JP5162347B2 - Dye-sensitized solar cell, method for producing the same, and dye-sensitized solar cell module - Google Patents

Description

  The present invention relates to a dye-sensitized solar cell, a method for producing the same, and a dye-sensitized solar cell module including a plurality of dye-sensitized solar cells.

  Solar cells that can convert sunlight into electric power are attracting attention as an energy source to replace fossil fuels. At present, solar cells and thin-film silicon solar cells using a crystalline silicon substrate have been put into practical use. However, the former has a problem that the manufacturing cost of the silicon substrate is high, and the latter has a problem that the manufacturing cost becomes high because it is necessary to use various semiconductor manufacturing gases and complicated apparatuses. For this reason, 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, but they have not yet solved the above problem.

As a new type of solar cell, a wet solar cell using photo-induced electron transfer of a metal complex has been proposed (for example, see Patent Document 1).
In this wet solar cell, a photoelectric conversion layer having an absorption spectrum in the visible light region by adsorbing a photosensitizing dye and an electrolyte layer are sandwiched between two glass substrate electrodes having electrodes formed on the surface. It has a structure. When this wet solar cell is irradiated with light from the transparent electrode side, electrons are generated in the photoelectric conversion layer, and the generated electrons move from one electrode to the opposite electrode through an external electric circuit, and the moved electrons Is carried by the ions in the electrolyte and returns to the photoelectric conversion layer. Electrical energy is extracted by repeating such a series of electron movements.

  However, since the basic structure of the dye-sensitized solar cell described in Patent Document 1 is a structure in which an electrolytic solution is injected between the electrodes of two glass substrates, a trial production of a small-area solar cell is possible. It is difficult to apply to a solar cell having a large area such as 1 m square. 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 transparent electrode increases, and the internal series electric resistance as a solar cell increases accordingly. To do. As a result, there arises a problem that the fill factor (FF: fill factor) in the current-voltage characteristics during photoelectric conversion, and further, the short-circuit current is lowered and the photoelectric conversion efficiency is lowered.

  In order to solve the above problem, a dye-sensitized solar cell module in which a plurality of dye-sensitized solar cells are connected in series has been proposed as shown in FIG. This dye-sensitized solar cell module electrically connects an electrode (conductive layer) of a solar cell and an electrode (counter electrode) of an adjacent solar cell (see, for example, Patent Document 2).

  In this dye-sensitized solar cell module, first, a current collecting electrode 105 made of a transparent conductive film is formed in a strip shape on one glass substrate 101, and a porous oxidation in which a dye is adsorbed on the current collecting electrode 105. A photoelectric conversion layer 104 made of a titanium layer is formed, and platinum as a counter electrode 103 is formed in a strip shape on the other glass substrate 102. A plurality of dye-sensitized solar cells are formed on the same substrate by laminating the two glass substrates 101 and 102 and sealing the periphery, and injecting an electrolyte between the substrates to form the carrier transport layer 106. A dye-sensitized solar cell module in which batteries (hereinafter sometimes referred to as cells) are electrically connected in series is produced. In this case, the collector electrode 105 of one cell and the counter electrode 103 of the adjacent cell are connected by the conductive connection layer 108. In order to prevent the conductive connection layer 108 from coming into contact with the electrolytic solution, protective layers 107 are formed on both sides of the conductive connection layer 108 so as not to overlap the photoelectric conversion layer 104. Such a series connection structure is generally referred to as a Z type.

  As another Z-type dye-sensitized solar cell module, one having the structure shown in FIG. 6 can be cited (see, for example, Patent Documents 3 and 4). In this dye-sensitized solar cell module, each cell has a transparent conductive film 42 on a glass substrate 41, a photoelectric conversion layer 43 made of a porous titanium oxide layer adsorbed with the dye, a porous insulating layer 44, and a counter electrode 45. The counter electrode side is covered with a top cover 47, and an electrolyte solution 46 is injected between the top cover 47 and the glass substrate 41. In this case, the periphery of the photoelectric conversion layer 43 is covered with the porous insulating layer 44. Further, two adjacent cells are connected in series by bringing the counter electrode 45 of one cell into contact with the transparent conductive film 42 of the adjacent cell.

Japanese Patent No. 2664194 JP 2001-357897 A International Publication No. 97/16838 Pamphlet JP-A-2005-285781

  However, since the dye-sensitized solar cell module shown in FIG. 5 has a structure in which the distance between the substrates is difficult to be kept constant due to the bending of the substrates 101 and 102 generated when the area is increased, the photoelectric conversion layer 104 and the counter electrode 103 By changing the distance, the transport distance of the electrolyte changes. As a result, the performance of the single cell inside the module changes, so that the module performance deteriorates. Further, since the conductive connection portion 108 is in physical contact with the current collecting electrode 105 and the counter electrode 103, it can be said that the contact portion between each electrode and the conductive connection layer 108 is detached due to an impact or the like and is likely to fail. .

  In the dye-sensitized solar cell module shown in FIG. 6, the single-cell transparent conductive film 42 and the counter electrode 45 are formed on one substrate 41, and thus the conductive connection layer shown in FIG. 5 is omitted. Impact resistance is improved. However, since the photoelectric conversion layer 43 has a film thickness of several tens of μm, when the porous insulating layer 44 is formed using a printing method to cover the photoelectric conversion layer 43, a portion having a height difference of several tens of μm is formed. It will be printed. Therefore, it can be said that the formation of the porous insulating layer 44 is poor, particularly in the inclined portion of the photoelectric conversion layer 43, and the counter electrode 45 and the photoelectric conversion layer 43 are in contact with each other and a failure due to an internal short circuit is likely to occur. .

  Further, in the dye-sensitized solar cell module shown in FIGS. 5 and 6, since the photoelectric conversion layer is formed on the glass substrate having the transparent conductive film, the outer surface of the glass substrate becomes the light receiving surface. In addition, as the glass substrate on which the photoelectric conversion layer is formed, a glass substrate having heat resistance that can withstand high-temperature firing of the photoelectric conversion layer is used. Therefore, in the dye-sensitized solar cell module shown in FIGS. 5 and 6, it is necessary to dispose tempered glass on the light receiving surface side of the glass substrate with a transparent conductive film in order to provide sufficient strength. This increases the weight and costs of the two substrates.

  The present invention has been made in view of the above-described problems, and is a dye-sensitized solar cell that is less prone to failure, can be installed outdoors, and can be easily manufactured at low cost, its manufacturing method, and dye increase. An object is to provide a solar cell module.

Thus, according to the present invention, at least the first electrode layer, the catalyst layer, the porous insulating layer containing the carrier transport material inside, the carrier transport material inside, and the dye adsorbed on the insulating substrate. The porous semiconductor layer, the translucent second electrode layer, and the translucent cover member are laminated in this order, and the peripheral portion between the insulating substrate and the cover member is a sealing portion. A sealed dye-sensitized solar cell is provided.
According to another aspect of the present invention, at least a first electrode layer, a catalyst layer, a porous insulating layer, a porous semiconductor layer on which a dye is adsorbed, and a second electrode layer are laminated in this order on an insulating substrate. The step (1) of covering, and covering the surface of the second electrode layer with a translucent cover member, and sealing a peripheral portion between the insulating substrate and the translucent cover member with a sealing portion In the step (2), a carrier transport material is injected into an inner region between the insulating substrate and the translucent cover member, and the carrier transport material is infiltrated into the porous semiconductor layer and the porous insulating layer. The manufacturing method of a dye-sensitized solar cell provided with process (3) is provided.
Further, according to still another aspect of the present invention, two or more dye-sensitized solar cells are formed by being electrically connected in series on the same insulating substrate, and adjacent two dye-sensitized solar cells. Provided is a dye-sensitized solar cell module in which an inter-battery sealing portion is formed between batteries.

