WO2013077317A1 - Photoelectric conversion element and photoelectric conversion element module - Google Patents

Abstract

Provided is a photoelectric conversion element characterized in having: a translucent substrate; a supporting substrate, which is disposed to face the translucent substrate; and a sealing material for fixing, between the translucent substrate and the supporting substrate, a conductive layer, a photoelectric conversion layer in contact with the conductive layer, a catalyst layer, a counter electrode conductive layer, a carrier transport material, the translucent substrate, and the supporting substrate. The photoelectric conversion element is also characterized in that, with respect to a projection area obtained when the photoelectric conversion layer is perpendicularly projected toward the translucent substrate, a ratio of a projection area obtained when a portion where any one of the conductive layer, the catalyst layer and the counter electrode conductive layer is in contact with the carrier transport material is perpendicularly projected toward the translucent substrate is 1.2 or less. A photoelectric conversion element module that includes the photoelectric conversion element is also provided.

Description

Photoelectric conversion element and photoelectric conversion element module

The present invention relates to a photoelectric conversion element and a photoelectric conversion element module.

As an alternative energy source to fossil fuels, solar cells that convert sunlight into electric power are attracting attention. Currently, solar cells using crystalline silicon substrates and thin-film silicon solar cells have been put into practical use. However, the former solar cell has a problem that the production cost of the silicon substrate is high. The latter thin-film silicon solar cell has a problem that the manufacturing cost increases because it is necessary to use various semiconductor manufacturing gases and complicated devices. For this reason, none of the solar cells has been able to solve the problem of reducing the cost per power generation output by increasing the efficiency of photoelectric conversion.

Furthermore, as a new type of solar cell, a photoelectric conversion element using photoinduced electron transfer of a metal complex has been proposed (for example, Japanese Patent No. 2664194 (Patent Document 1)). In the structure of this photoelectric conversion element, 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. A first electrode and a second electrode are formed on the surfaces of the two glass substrates, respectively.

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. Electric energy can be taken out by such a series of electron movements.

The photoelectric conversion element described in Patent Document 1 has a structure in which an electrolytic solution is injected between the electrodes of two glass substrates. For this reason, trial production of a small area solar cell is possible, but it is difficult to produce a large area solar cell 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 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.

As an attempt to prevent a decrease in FF, JP 2003-203681 A (Patent Document 2) proposes a dye-sensitized solar cell module in which a current collecting electrode 103 is formed on a first electrode 102. . FIG. 5 (a) is a top view of the dye-sensitized solar cell module of Patent Document 2, and FIG. 5 (b) is a cross-section when the dye-sensitized solar cell module of Patent Document 2 is cut along AA. FIG.

In the dye-sensitized solar cell module of Patent Document 2, a plurality of strip-like photoelectric conversion layers 104 are formed in the same plane on the first electrode 102 as shown in FIG. Between the photoelectric conversion layers 104, a grid-like current collecting electrode 103 made of an alloy of gold and silver is formed. By forming the current collecting electrode 103, the electric resistance can be reduced, and the FF can be dramatically improved and the short-circuit current density can be improved.

Further, as an attempt to prevent a decrease in FF different from that of Patent Document 2, Japanese Patent No. 4474691 (Patent Document 3) discloses a dye-sensitized solar cell shown in FIGS. 6 (a) and 6 (b). Has been proposed. FIG. 6A is a schematic cross-sectional view of the dye-sensitized solar cell disclosed in Patent Document 3, and FIG. 6B illustrates another form of the dye-sensitized solar cell disclosed in Patent Document 3. It is a schematic diagram.

In the dye-sensitized solar cell of Patent Document 3, as shown in FIG. 6A, 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 another dye-sensitized solar cell disclosed in Patent Document 3, as shown in FIG. 6B, the current collecting electrode 204 is formed in a line shape or a lattice shape to prevent the movement of the electrolyte. A shape that has not been proposed has also been proposed. Thus, by forming the current collection electrode 204 on the photoelectric conversion layer 203 of 5 cm square, FF can improve remarkably and a short circuit current density can be improved.

Japanese Patent No. 2664194 JP 2003-203681 A Japanese Patent No. 4474691

However, even if the shape of the current collecting electrode is changed as shown in Patent Document 2, the upper limit of the FF is only about 0.66 to 0.67, and further improvement of the FF cannot be expected. In addition, 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 increases and the open circuit voltage decreases, resulting in improved conversion efficiency. I did not.

Further, in the dye-sensitized solar cell of Patent Document 3, depending on the film thickness of the photoelectric conversion layer 203, an electron distribution occurs in the film thickness direction of the photoelectric conversion layer 203, and an electron distribution from the light receiving surface toward the film thickness direction. Becomes smaller. For this reason, even if the current collection electrode 204 is installed in a place where the distribution of electrons is small, there is a problem that current collection does not proceed efficiently.

The present invention has been made in view of the current situation as described above, and an object of the present invention is to provide a photoelectric conversion element and a photoelectric conversion element module that improve FF and improve conversion efficiency.

As a result of intensive studies to solve the above-described problems, the present inventors have found that the conductive layer, the catalyst layer, and the counter electrode conductivity with respect to the projected area when the photoelectric conversion layer is vertically projected onto the light-transmitting substrate. Photoelectric conversion that improves the FF and improves the conversion efficiency by setting the ratio of the projected area when the portion where the layer and the carrier transport material are in contact with each other to be projected vertically onto the light-transmitting substrate is 1.2 or less It came to complete an element and a photoelectric conversion element module.

That is, the photoelectric conversion element of the present invention includes a light-transmitting substrate, a support substrate placed opposite to the light-transmitting substrate, a conductive layer and the conductive layer between the light-transmitting substrate and the support substrate. A photoelectric conversion layer in contact with the layer; a catalyst layer; a counter electrode conductive layer; a carrier transport material; and a sealing material for fixing the translucent substrate and the support substrate; When the area where one of the conductive layer, catalyst layer, and counter electrode conductive layer is in contact with the carrier transport material is projected vertically onto the light-transmitting substrate with respect to the projected area when projected vertically onto the substrate The ratio of the projected area is 1.2 or less.

