine particles having a small particle size is 10 times or more the average particle size of the semiconductor fine particles having a large particle size. It is preferable. When two or more kinds of semiconductor fine particles are mixed, it is effective to use a semiconductor compound having a strong adsorption action as a semiconductor fine particle having a small particle size.

The porous semiconductor preferably has a large surface area, for example, about 10 to 200 m ² / g.

FIG. 5 is a graph showing the relationship between the thickness of the porous semiconductor and the short-circuit current when the auxiliary electrode is formed on the porous semiconductor made of titanium oxide. From the results shown in FIG. 5, it is clear that the short-circuit current value increases when the thickness of the porous semiconductor is 8 μm or less. This is presumably because the electrons collected by the first electrode due to the resistance of the porous semiconductor can be effectively carried out by installing the auxiliary electrode. From the above results, it is derived that the porous semiconductor preferably has a film thickness of 8 μm or less.

In order to further increase the current value of the dye-sensitized solar cell, it is preferable to stack each of the porous semiconductor and the auxiliary electrode as one unit. Thereby, the electric current value of a dye-sensitized solar cell can be improved. When laminating a porous semiconductor and an auxiliary electrode, it is preferable to use a transparent oxide semiconductor such as ITO as a material to be used for the auxiliary electrode. It is preferable to consider the light transmittance by disposing the auxiliary electrode with respect to the surface.

(Dye)
The dye adsorbed on the porous semiconductor functions as a photosensitizer. In order to strongly adsorb such a dye to a porous semiconductor, a dye molecule having an interlock group such as a carboxyl group, an alkoxy group, a hydroxyl group, a sulfonic acid group, an ester group, a mercapto group, or a phosphonyl group is preferable. . Here, the interlock group is generally present when the dye is fixed to the porous semiconductor, and provides an electrical bond that facilitates the movement of electrons between the excited state dye and the semiconductor conduction band. To do.

As the dye adsorbed on the porous semiconductor, various organic dyes having absorption in the visible light region and infrared light region, metal complex dyes and the like can be used, and one or more of these dyes can be used. May be used in combination.

Examples of the organic dyes include azo dyes, quinone dyes, quinone imine dyes, quinacridone dyes, squarylium dyes, cyanine dyes, merocyanine dyes, triphenylmethane dyes, xanthene dyes, porphyrin dyes, Examples include perylene dyes, indigo dyes, and naphthalocyanine dyes. The extinction coefficient of such an organic dye is generally larger than the extinction coefficient of a metal complex dye described later.

The above-mentioned metal complex dye is one in which a transition metal is coordinated to a metal atom. Examples of such metal complex dyes include porphyrin dyes, phthalocyanine dyes, naphthalocyanine dyes, ruthenium dyes, and the like. As metal atoms constituting such a metal complex dye, Cu, Ni, Fe, Co, V, Sn, Si, Ti, Ge, Cr, Zn, Ru, Mg, Al, Pb, Mn, In, Mo, Y, Zr, Nb, Sb, La, W, Pt, Ta, Ir, Pd, Os, Ga, Tb, Eu, Rb, Bi, Se, As, Sc, Ag, Cd, Hf, Re, Au, Ac, Tc, Te, Rh, etc. can be mentioned. Among these, phthalocyanine dyes and ruthenium dyes in which a metal is coordinated are preferable, and ruthenium metal complex dyes are particularly preferable.

In particular, ruthenium-based metal complex dyes represented by the following formulas (1) to (3) are preferable. Examples of commercially available ruthenium-based metal complex dyes include trade name Ruthenium 535 dye, Ruthenium 535-bis TBA dye, Ruthenium 620-1H3TBA dye manufactured by Solaronix.

≪Auxiliary electrode≫
In the present invention, the auxiliary electrode 4 is provided together with the first electrode 2 in order to efficiently take out electrons from the photoelectric conversion layer 3. Such an auxiliary electrode 4 includes two or more kinds of materials. The auxiliary electrode 4 preferably has a coating material 5 on at least a part of its surface. The auxiliary electrode 4 is not necessarily required to have optical transparency as long as it has conductivity. For example, indium tin composite oxide (ITO), tin oxide (SnO ₂ ), tin oxide In addition to fluorine doped (FTO), zinc oxide (ZnO), etc., metals that do not corrode to the electrolyte, such as titanium, nickel, and tantalum, can also be used.

Such an auxiliary electrode 4 can be formed on the photoelectric conversion layer 3 by a known method such as sputtering or spraying. The auxiliary electrode 4 preferably has a film thickness of about 0.02 μm to 5 μm, and the lower the film resistance, the more preferably 40Ω / sq or less.

≪Coating material≫
In the present invention, the coating material 5 is preferably provided on at least a part of the surface of the auxiliary electrode 4 in order to reduce the leakage current from the auxiliary electrode 4 to the carrier transport material. Such a coating material 5 may contain a metal oxide. Examples of the metal oxide include titanium oxide, nickel oxide, tungsten oxide, tin oxide, and zinc oxide. When the auxiliary electrode 4 contains a metal such as titanium as a main component, it is preferably a metal oxide constituting the auxiliary electrode 4. Since such a metal oxide can be formed by oxidizing the auxiliary electrode 4, the manufacturing method is simple and the generation of leakage current can be effectively reduced. The coating material 5 may be made of an organic material in addition to the above oxide. Examples of organic substances include deoxycholic acid, chenodeoxycholic acid, taurodeoxycholic acid, and the like.

When the coating material 5 is made of a metal oxide constituting the auxiliary electrode 4, the thickness of the coating material 5 is preferably about 10 to 120 nm. The thickness of 10 nm or more is preferable because the leakage current from the auxiliary electrode 4 can be sufficiently reduced. If the thickness is less than 120 nm, the coating material 5 can be formed in a short time and contact with the photoelectric conversion layer. It is preferable because an oxide is hardly formed at the interface and electrons can be efficiently collected from the photoelectric conversion layer 3. When the coating material 5 consists of organic substance, it is preferable that the thickness of the coating material 5 is 1 molecule or more. This is because the organic substance can sufficiently reduce the leakage current with a thickness of about one molecule.

