JP4696459B2 - Module aggregate - Google Patents

Description

  The present invention relates to a module assembly including two or more modules each including a plurality of photoelectric conversion units and in which two or more modules are stacked.

  The dye-sensitized solar cell proposed by Gretzell et al. (Also called “Gretzel cell”) is noticeable because it achieves significantly higher photoelectric conversion efficiency (on the order of 7%) compared to conventional dye-sensitized solar cells. I was bathed. In a dye-sensitized solar cell, a semiconductor layer carrying a dye and a charge transporter are disposed between a pair of electrodes, and excited electrons generated by the dye absorbing light are injected into the semiconductor layer. Is subjected to photoelectric conversion (see, for example, Non-Patent Document 1).

A module in which the above dye-sensitized solar cells are connected is known. The module includes a pair of substrates, a plurality of photoelectric conversion units including a semiconductor layer, and a plurality of connection units, and the photoelectric conversion units and the connection units are parallel to the main surface of the substrate between the substrates. Alternatingly arranged. The connection part contains sealing resin etc. which hold | maintain a charge transport body between a pair of electrodes (for example, refer patent document 2).
Gratzel, 1 other, “Nature” (UK), Oct. 24, 1991, volume 353, p. 737-740 International Publication No. 96/29716 Pamphlet

  However, the light incident on the connection portion is not converted into electrical energy. In order to increase the photoelectric conversion efficiency of the module ((maximum output of the module / light energy irradiated to the module) × 100), the module filling rate ((total of the area of the light receiving side of the semiconductor layer included in the module / It is necessary to increase the area of the light receiving surface of the module) × 100). In order to increase the module filling rate, it is necessary to narrow the width of the connecting portion. However, if the width of the connecting portion is too narrow, sealing with the sealing resin is incomplete and the charge transporter is likely to leak. Therefore, there is a limit to a method for increasing the photoelectric conversion efficiency by narrowing the width of the connection portion.

  The module assembly of the present invention includes a pair of substrates, a plurality of photoelectric conversion units, and a plurality of connection units, and the photoelectric conversion units and the connection units are parallel to the main surface of the substrate between the substrates. Including two or more modules alternately arranged in any direction, wherein the two or more modules are stacked in a direction perpendicular to the main surface of the substrate, and the photoelectric conversion unit is formed of the pair of substrates. A first electrode provided on one substrate; a semiconductor layer disposed in contact with an opposite surface of the surface of the first electrode on the one substrate side; A second electrode provided on the other substrate; and a charge transporter disposed between the first electrode and the second electrode, wherein the connection portion is provided between the pair of substrates. One outermost layer of the plurality of modules including the filled sealing resin and stacked When a module is an upper layer and a module disposed adjacent to the upper layer is a lower layer, at least a part of the lower semiconductor layer is disposed immediately below at least a part of the connection portion of the upper layer. A structure including the pair of substrates in the upper layer, the connection portion in the upper layer, the substrate on the upper layer side in the lower layer, and the first electrode in the lower layer, disposed at least partly above However, it has translucency.

  In the module assembly of the present invention, when two or more modules are stacked, the outermost module of one of the stacked modules is the upper layer, and the module disposed adjacent to the upper layer is the lower layer. , At least a part of the lower semiconductor layer is disposed immediately below at least a part of the upper layer connection part, and a pair of upper substrate disposed immediately above at least a part of the semiconductor layer, and the upper layer connection part Since the structure including the lower upper substrate and the lower first electrode has translucency, light transmitted through the upper connection portion can be photoelectrically converted by the lower semiconductor layer. The photoelectric conversion efficiency can be increased.

  Hereinafter, an example of the module assembly of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a sectional view showing an outline of an example of a module assembly of the present invention.

  As shown in FIG. 1, in the module assembly 1, the number of modules included in the module assembly 1 is two, and two layers of modules 2 and 3 are stacked in a direction perpendicular to the substrates 8 and 9. Yes. Hereinafter, the outermost module 2 of the plurality of stacked modules is also referred to as an “upper layer 2”, and the module 3 disposed adjacent to the upper layer 2 is also referred to as a “lower layer 3”. Each of the modules 2 and 3 includes a pair of substrates 8 and 9 arranged in parallel to each other, a plurality of photoelectric conversion units 5, and a plurality of connection units 15. The substrates are alternately arranged between the substrates in a direction parallel to the main surfaces of the substrates 8 and 9. The module assembly 1 is disposed between the upper layer 2 and the lower layer 3, and includes a joint portion 11 that joins the upper layer 2 and the lower layer 3. The joining part 11 has translucency.