The present invention has the following effects.
(1) After forming a relatively thin laminated film (thickness of 1 μm or less) of the first electrode layer and the catalyst layer on the insulating substrate, the porous insulating layer can be formed. Therefore, the step (height difference) between the surface of the insulating substrate and the surface of the laminated film can be reduced, and even if the porous insulating layer is formed using a printing method, the porous insulating layer is formed at the stepped portion. Defects can be prevented. As a result, it is possible to provide a dye-sensitized solar cell and a module thereof in which the catalyst layer and the porous semiconductor layer are brought into contact with each other due to poor formation of the porous insulating layer and there are few failures due to an internal short circuit.

  (2) In the structure of the present invention, since the element is formed on the substrate on the non-light-receiving surface side, various materials can be used for the light-transmitting cover member on the light-receiving surface side. Therefore, when installing a dye-sensitized solar cell or its module on the roof of a general house for outdoor installation that requires high strength (for household power supply), a tempered glass whose performance deteriorates when heated is used as a translucent cover member. It is possible to use. Accordingly, it is not necessary to install tempered glass again on the light receiving surface side of the element forming substrate having the conventional structure (see FIG. 5), so that the light incident loss due to the two glass substrates is eliminated, the short circuit current is further increased, and the dye The weight of the sensitized solar cell and its module can be reduced and the cost can be reduced.

(3) In the conventional structure (see FIG. 6), since the catalyst layer is formed on the porous insulating layer, it was necessary to take measures to prevent the catalyst material from adhering to the porous semiconductor layer. In FIG. 1, since the catalyst material is directly formed on the first electrode layer on the insulating substrate side, any catalyst material can be used as long as it is bound on the first electrode layer.
(4) As the insulating substrate with the first electrode layer, titanium, nickel, tantalum on an inexpensive insulating substrate (such as a ceramic substrate) instead of expensive FTO glass in which a transparent conductive film is formed on a glass substrate. What formed the metal film which does not show corrosivity with respect to electrolyte solution etc. can be used, and the further cost reduction of a dye-sensitized solar cell (or its module) can be aimed at.

The dye-sensitized solar cell of the present invention comprises, on an insulating substrate, at least a first electrode layer, a catalyst layer, a porous insulating layer containing a carrier transport material inside, a carrier transport material inside, and a dye The adsorbed porous semiconductor layer, the translucent second electrode layer, and the translucent cover member are laminated in this order, and the peripheral portion between the insulating substrate and the cover member is a sealed portion It is sealed with.
That is, this dye-sensitized solar cell is mainly characterized in that each layer constituting the power generation element is formed in the above order on the insulating substrate.

Moreover, in this invention, the porous insulating layer may be laminated | stacked continuously on a part of insulating board | substrate from on the catalyst layer. In this way, the end portion of the catalyst layer can be reliably covered with the porous insulating layer, and the porous semiconductor layer formed on the porous insulating layer can be brought into contact with the catalyst layer to reliably cause an internal short circuit. Can be prevented.
Hereinafter, embodiments of a dye-increasing solar cell and a dye-increasing solar cell module using the dye-increasing solar cell of 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.

(Embodiment 1-1)
FIG. 1 is a schematic sectional view showing Embodiment 1-1 of the dye-sensitized solar cell of the present invention. More specifically, the dye-sensitized solar cell includes a first electrode layer 2 and a catalyst layer 3 on an insulating substrate 1, a porous insulating layer 4 containing a carrier transport material 9 inside, and a carrier transport inside. The porous semiconductor layer 5 containing the material 9 and adsorbing the dye, the second electrode layer 6 having translucency, and the cover member 7 having translucency are laminated in this order. In addition, the sealing part 8 is formed in the peripheral part of the electric power generation element part laminated | stacked from the 1st electrode layer 2 to the 2nd electrode layer 6, and the carrier transport material 9 is sealed by this.

  Further, the first electrode layer 2 has a scribe line 10 from which a part thereof is removed in an inner region in the vicinity of the sealing portion 8. Therefore, the 1st electrode layer 2 is divided | segmented into the wide part and narrow part which become a solar cell formation area on both sides of the scribe line 10. The portion exposed to the outside in the first electrode layer having a large width and the portion exposed to the outside in the first electrode layer having a small width are electrically connected to an external circuit.

The porous insulating layer 4 is formed from the catalyst layer 3 to the bottom of the scribe line (the surface of the substrate 1). Further, the second electrode layer 6 is formed from the porous semiconductor layer 5 to the narrow first electrode layer. The narrow first electrode layer that is electrically connected to the second electrode layer 6 serves as the extraction electrode 2 a of the second electrode layer 6.
In addition, each component of the dye-sensitized solar cell and the dye-sensitized solar cell module shown in FIGS. 1 to 4 is not necessarily shown in an absolute or relative scale ratio. Hereinafter, the dye-sensitized solar cell may be abbreviated as a solar cell.

  In the solar cell of Embodiment 1-1, the surface of the translucent cover member 7 can be a light receiving surface, the second electrode layer 6 is a negative electrode, and the first electrode layer 2 is a positive electrode. When light indicated by an arrow is irradiated on the light receiving surface of the translucent cover member 7, electrons are generated in the porous semiconductor layer 5, and the generated electrons move from the porous semiconductor layer 5 to the second electrode layer 6, Electrons move from the extraction electrode 2 a through the external circuit to the first electrode layer 2, and are carried by the ions in the carrier transport material 9 in the porous insulating layer 4 through the catalyst layer 3 to the porous semiconductor layer 5. Moving.

In this solar cell, the first electrode layer 2, the catalyst layer 3, the porous insulating layer 4, the porous semiconductor layer 5 on which the dye is adsorbed, and the second electrode layer 6 are laminated in this order on the insulating substrate 1. (1) and the surface of the second electrode layer 6 is covered with a translucent cover member 7, and the periphery between the insulating substrate 1 and the translucent cover member 7 is sealed with a sealing portion. In step (2), a carrier transport material 9 is injected into an inner region between the insulating substrate 1 and the translucent cover member 7, and the carrier transport material 9 is inserted into the porous semiconductor layer 5 and the porous insulating layer 4. It can manufacture by the manufacturing method of a dye-sensitized solar cell provided with the process (3) which osmose | permeates. When the second electrode layer 6 is a dense film, a plurality of small holes are formed in the second electrode layer 6 on the porous semiconductor layer 5 in the step (1).
Next, each component in this solar cell will be described.

(Insulating substrate)
The material of the insulating substrate 1 is not particularly limited as long as it is insulative and has heat resistance to the process temperature necessary when forming the porous semiconductor layer 5 and the like. Examples thereof include a glass substrate, a heat-resistant resin plate such as a flexible film, and a ceramic substrate.
For example, when the porous semiconductor layer 5 is formed, when using a porous semiconductor preparation paste containing ethyl cellulose, it is preferable to use the insulating substrate 1 having a heat resistance of about 500 ° C. Further, when the carrier transporting material 9 contains a solvent that may volatilize, it is necessary to use the insulating substrate 1 made of a material having low permeability to the solvent. Even when the insulating substrate 1 made of a material having low solvent permeability is used, one or both surfaces of the insulating substrate 1 may be coated with a film of a material having low moisture permeability such as SiO ₂ .

(First electrode layer)
The first electrode layer 2 is formed on the insulating substrate 1 and has a function of supplying electrons to the catalyst layer 3 that supplies electrons to the redox species in the carrier transport material 9.
The first electrode layer 2 is not particularly limited as long as it has conductivity, and may or may not have translucency. Examples of the material thereof include transparent conductive metal oxide. Material, metal, carbon and the like.

Examples of the transparent conductive metal oxide include ITO (indium-tin composite oxide), fluorine-doped tin oxide, boron, zinc oxide doped with gallium or aluminum, titanium oxide doped with niobium or tantalum, and the like. It is done.
Examples of the metal include gold, silver, aluminum, and indium.
Examples of the carbon include carbon black, carbon whisker, carbon nanotube, and fullerene.
As the material of the first electrode layer 2, a metal or an oxide conductive material is preferable because higher conductivity is preferable. Further, when the carrier transport material 9 contains a halogen-based redox species having high corrosivity, the first electrode layer 2 made of a refractory metal material such as corrosion-resistant Ni, Ti or Ta is used from the viewpoint of long-term stability. Is preferred.