When the coating material 5 or the auxiliary electrode 4 has a dense film-like structure, it is preferable to form a plurality of small holes in the coating material 5 or the auxiliary electrode 4 so that the carrier transport material can easily pass therethrough. Such small holes can be formed by subjecting the auxiliary electrode 4 or the coating material 5 to physical contact or laser processing. The size of the small holes is preferably about 0.1 to 100 μm, more preferably about 1 to 50 μm. The interval between the small holes is preferably about 1 to 200 μm, and more preferably about 10 to 300 μm.

Also, the same effect can be obtained by forming a striped opening in the first electrode 2. The stripe-shaped openings are preferably spaced at an interval of about 1 μm to 200 μm, more preferably at an interval of about 10 μm to 300 μm.

≪Carrier transport material≫
In this embodiment, the carrier transport material 6 is filled in the support body 1 including the first electrode 2, the cover body 7 including the second electrode 9, the region surrounded by the sealing material 8, and the photoelectric conversion layer 3. ing. The dye-sensitized solar cell of the present invention is not limited to that shown in FIG. 1, and may have the structure of the dye-sensitized solar cell shown in FIG. In the case of the dye-sensitized solar cell shown in FIG. 2 as well, the carrier transport material includes the support 1, the cover 7 and the sealing member provided with the first electrode 2, as in the dye-sensitized solar cell shown in FIG. The region surrounded by the material 8, the photoelectric conversion layer 3, and the porous insulating layer 10 are filled.

Such a carrier transport material 6 is composed of a conductive material capable of transporting ions. As a suitable material, a liquid electrolyte, a solid electrolyte, a gel electrolyte, a molten salt gel electrolyte, or the like can be used.

The liquid electrolyte is not particularly limited as long as it is a liquid substance containing redox species, and is generally not limited as long as it is generally used in the field of solar cells. Those composed of a reducing species and a molten salt capable of dissolving the same, and those composed of a redox species, a solvent capable of dissolving the same and a molten salt can be used.

Examples of the redox species include I ⁻ / I ³⁻ series, Br ²⁻ / Br ³⁻ series, Fe 2 ⁺ / Fe ³⁺ series, and quinone / hydroquinone series. Specifically, A combination of metal iodides such as lithium iodide (LiI), sodium iodide (NaI), potassium iodide (KI), calcium iodide (CaI ₂ ) and iodine (I ₂ ), tetraethylammonium iodide (TEAI), Tetraalkylammonium iodide (TPAI), tetrabutylammonium iodide (TBAI), combinations of tetraalkylammonium salts such as tetrahexylammonium iodide (THAI) and iodine, and lithium bromide (LiBr), sodium bromide (NaBr) ), potassium bromide (KBr), calcium bromide (CaBr ₂₎ Any combination of metal bromide and bromine are preferred, among these, the combination of LiI and I ₂ is particularly preferable.

Also, examples of the solvent for the redox species include carbonate compounds such as propylene carbonate, nitrile compounds such as acetonitrile, alcohols such as ethanol, water, and aprotic polar substances. Among these, carbonate compounds and nitrile compounds are particularly preferable. Two or more of these solvents can be used in combination.

The solid electrolyte is a conductive material that can transport electrons, holes, and ions, and can be used as an electrolyte for a solar cell and has no fluidity. Specifically, hole transport materials such as polycarbazole, electron transport materials such as tetranitrofluororenone, conductive polymers such as polyroll, polymer electrolytes obtained by solidifying liquid electrolytes with polymer compounds, copper iodide, thiocyanate Examples thereof include a p-type semiconductor such as copper acid, and an electrolyte obtained by solidifying a liquid electrolyte containing a molten salt with fine particles.

Gel electrolyte usually consists of electrolyte and gelling agent. Examples of gelling agents include polymer gelation such as crosslinked polyacrylic resin derivatives, crosslinked polyacrylonitrile derivatives, polyalkylene oxide derivatives, silicone resins, and polymers having a nitrogen-containing heterocyclic quaternary compound salt structure in the side chain. Agents and the like.

The molten salt gel electrolyte is usually composed of the gel electrolyte as described above and a room temperature molten salt. Examples of the room temperature molten salt include nitrogen-containing heterocyclic quaternary ammonium salt compounds such as pyridinium salts and imidazolium salts.

∙ Additives may be added to the above electrolyte as necessary. Additives include nitrogen-containing aromatic compounds such as t-butylpyridine (TBP), dimethylpropylimidazole iodide (DMPII), methylpropylimidazole iodide (MPII), ethylmethylimidazole iodide (EMII), ethylimidazoleioio Examples thereof include imidazole salts such as dye (EII) and hexylmethylimidazole iodide (HMII).

The electrolyte concentration in the electrolyte is preferably in the range of 0.001 mol / L to 1.5 mol / L, and more preferably in the range of 0.01 mol / L to 0.7 mol / L. However, in the dye-sensitized solar cell module 200, when the cover body 7 becomes a light receiving surface, incident light reaches the photoelectric conversion layer 3 through the electrolytic solution, and carriers are excited. For this reason, the performance of the solar cell may be lowered depending on the electrolyte concentration. Therefore, it is preferable to set the electrolyte concentration in consideration of this point.

≪Second electrode≫
In the present embodiment, the second electrode 9 is not particularly limited as long as it is conductive. As the second electrode 9, for example, an n-type or p-type semiconductor, a metal such as gold, platinum, silver, copper, aluminum, indium, titanium, tantalum, or tungsten, or SnO ₂ , ITO, CuI, or ZnO is used. Can do. Further, in the present embodiment, the second electrode 9 is the same as the support 1 in which the conductive layer is formed on the surface of the insulating substrate made of glass, plastic, transparent polymer sheet or the like, that is, the first electrode 2 is formed. Can be used. A catalyst layer may be formed on the surface of the second electrode 9.