  The photoelectric conversion unit 5 is in contact with the first electrode 6 provided on one of the pair of substrates 8 and 9 and the opposite surface of the first electrode 6 on the one substrate 8 side. A semiconductor layer 4 disposed and carrying a dye, a second electrode 7 provided on the other substrate 9, and a charge transporter 10 disposed between the first electrode 6 and the second electrode 7. Contains.

  The connecting portion 15 is a sealing resin 13 filled between a pair of substrates 8 and 9 and a first electrode extended from one photoelectric conversion portion 5 of a pair of adjacent photoelectric conversion portions 5. A conductor disposed between the part 6a, the second electrode part 7a extended from the other photoelectric conversion part 5, and the first electrode part 6a and the second electrode part 7a. 12 and so on. A part 6 a of the first electrode is provided on one substrate 8, and a part 7 a of the second electrode is provided on the other substrate 9. In the module assembly 1, the first electrode part 6 a and the second electrode part 7 a are electrically connected via the conductor 12, and a pair of adjacent photoelectric conversion units 5 are They are electrically connected in series.

  The upper layer 2 and the lower layer 3 are electrically connected in series by a wiring (not shown) connected to the extraction electrode 14.

  In the module assembly 1, the semiconductor layer 4 of the lower layer 3 is disposed immediately below the connection portion 15 of the upper layer 2, and the pair of substrates 8 and 9 of the upper layer 2 disposed immediately above the semiconductor layer 4, and the upper layer 2 Since the structure 17 including the connecting portion 15, the substrate 8 on the upper layer 2 side of the lower layer 3, and the first electrode 6 of the lower layer 3 has translucency, the upper layer 2 side of the module assembly 1 Is the light receiving side, the total area of the light receiving side surface of the semiconductor layer 4 of the module assembly 1 is larger than the module alone. If the module assembly 1 is used with the upper layer 2 side facing the light 16, the light transmitted through the connection portion 15 of the upper layer 2 can be photoelectrically converted by the semiconductor layer 4 of the lower layer 3. The maximum output is larger than the single unit. In FIG. 1, the portion surrounded by a dotted line and indicated with dots is the structure 17.

  The light transmittance is preferably 20% or more when the structure 17 is irradiated with light having a wavelength of 550 nm along a direction orthogonal to the substrate 8. If the light transmittance of the structure 17 is too low, the amount of light that can be received by the semiconductor layer 4 of the lower layer 3 is small, and the contribution to the improvement of power generation is small. The higher the upper limit of the transmittance, the better. However, the light transmission loss due to the substrates 8 and 9, the first electrode part 6a, the second electrode part 7a, the conductor 12, the sealing resin 13, and the like is reduced. Considering 90% or less is preferable.

The width of the connection portion 15 is preferably at least 1 micron or more from the viewpoint of preventing leakage of the charge transporter 10. However, when the size of the module is reduced by setting the width of the connecting portion 15 to 1 micron or more, the module filling rate decreases. In the module assembly 1 of the present embodiment, the light transmitted through the connection portion 15 of the upper layer 2 (module 2) can be photoelectrically converted by the semiconductor layer 4 of the lower layer 3 (module 3). In the case of a small size, for example, when the area of the light receiving surface of the module is 20 cm ² or less, the photoelectric conversion efficiency can be significantly increased.

  FIGS. 2A and 2B are plan views showing the outline of the modules 2 and 3 included in the module assembly 1 shown in FIG. 1, and FIG. 2C shows the outline of the module assembly 1. It is a top view. In FIG. 2A to FIG. 2C, the portion where the dot is described is colored with a pigment, and the color is darker as the number of dots is larger. In FIGS. 2A to 2C, reference numeral 14 denotes an extraction electrode.

  As shown in FIGS. 2A and 2B, the semiconductor layer 4 is colored in a predetermined color because it carries a dye. On the other hand, although the connection part 15 changes with materials, it is substantially colorless and transparent, for example. As shown in FIG. 2 (c), in the module assembly 1, the semiconductor layer 4 of the module 3 (lower layer 3) is disposed immediately below the connection portion 15 of the module 2 (upper layer 2). Is seen from the upper layer 2 side, the semiconductor layer 4 of the lower layer 3 can be seen through from the connecting portion 15 of the upper layer 2. In this way, in the module assembly 1, color unevenness when viewed from the upper layer side is suppressed, and color uniformity is improved.