The translucent first electrode layer 2 can be formed on the substrate 1 by a known method such as a sputtering method or a spray method, but the soda-lime float glass as the substrate 1 is used as a transparent conductive layer. You may use the commercial item of the electroconductive board | substrate which laminated | stacked FTO.
Furthermore, the first electrode layer 2 made of a metal film that does not show corrosiveness to an electrolytic solution such as titanium, nickel, or tantalum can be formed on the substrate 1 by a known method such as sputtering or vapor deposition. .
The film resistance of the first electrode layer 2 is preferably as low as possible, and particularly preferably 40Ω / sq or less. The total film thickness of the first electrode layer 2 and the catalyst layer 3 is preferably thin, and is preferably 3 μm or less from the viewpoint of preventing poor formation of the porous insulating layer 4, for example.

The first electrode layer 2 can be formed in a predetermined size by forming a pattern on the insulating substrate 1 or removing a part after forming a conductive film on the insulating substrate.
As a method for forming the pattern of the first electrode layer 2, for example, a method using a metal mask or a tape mask or a method using photolithography as used in the semiconductor field can be employed.
As a method for removing a part of the conductive film, a physical method using laser scribe or sand blaster, or a chemical method such as solution etching can be employed.

(Catalyst layer)
The catalyst layer 3 is formed on the first electrode layer 2 and has a function of promoting electron transfer to the redox species in the carrier transport material 9.
As a material of the catalyst layer 3, an organic conductive material such as a platinum group, ruthenium, a carbon-containing material, or PEDOT / PSS (H) is preferable. However, when a highly corrosive halogen-based redox species is used for the carrier transport material 9, a material with high corrosion resistance is preferable from the viewpoint of long-term stability, and platinum is used for promoting electron transfer to the redox species. It is particularly preferable to use a material containing (Pt) or ruthenium (Ru).
Examples of the carbon-containing material include carbon black, ketjen black, carbon nanotube, and fullerene.

For example, when platinum is used, the catalyst layer 3 can be formed on the first electrode layer 2 by a known method such as sputtering, thermal decomposition of chloroplatinic acid, or electrodeposition. When a carbon-containing material is used, the catalyst layer 3 can be formed by applying carbon paste dispersed in a solvent onto the first electrode layer 2 by screen printing or the like.
The form of the catalyst layer 3 is not particularly limited, and can be a dense film, a porous film, or a cluster. The shape of the catalyst layer 3 is not particularly limited, and the catalyst layer 3 may be formed on the entire surface of the first electrode layer 2 or may have a dot shape (see FIG. 2), a lattice shape, or a stripe shape. It may be formed in the part.

(Porous insulation layer)
The porous insulating layer 4 has a function of preventing physical contact and electrical connection between the catalyst layer 3 and the porous semiconductor layer 4 on which the dye is adsorbed, and a first electrode of two adjacent solar cells in the solar cell module. The function of preventing physical contact and electrical connection between the layer 2 and the second electrode layer 6; the carrier transport material 9 is impregnated inside; and the oxidation-reduction species in the carrier transport material 9 are impregnated with the catalyst layer 3 and the porous semiconductor. It has a function of moving between the layers 5. Furthermore, since light enters from the cover member 7, the porous insulating layer 4 preferably has a function of reflecting light that has passed through the porous semiconductor layer 5 having a high refractive index and adsorbed with a dye.

The porous insulating layer 4 is obtained by dispersing the material particles of the porous insulating layer 4 in a suitable solvent and further mixing a polymer compound such as ethyl cellulose and polyethylene glycol (PEG) to obtain a paste. It can be formed by covering the step portion corresponding to the thickness of the first electrode layer 2 and the catalyst layer 3 from the top of the catalyst layer 3, continuously coating the surface of the insulating substrate 1, drying and baking. it can.
At this time, as described above, by forming the total thickness of the first electrode layer 2 and the catalyst layer 3 to be 1 μm or less, the thickness of the porous insulating layer 4 at the stepped portion is reduced and the catalyst layer is reduced. The formation failure of the porous insulating layer 4 that exposes the 3rd to 1st electrode layers 2 can be prevented, and the catalyst layer 3 to the 1st electrode layer 2 come into contact with the porous semiconductor layer 5 and the inside of the solar cell. Failure caused by short-circuiting can be prevented.

As a technique for preventing physical contact between the catalyst layer 3 to the first electrode layer 2 and the porous semiconductor layer 5 with the porous insulating layer 4, it is considered that the porous insulating layer 4 is formed on the catalyst layer 3 without any gap. It is done. In this case, it is necessary to form the porous insulating layer 4 with a certain film thickness, and in some cases, it is necessary to perform the film forming process twice or more.
As a film thickness of the porous insulating layer 4, 0.1-20 micrometers is preferable and 0.5-10 micrometers is more preferable. In this case, the transport distance of the redox species in the carrier transport material 9 contained in the porous insulating layer 4 can be shortened by making the porous insulating layer 4 thinner than the porous semiconductor layer 5.

As a method for preventing the electrical connection between the catalyst layer 3 to the first electrode layer 2 and the porous semiconductor layer 5 by the porous insulating layer 4, a method using a high resistance material as a material of the porous insulating layer 4 or a contact area is used. A technique for reducing this is conceivable.
As the high resistance material, generally a high resistance metal oxide is preferable, and examples thereof include titanium oxide, niobium oxide, zirconium oxide, silicon oxide (silica glass, soda glass), aluminum oxide, and barium titanate. One or more of these materials can be selectively used. Among these, higher resistance zirconium oxide, magnesium oxide, and aluminum oxide are preferable. These materials are preferably in the form of particles, and the average primary particle size is suitably 5 to 500 nm.
Further, in the case of a technique for reducing the contact area, it is preferable to reduce the area of the film surface of the porous insulating layer 4. Specifically, it is conceivable to increase the size of the material particles of the porous insulating layer 4.
When the catalyst layer 3 is partially formed on the first electrode layer 2, both the first electrode layer 2 and the catalyst layer 3 are in physical contact with the porous semiconductor layer 5 by the porous insulating layer 4. It is necessary to avoid electrical connection.

(Porous semiconductor layer)
The porous semiconductor layer 5 is formed on the porous insulating layer 4, adsorbs a pigment, contains the carrier transport material 9, and functions as a photoelectric conversion layer.
The porous semiconductor layer 5 is composed of a semiconductor, and various forms such as a particle form and a film form can be used, but a film form is preferable.
The material constituting the porous semiconductor layer 5 is not particularly limited as long as it is generally used for a photoelectric conversion material in this field. Examples of such materials include titanium oxide, zinc oxide, tin oxide, iron oxide, niobium oxide, cerium oxide, tungsten oxide, barium titanate, strontium titanate, cadmium sulfide, lead sulfide, zinc sulfide, and indium phosphide. , Semiconductor compounds such as copper-indium sulfide (CuInS ₂ ), CuAlO ₂ , SrCu ₂ O ₂ , and combinations thereof. Among these, titanium oxide is preferable from the viewpoint of photoelectric conversion efficiency, stability, and safety.

A method for forming the film-like porous semiconductor layer 5 on the porous insulating layer 4 is not particularly limited, and a known method may be mentioned. For example, a method of applying a suspension containing semiconductor particles on the porous insulating layer 4 and performing at least one of drying and baking can be mentioned.
In this method, first, semiconductor fine particles are suspended in a suitable solvent to obtain a suspension. Examples of the semiconductor particles include commercially available single or compound semiconductor particles having an average particle size suitable, for example, an average primary particle size of about 1 nm to 500 nm. Examples of the solvent include glyme solvents such as ethylene glycol monomethyl ether, alcohols such as isopropyl alcohol, alcohol mixed solvents such as isopropyl alcohol / toluene, and water. Further, instead of such a suspension, a commercially available titanium oxide paste (eg, Solaronix, Ti-nanoxide, D, T / SP, D / SP) may be used.