≪Catalyst layer≫
In the present embodiment, the catalyst layer (not shown) is preferably provided in contact with the second electrode 9. Such a catalyst layer is not particularly limited as long as it can transfer electrons on its surface, and any material can be used, for example, noble metal materials such as platinum and palladium, carbon black, ketjen black, and carbon nanotubes. And carbon-based materials such as fullerene.

The dye-sensitized solar cell of the present embodiment is not limited to the form shown in FIG. 1 and may have a structure shown in FIG. 2, for example. As shown in FIG. 2, when the porous insulating layer 10 is formed on the coating material 5, the second electrode 9 may be formed on the porous insulating layer 10. In that case, the following cover body 7 is installed on the second electrode 9 and a carrier transport material is injected. Below, the porous insulating layer which comprises the dye-sensitized solar cell of FIG. 2 is demonstrated.

≪Porous insulation layer≫
In the present embodiment, the porous insulating layer 10 is provided to prevent the auxiliary electrode 4 and the second electrode 9 from conducting. Examples of the material constituting the porous insulating layer 10 include silicon oxide such as niobium oxide, zirconium oxide, silica glass, and soda glass, aluminum oxide, and barium titanate. One or two of these materials are used. More than one species can be selectively used. The material used for the porous insulating layer 10 is preferably in the form of particles, and the average particle size thereof is more preferably 5 to 500 nm, still more preferably 10 to 300 nm. Further, titanium oxide or rutile type titanium oxide having a particle size of 100 nm to 500 nm can be suitably used.

≪Cover body≫
In the present embodiment, a cover body 7 that can hold the carrier transporting material 6 inside and can prevent intrusion of water or the like from the outside is used. When such a cover body 7 serves as a light receiving surface, the same light transmittance as that of the support body 1 is required, and therefore the same material as that of the support body 1 is used. Considering the case where the dye-sensitized solar cell is installed outdoors, the cover body 7 is preferably made of tempered glass or the like.

Here, it is preferable that the cover body 7 (including the case where the catalyst layer and the second electrode are formed on the surface thereof) is not in contact with the photoelectric conversion layer 3 formed on the support 1. Thereby, a sufficient amount of the carrier transport material 6 can be held inside the photoelectric conversion element. Such a cover body 7 preferably includes an injection port for injecting the carrier transport material. The carrier transport material is injected from such an injection port using a vacuum injection method or a vacuum impregnation method. Moreover, since the cover body 7 and the photoelectric conversion layer 3 formed on the support body 1 are not in contact, the injection speed when the carrier transport material is injected from the injection port can be increased. For this reason, the manufacturing tact of a photoelectric conversion element and a photoelectric conversion element module can be improved.

≪Sealing material≫
In the present embodiment, the sealing material 8 is provided to bond the support 1 and the cover 7 together. Such a sealing material 8 is preferably made of a silicone resin, an epoxy resin, a polyisobutylene-based resin, a hot-melt resin, a glass-based material, or the like, and may be a laminated structure using two or more of these.

Examples of the material constituting the sealing material 8 include a model manufactured by Three Bond, model number: 31X-101, a model manufactured by Three Bond, model number: 31X-088, and a commercially available epoxy resin. When the sealing material 8 is formed using a silicone resin, an epoxy resin, or a glass frit, it is preferably formed using a dispenser. When the sealing material 8 is formed using a hot melt resin, a sheet-like material is used. It can be formed by drilling a patterned hole in the hot melt resin.

<Dye-sensitized solar cell module>
Below, the structure of the dye-sensitized solar cell module of this embodiment is demonstrated using FIG. FIG. 3 is a cross-sectional view schematically showing an example of the dye-sensitized solar cell module of the present embodiment. As shown in FIG. 3, the dye-sensitized solar cell module 200 of the present embodiment includes a first electrode 2 formed on a support 1, a photoelectric conversion layer 3 formed on the first electrode, and a photoelectric The auxiliary electrode 4 formed on the conversion layer 3, the coating material 5 positioned on the surface of the auxiliary electrode 4, the porous insulating layer 10 formed on the coating material 5, and the porous insulating layer 10. And the second electrode 9.

Further, an inter-cell insulating portion 11 is formed on the first electrode 2, and the dye-sensitized solar cell is partitioned by the inter-cell insulating portion 11. The inter-cell insulating portion 11 will be described later. And the sealing material 8 is installed on the insulation part 11 between cells, the cover body 7 is distribute | arranged on it, and the edge part of each dye-sensitized solar cell is sealed. Although not shown, a carrier transport material 6 is injected between the first electrode 2 and the cover body 7 from an injection port formed in the cover body 7. The carrier transport material 6 is also included in the porous insulating layer 10 and the photoelectric conversion layer 3.

In the dye-sensitized solar cell module 200 of the present embodiment, as a method of connecting adjacent dye-sensitized solar cells, as shown in FIG. 3, one dye-sensitized solar cell of adjacent dye-sensitized solar cells is used. It is preferable to electrically connect the first electrode 2 and the second electrode 9 of the other dye-sensitized solar cell in series. By connecting in this way, each dye-sensitized solar cell is connected in series, and the output per unit area of a dye-sensitized solar cell module can be enlarged.

FIG. 4 is a cross-sectional view schematically showing another example of the dye-sensitized solar cell module of the present embodiment. As shown in FIG. 4, the dye-sensitized solar cell module of the present embodiment may connect adjacent dye-sensitized solar cells in series. That is, the dye-sensitized solar cell module shown in FIG. 4 includes the auxiliary electrode 4 of one dye-sensitized solar cell of the adjacent dye-sensitized solar cell and the second electrode 9 of the other dye-sensitized solar cell. They are connected in series. By connecting in this way, the non-power generation part in a light-receiving surface can be reduced, and the output per unit area of a dye-sensitized solar cell module can be enlarged.