  The sealing resin 13 shown in FIG. 1 is not particularly limited as long as it has translucency. For example, silicone resin, polyolefin, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, Of ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, low density polyethylene, acrylic resin, silicone resin, ionomer resin In addition, polystyrene, polyolefin, polydiene, polyester, and polyurethane elastomers can be used.

As a material of the conductor 12, at least one selected from the group consisting of a light-transmitting material, for example, indium-tin composite oxide (ITO) and tin oxide (SnO ₂ ) can be used. When using the material which has translucency as a material of the conductor 12, there is no restriction | limiting in particular about the shape of the conductor 12, For example, foil shape, string shape, etc. are mentioned.

  The conductor 12 may include a material that does not have translucency. However, when the conductor 12 includes a material that does not have translucency, the conductor 12 includes a plurality of holes through which light incident perpendicularly to the main surface of the substrate 8 is transmitted. It is preferable that the porous body provided is included. When the conductor 12 includes the porous body, a part of the light can pass through the hole, so that the translucency of the connection portion 15 can be ensured.

  As the material having no translucency, a metal material having a relatively low resistivity, for example, at least one metal selected from the group consisting of Au, Pt, Ag, Cu, Al, Ni, Zn, Ti, and Cr, Or it is preferable that the alloy which consists of 2 or more types of metals chosen from the said group is included. When the conductor 12 contains these materials, the resistance loss of the conductor 12 can be reduced.

  Examples of the porous body include a mesh, a foam, and a punching metal. What is necessary is just to select suitably the shape of a hole of a porous body, distribution of a hole, etc. in the range which does not reduce the surface resistance of the conductor 12 remarkably. For example, when the porous body is a mesh, for example, the mesh opening ratio ((total area of openings / total area) × 100) is suitably 30% to 80%. The porous body may be formed by combining conductive fiber materials such as metal wires and carbon fibers, for example. When the porous body is formed by combining the conductive fiber materials, disconnection or the like hardly occurs, which is preferable. The porous body may be formed by a method such as screen printing.

  In FIG. 1, the mark “X” attached to the conductor 12 merely indicates that the conductor 12 is a mesh, and does not represent the penetration direction of the holes of the mesh.

  The thickness of the semiconductor layer 4 is preferably 0.1 μm to 100 μm. If the thickness of the semiconductor layer 4 is 0.1 μm to 100 μm, a sufficient photoelectric conversion effect can be obtained, and the transparency of visible light and near infrared light can be secured. The thickness of the semiconductor layer 4 is more preferably 1 μm to 50 μm, further 5 μm to 30 μm, and particularly 10 μm to 20 μm.

  When semiconductor particles are used for forming the semiconductor layer 4, the semiconductor particle size is generally preferably 5 nm to 1000 nm, and particularly preferably 10 nm to 100 nm. If the particle size is 5 nm to 1000 nm, the semiconductor layer 4 having a surface area capable of adsorbing a sufficient amount of dye and vacancies of an appropriate size can be formed, so that the oxidant contained in the charge transporter 10 and The reductant moves smoothly in the semiconductor layer 4, and as a result, a large photocurrent is obtained.

The material of the semiconductor layer 4 includes Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, Si, and Cr. Oxides, perovskite oxides such as SrTiO ₃ and CaTiO ₃ , CdS, ZnS, In ₂ S ₃ , PbS, Mo ₂ S, WS ₂ , Sb ₂ S ₃ , Bi ₂ S ₃ , ZnCdS ₂ , Cu ₂ S, etc. Sulfides, CdSe, In ₂ Se ₃ , WSe ₂ , HgSe, PbSe, CdTe and other metal chalcogenides, GaAs, Si, Se, Cd ₂ P ₃ , Zn ₂ P ₃ , InP, AgBr, PbI ₂ , HgI ₂ , And BiI ₃ . Each of these may be used alone or as a composite comprising two or more types.