The above sealing material is preferably in contact with the photoelectric conversion layer. It is preferable to have a porous insulating layer between the photoelectric conversion layer and the catalyst layer. The porous insulating layer preferably has a portion containing a material constituting the sealing material inside.

It is preferable to have an insulating layer in contact with the conductive layer other than the projection surface when the photoelectric conversion layer is vertically projected toward the conductive layer. Moreover, it is preferable to have an insulating layer in contact with the counter electrode conductive layer other than the projection surface when the photoelectric conversion layer is vertically projected toward the counter electrode conductive layer. The insulating layer is preferably in contact with the conductive layer and the counter electrode conductive layer.

The support substrate has an injection hole for injecting the carrier transport material, and the injection hole is preferably located on at least a part of the projection surface on which the photoelectric conversion layer is projected onto the support substrate.

It is preferable that the support substrate has an injection hole seal for sealing the injection hole, and at least a part of the material constituting the injection hole seal is in contact with the conductive layer or the counter electrode conductive layer.

The present invention is also a photoelectric conversion element module in which two or more photoelectric conversion elements are electrically connected in series, and at least one of the two or more photoelectric conversion elements is the photoelectric conversion element. It is characterized by that. The present invention is also a photoelectric conversion element module in which two or more photoelectric conversion elements are electrically connected in parallel, and at least one of the two or more photoelectric conversion elements is the photoelectric conversion element. It is characterized by that.

The present invention is also a photoelectric conversion element module in which three or more photoelectric conversion elements are electrically connected in series and / or in parallel. At least one of the three or more photoelectric conversion elements is the photoelectric conversion element described above. It is characterized by being. All the photoelectric conversion elements constituting the photoelectric conversion element module are the photoelectric conversion elements described above.

According to the present invention, a FF can be improved, and a photoelectric conversion element and a photoelectric conversion element module with high conversion efficiency can be provided.

(A) is a top view of the photoelectric conversion element of the present invention, and (b) is a cross-sectional view when the photoelectric conversion element of (a) is cut along AA. (A) is a cross-sectional view when the photoelectric conversion element of the present invention is cut along one surface, and (b) is a cross-sectional view when the photoelectric conversion element of (a) is cut along BB. is there. (A) is a cross-sectional view when the photoelectric conversion element of the present invention is cut along one surface, and (b) is a cross-sectional view when the photoelectric conversion element of (a) is cut along CC. is there. It is sectional drawing which shows typically an example of the structure of the photoelectric conversion element module of this invention. (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 photoelectric conversion element and the photoelectric conversion element module of the present invention will be described with reference to the drawings. In the drawings of the present invention, the same reference numerals represent the same or corresponding parts. In addition, dimensional relationships such as length, width, thickness, and depth are changed as appropriate for clarity and simplification of the drawings, and do not represent actual dimensional relationships.

(Embodiment 1)
<Photoelectric conversion element>
FIG. 1A is a top view of the photoelectric conversion element of the present invention, and FIG. 1B is a cross-sectional view of the photoelectric conversion element of FIG. As shown in FIG. 1, the photoelectric conversion element 10 of the present invention includes a light-transmitting substrate 1, a support substrate 7 that is installed to face the light-transmitting substrate 1, and the light-transmitting substrate 1 and the support substrate. 7, the conductive layer 2, the photoelectric conversion layer 3 in contact with the conductive layer 2, the catalyst layer 5, the counter electrode conductive layer 6, the translucent substrate 1, the support substrate 7, and the sealing material 9. The carrier transport material 4 injected into the enclosed region, and the sealing material 9 for fixing the translucent substrate 1 and the support substrate 7 are included. The photoelectric conversion layer 3 includes a porous semiconductor, a carrier transport material, and a photosensitizer, and is a conductive layer with respect to the projected area when the photoelectric conversion layer 3 is vertically projected toward the translucent substrate 1. 2, the ratio of the projected area when the portion where any one of the catalyst layer 5 and the counter electrode conductive layer 6 is in contact with the carrier transporting material 4 is vertically projected toward the translucent substrate 1 is 1.2 or less. It is characterized by that. By setting it as such a structure, FF can be improved and the photoelectric conversion efficiency of a photoelectric conversion element can be improved.

The carrier transport material 4 is filled not only in the photoelectric conversion layer 3 but also in the gaps in the catalyst layer 5. Below, each part which comprises the photoelectric conversion element 10 of this invention is demonstrated.

≪Translucent substrate≫
In the present invention, the translucent substrate 1 needs to be made of a light transmissive material because at least the light receiving surface needs to have light transmissive properties. However, the translucent substrate 1 is not necessarily required to be transmissive to light in all wavelength regions, and may be any material that substantially transmits light having a wavelength having effective sensitivity to a dye described later. Good. The translucent substrate 1 preferably has a thickness of about 0.2 to 5 mm.

The material constituting such a translucent substrate 1 is not particularly limited as long as it is a material generally used for solar cells. For example, a glass substrate such as soda glass, fused quartz glass, and crystalline quartz glass, flexible A heat resistant resin plate such as a conductive film can be used. Examples of the flexible film include tetraacetyl cellulose (TAC), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polycarbonate (PC), polyarylate (PA), polyetherimide (PEI), phenoxy resin, and Teflon. (Registered trademark).

When forming another member with heating on the translucent substrate 1, that is, for example, when forming the photoelectric conversion layer 3 made of a porous semiconductor with heating at about 250 ° C. on the translucent substrate, It is preferable to use Teflon (registered trademark) as the translucent substrate 1. This is because Teflon (registered trademark) has a heat resistance of 250 ° C. or higher. The translucent board | substrate 1 can be utilized as a base | substrate when attaching to another structure. That is, it is possible to easily attach to other structures by using metal processed parts and screws on the periphery of the translucent substrate 1.