≪Insulation between cells≫
In the present embodiment, the inter-cell insulating portion 11 is provided to electrically insulate between the dye-sensitized solar cells. Such an inter-cell insulating portion 11 needs to be a material that can electrically insulate the dye-sensitized solar cells from each other, and it is preferable to use a material that can be easily formed in a desired shape on the support 1. As a material constituting such an inter-cell insulating portion 11, an ultraviolet curable resin, a thermosetting resin, or the like can be used. For example, a silicone resin, an epoxy resin, a polyisobutylene resin, a hot melt resin, a glass material. In addition, two or more of these may be used to form a laminated structure.

However, when the photoelectric conversion layer 3 is formed after the inter-cell insulating portion 11 is formed, it is necessary to have heat resistance with respect to the temperature when the photoelectric conversion layer 3 is formed. Further, when the support 1 is used as a light receiving surface, the inter-cell insulating portion 11 is also irradiated with ultraviolet rays, and therefore, it is preferable to use a material having light resistance to ultraviolet rays. For this reason, it is preferable to use a glass-based material.

As the glass-based material used for the inter-cell insulating portion 11, for example, a commercially available glass paste or glass frit can be used. In particular, in consideration of reactivity with the carrier transport material and environmental problems, a lead-free glass-based material is preferable. Furthermore, when forming the inter-cell insulating part 11 on the support 1 made of a glass material, it is preferable to form it at a firing temperature of 550 ° C. or less. For example, a bismuth glass paste or a tin phosphate glass paste is suitably used. Can be used.

<Method for producing dye-sensitized solar cell module>
Below, each process of the manufacturing method of the dye-sensitized solar cell module 200 of FIG. 3 is demonstrated.

≪First electrode patterning≫
First, a scribe line 12 is formed by patterning a predetermined location of the first electrode 2 using a laser scribing method on the first electrode 2 formed on the support 1.

≪Formation of insulation between cells≫
The inter-cell insulating portion 11 is formed on the scribe line 12 formed as described above. The inter-cell insulating portion 11 is formed so as to divide the photoelectric conversion layer 3 to be formed later. The formation method of the inter-cell insulating part 11 is not particularly limited. For example, when the inter-cell insulating part 11 is formed using a silicone resin, an epoxy resin, or a glass-based material, a dispenser can be used. Moreover, when forming the insulation part 11 between cells using hot-melt resin, it can form by making the hole patterned in the sheet-like hot-melt resin.

≪Formation of porous semiconductor≫
A porous semiconductor constituting the photoelectric conversion layer 3 is formed on the support 1. The method for forming the porous semiconductor is not particularly limited, and a known method can be used. That is, for example, a suspension in which semiconductor fine particles are suspended in a suitable solvent is applied to a predetermined place using a known method such as a doctor blade method, a squeegee method, a spin coating method, or a screen printing method, followed by drying and baking. It is formed by performing at least one.

When it is desired to form the photoelectric conversion layer 3 in the region divided by the inter-cell insulating portion 11, the viscosity of the suspension is adjusted to be low and applied to the region divided by the inter-cell insulating portion 11 from a dispenser or the like. Is preferred. Thereby, it spreads to the edge part of the said area | region with the dead weight of a paste, and is leveled easily.

Examples of the solvent used in the suspension include glyme solvents such as ethylene glycol monomethyl ether, alcohols such as isopropyl alcohol, alcohol-based mixed solvents such as isopropyl alcohol / toluene, and water. Instead of such a suspension, a commercially available titanium oxide paste (for example, Solaronix, Ti-nanoxide, T, D, T / SP, D / SP) may be used.

A porous semiconductor is formed on the support 1 by applying the suspension thus obtained onto the first electrode 2 and then performing at least one of drying and baking. As a method for applying the suspension, known methods such as a doctor blade method, a squeegee method, a spin coating method, and a screen printing method can be used.

Here, the conditions (temperature, time, atmosphere, etc.) necessary for drying and firing the porous semiconductor may be set as appropriate according to the type of semiconductor fine particles. For example, in an air atmosphere or an inert gas atmosphere It is preferable to dry and bake at a temperature of about 50 to 800 ° C. for about 10 seconds to 12 hours. This drying and baking may be performed once at a single temperature or twice or more at different temperatures.

The porous semiconductor may be a laminate of a plurality of layers. In order to laminate the porous semiconductor, it is preferable to prepare a suspension of different semiconductor fine particles and repeat at least one of the steps of coating, drying, and baking twice or more.

After forming the porous semiconductor in this way, it is preferable to perform post-treatment in order to improve electrical connection between the semiconductor fine particles. For example, when the porous semiconductor is made of titanium oxide, the performance of the porous semiconductor can be improved by post-treatment with an aqueous titanium tetrachloride solution. Further, the surface area of the porous semiconductor may be increased, or the defect level on the semiconductor fine particles may be reduced.

≪Formation of auxiliary electrode≫
The auxiliary electrode 4 is formed on the porous semiconductor produced above (that is, the photoelectric conversion layer 3 before dye adsorption). One end of the auxiliary electrode 4 is formed up to the end of the porous semiconductor in order to contact the first electrode 2. The method for forming the auxiliary electrode 4 is not particularly limited, and for example, a known method such as a sputtering method or a spray method can be used.

≪Formation of coating material≫
Next, the coating material 5 is formed on the surface of the auxiliary electrode 4 produced as described above. The coating material 5 may be formed by oxidizing a metal constituting the auxiliary electrode, or may be formed by applying an organic substance. That is, the coating material 5 is located on the outermost surface of the auxiliary electrode. As a method of forming the coating material 5, when the auxiliary electrode 4 is made of a metal, the auxiliary electrode 4 is baked in oxygen, whereby the surface of the auxiliary electrode 4 is oxidized to form the coating material 5. Moreover, when using an organic material as the coating material 5, you may form a coating material by dipping in what dissolved organic substances, such as deoxycholic acid, in organic solvents, such as ethanol.