Examples of the composite include CdS / TiO ₂ , CdS / AgI, Ag ₂ S / AgI, CdS / ZnO, CdS / HgS, CdS / PbS, ZnO / ZnS, ZnO / ZnSe, CdS / HgS, CdS _x / _{CdSe 1-x, CdS x /} Te 1-x, CdSe x / Te 1-x, ZnS / CdSe, ZnSe / CdSe, CdS / ZnS, TiO 2 / Cd 3 P 2, CdS / CdSeCd y Zn 1-y S , CdS / HgS / CdS, and the like.

  The semiconductor layer 4 can be formed by a conventionally known method. For example, a paste in which semiconductor particles are dispersed in a binder is applied to the first electrode 6 using, for example, a doctor blade or a bar coater. Examples of the binder include ethyl cellulose. Alternatively, semiconductor particles are applied to the surface of the first electrode 6 by spraying, dip coating, screen printing, spin coating, electrodeposition, or the like. Thereafter, heating (sintering) and / or pressurization is performed as necessary.

  For heating (sintering), it is preferable to use an electric furnace, a hot plate, a microwave, or the like. The heating temperature is preferably about 400 to 600 ° C. when the substrate 8 is a glass substrate, and about 80 to 250 ° C. when the substrate 8 is a plastic film. The pressurization is performed using, for example, a press or a calendar (roll press). The roll press is preferable because the plurality of semiconductor layers 4 can be continuously formed when the substrate 8 is a plastic film having flexibility. The pressure is preferably about 1 MPa to 200 MPa.

  The thickness of the semiconductor layer 4 can be controlled by repeating coating and heating (sintering), and by controlling the thickness of the semiconductor layer 4, the roughness factor (ratio of the actual surface area inside the porous to the substrate area) Can be controlled. The roughness factor is preferably 20 or more, and more preferably 150 or more. If the roughness factor is 20 or more, the semiconductor layer 4 can carry a sufficient amount of the dye, and the photoelectric conversion characteristics can be improved. The upper limit of the roughness factor is usually preferably about 5000.

  The porosity of the semiconductor layer 4 is preferably 50% or more. The upper limit value of the porosity of the semiconductor layer 4 is preferably about 80% from the viewpoint of resistance loss. The porosity can be calculated from an adsorption-desorption isotherm curve of nitrogen gas or krypton gas obtained by measurement under liquid nitrogen temperature.

  The dye may be any dye that is commonly used in conventional dye-sensitized photoelectric conversion elements, and may be any of inorganic dyes and organic dyes.

Examples of the inorganic dye include a RuL ₂ (H ₂ O) ₂ type ruthenium-cis-diaqua-bipyridyl complex (where L is 4,4′-dicarboxyl-2,2′-bipyridine), or Ruthenium-tris (RuL ₃ ), ruthenium-bis (RuL ₂ ), osnium-tris (OsL ₃ ), osnium-bis (OsL ₂ ) type transition metal complexes, or zinc-tetra (4-carboxyphenyl) porphyrin, iron -A hexacyanide complex, a phthalocyanine, etc. are mentioned.

As organic dyes, 9-phenylxanthene dyes, coumarin dyes, acridine dyes, triphenylmethane dyes, tetraphenylmethane dyes, quinone dyes, azo dyes, indigo dyes, cyanine dyes, merocyanine dyes Examples thereof include dyes and xanthene dyes. Of these, a ruthenium-bis (RuL ₂ ) induction conductor having a broad absorption spectrum in the visible light region is particularly preferable.

The dye adsorption amount is preferably 1 × 10 ⁻⁸ to 1 × 10 ⁻⁶ mol / cm ² , and particularly preferably 0.1 × 10 ^{−7 to} 9.0 × 10 ⁻⁷ mol / cm ² . When the adsorption amount of the dye is 1 × 10 ⁻⁸ to 1 × 10 ⁻⁶ mol / cm ^2, it is economical and the photoelectric conversion efficiency of the photoelectric conversion unit 5 can be increased.

  Examples of the method for adsorbing the dye to the semiconductor layer 4 include a method of immersing the semiconductor layer 4 in a solution in which the dye is dissolved in a solvent. Examples of the solvent include water, alcohols such as ethanol and butanol, acetonitrile, toluene, dimethylformamide, and the like. While the semiconductor layer 4 is immersed in the solution, the adsorption of the dye to the semiconductor layer 4 may be promoted by heating and refluxing the solution or applying an ultrasonic wave to the solution.