Next, the obtained suspension is applied onto the porous insulating layer 4 by a known method such as a doctor blade method, a squeegee method, a spin coating method, a screen printing method, etc., and is dried by at least one of drying and baking. The semiconductor layer 5 is formed. A screen printing method using a paste is preferable from the viewpoint of thickening and manufacturing cost.
What is necessary is just to set suitably the temperature, time, atmosphere, etc. which are required for drying and baking according to the kind of semiconductor particle for formation of the porous semiconductor layer 5, for example, 50-800 under an air atmosphere or inert gas atmosphere. The range is about 10 seconds to 12 hours in the range of about ° C. This drying and baking may be performed once at a single temperature or twice or more by changing the temperature.
The porous semiconductor layer 5 may be composed of a plurality of layers. In such a case, the steps of preparing a suspension of different semiconductor particles and performing at least one of coating, drying and baking are repeated two or more times. That's fine.

After the formation of the porous semiconductor layer 5, for the purpose of improving the electrical connection between the semiconductor fine particles, increasing the surface area of the porous semiconductor layer 5, and reducing the defect level on the semiconductor fine particles, for example, the porous semiconductor layer 5 When is a titanium oxide film, it may be treated with a titanium tetrachloride aqueous solution. Various known methods can be used.
Although the film thickness of the porous semiconductor layer 5 is not specifically limited, For example, about 5-50 micrometers is preferable from a viewpoint of photoelectric conversion efficiency.
In order to improve the photoelectric conversion efficiency, it is necessary to adsorb more dye to be described later to the porous semiconductor layer 5. For this reason, the membrane-like porous semiconductor layer 5 preferably has a large specific surface area, and preferably about 10 to 200 m ² / g. In addition, the specific surface area shown in this specification is a value measured by the BET adsorption method.

(Dye)
The dye is adsorbed on the porous semiconductor layer 5 and functions as a photosensitizer.
Examples of the dye include organic dyes and metal complex dyes that absorb light in various visible light regions and / or infrared light regions. In the present invention, one or more of these dyes are selectively used. be able to.
Examples of organic dyes include azo dyes, quinone dyes, quinone imine dyes, quinacridone dyes, squarylium dyes, cyanine dyes, merocyanine dyes, triphenylmethane dyes, xanthene dyes, porphyrin dyes, and phthalocyanines. And dyes, perylene dyes, indigo dyes, naphthalocyanine dyes and the like.
As metal complex dyes, Cu, Ni, Fe, Co, V, Sn, Si, Ti, Ge, Cr, Zn, Ru, Mg, Al, Pb, Mn, In, Mo, Y, Zr, Nb, Sb, Metals such as La, W, Pt, TA, Ir, Pd, Os, Ga, Tb, Eu, Rb, Bi, Se, As, Sc, Ag, Cd, Hf, Re, Au, Ac, Tc, Te, Rh Specific examples include ruthenium metal complex dyes such as ruthenium bipyridine metal complex dyes, ruthenium terpyridine metal complex dyes, and ruthenium quarter pyridine metal complex dyes. .

  In order to firmly adsorb the dye to the porous semiconductor layer 5, an intercalation such as a carboxyl group, an alkoxy group, a hydroxyl group, a hydroxyalkyl group, a sulfonic acid group, an ester group, a mercapto group, or a phosphonyl group is contained in the dye molecule. Those having a lock group are preferred, and among these, a carboxyl group (COOH group) is particularly preferred. In general, the interlock group provides an electrical bond that facilitates electron transfer between the excited state dye and the conduction band of the porous semiconductor layer 5.

As a method for adsorbing the dye to the porous semiconductor layer 5, for example, a laminate in which the first electrode layer 2, the catalyst layer 3, the porous insulating layer 4 and the porous semiconductor layer 5 are formed on the insulating substrate 1 is used. A typical example is a method of immersing in a solution in which a dye is dissolved (dye adsorption solution). At this time, the dye adsorbing solution may be heated when the dye adsorbing solution penetrates to the back of the fine holes in the porous semiconductor layer 5.
The solvent for dissolving the dye may be any solvent that dissolves the dye. Specifically, alcohols (for example, ethanol), ketones (for example, acetone), ethers (for example, diethyl ether, tetrahydrofuran, etc.), nitrogen compounds (For example, acetonitrile), halogenated aliphatic hydrocarbon (for example, chloroform), aliphatic hydrocarbon (for example, hexane), aromatic hydrocarbon (for example, benzene), esters (for example, ethyl acetate), water, and the like. Two or more of these solvents can be used in combination.
The concentration of the dye in the solution can be appropriately adjusted depending on the kind of the dye and the solvent to be used, but is preferably as high as possible in order to improve the adsorption function, for example, 1 × 10 ⁻⁵ mol / liter. The above is preferable. In preparing the dye adsorption solution, heating may be performed to improve the solubility of the dye.

(Carrier transport material)
The carrier transport material 9 has a function of conducting ions between the porous semiconductor layer 5 on which the dye is adsorbed and the catalyst layer 3.
The carrier transport material 9 is composed of a conductive material capable of transporting ions, and for example, an ion conductor such as an electrolytic solution or a polymer electrolyte is preferable. The ion conductor preferably contains a redox species.
As the redox species, metals such as iron and cobalt, and halogen substances such as chlorine, bromine and iodine are used. When iodine is used as a redox species, it is not particularly limited as long as it can generally be used for batteries, etc. Among them, metal iodide such as lithium iodide, sodium iodide, potassium iodide, calcium iodide and iodine The combination of is most preferable. Further, an imidazole salt such as dimethylpropylimidazole iodide may be mixed.

Examples of the solvent for the electrolyte include carbonate compounds such as propylene carbonate, nitrile compounds such as acetonitrile, alcohols such as ethanol, water, aprotic polar substances, and the like. Among them, carbonate compounds and nitrile compounds are included. preferable. Two or more of these solvents can be used in combination.
On the other hand, when volatilization of the electrolytic solution becomes a problem, a molten salt may be used.
The electrolyte concentration is selected depending on various electrolytes, but is preferably in the range of 0.01 to 1.5 mol / liter.

  You may add an additive to the above-mentioned electrolyte as needed. Examples of such additives include nitrogen-containing aromatic compounds such as t-butylpyridine (TBP), dimethylpropylimidazole iodide (DMPII), methylpropylimidazole iodide (MPII), ethylmethylimidazole iodide (EMII), Examples include imidazole salts such as ethylimidazole iodide (EII) and hexylmethylimidazole iodide (HMII).

(Second electrode layer)
The second electrode layer 6 has a function of transporting electrons generated in the porous semiconductor layer 5 to which the dye is adsorbed to an external circuit, and in the solar cell module, the second electrode layer 6 is electrically connected to the first electrode layer 2 of another adjacent solar cell. Connected in series.
The second electrode layer 6 has translucency so that light incident on the cover member 7 reaches the porous semiconductor layer 5 on which the dye is adsorbed.

As the material of the second electrode layer 6, transparent materials such as indium tin composite oxide (ITO), tin oxide (SnO ₂ ), tin oxide doped with fluorine (FTO), zinc oxide (ZnO), indium oxide, etc. Alternatively, a thin film made of an opaque metal material such as aluminum, titanium, nickel, or tantalum can be used. However, when a metal material is used, there is a material that is corroded by the carrier transport material 9, and therefore, a portion that is in contact with the carrier transport material 9 may be coated with a material resistant to corrosion. An oxide transparent conductive film containing at least one of indium tin composite oxide, tin oxide, tin oxide doped with fluorine, zinc oxide, and indium oxide is preferable. With this oxide transparent conductive film, the resistance can be reduced without extremely reducing the light transmittance.
Since the second electrode layer 6 is in contact with the carrier transport material 9, it is preferable not to use a carbon-containing material or a material that promotes platinum-based redox. This is because the electrons in the second electrode layer 6 move to the redox species by the redox reaction, causing an internal short circuit.