In addition, when producing the dye-sensitized solar cell module shown by FIG. 4, the auxiliary electrode 4 of one dye-sensitized solar cell of adjacent dye-sensitized solar cells, and the other dye-sensitized solar cell of Adjacent dye-sensitized solar cells are connected in series by contacting the second electrode 9. For this reason, it is preferable to form the coating material 5 by oxidizing the surface of the auxiliary electrode 4 after the second electrode 9 is formed, that is, after series connection is performed. Thereby, since the coating material 5 does not intervene between the auxiliary electrode 4 and the second electrode 9, there is an advantage that the series resistance is reduced.

≪Formation of porous insulating layer≫
A porous insulating layer 10 is formed on the porous semiconductor in which the auxiliary electrode 4 is formed (that is, the photoelectric conversion layer 3 before dye adsorption). Such a porous insulating layer 10 can be formed using a method similar to that of the above-described porous semiconductor. That is, the above-mentioned fine particle insulator is dispersed in a suitable solvent, and a polymer compound such as ethyl cellulose and polyethylene glycol (PEG) is further mixed to prepare a paste. The paste thus obtained is applied onto the auxiliary electrode 4, and at least one of drying and baking is performed. Thereby, the porous insulating layer 10 can be formed on the auxiliary electrode 4.

<< Formation of second electrode >>
A second electrode 9 is formed on the porous insulating layer 10. For the second electrode 9, a method similar to the method of forming the auxiliary electrode 4 can be used. When the second electrode 9 has a dense film structure, a small hole may be formed in the second electrode 9. In the dye-sensitized solar cell module shown in FIG. 3, each dye-sensitized solar cell is electrically connected in series by connecting the second electrode 9 and the first electrode 2. In the dye-sensitized solar cell module shown in FIG. 4, the dye-sensitized solar cells are electrically connected in series by connecting the second electrode 9 and the auxiliary electrode 4.

(Dye adsorption)
Next, the photoelectric converting layer 3 is produced by making a porous semiconductor adsorb | suck a pigment | dye. The method for adsorbing the dye is not particularly limited, and for example, a method of immersing the porous semiconductor in the above-described dye adsorption solution can be used. At this time, the dye adsorbing solution may be heated in order to penetrate the dye adsorbing solution to the depths of the micropores in the porous semiconductor.

The solvent for dissolving the dye is not particularly limited as long as it dissolves the dye, and examples thereof include alcohol, toluene, acetonitrile, tetrahydrofuran (THF), chloroform, dimethylformamide and the like. As the solvent, a purified one is preferably used, and two or more kinds may be mixed and used.

The concentration of the dye contained in the dye adsorption solution can be appropriately set according to the conditions such as the dye to be used, the type of solvent, the dye adsorption process, etc., but it is a high concentration to improve the adsorption function. For example, it is preferably 1 × 10 ⁻⁵ mol / L or more. In preparing the dye adsorption solution, heating may be performed to improve the solubility of the dye.

≪Formation of sealing material≫
In the present embodiment, the sealing material 8 can be formed by a method similar to the method for forming the inter-cell insulating portion 11. In particular, the sealing material 8 is preferably formed on the second electrode 9 in the dye-sensitized solar cell module of FIG. 3, and the second electrode 9 and the auxiliary electrode 4 are formed in the dye-sensitized solar cell module of FIG. It is preferable to be formed on the inter-cell insulating portion 11 so as to cover it.

≪Cover body layout≫
Next, the cover body 7 is disposed on the sealing material 8 and then the sealing material 8 is cured to fix the cover body 7 and the sealing material 8 together. The cover body 7 is formed with an injection port, and is surrounded by the support body 1, the cover body 7, the inter-cell insulating portion 11, and the sealing material 8 by injecting the carrier transport material from the injection port. The carrier transport material 6 is injected into each region to be processed.

≪Injection of carrier transport material≫
Next, the carrier transporting material 6 is injected between the support 1 and the cover body 7 from the injection port of the cover body 7. Thereby, the carrier transport material 6 is filled in the region between the support 1 and the cover body 7. The carrier transport material is also filled in the holes of the photoelectric conversion layer 3 and the porous insulating layer 10. Moreover, when the auxiliary electrode 4, the coating material 5, or the 2nd electrode 9 has a small hole, it fills also in a small diameter.

≪Final sealing≫
Finally, the carrier transport material is sealed in the cell by closing the inlet of the cover body 7 with resin. The dye-sensitized solar cell module 200 of this embodiment can be manufactured through the above steps.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. In the following, the film thickness of each layer was measured using a product name: Surfcom 1400A manufactured by Tokyo Seimitsu Co., Ltd., unless otherwise specified.

<Example 1>
In this example, the dye-sensitized solar cell shown in FIG. 1 was produced. Below, the preparation procedure is demonstrated concretely.

(Formation of porous semiconductor)
First, on a support 1 made of glass was prepared fluorine-doped TCO coated glass in which the first electrode 2 is formed consisting of SnO ₂ (manufactured by Nippon Sheet Glass Co., Ltd.). On the first electrode 2 of the glass with TCO, a titanium oxide paste (manufactured by Solaronix, trade name: Ti-Nanoxide D / SP, average particle size of 13 nm) is used by a screen printer using a 5 mm × 5 mm pattern. Applied. Then, the titanium oxide paste coating film was pre-dried at 80 ° C. for 20 minutes and then baked at 450 ° C. for 1 hour to form a porous semiconductor made of titanium oxide having a thickness of 7 μm.

(Formation of auxiliary electrode)
Next, a metal mask having an opening of 5 mm × 10 mm was prepared, and one end of the metal mask was installed so as to cover the end of the porous semiconductor. Then, with the positional relationship shown in FIG. 1, an auxiliary electrode 4 made of titanium having a film thickness of about 500 nm is deposited at an evaporation rate of 5 mm / s using an electron beam vapor deposition device (product name: ei-5, manufactured by ULVAC, Inc.). A film was formed.

Then, using a laser scribing device (manufactured by Seishin Shoji Co., Ltd.) equipped with a YAG laser (basic wavelength: 1.06 μm) as the auxiliary electrode 4, the titanium is evaporated by irradiating the laser beam, thereby obtaining a Scribe lines were produced at 100 μm intervals. Thus, the stripe-shaped auxiliary electrode 4 was formed.