  The first electrode 6 functions as a negative electrode. The shape of the first electrode 6 is not particularly limited as long as the first electrode 6 is conductive and translucent. For example, the first electrode 6 is incident on the main surface of the film, plate, or substrate 8 perpendicularly. Any of the porous bodies provided with the hole which light permeate | transmits may be sufficient.

  Examples of the material of the first electrode 6 include light-transmitting materials such as indium-tin composite oxide and fluorine-doped tin oxide. When the first electrode 6 is a porous body, the material of the first electrode 6 does not necessarily have translucency as long as it has conductivity. For example, platinum, gold, silver , Copper, aluminum, rhodium, indium, tin, cerium and other metals, or carbon materials.

  The second electrode 7 functions as a positive electrode. The material of the second electrode 7 may be the same as the material of the first electrode 6, but platinum, palladium, a carbon material, and conductivity are provided on the surface of the second electrode 7 in contact with the charge transporter 10. It is preferable that at least one material selected from the group consisting of polymers is included. These materials function as a catalyst in the reaction of giving electrons to the reductant contained in the charge transporter 10. Therefore, when these materials are included in the surface of the second electrode 7 that contacts the charge transporter 10, the function of the second electrode 7 as the positive electrode is improved. Examples of the carbon material include graphite, and examples of the conductive polymer include polyethylene dioxythiophene. Note that a film made of a conductive material different from the material of the second electrode 7 may be provided between the second electrode 7 and the substrate 9.

  The higher the light transmittance of the first electrode 6 and the second electrode 7, the better. However, the transmittance when irradiating light with a wavelength of 550 nm is usually 70% to 90%. .

  For the charge transporter 10, for example, an electrolytic solution in which the following compound is dissolved in the following solvent is used. The above compound is not particularly limited as long as a solution containing an oxidant (oxidized electrolyte) and a reductant (reduced electrolyte) can be obtained by dissolving in a solvent, but the oxidant and reductant are not limited. It is preferable that the charges have the same sign.

  As the compound, for example, chlorine compound and chlorine, iodine compound and iodine, bromine compound and bromine, quinone and hydroquinone, fumaric acid and succinic acid can be used. Of these, iodine compounds and iodine are preferable. Examples of the iodine compound include metal iodides such as lithium iodide and potassium iodide, quaternary ammonium salt compounds such as tetraalkylammonium iodide and pyridinium iodide, and diimidazolium iodide such as dimethylpropylimidazolium iodide. Compounds are particularly preferred.

Examples of the oxidant and reductant include I ₃ ⁻ / I ⁻ , Cl ₃ ⁻ / Cl ⁻ , Br ₃ ⁻ / Br ⁻ , thallium ion (III) / thallium ion (I), mercury ion (II) / mercury ion ( I), ruthenium ion (III) / ruthenium ion (II), copper ion (II) / copper ion (I), iron ion (III) / iron ion (II), vanadium ion (III) / vanadium ion (II) , Manganate ions / permanganate ions, ferricyanide ions / ferrocyanide ions, and the like. A method for producing a solution containing these oxidant and reductant is publicly known, and conventionally known methods can be employed.

  The solvent is not particularly limited as long as the ion conductivity is excellent, and any of an aqueous solvent and an organic solvent may be used. In particular, an organic solvent in which an oxidized form and a reduced form can exist in a stable state is preferable.

  Examples of the organic solvent include carbonate compounds such as dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, and propylene carbonate, ester compounds such as methyl acetate, methyl propionate, and γ-butyrolactone, diethyl ether, and 1,2-dimethoxy. Ether compounds such as ethane, 1,3-dioxosilane, tetrahydrofuran, 2-methyl-tetrahydrofuran, heterocyclic compounds such as 3-methyl-2-oxazozirinone, 2-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, Nitrile compounds such as acetonitrile, methoxyacetonitrile, propionitrile, sulfolane, N, N, N ′, N′-tetramethylurea, didimethylsulfoxide, dimethylformamide, formamide , N-methylformamide, N-methylacetamide, N-methylpropionamide and the like. These may be used alone or in combination of two or more.

  Among them, it is preferable to use a solvent having a boiling point of 100 ° C. or higher. When the boiling point of the solvent is too low, when the module assembly 1 is stored in a high temperature environment, sealing failure may occur as the internal pressure increases. If a solvent having a boiling point of 100 ° C. or higher is used, it is possible to provide a module assembly that is less susceptible to sealing failure and has good long-term stability. If a nitrile solvent having a boiling point of 100 ° C. or higher is used, the viscosity of the nitrile solvent is low, so that not only the long-term stability of the module assembly but also the ion conductivity of the charge transporter 10 is improved.