The second electrode layer 6 can be formed on the porous insulating film 4 by a known method such as sputtering, spraying, or vapor deposition. The film thickness of the second electrode layer 6 is suitably about 0.02 to 5 μm, and the film resistance is preferably as low as possible, and particularly preferably 40Ω / sq or less.
When the second electrode layer 6 has a dense structure, it is easy to impregnate the porous semiconductor layer 5 with the dye adsorption solution (shortening the dye adsorption time), and the porous semiconductor of the carrier transport material 9 In order to facilitate the impregnation of the layer 5 and the porous insulating layer 4, the second electrode layer 6 has a plurality of small holes (not shown) penetrating from the cover member 7 side to the porous semiconductor layer 5 side. It is preferable.
The small holes can be formed by physical contact or laser processing, and laser processing is preferable because the size and distribution of the small holes can be controlled with high accuracy. The size of the small holes is preferably about 0.1 μm to 100 μm, more preferably about 1 μm to 50 μm. The distance between the small holes is preferably about 1 μm to 200 μm, and more preferably about 10 μm to 300 μm.

(Cover member)
The cover member 7 functions as a light receiving surface of the dye-sensitized solar cell.
Since the cover member 7 does not receive the heating process performed at the time of light emitting element formation, it becomes possible to use the tempered glass and the resin film whose performance deteriorates after baking as the material. In particular, in order to adapt a solar cell and a solar cell module to a building, it is important to satisfy the JIS8917A8 test. By using tempered glass as a light receiving surface, it is possible to cope with only two supports.
Thus, by using tempered glass on the light receiving surface, it is possible to reduce the weight of a single support as compared with the conventional structure while having high strength, and to reduce the cost. Can be provided.

Further, the cover member 7 may be in contact with the second electrode layer 6. This is because reduction of the material and absorption of light by the carrier transport material 9 can be reduced by reducing the carrier transport material 9 existing between them. As a result, the amount of light absorption of the porous semiconductor layer 5 on which the dye is adsorbed can be increased, and the photoelectric conversion efficiency of the dye-sensitized solar cell can be improved.
When a resin film is used as the material for the cover member 7, two resin films are arranged on the non-light-receiving surface side of the insulating substrate 1 and the light-receiving surface side of the porous semiconductor layer 5, and the outer peripheral edges are heated. By fusing, the entire solar cell can be sealed, and a sealing portion described later can be omitted.
In addition, as a material of the cover member 7, when the carrier transport material 9 includes a solvent that may be volatilized, it is necessary to select a material having low permeability to the solvent. When using a material with low solvent permeability, one or both surfaces of the cover member 7 may be coated with a material with low moisture permeability such as SiO ₂ .

(Sealing part)
The sealing portion 8 is formed in order to seal the carrier transport material 9 around the power generation element between the insulating substrate 1 and the cover member 7.
It is preferable that the sealing part 8 is not formed on the porous insulating layer 4. This is because the porous insulating layer 4 is a porous body, and the redox species in the carrier transport material 9 can move through the porous insulating layer 4. However, this is not a limitation as long as the material of the sealing portion 8 can be sufficiently permeated into the porous insulating layer 4.
The material of the sealing part 8 will not be specifically limited if it is a material which can generally be used for a solar cell and does not permeate the redox species in the carrier transport material 9. Examples of such materials include ultraviolet curable resins and thermosetting resins. Specific examples include silicone resins, epoxy resins, polyisobutylene resins, hot melt resins, and glass frit. It is also possible to form the sealing portion 8 by laminating two or more kinds of materials in two or more layers.
The sealing portion 8 between the dye-sensitized solar cells has a function of preventing the carrier transport material 9 of the adjacent dye-sensitized solar cells from contacting electrically and spatially, such as a dye-sensitized solar cell module. The peripheral sealing portion 8 has a function of holding the carrier transporting material 9.

As the ultraviolet curable resin, manufactured by ThreeBond Co., Ltd., model number: 31X-101, and as the thermosetting resin, manufactured by ThreeBond Co., Ltd., model number: 31X-088, or a commercially available epoxy resin can be used.
The sealing part 8 can be formed by using a dispenser when using a silicone resin, an epoxy resin, or a glass frit, and when using a hot melt resin, it is patterned into a sheet-like hot melt resin. It can be formed by making a hole.

(Embodiment 1-2)
FIG. 2 is a schematic cross-sectional view showing a dye-sensitized solar cell module obtained by electrically connecting a plurality of solar cells of Embodiment 1-1 in series. In FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals.

  This solar cell module is formed by electrically connecting two or more dye-sensitized solar cells on the same insulating substrate 1 in series, and the inter-cell sealing portion 18 between two adjacent solar cells. Is formed. In addition, a part of the second electrode layer 6 of any one first solar cell included in the solar cell module is the first electrode layer 2 of one second solar cell adjacent to the first dye-sensitized solar cell. A part of the porous insulating layer 4 of the first solar cell that is electrically connected is formed on at least a part of the insulating substrate 1 between the first solar cell and the second solar cell. FIG. 2 illustrates the case where the catalyst layer 3 is formed in a dot shape on the first electrode layer 2.

When manufacturing this solar cell module, first, the conductive layer formed on the substrate 1 is patterned at a predetermined interval by a laser scribing method to form a plurality of scribe lines 10 from which the conductive layer has been removed. Thereby, the some 1st electrode layer 2 electrically isolate | separated mutually is formed, and each 1st electrode layer 2 becomes a solar cell formation area.
Of the plurality of first electrode layers 2, the first electrode layer 2 on one end side in the direction orthogonal to the scribe line is formed with a small width, and on the first electrode layer 2 with the small width, No battery is formed, and the first electrode layer 2 is used as the extraction electrode 2a of the second electrode layer 5 of the adjacent solar cell.

  Next, a catalyst layer 3 is formed on each first electrode layer 2, and porous insulation is provided over a part of the bottom surface of the scribe line 10 (the surface of the substrate 1) on one end side of the first electrode layer 2 from the catalyst layer 3. Layer 4 is formed. In the case of Embodiment 1-2, the porous insulating layer is formed so that the catalyst layer 3 is formed except for the left portion of each first electrode layer 2 and covers the surface and the right end of the first electrode 2 including the catalyst layer 3. 4 is formed. At this time, the right end portion of the porous insulating layer 4 does not cover the right portion of the scribe line 10. In addition, as described above, by forming the total thickness of the first electrode layer 2 and the catalyst layer 3 to be 1 μm or less, there is a level difference between the right end of the first electrode layer 2 and the catalyst layer 3. It becomes small and the formation defect of the porous insulating layer 4 in the level | step-difference part is prevented. Therefore, at least one of the catalyst layer 3 and the first electrode layer 2 does not come into contact with the second electrode layer 6 to cause a failure due to an internal short circuit of the solar cell.

Next, the porous semiconductor layer 5 is formed on the porous insulating layer 4. In this case, the porous semiconductor layer 5 is not formed in the region of the scribe line 10 on the porous insulating layer 4.
Next, the second electrode layer 6 is formed from the porous semiconductor layer 5 to the exposed bottom surface of the scribe line 10. When the second electrode layer 6 has a dense structure, a plurality of small holes (not shown) are formed in the second electrode layer 6 according to the description in Embodiment 1-1.
Next, a sensitizing dye is adsorbed to the porous semiconductor layer 6 according to the description in Embodiment 1-1.
Subsequently, a sealing material is applied between the periphery of the first electrode layer 2 and the extraction electrode 2a and the solar cell formation region, and a transparent cover member 7 (for example, reinforced) is formed on the sealing material and the second electrode layer 6. Glass) is placed, and the sealing material is cured to form the sealing portion 8 and the inter-battery sealing portion 18. In FIG. 2, the inter-battery sealing portion 18 is formed on the exposed surfaces of the first electrode 2 and the porous insulating layer 4 of one solar cell.