(Formation of coating material)
The auxiliary electrode 4 was baked under oxygen at 450 ° C. for 30 minutes. As a result, the surface of the auxiliary electrode 4 was oxidized, and the coating material 5 was formed on the surface of the auxiliary electrode 4. When the Raman spectroscopic analysis was performed on the surface of the auxiliary electrode 4, a peak of titanium oxide was confirmed. From the result of this Raman spectroscopic analysis, it became clear that the coating material 5 was formed of titanium oxide.

(Dye adsorption)
Then, a dye (Solaronix, trade name: Ruthenium 620-1H3TBA) in a mixed solvent of 1: 1 volume ratio of acetonitrile (manufactured by Aldrich Chemical Company) and t-butyl alcohol (manufactured by Aldrich Chemical Company) at a concentration of 4 × 10. ^-4 mol / L was dissolved to obtain a dye adsorption solution.

Then, the support with a porous semiconductor produced as described above was immersed in a dye adsorption solution at 40 ° C. for 20 hours to adsorb the dye to the porous semiconductor. Thereafter, the porous semiconductor was washed with ethanol (manufactured by Aldrich Chemical Company) and dried at about 80 ° C. for about 10 minutes. In this way, the photoelectric conversion layer 3 in which the dye was adsorbed on the porous semiconductor was produced.

(Production of solar cells)
A glass similar to the glass with TCO glass used in the above support was prepared and used as the cover 7. A catalyst layer made of platinum having a thickness of 30 nm is formed on the TCO surface of the cover body 7 using an electron beam vapor deposition device (product name: ei-5, manufactured by ULVAC, Inc.) at a deposition rate of 5 mm / S. An electrode 9 was produced.

The sealing material 8 made of an ultraviolet curable resin was applied around the first electrode 2, and the cover body 7 was installed so as not to contact the second electrode 9 and the auxiliary electrode 4. And the ultraviolet curable resin was hardened by irradiating an ultraviolet-ray using the ultraviolet irradiation lamp (EFD company make, brand name: Novacure), and the cover body 7 and the support body 1 were fixed.

≪Formation of carrier transport material≫
First, an electrolyte serving as a carrier transport material was prepared. Specifically, acetonitrile as a solvent, LiI (manufactured by Aldrich Chemical Company) as a redox species has a concentration of 0.1 mol / L, I ₂ (manufactured by Tokyo Chemical Industry Co., Ltd.) has a concentration of 0.01 mol / L, and As additives, t-butylpyridine (TBP, manufactured by Aldrich Chemical Company) was dissolved to a concentration of 0.5 mol / L, and dimethylpropylimidazole iodide (DMPII, manufactured by Shikoku Kasei Kogyo Co., Ltd.) was dissolved to a concentration of 0.6 mol / L. To prepare an electrolyte.

≪Final sealing≫
Finally, after injecting the carrier transport material 6 from the injection port provided in the cover body 7, the injection port was sealed with a resin, thereby producing the dye-sensitized solar cell 100 shown in FIG.

<Example 2>
In this example, the dye-sensitized solar cell of this example was produced by the same method as in Example 1 except that three layers of porous semiconductors and auxiliary electrodes were alternately laminated. That is, the porous semiconductor (titanium oxide) of this example has a total film thickness of 18 μm, and the auxiliary electrode 4 is made of 3 ITO with a film thickness of about 600 nm in consideration of light transmittance. It was formed by laminating layers. The auxiliary electrode 4 was produced using a sputtering apparatus (ULVAC DC sputtering apparatus MLH-6300 type) at a tray speed of 10 mm / min.

The auxiliary electrode 4 having the three-layer structure as described above was immersed in an organic solvent containing deoxycholic acid for 24 hours. The organic solvent contained deoxycholic acid at a concentration of 100 mM, and ethanol was used as the solvent. Then, after the auxiliary electrode 4 was taken out from the organic solvent, ethanol was removed by evaporation at 80 ° C. for 10 minutes. Then, the dye-sensitized solar cell 100 was produced by forming the coating material 5 by the method similar to Example 1. FIG.

<Comparative Example 1>
A dye-sensitized solar cell of Comparative Example 1 was produced in the same manner as in Example 1 except that the auxiliary electrode 4 and the coating material 5 were not formed.

<Comparative Example 2>
A dye-sensitized solar cell of Comparative Example 2 was produced in the same manner as in Example 1 except that the coating material 5 was not formed with respect to Example 1.

<Comparative Example 3>
A dye-sensitized solar cell of Comparative Example 1 was produced in the same manner as in Example 2, except that the auxiliary electrode 4 and the coating material 5 were not formed.

<Example 3>
In this example, the dye-sensitized solar cell module shown in FIG. 3 was produced. Each step will be described below.

≪First electrode patterning≫
First, TCO glass (manufactured by Nippon Sheet Glass Co., Ltd.) in which the first electrode 2 made of SnO ₂ was formed on the support 1 was prepared. TCO glass having a size of 44 mm × 70 mm × thickness 1 mm was used. Then, this TCO glass is set in a laser scribing device (manufactured by Seishin Shoji Co., Ltd.) equipped with a YAG laser (fundamental wavelength: 1.06 μm), and laser light is emitted at an interval of 7.5 mm with respect to the first electrode 2. Was irradiated. As a result, the material constituting the first electrode 2 was evaporated to produce a scribe line 12 having a width of 50 μm.

≪Formation of insulation between cells≫
A screen printing plate that can be formed so that the inter-cell insulating portions 11 are arranged at intervals of 5 mm is disposed on the scribe line 12 produced above. Then, a glass paste (manufactured by Noritake Company Limited, trade name: glass paste) was applied using a screen printing machine (Neurong Seimitsu Kogyo Co., Ltd., model: LS-34TVA). And after drying this coating film for 15 minutes at 100 degreeC, it baked for 60 minutes at 500 degreeC using the baking furnace, and formed the 1 mm x 50 mmx8 micrometer strip-shaped inter-cell insulation part 11.