≪Conductive layer≫
In the present invention, the conductive layer 2 only needs to be a material that substantially transmits light having a wavelength having effective sensitivity to the photosensitizer described below, and is not necessarily transparent to light in all wavelength regions. There is no need to have. Examples of such materials include indium tin composite oxide (ITO), tin oxide (SnO ₂ ), tin oxide doped with fluorine (FTO), zinc oxide (ZnO), titanium oxide doped with tantalum or niobium, and the like. Can be mentioned.

The conductive layer 2 can be formed on the translucent substrate 1 by a known method such as a sputtering method or a spray method. The film thickness of the conductive layer 2 is 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 translucent substrate 1, it is preferable to laminate | stack the conductive layer 2 which consists of FTO on the translucent substrate 1, and the translucent substrate 1 with the conductive layer 2 of a commercial item is attached. It may be used.

≪Photoelectric conversion layer≫
In the present invention, the photoelectric conversion layer 3 includes a porous semiconductor, a carrier transport material, and a photosensitizer, and is made of a porous semiconductor that has adsorbed the photosensitizer. In the photoelectric conversion layer 3 having such a configuration, the carrier transport material can move inside and outside the layer. Below, a porous semiconductor and a photosensitizer are each 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 of two or more. 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 as titanium oxide constituting the porous semiconductor, the content of anatase type titanium oxide is high. It is preferable that it contains 80% or more of 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 titanium oxide fine particles. 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). It can also be obtained by high-temperature hydrolysis of chlorides 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 mixing two or more kinds of semiconductor fine particles, it is effective to use a semiconductor compound having a strong adsorption action as a semiconductor fine particle having a small particle size.

The film thickness of the porous semiconductor, that is, the film thickness of the photoelectric conversion layer 3 is not particularly limited, but is preferably about 0.1 to 100 μm, for example. The porous semiconductor preferably has a large surface area, for example, about 10 to 200 m ² / g.

(Photosensitizer)
The photosensitizer adsorbed on the porous semiconductor is provided to convert light energy incident on the photoelectric conversion element into electric energy. In order to firmly adsorb such a photosensitizer to the porous semiconductor, those having an interlock group in the molecule constituting the photosensitizer are 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. Specifically, functional groups such as a carboxyl group, an alkoxy group, a hydroxyl group, a sulfonic acid group, an ester group, a mercapto group, and a phosphonyl group can be given.

As the photosensitizer adsorbed on the porous semiconductor, various organic dyes having absorption in the visible light region and the infrared light region, metal complex dyes, and the like can be used. Two or more kinds may be used in combination. The extinction coefficient of the organic dye is generally larger than the extinction coefficient of the metal complex dye described later.

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 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. The metal atoms constituting the metal complex dye include Cu, Ni, Fe, Co, V, Sn, Si, Ti, Ge, Cr, Zn, Ru, Mg, Al, Pb, Mn, In, Mo, Y, and 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 and the like. 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.

≪Carrier transport material≫
In the present invention, a carrier transport material is filled in the entire space or gap in the photoelectric conversion element 10 shown in FIG. That is, the carrier transport material 4 is included in a region surrounded by the conductive layer 2, the support substrate 7, and the sealing material 9 as shown in FIG. 1. Further, the carrier transport material 4 is also filled in the gaps between the photoelectric conversion layer 3 and the catalyst layer 5. In the present specification, the carrier transport material 4 means a region filled with only the carrier transport material without other components for convenience.

Such a carrier transport material 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. A reducing species and a molten salt that can dissolve the reducing species, or a redox species, a solvent that can dissolve the reducing species, 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 iodide 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 may be any 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 photoelectric conversion element module, when the support substrate 7 serves as 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 reduced depending on the electrolyte concentration. Therefore, it is preferable to set the electrolyte concentration in consideration of this point.

≪Catalyst layer≫
In the present invention, the catalyst layer 5 is provided in contact with the counter electrode conductive layer 6, and the catalyst layer 5 can efficiently transfer electrons to and from the counter electrode conductive layer 6. Such a catalyst layer 5 is not particularly limited as long as it is a material that can transfer electrons on the surface thereof, and any material can be used. For example, noble metal materials such as platinum and palladium, carbon black, ketjen black, carbon Examples thereof include carbon materials such as nanotubes and fullerenes.

≪Counterelectrode conductive layer≫
In the present invention, the counter electrode conductive layer 6 is not particularly limited as long as it has conductivity, and may not necessarily have light transmittance. However, in the case where the support substrate 7 is a light receiving surface, it is necessary to have light transmission like the conductive layer.

Examples of the material constituting the counter electrode conductive layer 6 include indium tin composite oxide (ITO), tin oxide (SnO ₂ ), tin oxide doped with fluorine (FTO), and zinc oxide (ZnO). In addition to metals that can be used, metals that are not corrosive to the electrolyte, such as titanium, nickel, and tantalum, may be used. The counter electrode conductive layer 6 made of such a material can be formed by a known method such as a sputtering method or a spray method. Moreover, when a catalyst layer has sufficient electroconductivity, it can also serve as a catalyst layer and a counter electrode conductive layer only with a single layer.

The film thickness of the counter electrode conductive layer 6 is preferably about 0.02 μm to 5 μm. The film resistance of the counter electrode conductive layer 6 is preferably as low as possible, and is preferably 40Ω / sq or less. When the material constituting the counter electrode conductive layer 6 has a dense structure, a plurality of counter electrode conductive layers 6 are provided in the counter electrode conductive layer 6 so that the photosensitizer can be easily adsorbed or the carrier transport material can easily pass through. It is preferable to form a small hole.

Such small holes can be formed by subjecting the counter electrode conductive layer 6 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. Further, a similar effect can be obtained by forming a stripe-shaped opening in the counter electrode conductive layer 6. 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.