Thereafter, an electrolytic solution is injected into the substrate 1 through an injection hole formed in advance, the electrolytic solution is infiltrated into the porous insulating layer 4 and the porous semiconductor layer 5, and the injection hole is sealed with a resin. Thus, a dye-sensitized solar cell module in which a plurality of dye-sensitized solar cells are electrically connected in series is completed.
In addition, the formation method of each layer which comprises this solar cell module, selection of a material, etc. can be performed according to description in Embodiment 1-1.

  In the solar cell module of Embodiment 1-2, the surface of the translucent cover member 7 is a light receiving surface, the second electrode layer 5 is a negative electrode, and the first electrode layer 2 is a positive electrode. When light indicated by an arrow is irradiated on the light receiving surface of the translucent cover member 7, electrons are generated in each porous semiconductor layer 5, and the generated electrons are transferred from each porous semiconductor layer 5 to each second electrode layer 6. Moved, moved from each second electrode layer 6 to each first electrode layer 2 of the adjacent solar cell, and the moved electrons are carried by the ions in the electrolyte in each porous insulating layer 4 through each catalyst layer 3. Then, it moves to each second electrode layer 6. In FIG. 2, the first electrode layer 2 of the left solar cell in the series connection direction and the extraction electrode 2 a of the right solar cell are electrically connected to an external circuit, so that electricity is taken out to the outside.

(Embodiment 2-1)
FIG. 3 is a schematic sectional view showing Embodiment 2-1 of the dye-sensitized solar cell of the present invention. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals.
Hereinafter, the points of the embodiment 2-1 different from the embodiment 1-1 will be mainly described.

In the solar cell of Embodiment 2-1, the porous insulating layer 4 is formed over the entire bottom surface of the scribe line 10 on the right side from the catalyst layer 3.
Further, the porous insulating layer 5 on the porous insulating layer 4 is formed even on the portion of the porous insulating layer 4 formed on the scribe line 10.
The second electrode layer 6 is formed from the porous semiconductor layer 5 to the extraction electrode 2a.
In the embodiment 2-1, the configuration other than the above-described configuration is substantially the same as the embodiment 1-1.
In the solar cell of Embodiment 2-1, as described above, the porous insulating layer 5 on the porous insulating layer 4 is formed on the portion of the porous insulating layer 4 formed on the scribe line 10. Therefore, the area of the porous semiconductor layer 5 becomes wider than that of Embodiment 1-1, and the generated current can be increased.

(Embodiment 2-2)
FIG. 4 is a schematic cross-sectional view showing a solar cell module formed by electrically connecting a plurality of the solar cells of Embodiment 2-2 in series. In FIG. 4, the same components as those in FIG. 1 are denoted by the same reference numerals.
This solar cell module is formed by electrically connecting two or more dye-sensitized solar cells on the same insulating substrate 1 in series, and the inter-cell sealing portion 18 between two adjacent solar cells. Is formed. In addition, a part of the second electrode layer 6 of any one first solar cell included in the solar cell module is the first electrode layer 2 of one second solar cell adjacent to the first dye-sensitized solar cell. Electrically connected. A part of the porous insulating layer 4 of the first solar cell is formed on the entire surface of the insulating substrate 1 between the first solar cell and the second solar cell. Furthermore, a part of the porous semiconductor layer 4 of the first solar cell is formed on a part of the porous insulating layer 4 of the first solar cell formed between the first solar cell and the adjacent second solar cell. Is formed.
FIG. 4 illustrates the case where the catalyst layer 3 is formed in a dot shape on the first electrode layer 2.

The manufacturing method of this solar cell module is the same as the manufacturing method of Embodiment 1-2 except that the porous insulating layer 4, the porous semiconductor layer 5, and the second electrode layer 6 are formed as described above.
Also in this solar cell module, when the surface of the translucent cover member 7 is irradiated with light indicated by an arrow, it operates in the same manner as in Embodiment 1-2 to generate electric power.

(Other embodiments)
In the above-described embodiment, the case where the carrier transport layer 9 is interposed between the translucent cover member 7 and the second electrode layer 6 is illustrated, but the translucent cover member 7 is connected to the second electrode layer 6. It may be provided in contact.

The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples.
The film thickness of each layer in Examples and Comparative Examples was measured using a product name: Surfcom 1400A manufactured by Tokyo Seimitsu Co., Ltd. unless otherwise specified.

Example 1
A dye-sensitized solar cell module having the structure shown in FIG. 2 was produced. The manufacturing process is shown below.
<Patterning of the first electrode layer>
A first conductive layer 2 made of SnO ₂ film is formed on an insulating substrate 1 made of glass, and a conductive glass substrate (length 60 mm × width 36 mm × thickness about 500 nm, manufactured by Nippon Sheet Glass Co., Ltd., fluorine-doped) A glass with a SnO ₂ film), and the first electrode layer 2 is irradiated with a laser beam (YAG laser, fundamental wavelength: 1.06 μm, manufactured by Saishin Shoji Co., Ltd.) to evaporate SnO ₂ and scribe with a width of 200 μm. Line 10 was formed. Four scribe lines 10 were formed at a position of 9.1 mm from the left end of the insulating substrate 1 and at intervals of 6.2 mm therefrom.

<Preparation of catalyst layer>
A screen plate in which five openings are arranged on the conductive glass substrate is prepared, and a platinum chloride paste (catalyst forming material) using a screen printing machine (manufactured by Neurong Seimitsu Co., Ltd., model: LS-34TVA) Solaronix T-Catalytic) was applied, and the resulting coating film was baked at 450 ° C. for 1 hour to form a catalyst layer 3. When the catalyst layer 3 was observed with AFM, a large number of island-shaped (dot-shaped) Pt having a height of several tens of nm and a size of about 100 nm were formed on the first electrode layer 2.

<Preparation of porous insulating layer>
Zirconium oxide fine particles were dispersed in terpineol, and ethyl cellulose was further mixed to prepare a paste.
A screen plate having five 5.2 mm × 52 mm openings is prepared, and the obtained paste is placed on the catalyst layer 3 using a screen printing machine (manufactured by Neurong Seimitsu Kogyo Co., Ltd., model: LS-34TVA). It was applied and leveled at room temperature.
Next, the obtained coating film was pre-dried and fired at 500 ° C. to form a porous insulating layer (zirconium oxide film) 4.
The porous insulating layer 4 is formed in a shape of a width of 5.2 mm, a length of 52 mm, and a film thickness of 5 μm with a position of 6.5 mm from the left end of the insulating substrate 1 as a center, and a center interval of 6 from the center. 4 pieces of the same size and film thickness were formed at 2 mm. A part of the porous insulating layer 4 was formed on a part of the insulating substrate 1 in the scribe line 10.

<Preparation of porous semiconductor layer>
A screen plate with five 5 mm x 50 mm openings is prepared, and a commercially available titanium oxide paste (manufactured by Solaronix, trade name: Ti-Nanoxide D / SP, average particle size 13 nm) is used as a screen printer (Nerong Precision Industries). It was applied using a model of LS-34TVA manufactured by Co., Ltd. and leveled at room temperature.
Next, the obtained coating film was pre-dried and then fired at 500 ° C., and this process was repeated a plurality of times to form a porous semiconductor layer (titanium oxide film) 6 having a total film thickness of 20 μm.
One porous semiconductor layer 5 is formed with a width of 5 mm and a length of 50 mm centered at a position 6.5 mm from the left end of the insulating substrate 1, and a similar size with a center interval of 6.2 mm from the center. Individually formed.