  Examples of the nitrile solvent having a boiling point of 100 ° C. or higher include 3-methoxypropionitrile, succinonitrile, butyronitrile, isobutyronitrile, valeronitrile, benzonitrile, α-tolunitrile and the like. In particular, 3-methoxypropionitrile is preferable because it can improve the photoelectric conversion efficiency and long-term stability of the module assembly 1.

  A normal temperature molten salt or the like may be used as the solvent. Examples of the room temperature molten salt include imidazolium salts described in JP-A-9-507334. Among these, 1-methyl-3-propylimidazolium iodide is preferable because it has a low viscosity and can improve the ionic conductivity of the charge transporter 10 and increase the photoelectric conversion efficiency of the photoelectric conversion unit. A mixed solvent of a room temperature molten salt and an organic solvent may be used as the solvent.

  The charge transporter 10 may have a structure in which a solution (electrolytic solution) containing an oxidant and a reductant is held in a polymer matrix. Examples of the polymer matrix include polyvinylidene fluoride polymer compounds. Examples of the polyvinylidene fluoride polymer compound include a homopolymer of vinylidene fluoride, a copolymer of vinylidene fluoride and other monomers, and preferably a copolymer of vinylidene fluoride and a monomer capable of radical polymerization with vinylidene fluoride. A polymer etc. are mentioned.

  Examples of the monomer include hexafluoropropylene, tetrafluoroethylene, trifluoroethylene, ethylene, propylene, acrylonitrile, vinylidene chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, and styrene.

  It is preferable that the said monomer is 1-50 mol% with respect to the monomer whole quantity used for the production | generation of a copolymer, Furthermore, 1-25 mol% is contained. For example, an ion conductive film made of a vinylidene fluoride-hexafluoropropylene copolymer obtained by copolymerizing 75 to 99 mol% of vinylidene fluoride and 1 to 25 mol% of hexafluoropropylene is preferable as the polymer matrix. . Further, two or more kinds of vinylidene fluoride-hexafluoropropylene copolymers having different copolymerization ratios may be mixed and used.

  The polymer matrix may be formed from two or more of the above monomers and vinylidene fluoride. For example, a copolymer of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene, a copolymer of vinylidene fluoride, tetrafluoroethylene and ethylene, a copolymer of vinylidene fluoride, tetrafluoroethylene and propylene, etc. There may be.

  In the polymer matrix, one or more kinds of polymer compounds selected from the group consisting of polyacrylate polymer compounds, polyacrylonitrile polymer compounds, and polyether polymer compounds are mixed with polyvinylidene fluoride polymer compounds. It may be a mixture. The mixing ratio of the polyvinylidene fluoride polymer compound and the polymer compound is usually 200 parts by mass or less with respect to 100 parts by mass of the polyvinylidene fluoride polymer compound.

  The number average molecular weight of the polyvinylidene fluoride polymer compound is usually 10,000 to 2,000,000, preferably 100,000 to 1,000,000.

  The charge transport layer 10 may be a gelled electrolyte obtained by adding a gelling agent to a solution (electrolyte) containing an oxidant and a reductant. Examples of the gelling agent include polyvinylidene fluoride.

  For the substrates 8 and 9, for example, a glass substrate having translucency or a plastic film having translucency is used. However, when forming the semiconductor layer 4, it is easy to apply pressure to the material forming the semiconductor layer 4. In this respect, a plastic film is preferable.

  Examples of plastic film materials include regenerated cellulose, diacetate cellulose, triacetate cellulose, tetraacetyl cellulose, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, polycarbonate, polyethylene naphthalate, and polyethersulphate. Phon, polyetheretherketone, polysulfone, polyetherimide, polyimide, polyarylate, cycloolefin polymer, norbornene resin, polystyrene, hydrochloric acid rubber, nylon, polyacrylate, polyvinyl fluoride, polytetrafluoroethylene, etc. One or more of these can be used. In particular, it is preferable to use one or more resins selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyimide, polyarylate, cycloolefin polymer, and norbornene resin. Plastic films using these resins are tough and have excellent heat resistance. As the material of the substrate 9, for example, the same material as that of the substrate 8 is used.