≪Support substrate≫
In the present invention, it is necessary to use the support substrate 7 that can hold the carrier transport material 4 inside and prevent the intrusion of water or the like from the outside. When such a support substrate 7 serves as a light receiving surface, it is necessary to use the same material as that of the translucent substrate 1 because the same light transmissivity as that of the translucent substrate 1 is required. Considering the case where the photoelectric conversion element is installed outdoors, the support substrate 7 is preferably made of tempered glass or the like.

Here, it is preferable that the support substrate 7 (including a catalyst layer or a counter electrode conductive layer formed on the surface thereof) does not come into contact with the photoelectric conversion layer 3 formed on the translucent substrate 1. Thereby, a sufficient amount of the carrier transport material 4 can be held inside the photoelectric conversion element. Such a support substrate 7 preferably includes an injection port for injecting the carrier transport material 4. The carrier transport material can be injected from such an inlet using a vacuum injection method, a vacuum impregnation method, or the like.

Further, since the support substrate 7 and the photoelectric conversion layer 3 formed on the translucent substrate 1 are not in contact with each other, 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.

In the present embodiment, the support substrate 7 has an injection hole 8 ′ for injecting the carrier transport material 4. The injection hole 8 ′ is preferably located on at least a part of a projection surface obtained by projecting the photoelectric conversion layer 3 onto the support substrate 7. By providing the injection hole 8 ′ at such a position, it is possible to reduce the area of the conductive layer portion located at the same projection portion as the injection hole, so that the ratio of the projection area can be reduced.

≪Sealing material≫
In the present invention, the sealing material 9 is provided to bond the translucent substrate 1 and the support substrate 7 together. Such a sealing material 9 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 have a laminated structure using two or more of these.

Examples of the material constituting the sealing material 9 include commercially available epoxy resins such as Three Bond, model number 31X-101, Three Bond, model number 31X-088, and the like. it can. When the sealing material 9 is formed using a silicone resin, an epoxy resin, or a glass frit, it is preferably formed using a dispenser, and when the sealing material 9 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.

In the present invention, the sealing material 9 is preferably in contact with the photoelectric conversion layer 3. When the sealing material 9 is in contact with the photoelectric conversion layer 3, the ratio of the projected area can be reduced.

≪Injection hole sealing≫
An injection hole seal 8 for sealing the injection hole 8 ′ is provided on the support substrate 7. Here, it is preferable that at least a part of the material constituting the injection hole seal 8 is in contact with the conductive layer 2 or the counter electrode conductive layer 6. Since the material constituting the injection hole seal 8 is in contact with the conductive layer 2 or the counter electrode conductive layer 6, the area of the conductive layer or the counter electrode conductive layer in contact with the electrolyte around the seal hole can be reduced. , The proportion of the projected area can be reduced. In addition, as a material which comprises the injection hole seal | sticker 8, the material same as the material which comprises said sealing material 9 can be used. Below, the formation method of a porous semiconductor and the adsorption | suction method of a photosensitizer are demonstrated.

<< Method of forming porous semiconductor >>
The method for forming the porous semiconductor on the conductive layer 2 is not particularly limited, and a known method can be used. That is, for example, a porous semiconductor is formed by applying a suspension in which semiconductor fine particles are suspended in a suitable solvent to a predetermined place using a known method, and performing at least one of drying and baking.

When it is desired to form the photoelectric conversion layer 3 so that the photoelectric conversion layer 3 and the sealing material 9 are in contact with each other, the viscosity of the suspension is adjusted low, and this is divided into regions divided by the sealing material 9 from a dispenser or the like. It is preferable to apply. 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 conductive layer 2 by applying the suspension thus obtained onto the conductive layer 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 In the case of drying and baking at a temperature of 50 to 800 ° C., it is preferably performed for 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 a post-treatment in order to improve the performance of the porous semiconductor. By performing post-processing on the porous semiconductor, the electrical connection between the semiconductor fine particles can be improved, the surface area of the porous semiconductor can be increased, and the defect level on the semiconductor fine particles can be reduced. For example, the performance of a porous semiconductor can be improved by post-processing a porous semiconductor made of titanium oxide with a titanium tetrachloride aqueous solution.

≪Adsorption of photosensitizer≫
Next, the photoelectric conversion layer 3 is produced by making a photosensitizer adsorb | suck to a porous semiconductor. The method for adsorbing the photosensitizer is not particularly limited. 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 photosensitizer may be any solvent that can dissolve the photosensitizer, 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.

(Embodiment 2)
2A is a cross-sectional view when the photoelectric conversion element of the present invention is cut along one surface, and FIG. 2B is a cross-section when the photoelectric conversion element of FIG. 2A is cut along BB. FIG.

The photoelectric conversion element of the present embodiment may be the one shown in FIG. 2 (a) and FIG. 2 (b). That is, in the photoelectric conversion element of this embodiment, as shown in FIG. 2B, the translucent substrate 11 and the support substrate 17 are fixed by the sealing material 19, and the translucent substrate 11 includes a conductive layer 12 formed on the conductive layer 12 and a photoelectric conversion layer 13 formed on the conductive layer 12.

The conductive layer 12 is provided with a scribe line 12 '. A porous insulating layer 111 is provided on the scribe line 12 ′ and the photoelectric conversion layer 13. A catalyst layer 15 and a counter electrode conductive layer 16 are provided on the porous insulating layer 111. Further, the support substrate 17 is bonded to the translucent substrate 11 by the sealing material 19. A region surrounded by the support substrate 17, the sealing material 19, and the translucent substrate 11 is filled with the carrier transport material 14. The carrier transport material 14 is also filled in the voids of the photoelectric conversion layer 13, the porous insulating layer 111, and the catalyst layer 15. In the following, a porous insulating layer that is not used in Embodiment 1 will be described. Each part other than the porous insulating layer 111 can be the same as that described in the first embodiment.