<Preparation of second electrode layer>
Prepare a metal mask with five openings, apply a coating solution, which is a material of the second electrode layer, onto the porous semiconductor 5 by spraying, dry, and calcinate to fluorinate tin oxide The 2nd electrode layer 6 which consists of was formed with a film thickness of 400 nm.
The second electrode layer 6 is formed on the catalyst layer 3 from the left end of the first electrode layer 1 in the other solar cell formation region adjacent to the porous semiconductor layer 5 in one solar cell formation region to 0.3 mm. It was formed continuously.
After the formation of the second electrode layer 6, when the resistance between the first electrode layers 2 between the solar cell formation regions was measured, it was 10 MΩ or more. From this, it is considered that an internal short circuit due to poor formation of the porous insulating layer has not occurred.

<Adsorption of sensitizing dye>
N719 (Ru535bisTBA manufactured by Solaronix) represented by the formula (1) as a sensitizing dye was dissolved in ethanol (manufactured by Aldrich Chemical Company) to a concentration of 3 × 10 ⁻⁴ mol / liter to prepare a dye solution.
Next, the laminate obtained through the above steps was immersed in a dye solution for 100 hours to adsorb the sensitizing dye to the porous semiconductor layer 5. Thereafter, the laminate was washed with ethanol (manufactured by Aldrich Chemical Company) and dried to obtain a photoelectric conversion layer.

<Preparation of redox electrolyte solution>
The redox electrolyte used as the carrier transporting material 9 is acetonitrile (made by Aldrich Chemical Company) as a solvent, lithium iodide at a concentration of 0.1 mol / liter (made by Aldrich Chemical Company), and a concentration of 0.01 mol / liter. Of iodine (manufactured by Aldrich Chemical Company), TBP at a concentration of 0.5 mol / liter (manufactured by Aldrich Chemical Company), and dimethylpropylimidazole iodide (DMPII, manufactured by Shikoku Kasei) at a concentration of 0.6 mol / liter did.

<Formation of sealing part and injection of electrolyte>
An ultraviolet curable material (manufactured by ThreeBond, model number: 31X-101) was applied between solar cell formation regions with a dispenser (ULTRASAVE manufactured by EFD), and a separately prepared glass substrate 7 and substrate 1 each having a length of 56 mm × width 32 mm. Pasted together. The substrate 1 was previously provided with electrolyte injection holes.
Next, an ultraviolet irradiation lamp (manufactured by EFD, trade name: NOVACURE) is used to irradiate the coating portion with ultraviolet rays to cure the ultraviolet curable material to form an inter-battery sealing portion 18, and two substrates 1, 7 was fixed. Thereafter, an ultraviolet curable material was similarly applied to the peripheral portions on the first electrode 2 and the extraction electrode 2a and cured to form the sealing portion 8.
Next, the redox electrolyte solution was injected from the electrolyte injection hole of the substrate 1 using the capillary effect, and the electrolyte injection hole was sealed with resin, thereby completing the solar cell module corresponding to FIG. .

When the obtained solar cell module was irradiated with light having an intensity of 1 kW / m ² (AM1.5 solar simulator) and the IV characteristics were measured, the photoelectric conversion efficiency was 4.1%.
Moreover, when the solar cell module which connected the 30 solar cells in series with the manufacturing method of Example 1 is produced, and the resistance of the 1st electrode layers 1 between solar cells is measured after formation of the 2nd electrode layer 6, it is 10 Mohm. The above is shown.

(Comparative Example 1)
A dye-sensitized solar cell module having the structure shown in FIG. 6 was produced. The manufacturing process is shown below.
<Patterning of transparent conductive film>
A transparent conductive film 42 made of SnO ₂ film is formed on an insulating substrate 41 made of glass, and a conductive glass substrate having a length of 60 mm, a width of 50 mm and a thickness of about 500 nm (made by Nippon Sheet Glass Co., Ltd., with SnO ₂ film) Glass) was prepared, and the transparent conductive film 42 was irradiated with laser light (YAG laser, fundamental wavelength: 1.06 μm, manufactured by Seishin Shoji Co., Ltd.) to evaporate SnO ₂ to form a scribe line having a width of 100 μm. Three scribe lines were formed at a position of 9.4 mm from the left end of the insulating substrate 1 and at intervals of 8 mm.

<Preparation of porous titanium oxide layer>
In forming the porous titanium oxide layer 43, first, a screen plate in which five openings of 5 mm × 50 mm are arranged is prepared, and a titanium oxide paste (made by Solaronix, trade name Ti--) is formed on the patterned transparent conductive film 42. Nanoxide D / SP, average particle size 13 nm) was applied using a screen printer. Then, it baked at 500 degreeC and formed the porous titanium oxide layer 43 with a film thickness of 15 micrometers. One porous titanium oxide layer 43 is formed with a size of 5 mm × 50 mm centered on a position 6.75 mm from the left end of the transparent substrate 41, and four with a similar size at a center interval of 8 mm from the center. did.

<Preparation of intermediate porous layer>
The intermediate porous layer 44 was formed by first preparing a screen plate with five 5.5 mm × 52 mm openings, and applying a paste material on the porous titanium oxide layer 43 using a screen printing machine. Thereafter, baking was performed at 500 ° C. to form an intermediate porous layer 44 having a thickness of 7 μm.
One porous titanium oxide layer 43 is formed with a size of 5.5 mm × 52 mm centered at a position of 6.8 mm from the left end of the transparent substrate 41, and 4 with a similar size at a center interval of 8 mm from the center. Individually formed.

<Preparation of catalyst layer and counter electrode>
A metal mask having five openings is prepared, and Pt is deposited on the intermediate porous layer 44 by using an electron beam deposition device ei-5 (manufactured by ULVAC, Inc.) at a deposition rate of 5 mm / S. A 50 nm catalyst layer 15 was formed, and a Ti conductive film 45 having a film thickness of about 200 nm was formed thereon by forming a Ti film at a deposition rate of 5 Å / S.
The catalyst layer was formed only on the intermediate porous layer 44, and the counter electrode 45 was formed on the transparent conductive film 42 adjacent to the catalyst layer.
When the resistance between solar cells was measured after vapor deposition, a part of the resistance was 1 kΩ or less. From this, it is considered that there is a possibility that an intermediate short circuit has occurred due to the formation failure of the intermediate porous layer.

<Adsorption of sensitizing dye and adjustment of electrolyte solution>
Thereafter, adsorption of the sensitizing dye and adjustment of the electrolytic solution were performed in the same manner as in Example 1.

<Formation of sealing part and injection of electrolyte>
An ultraviolet curable material (manufactured by ThreeBond, model number: 31X-101) was applied between the solar cell formation regions, and a separately prepared top cover 47 of 56 mm length × 32 mm width and the substrate 41 were bonded together. The top cover 47 was previously provided with electrolyte injection holes.
Next, an ultraviolet ray irradiation lamp (manufactured by EFD, trade name: NOVACURE) is used to irradiate the application portion with ultraviolet rays to cure the ultraviolet curable material to form an inter-battery sealing portion (not shown), and the top cover 47 A sealing portion (not shown) was formed by applying and curing an ultraviolet curable material also on the periphery of the substrate.
Next, a redox electrolyte solution was injected from the electrolyte injection hole of the top cover 47 using the capillary effect, and the electrolyte injection hole was sealed with resin, thereby completing a solar cell module corresponding to FIG. .

When the obtained solar cell module was irradiated with light (AM1.5 solar simulator) indicated by an arrow having an intensity of 1 kW / m ² to measure IV characteristics, the photoelectric conversion efficiency was 3.2%.
From this, it was found that the comparative example 1 which is the prior art has a failure due to a short circuit as compared with the example 1.

(Example 2)
A solar cell module was produced in the same manner as in Example 1 except that tempered glass (chemically tempered glass: manufactured by Nippon Sheet Glass) was used for the cover member 7.
Moreover, when the IV characteristic of the solar cell module of Example 2 was measured under the same conditions as in Example 1, the photoelectric conversion efficiency was 4.0%. In Example 2, a solar cell module having a photoelectric conversion rate comparable to that of Example 1 and having a structure using only tempered glass on the light receiving surface was obtained.