(Formation of porous semiconductor)
Next, a screen plate in which five openings of 5 mm × 50 mm were arranged was prepared. Then, the screen plate was set so that one of the screen plates was in contact with the inter-cell insulating portion 11, and a titanium oxide paste (manufactured by Solaronix, trade name: Ti-Nanoxide D / SP, average particle size 13 nm) was screen printed. It applied using. The coating film obtained here was preliminarily dried at 80 ° C. for 20 minutes and then baked at 450 ° C. for 1 hour to form a porous semiconductor having a thickness of 7 μm made of titanium oxide.

(Formation of auxiliary electrode)
Next, a metal mask in which five openings of 5.5 mm × 50 mm were arranged was prepared, and the metal mask was arranged so that the end of the porous semiconductor covered 0.5 mm of the opening. Then, an auxiliary electrode 4 made of titanium having a thickness of about 500 nm was formed at an evaporation rate of 5 Å / S using an electron beam evaporation device ei-5 (manufactured by ULVAC, Inc.).

Then, the auxiliary electrode 4 was irradiated with laser light at intervals of 100 mm using a laser scribing device (manufactured by Seishin Shoji Co., Ltd.) equipped with a YAG laser (basic wavelength: 1.06 μm). As a result, a part of the auxiliary electrode 4 was evaporated to prepare a scribe line having a width of 50 μm.

(Formation of porous insulating layer)
Next, zirconium oxide fine particles (particle size: 100 nm, manufactured by C.I. Kasei Co., Ltd.) were dispersed in terpineol, and ethyl cellulose was further mixed to prepare a zirconium paste. The weight ratio of the zirconium oxide fine particles, terpineol, and ethyl cellulose was 65: 30: 5.

Then, a screen printing plate in which strip shapes are arranged at 1 mm intervals so that the shape after firing is 6 mm × 50 mm × 3.5 μm is prepared, and a screen printing machine (manufactured by Neurong Precision Industry Co., Ltd., model: LS-34TVA) is prepared. ) Was applied onto the first electrode 2 and leveled at room temperature for 1 hour. After the leveling, the obtained coating film was pre-dried at 80 ° C. for 20 minutes, and then fired at 450 ° C. for 1 hour to form a porous insulating layer 10 made of zirconium oxide.

(Formation of second electrode)
Next, after forming a catalyst layer (not shown) on the porous insulating layer 10, the second electrode 9 was formed on the catalyst layer. Specifically, a metal mask in which five openings of 5 mm × 50 mm are arranged is prepared, and platinum is deposited on the porous insulating layer 10 using an electron beam vapor deposition device (manufactured by ULVAC, Inc., apparatus name: ei-5). A catalyst layer (not shown) made of platinum having a thickness of about 20 nm was formed at a deposition rate of 5 Å / S. Then, the 2nd electrode 9 was produced on the conditions similar to the conditions when forming a catalyst layer using the metal mask and electron beam vapor deposition device similar to the above. The second electrode 9 produced in this way was also formed in a stripe shape like the first electrode 2.

(Dye adsorption)
First, a dye (Solaronix, trade name: Ruthenium 620-1H3TBA) in a mixed solvent of acetonitrile (by Aldrich Chemical Company) and t-butyl alcohol (from Aldrich Chemical Company) at a volume ratio of 1: 1 with a concentration of 4 × 10. ^-4 mol / L was dissolved to obtain a dye adsorption solution.

Then, the support 1 with a porous semiconductor produced as described above was immersed in a dye adsorption solution at 40 ° C. for 20 hours to adsorb the dye to the porous semiconductor. Thereafter, the porous semiconductor was washed with ethanol (manufactured by Aldrich Chemical Company) and dried at about 80 ° C. for about 10 minutes.

≪Formation of sealing material≫
Next, after an ultraviolet curable resin (model number: 31X-101, manufactured by ThreeBond Co., Ltd.) is applied to the second electrode 9 on the inter-cell insulating portion 11, the carrier transport material 6 to be injected later flows out to the adjacent unit cell. The sealing material 8 made of an ultraviolet curable resin was also applied to the end portion of the inter-cell insulating portion 11 formed in a strip shape so as not to be present.

≪Cover body layout≫
And 38 mm x 55 mm x 1.0 mm glass was prepared as the cover body 7, and this cover body 7 was arrange | positioned on the sealing material 8, and was bonded together. The cover body was previously provided with an inlet for injecting the carrier transport material. Subsequently, the cover body was fixed by irradiating ultraviolet rays using an ultraviolet irradiation lamp (trade name: Novacure, manufactured by EFD) to cure the ultraviolet curable resin.

≪Injection of carrier transport material≫
As an additive, acetonitrile was used as a solvent, and LiI (manufactured by Aldrich Chemical Company) as a redox species had a concentration of 0.1 mol / L, and I ₂ (manufactured by Tokyo Chemical Industry Co., Ltd.) had a concentration of 0.01 mol / L. t-Butylpyridine (TBP, manufactured by Aldrich Chemical Company) was added at a concentration of 0.5 mol / L, and dimethylpropylimidazole iodide (DMPII, manufactured by Shikoku Kasei Kogyo Co., Ltd.) was added at a concentration of 0.6 mol / L and dissolved. To prepare a carrier transport material.

≪Final sealing≫
Finally, after injecting the carrier transport material from the injection port provided in the cover body, the injection port was sealed with a resin, thereby producing the dye-sensitized solar cell module 200 shown in FIG.

<Example 4>
In this example, the dye-sensitized solar cell module 200 shown in FIG. 4 was produced. In the following, the method for manufacturing the dye-sensitized solar cell module of this example will be described focusing on the differences from Example 3. First, TCO glass (manufactured by Nippon Sheet Glass Co., Ltd.) in which the first electrode 2 made of SnO ₂ was formed on the support 1 was prepared. TCO glass having a size of 34 mm × 70 mm × thickness 1 mm was used. Then, this TCO glass is set in a laser scribing device (manufactured by Seishin Shoji Co., Ltd.) equipped with a YAG laser (fundamental wavelength: 1.06 μm), and laser light is emitted at an interval of 6.5 mm with respect to the first electrode 2. Was irradiated. As a result, the material constituting the first electrode 2 was evaporated to produce a scribe line 12 having a width of 50 μm.