≪Porous insulation layer≫
In the present embodiment, a porous insulating layer 111 is provided between the photoelectric conversion layer 13 and the catalyst layer 15. The porous insulating layer 111 is provided to reduce the leakage current from the photoelectric conversion layer 13 to the counter electrode conductive layer 16. The porous insulating layer 111 is provided in contact with the photoelectric conversion layer 3 and contains a carrier transport material therein. As shown in FIG. 2A, the leakage current from the photoelectric conversion layer 3 can be reduced by forming the porous insulating layer 111 so as to cover the top and side surfaces of the photoelectric conversion layer 3.

It is preferable that the porous insulating layer 111 has a portion including the material constituting the sealing material 19 inside. As described above, when part of the porous insulating layer 111 includes the sealing material, the conductive layer portion in contact with the porous insulating layer is covered, and as a result, the ratio of the projected area can be reduced.

Examples of the material constituting the porous insulating layer 111 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. The above can be used in combination. The material used for the porous insulating layer 111 is preferably in the form of particles, and the average particle diameter is more preferably 5 to 500 nm, and 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.

The porous insulating layer 111 is preferably made of a material having a conductivity of 1 × 10 ¹² Ω · cm or less, and the lower the conductivity, the more preferable. By using a material having such conductivity, leakage current from the photoelectric conversion layer 13 to the counter electrode conductive layer 16 can be reduced. On the other hand, it is not preferable that the porous insulating layer 111 is made of a material having a conductivity exceeding 1 × 10 ¹² Ω · cm because leakage current easily flows and the photoelectric conversion efficiency decreases due to a decrease in fill factor.

The porous insulating layer 111 preferably has a thickness of 0.2 μm to 20 μm, more preferably 0.5 μm to 5 μm. If the thickness of the porous insulating layer 111 exceeds 20 μm, the short circuit current value (Jsc) is lowered, which is not preferable. Further, it is not preferable that the thickness of the porous insulating layer 111 is less than 0.2 μm because a leak current is likely to occur.

≪Formation of porous insulating layer≫
Next, a method for forming the porous insulating layer 111 on the photoelectric conversion layer 3 will be described. The porous insulating layer 111 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 photoelectric conversion layer 3, and at least one of drying and baking is performed. Thereby, the porous insulating layer 111 is formed on the photoelectric conversion layer 3.

(Embodiment 3)
3A is a cross-sectional view when the photoelectric conversion element of the present invention is cut along one surface, and FIG. 3B is a cross-section when the photoelectric conversion element of FIG. FIG. The photoelectric conversion element of this embodiment may have the form shown in FIG. The photoelectric conversion element shown in FIG. 3 is different from the photoelectric conversion element of Embodiment 2 in that an insulating layer 122 is provided between the sealing material 29 and the translucent substrate 21, and the upper surface of the porous insulating layer 121. The catalyst layer 25 and the counter electrode conductive layer 26 are the same except that the catalyst layer 25 and the counter electrode conductive layer 26 are provided. In the following, an insulating layer that is not used in the first and second embodiments will be described.

≪Insulating layer≫
The insulating layer 122 used in this embodiment is provided in order to suppress contact between the conductive layer 22 or the counter electrode conductive layer 26 and the carrier transport material 24. By suppressing the contact between the conductive layer 22 or the counter electrode conductive layer 26 and the carrier transporting material 24, the area of the conductive layer or the counter electrode conductive layer in contact with the substantial electrolyte can be reduced, so the ratio of the projected area is reduced. be able to.

The material for forming the insulating layer 122 may be any material that can be electrically insulated, and the internal structure is preferably dense. Examples of the material constituting the insulating layer 122 include a silicone resin, an epoxy resin, a polyisobutylene resin, a hot melt resin, a glass material, and the like. A multilayer structure using two or more of these materials It may be.

However, when the insulating layer 122 is formed before the porous semiconductor is formed, the insulating layer 122 needs to have heat resistance against the heating temperature at the time of forming the porous semiconductor. Further, when the light-transmitting substrate 1 is used as a light receiving surface, the insulating layer 122 is also irradiated with ultraviolet rays, so that light resistance to ultraviolet rays is required. From the above viewpoint, it is more preferable to use a glass-based material as the insulating layer 122, and it is more preferable to use a bismuth-based glass paste.

Examples of the glass-based materials mentioned above include those commercially available as glass paste and glass frit. In consideration of reactivity with the carrier transport material and environmental problems, a lead-free material is preferable. Furthermore, when forming the insulating layer 122 on the translucent board | substrate 21 which consists of glass materials, it is preferable to form with the calcination temperature of 550 degrees C or less.

The insulating layer 122 is preferably in contact with the conductive layer 22 other than the projected surface when the photoelectric conversion layer 23 is vertically projected toward the conductive layer 22. Thereby, the area of the conductive layer in contact with the electrolytic solution can be reduced. Further, the insulating layer 122 may be in contact with the counter electrode conductive layer 26 other than the projection surface when the photoelectric conversion layer 23 is vertically projected toward the counter electrode conductive layer 26. Thereby, the area of the counter electrode conductive layer in contact with the electrolytic solution can be reduced. The insulating layer 122 is preferably in contact with the conductive layer 22 and the counter electrode conductive layer 26. Thereby, the area of both the conductive layer in contact with the electrolytic solution and the counter electrode conductive layer can be reduced.

≪Photoelectric conversion element module≫
The present invention is also a photoelectric conversion element module in which two or more photoelectric conversion elements are electrically connected in series, and at least one of the two or more photoelectric conversion elements is the photoelectric conversion element of the present invention. It is characterized by. FIG. 4 is a cross-sectional view schematically showing an example of the structure of the photoelectric conversion element module of the present invention.

The photoelectric conversion element module of FIG. 4 is obtained by connecting four photoelectric conversion elements of the present invention. Each photoelectric conversion element includes a translucent substrate 31 and the translucent substrate as shown in FIG. A conductive layer 32 formed on 31, a photoelectric conversion layer 33 formed on the conductive layer 32, a porous insulating layer 311 formed in contact with the photoelectric conversion layer 33, and the porous insulating layer 311. And a catalyst layer 35 formed in contact with the substrate. A portion where the conductive layer 32, the catalyst layer 35, the counter electrode conductive layer 36, and the carrier transport material 34 are in contact with the projected area when the photoelectric conversion layer 33 is vertically projected toward the translucent substrate 31. The ratio of the projected area when projected vertically onto the translucent substrate 31 is 1.2 or less.