(Comparative Example 2)
A solar cell module was produced in the same manner as in Comparative Example 1 except that tempered glass (chemically tempered glass: manufactured by Nippon Sheet Glass) was superposed and integrated on the transparent substrate 41.
The solar cell module of Comparative Example 2 was heavier than Example 2 due to the tempered glass on the light receiving surface side. That is, it was shown that Example 2 can be made lighter than Comparative Example 2, and that the solar cell module can be reduced in weight and cost can be reduced as compared with the prior art.

(Example 3)
A dye-sensitized solar cell module having the structure shown in FIG. 3 was produced. The manufacturing process is shown below. Note that Example 3 is the same as Example 2 except for the following two steps.
<Preparation of porous insulating layer>
The porous insulating layer 4 was formed over the entire surface of the scribe line 10 from the catalyst layer 3. One porous insulating layer 4 is formed in a shape having a width of 5.4 mm, a length of 52 mm, and a film thickness of 5 μm around the position of 6.6 mm from the left end of the insulating substrate 1, and a center interval of 6 from the center. .4 pieces of the same size were formed at intervals of 2 mm.

<Preparation of porous semiconductor layer>
One porous semiconductor layer 5 is formed with a width of 5.1 mm, a length of 50 mm, and a film thickness of 20 μm centering on a position of 6.6 mm from the left end of the insulating substrate 1, and a center interval from the center. Four pieces of the same size were formed at 6.2 mm.
By forming the porous semiconductor layer 5 in this way, the porous semiconductor layer 5 can be enlarged up to a part of the porous insulating layer 4 on the scribe line 10.

About this solar cell module, when the resistance between solar cells was measured on the same conditions as Example 1, 10 Mohm or more was shown, and when the IV characteristic of the module was measured, it was photoelectric conversion efficiency 4.3%.
From these facts, it is considered that Example 3 has an increased amount of light absorption and improved photoelectric conversion efficiency because the width of the porous semiconductor layer 5 on which the dye is adsorbed is wider than Example 2.
Moreover, when the solar cell module which connected the 30 solar cells in series with the manufacturing method of Example 3 is produced, and the resistance of the 1st electrode layers 1 between solar cells is measured after formation of the 2nd electrode layer 6, it is 10 Mohm. The above is shown.

Example 4
A solar cell module of Example 4 was made in the same manner as Example 3 except for the following steps.
In Example 4, the second electrode layer 6 is irradiated with laser light (YAG laser, fundamental wavelength: 1.06 μm, manufactured by Seishin Shoji Co., Ltd.), the current value and frequency are adjusted, and small holes with a hole diameter of 40 μm are spaced apart. A plurality of films were formed at 80 μm. The dye adsorption time was 75 hours.
As a result, when the IV characteristic of the solar cell module produced under the same conditions as in Example 1 was measured, the photoelectric conversion efficiency was 4.2%.
From this result, it was shown that in Example 4, by forming a small hole in the second electrode layer 6 compared to Example 3, the dye adsorption time was shortened and the production time was shortened.

(Example 5)
In Example 5, a solar cell module was produced in the same manner as in Example 4 except that the interval between the small holes formed in the second electrode layer 6 was narrowed to 40 μm and the dye adsorption time was 63 hours.
As a result, when the IV characteristics of the solar cell module were measured under the same conditions as in Example 1, the photoelectric conversion efficiency was 4.2%.
From this result, it was shown that, compared with Example 4, Example 5 shortened the dye adsorption time and shortened the production time by narrowing the space between the small holes.

(Example 6)
A solar cell module of Example 6 was produced in the same manner as Example 3 except that the cover member 7 and the second electrode layer 6 were brought into contact with each other.
When the IV characteristics of this solar cell module were measured under the same conditions as in Example 1, the photoelectric conversion efficiency was 4.5%.
From this result, in comparison with Example 3, Example 6 is reduced in the amount of carrier transport material 9 existing between the cover member 7 and the second electrode layer 6, and the light absorption of the carrier transport material 9 is reduced. It was shown that the conversion efficiency is improved. In addition, since the amount of electrolyte used is reduced, the cost can be reduced.

It is a schematic sectional drawing which shows Embodiment 1-1 of the dye-sensitized solar cell of this invention. It is a schematic sectional drawing which shows the dye-sensitized solar cell module formed by electrically connecting several solar cells of Embodiment 1-1 electrically in series. It is a schematic sectional drawing which shows Embodiment 2-1 of the dye-sensitized solar cell of this invention. It is a schematic sectional drawing which shows the dye-sensitized solar cell module formed by electrically connecting several solar cells of Embodiment 2-2 in series. It is a schematic sectional drawing of the dye-sensitized solar cell module shown by patent document 2. FIG. It is a schematic sectional drawing of the dye-sensitized solar cell module shown by patent document 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulation board | substrate 2 1st electrode layer 3 Catalyst layer 4 Porous insulation layer 5 Porous semiconductor layer 6 2nd electrode layer 7 Cover member 8 Sealing part 9 Carrier transport material 18 Inter-battery sealing part

Claims (13)

  On the insulating substrate, at least a first electrode layer, a catalyst layer, a porous insulating layer containing a carrier transport material inside, a porous semiconductor layer containing a carrier transport material inside and adsorbed with a dye, translucent A second electrode layer having a property and a cover member having a light transmitting property are laminated in this order, and a peripheral portion between the insulating substrate and the cover member is sealed by a sealing portion. Dye-sensitized solar cells.   The dye-sensitized solar cell according to claim 1, wherein the porous insulating layer is continuously laminated on a part of the insulating substrate from above the catalyst layer.   The dye-sensitized solar cell according to claim 1 or 2, wherein the second electrode layer has a plurality of small holes penetrating from the cover member side to the porous semiconductor layer side.   The dye-sensitized solar cell according to claim 3, wherein the small holes are formed by laser processing.   The dye-sensitized solar cell according to any one of claims 1 to 4, wherein the second electrode layer is made of a metal oxide.   The dye-sensitized solar according to any one of claims 1 to 5, wherein the second electrode layer includes at least one of tin oxide, fluorine-doped tin oxide, zinc oxide, and indium oxide. battery.   The dye-sensitized solar cell according to any one of claims 1 to 6, wherein the cover member is tempered glass.   The dye-sensitized solar cell according to any one of claims 1 to 7, wherein the porous insulating layer is thinner than the porous semiconductor layer.   The dye-sensitized solar cell according to any one of claims 1 to 8, wherein the cover member is in contact with the second electrode layer. A step (1) of laminating at least a first electrode layer, a catalyst layer, a porous insulating layer, a porous semiconductor layer having a dye adsorbed thereon, and a second electrode layer in this order on an insulating substrate;
Covering the surface of the second electrode layer with a translucent cover member and sealing a peripheral portion between the insulating substrate and the translucent cover member with a sealing portion (2);
A step (3) of injecting a carrier transport material into an inner region between the insulating substrate and the translucent cover member and allowing the carrier transport material to penetrate into the porous semiconductor layer and the porous insulating layer; A method for producing a dye-sensitized solar cell, comprising:   Two or more dye-sensitized solar cells according to any one of claims 1 to 9, wherein two or more dye-sensitized solar cells are formed in series on the same insulating substrate and adjacent to each other. A dye-sensitized solar cell module in which an inter-battery sealing portion is formed between the two. One second dye-sensitized solar cell in which a part of the second electrode layer of any one first dye-sensitized solar cell included in the dye-sensitized solar cell module is adjacent to the first dye-sensitized solar cell. Electrically connected to the first electrode layer of the battery;
A part of the porous insulating layer of the first dye-sensitized solar cell was formed on at least a part of the insulating substrate between the first dye-sensitized solar cell and the second dye-sensitized solar cell. The dye-sensitized solar cell module according to claim 11.   The porosity of the first dye-sensitized solar cell in which a part of the porous semiconductor layer of the first dye-sensitized solar cell is formed between the first dye-sensitized solar cell and the second dye-sensitized solar cell. The dye-sensitized solar cell module according to claim 12, which is formed on a part of the insulating layer.

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