Thereafter, the inter-cell insulating portion 11, the porous semiconductor, and the auxiliary electrode 4 were formed in this order by the same method as in Example 3. Note that the auxiliary electrode 4 is different from the third embodiment in that the end of the auxiliary electrode 4 is also formed above the inter-cell insulating portion 11. Thereafter, the porous insulating layer 10 was formed so as to be in contact with the inter-cell insulating portion 11.

Then, by forming the second electrode 9 so as to be in contact with the auxiliary electrode 4 on the inter-cell insulating portion 11, adjacent dye-sensitized solar cells were electrically connected in series. That is, the auxiliary electrode 4 of one dye-sensitized solar cell of adjacent dye-sensitized solar cells and the second electrode 9 of the other dye-sensitized solar cell were connected in series. Thereafter, the auxiliary electrode 4 was baked under oxygen at 450 ° C. for 30 minutes to form the coating material 5 on the surface of the auxiliary electrode 4. As described above, the dye-sensitized solar cell module of this example was produced.

<Measurement of Photoelectric Conversion Efficiency of Dye-Sensitized Solar Cells of Examples 1-2 and Comparative Examples 1-3>
The dye-sensitized solar cells of Examples 1 and 2 and Comparative Examples 1 to 3 were irradiated with light having an intensity of 1 kW / m ² (AM1.5 solar simulator), and the solar cell characteristics were measured. Table 1 below shows the measurement results of the short-circuit current value, open-circuit voltage, FF, and photoelectric conversion efficiency.

<Measurement of photoelectric conversion efficiency of dye-sensitized solar cell modules of Examples 3 to 4>
The solar cell characteristics of the dye-sensitized solar cell modules of Examples 3 to 4 were measured by the same method as described above. The results are shown in Table 1.

In Table 1, when the dye-sensitized solar cells of Examples 1 and 2 are compared with the dye-sensitized solar cells of Comparative Examples 1 to 3, the coating material is provided on the surface of the auxiliary electrode. Leakage current can be prevented, and thus the solar cell characteristics can be improved.

Moreover, by comparing the dye-sensitized solar cell module of Example 3 with that of Example 4, Example 4 has a higher short-circuit current value than Example 3, and high photoelectric conversion efficiency can be obtained. It became clear. This is because, in Example 4, the auxiliary electrode 4 of one dye-sensitized solar cell of adjacent dye-sensitized solar cells and the second electrode 9 of the other dye-sensitized solar cell are connected in series. Conceivable.

Although the embodiments and examples of the present invention have been described above, it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments and examples.

It should be considered that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

The present invention can be widely used for dye-sensitized solar cells and dye-sensitized solar cell modules.

DESCRIPTION OF SYMBOLS 1 Support body, 1st electrode, 3 photoelectric conversion layer, 4 auxiliary electrode, 5 coating material, 6 carrier transport material, 7 cover body, 8 sealing material, 9 2nd electrode, 10 porous insulation layer, between 11 cells Insulating part, 12 scribe line, 100 dye-sensitized solar cell, 102 first electrode, 103 current collecting electrode, 104 photoelectric conversion layer, 200 dye sensitized solar cell module, 201 first electrode, 203 photoelectric conversion layer, 204 current collection electrode.

Claims

A first electrode;
A second electrode provided facing the first electrode;
A photoelectric conversion layer in contact with the first electrode;
An auxiliary electrode provided in the layer of the photoelectric conversion layer or on the surface of the photoelectric conversion layer on the second electrode side, and in contact with the first electrode;
A carrier transport material in contact with the photoelectric conversion layer, the auxiliary electrode, and the second electrode;
The auxiliary electrode is a dye-sensitized solar cell including two or more materials.
The dye-sensitized solar cell according to claim 1, wherein the auxiliary electrode includes a coating material and has a coating material on a part of the surface thereof.
The auxiliary electrode contains a metal as a main component,
The dye-sensitized solar cell according to claim 2, wherein the coating material includes a metal oxide.
The dye-sensitized solar cell according to claim 3, wherein the coating material includes an oxide of a metal constituting the auxiliary electrode.
The dye-sensitized solar cell according to any one of claims 2 to 4, wherein the coating material contains an organic substance.
The dye-sensitized solar cell according to any one of claims 3 to 5, wherein the metal is titanium.
The dye-sensitized solar cell according to any one of claims 2 to 6, wherein the coating material has a laminated structure of a metal oxide and an organic substance.
The dye-sensitized solar cell according to any one of claims 1 to 7, wherein the photoelectric conversion layer has a thickness of 8 袖 m or less.
The dye-sensitized solar cell according to any one of claims 1 to 8, wherein the dye-sensitized solar cell has a structure in which two or more layers of the photoelectric conversion layer and the auxiliary electrode are alternately laminated.
A dye-sensitized solar cell module in which a plurality of the dye-sensitized solar cells according to any one of claims 1 to 9 are connected,
A dye-sensitized solar cell module in which the first electrode of one dye-sensitized solar cell of the adjacent dye-sensitized solar cells and the second electrode of the other dye-sensitized solar cell are connected in series.
A dye-sensitized solar cell module in which a plurality of the dye-sensitized solar cells according to any one of claims 1 to 9 are connected,
A dye-sensitized solar cell module in which the auxiliary electrode of one dye-sensitized solar cell of the adjacent dye-sensitized solar cells and the second electrode of the other dye-sensitized solar cell are connected in series.
A method for producing a dye-sensitized solar cell module according to claim 11,
Connecting the auxiliary electrode of one dye-sensitized solar cell of the adjacent dye-sensitized solar cells and the second electrode of the other dye-sensitized solar cell in series;
And a step of forming a coating material on the surface of the auxiliary electrode in this order.