The carrier transport material is filled in the gaps of the photoelectric conversion layer 33, the porous insulating layer 311, and the catalyst layer 35. A counter electrode conductive layer 36 is formed on the catalyst layer 35. The translucent substrate 31 and the support substrate 37 are connected by a sealing material 39. The conductive layer 32 is partially interrupted, and the interrupted portion is referred to as a scribe line 32 '. A collecting electrode 41 is provided at the end of the translucent substrate 31.

The photoelectric conversion element module of the present invention is not limited to the one shown in FIG. 4, and includes one in which two or more photoelectric conversion elements are electrically connected in series and / or in parallel. As long as at least one of the conversion elements is the photoelectric conversion element of the present invention, it does not depart from the present invention. The photoelectric conversion element module preferably includes three or more photoelectric conversion elements. It is preferable that all the photoelectric conversion elements constituting the photoelectric conversion element module are the photoelectric conversion elements of the present invention.

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 is a value measured using a surface roughness shape measuring instrument (trade name: Surfcom 1400A, manufactured by Tokyo Seimitsu Co., Ltd.) unless otherwise specified.

<Example 1>
In this example, the photoelectric conversion element 10 shown in FIG. 1 was produced. First, a transparent electrode substrate (manufactured by Nippon Sheet Glass Co., Ltd., glass with SnO ₂ film, sheet resistance: 10.5Ω / sq) having a size of 10 mm × 65 mm × thickness 1.0 mm was prepared. The transparent electrode substrate is obtained by forming a conductive layer 2 made of SnO ₂ on a translucent substrate 1 made of glass.

Using a screen plate having a pattern of 5 mm × 50 mm and a screen printing machine (manufactured by Neurong Seimitsu Kogyo Co., Ltd., model number: LS-150), a commercially available titanium oxide paste (Solaronix) Manufactured, trade name: D / SP), and leveling was performed at room temperature for 1 hour.

Thereafter, the coating film of titanium oxide paste was dried in an oven set at 80 ° C. for 20 minutes. Further, the coating film was baked in air for 60 minutes using a baking furnace (model number: KDF P-100, manufactured by Denken Co., Ltd.) set at 500 ° C. In the same manner as described above, a porous semiconductor having a film thickness of 25 μm was produced by repeating the application and baking of the titanium oxide paste four times each.

Next, the dye of the above formula (2) (manufactured by Solaronix, trade name: Ruthenium 620 1H3TBA) at a concentration ratio of 4 × 10 −4 mol / liter with respect to a mixed solvent of acetonitrile and t-butanol having a volume ratio of 1: 1 The dye adsorbing solution was prepared by dissolving as described above.

The porous semiconductor prepared above was immersed in this dye adsorption solution, and the state was kept at room temperature for 100 hours. Thereafter, the porous semiconductor was washed with ethanol and dried at about 60 ° C. for about 5 minutes, thereby adsorbing the dye to the porous semiconductor. In this way, a photoelectric conversion layer 3 made of a porous semiconductor adsorbed with a dye was produced.

A transparent electrode substrate having a size of 10 mm × 65 mm × thickness 1.0 mm similar to the above-described translucent substrate 1 and conductive layer 2 was used as the support substrate 7 and the counter electrode conductive layer 6. Then, a catalyst layer 5 made of Pt was formed on the surface of the counter electrode conductive layer 6.

And the translucent board | substrate 1 with which the photoelectric converting layer 3 was formed, and the support substrate 7 were bonded together using the heat sealing | fusion film (the Du Pont company make, High Milan 1702). And it was crimped | bonded so that the opening part (internal dimension) of a heat sealing | fusion film might be set to 5.5 mm x 51 mm by heating for 10 minutes in the oven set to about 100 degreeC.

Next, the support substrate 7 and the translucent substrate 1 were bonded together using a heat welding film having an opening (manufactured by DuPont, Himiran 1702). Subsequently, the support substrate 7 and the translucent substrate 1 were pressure-bonded by heating for 10 minutes in an oven set to about 100 ° C. This heat-sealing film becomes the sealing material 9.

Next, a carrier transport material prepared in advance was injected from an injection hole 8 ′ provided in the support substrate 7. Carrier transport materials are acetonitrile and solvent, and LiI (Aldrich) as a redox species has a concentration of 0.1 mol / liter and I ₂ (Kishida Chemical) has a concentration of 0.01 mol / liter. As the agent, t-butylpyridine (manufactured by Aldrich) adjusted to a concentration of 0.5 mol / liter and dimethylpropylimidazole iodide (manufactured by Shikoku Kasei Kogyo) to a concentration of 0.6 mol / liter was used. .

The injection hole 8 ′ was sealed by forming the injection hole seal 8 using an ultraviolet curable resin (manufactured by Three Bond Co., Ltd., model number: 31X-101 229). A collector electrode was formed by applying an Ag paste (trade name: Dotite, manufactured by Fujikura Kasei Co., Ltd.) to the translucent substrate 1 of the obtained photoelectric conversion element. The photoelectric conversion element (single cell) of this example was completed as described above.

<Examples 2 to 3, Comparative Example 1>
Photoelectric conversion of Examples 2 to 3 and Comparative Example 1 is the same as Example 1 except that the opening (inner dimensions) of the heat-sealing film is different from Example 1 as shown in Table 1 below. An element was produced.

<Example 4>
In this example, the photoelectric conversion element shown in FIG. 2 was produced. First, the conductive layer of the transparent electrode substrate used in Example 1 was cut by laser scribing to form a scribe line 12 ′. And the porous semiconductor with a film thickness of 25 micrometers was produced on the conductive layer by the method similar to Example 1. FIG.

A paste containing zirconia particles having an average particle size of 50 nm was applied on the porous semiconductor by a screen printing machine using a screen plate having a pattern of 5.8 mm × 51 mm. The paste was baked at 500 ° C. for 60 minutes to form a porous insulating layer 111 with a flat portion having a thickness of 13 μm.

Next, a catalyst layer 15 made of Pt was formed on the porous insulating layer 111 by vapor deposition. The catalyst layer 15 has the same position and size as the porous semiconductor. Further, a counter electrode conductive layer 16 having a size of 9 mm × 50 mm was formed on the catalyst layer 15 by vapor deposition. Next, the photoelectric conversion layer 13 was produced by adsorb | sucking a pigment | dye to a porous semiconductor by the method similar to Example 1. FIG.

Next, a support substrate 17 made of a glass substrate having a size of 11 mm × 60 mm was prepared. And the translucent board | substrate 11 in which said laminated body was formed, and the support substrate 17 were bonded together using the heat sealing | fusion film (the Du Pont company make, High Milan 1702). And the support substrate 17 and the translucent board | substrate 11 were crimped | bonded by heating for 10 minutes in the oven set to about 100 degreeC. This heat-sealing film becomes the sealing material 19. The above heat-sealing film was an opening having the same shape as the porous insulating layer, and the opening (inner dimension) of the heat-sealing film after thermocompression bonding was 5.8 mm × 51 mm.

An injection hole 18 ′ was formed in a portion where the photoelectric conversion layer 13 was projected on the support substrate 17. A photoelectric conversion element of this example was fabricated in the same manner as in Example 1 except that the injection hole 18 ′ was formed at such a position.

<Example 5 and Comparative Example 2>
The photoelectric conversion elements of Example 5 and Comparative Example 2 were the same as Example 4 except that the opening (inner dimensions) of the heat-sealing film was different as shown in Table 1 below. Produced.

<Example 6>
In this example, a photoelectric conversion element having the structure shown in FIG. 3 was produced. In the photoelectric conversion element of this example, the size of the porous insulating layer 121 was 5.8 mm × 50 mm, the insulating layers 122 were formed on both ends of the porous insulating layer 121, and the counter electrode conductive layer was 9 mm × It was produced by the same method as in Example 5 except that the thickness was 51 mm. Note that the insulating layer 122 having a size of 5.8 mm × 4 mm was formed using glass paste.

<Solar cell characteristics of photoelectric conversion elements of Examples 1 to 6 and Comparative Examples 1 to 2>
A black mask having an opening area of 1.5 cm ² was placed on the light receiving surfaces of the photoelectric conversion elements of Examples 1 to 6 and Comparative Example 1. Then, the light receiving surface of each photoelectric conversion element is irradiated with light having an intensity of 1 kW / m ² using an AM1.5 solar simulator, whereby a short circuit current value Jsc (mA / cm ² ) and an open circuit voltage Voc (V ), Fill factor (FF), and photoelectric conversion efficiency (%). The results are shown in Table 1.

In Table 1, when comparing the photoelectric conversion elements of Examples 1 to 6 and the photoelectric conversion elements of Comparative Examples 1 and 2, in Examples 1 to 6, the photoelectric conversion layer is projected vertically toward the light-transmitting substrate. The ratio of the projected area when the conductive layer, the catalyst layer, the counter electrode conductive layer, and the portion where the carrier transport material is in contact with the carrier transporting material is vertically projected toward the translucent substrate with respect to the projected area is 1.2. It is as follows. Thereby, FF can be improved and conversion efficiency can be improved.

<Example 7>
In this example, a photoelectric conversion element module having the structure shown in FIG. 4 was produced. First, a transparent electrode substrate (manufactured by Nippon Sheet Glass Co., Ltd., glass with SnO ₂ film) having a length of 70 mm and a width of 37 mm was prepared. The transparent electrode substrate is obtained by forming a conductive layer 32 made of SnO ₂ on a translucent substrate 31 made of glass.

The conductive layer 32 was cut by laser scribing to form a scribe line 32 ′ having a width of 60 μm parallel to the vertical direction. The scribe lines 32 'were formed at a position of 9.5 mm from the left end portion of the translucent substrate 31 and a total of four places at intervals of 7 mm therefrom.

Next, a porous semiconductor having a thickness of 25 μm, a width of 5 mm, and a length of 50 mm is formed around the position of 6.9 mm from the left end portion of the translucent substrate 31 by the same method as in Example 1. Three porous semiconductors of the same size were formed at intervals of 7 mm from the position.

Then, a porous insulating layer 311 was produced on the porous semiconductor by the same method as in Example 1. One such porous insulating layer 311 was formed with a width of 5.6 mm and a length of 51 mm centering on a position 6.9 mm from the left end of the translucent substrate 31. Three porous insulating layers having the same size were formed at an interval of 7 mm from the center of the leftmost porous insulating layer 24.

Next, a catalyst layer 35 made of Pt was formed on the porous insulating layer 311 by the same method as in Example 1. The catalyst layer 35 has the same position and size as the porous semiconductor. Then, a counter electrode conductive layer 36 was formed by the same method as in Example 4. The counter electrode conductive layer 36 is formed to have a width of 5.6 mm and a length of 50 mm centered at a position of 7.2 mm from the left end portion of the translucent substrate 31, and the center of the leftmost porous insulating layer 311 is formed. Three counter electrode conductive layers 36 having the same size were formed at intervals of 7 mm to 7 mm.

Next, the four porous semiconductors were immersed in the dye adsorption solution used in Example 1, and held at room temperature for 120 hours to adsorb the dye to the porous semiconductor. Next, an ultraviolet curable resin (31X-101, manufactured by ThreeBond Co., Ltd.) was applied between the photoelectric conversion layers 33 and around the translucent substrate 31 using a dispenser (ULTRASAVE manufactured by EFD). And the support substrate 37 which consists of a 65 mm long x 30 mm wide glass substrate was bonded together, and it irradiated with the ultraviolet-ray using the ultraviolet lamp (NOVACURE by EFD company). In this way, the sealing material 39 was formed by curing the ultraviolet curable resin. The opening formed by the sealing material 39 was 5.8 mm × 51 mm.

Thereafter, a carrier transport material was injected from an injection hole provided in advance in the support substrate 37 by the same method as in Example 1. And the photoelectric conversion element module of a present Example was completed by sealing an injection hole with ultraviolet curing resin. The current collecting electrode 41 was formed by applying Ag paste (trade name: Dotite, manufactured by Fujikura Kasei Co., Ltd.) on the translucent substrate of this photoelectric conversion element module.

<Example 8>
A photoelectric conversion element module of this example was fabricated in the same manner as in Example 7, except that the sealing portion was penetrated by about 0.2 mm into the porous insulating layer.

<Example 9>
Compared to Example 7, after forming the counter electrode conductive layer, forming scribe lines in the series direction of the photoelectric conversion layer produced four photoelectric conversion elements in the series direction and two rows in the parallel direction. Others were carried out similarly to Example 7, and produced the photoelectric conversion element module of a present Example.

<Comparative Example 3>
A photoelectric conversion element module of this comparative example was produced in the same manner as in Example 7, except that the opening of the sealing part was changed to 5.8 mm × 55 mm in Example 7.

<Solar cell characteristics of photoelectric conversion element modules of Examples 7 to 9 and Comparative Example 3>
A black mask having an opening area of 7.8 cm ² was placed on the light receiving surfaces of the photoelectric conversion element modules of Examples 7 to 9 and Comparative Example 3. Then, the light receiving surface of each photoelectric conversion element is irradiated with light having an intensity of 1 kW / m ² using an AM1.5 solar simulator, whereby a short circuit current value Jsc (mA / cm ² ) and an open circuit voltage Voc (V ), Fill factor (FF), and photoelectric conversion efficiency (%). The results are shown in Table 2.

By comparing the photoelectric conversion element modules of Examples 7 to 9 with those of Comparative Example 3, the same conclusions as those of Examples 1 to 6 and Comparative Examples 1 to 2 are derived. That is, the photoelectric conversion element modules of Examples 7 to 9 have higher FF and higher conversion efficiency than those of Comparative Example 3.

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.

1, 11, 21, 31 translucent substrate, 2, 12, 22, 32 conductive layer, 3, 13, 23, 33 photoelectric conversion layer, 4, 14, 24, 34 carrier transport material, 5, 15, 25, 35 catalyst layer, 6, 16, 26, 36 counter electrode conductive layer, 7, 17, 27, 37 support substrate, 8, 18, 28 injection hole sealing, 8 ', 18', 28 'injection hole, 9, 19, 29,39 sealing material, 10, 20, 30 photoelectric conversion element, 12 ', 22', 32 'scribe line, 111, 121, 311 porous insulating layer, 122 insulating layer, 41 collector electrode, 203 photoelectric conversion layer , 204 Current collecting electrode.

Claims (13)

1. A translucent substrate;
   A support substrate installed relative to the translucent substrate;
   Between the translucent substrate and the support substrate, a conductive layer, a photoelectric conversion layer in contact with the conductive layer, a catalyst layer, a counter electrode conductive layer, a carrier transport material, the translucent substrate and the support. Having a sealing material for fixing the substrate,
   With respect to the projected area when the photoelectric conversion layer is vertically projected toward the translucent substrate, a portion where any of the conductive layer, the catalyst layer, and the counter electrode conductive layer is in contact with the carrier transport material A photoelectric conversion element having a projected area ratio of 1.2 or less when vertically projected onto the translucent substrate.
2. The photoelectric conversion element according to claim 1, wherein the sealing material is in contact with the photoelectric conversion layer.
3. The photoelectric conversion element according to claim 1, further comprising a porous insulating layer between the photoelectric conversion layer and the catalyst layer.
4. The photoelectric conversion element according to claim 3, wherein the porous insulating layer has a portion including a material constituting the sealing material therein.
5. The photoelectric conversion element according to any one of claims 1 to 4, further comprising an insulating layer in contact with the conductive layer other than a projection surface when the photoelectric conversion layer is vertically projected toward the conductive layer.
6. The photoelectric conversion element according to any one of claims 1 to 4, further comprising an insulating layer in contact with the counter electrode conductive layer other than a projection surface when the photoelectric conversion layer is vertically projected toward the counter electrode conductive layer.
7. The photoelectric conversion element according to claim 5 or 6, wherein the insulating layer is in contact with the conductive layer and the counter electrode conductive layer.
8. The support substrate has an injection hole for injecting a carrier transport material,
   The photoelectric conversion element according to any one of claims 1 to 7, wherein the injection hole is located on at least a part of a projection surface obtained by projecting the photoelectric conversion layer onto the support substrate.
9. On the support substrate, has an injection hole seal for sealing the injection hole,
   The photoelectric conversion element according to claim 8, wherein at least a part of a material constituting the injection hole sealing is in contact with the conductive layer or the counter electrode conductive layer.
10. A photoelectric conversion element module in which two or more photoelectric conversion elements are electrically connected in series,
    10. A photoelectric conversion element module, wherein at least one of the photoelectric conversion elements is the photoelectric conversion element according to claim 1.
11. A photoelectric conversion element module in which two or more photoelectric conversion elements are electrically connected in parallel,
    10. A photoelectric conversion element module, wherein at least one of the photoelectric conversion elements is the photoelectric conversion element according to claim 1.
12. A photoelectric conversion element module in which three or more photoelectric conversion elements are electrically connected in series and in parallel,
    10. A photoelectric conversion element module, wherein at least one of the photoelectric conversion elements is the photoelectric conversion element according to claim 1.
13. A photoelectric conversion element module in which two or more photoelectric conversion elements are electrically connected in series and / or in parallel,
    A photoelectric conversion element module, wherein all of the photoelectric conversion elements are the photoelectric conversion elements according to any one of claims 1 to 9.

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