  The higher the light transmittance of the substrates 8 and 9, the better. However, the transmittance when irradiating light with a wavelength of 550 nm is usually preferably 60% to 90%.

  Although there is no restriction | limiting in particular about the thickness of the board | substrates 8 and 9, It is desirable that it is 0.1 micrometer or more from a viewpoint of intensity | strength.

  The material of the joint portion 11 is not particularly limited as long as it has translucency, and for example, the same material as that of the sealing resin 13 can be used. In general, the transmittance when the junction 11 is irradiated with light having a wavelength of 550 nm is desirably 40% to 90%.

  The module assembly 1 shown in FIG. 1 includes two layers of modules 2 and 3. However, the number of modules is not limited to two, and may be three or more. When the module assembly 1 includes three layers of modules, other substrates included in the module assembly 1 except for the substrate disposed outside the pair of substrates on the outermost layer opposite to the upper layer 2 Must have translucency.

  In the module assembly 1, the modules 2 and 3 are joined by the joining portion 11, but it is not always necessary to join them. The module assembly 1 is laminated so that the modules 2 and 3 can move. If necessary, the semiconductor layer 4 of the lower layer 3 can be disposed immediately below the connection portion 15 of the module 2 (upper layer 2). It may have a structure.

  Further, in the module assembly 1 shown in FIG. 1, the semiconductor layer 4 of the lower layer 3 is disposed immediately below all the connection portions 15 included in the upper layer, but the module assembly of the present embodiment is limited to this. Not. The semiconductor layer 4 of the lower layer 3 may be disposed immediately below a part of the connection portions 15 included in the upper layer.

  Further, in the module assembly 1 shown in FIG. 1, when viewed in plan from the upper layer 2 side, since the connection portion 15 of the upper layer 2 is accommodated in the semiconductor layer 4 of the lower layer 3, the connection portion 15 of the upper layer 2 is transmitted. Light can be effectively photoelectrically converted by the semiconductor layer 4 of the lower layer 3, which is preferable, but the module assembly of the present embodiment is not limited to this. If at least a part of the semiconductor layer 4 of the lower layer 3 is arranged immediately below at least a part of the connection part 15 of the upper layer 2, the connection of the upper layer 2 to the semiconductor layer 4 of the lower layer 3 when viewed in plan from the upper layer 2 side. The part 15 may not be accommodated.

In the example shown in FIG. 1, the planar shape of the semiconductor layer 4 included in the modules 2 and 3 is a rectangle, and the planar shape of the module assembly 1 is also a rectangle, but the module assembly 1 of the present embodiment. Is not limited to this. For example, as shown in FIGS. 3 to 6, the planar shape of the semiconductor layer 4 / the planar shape of the module assembly 1 is a sector / circle, a triangle / parallelogram, a triangle / hexagon, a square / rectangle, and the like. There may be.
(Embodiment 2)

  FIG. 7 shows another example of the module assembly of the present invention. In FIG. 7, constituent members having the same functions as those shown in FIG. In FIG. 7, a portion surrounded by a dotted line and provided with dots is a structure 17.

As shown in FIG. 7, the module assembly 21 of the present embodiment is different from the module assembly 1 of the first embodiment (see FIG. 1) in the number of boards. In the module assembly 1 of the first embodiment, the number of substrates is four, whereas in the module assembly 21 of the present embodiment, the number of substrates is three. In the module assembly 21 of the present embodiment, since the substrate 9 on the lower layer 3 side of the upper layer 2 also serves as the substrate 8 on the upper layer 2 side of the lower layer 3, there is no light transmission loss due to the joint 11 (see FIG. 1). In addition, the weight, thickness and cost can be reduced.
(Embodiment 3)

  FIG. 8 shows another example of the module assembly of the present invention. 8, constituent members having the same functions as those shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted. In FIG. 8, a portion surrounded by a dotted line and attached with a dot is a structure 17.

  As shown in FIG. 8, the module assembly 31 of the present embodiment is different from the module assembly 21 of the second embodiment (see FIG. 7) in that the surface of the lower layer 3 on the upper layer 2 side of the semiconductor layer 4 It is a ratio between the area and the area of the surface of the semiconductor layer 4 of the upper layer 2 on the first electrode 6 side. In the module assembly 21 of the second embodiment, the ratio is, for example, 1: 1 (see FIG. 7), whereas in the module assembly 31 of the present embodiment, the ratio is, for example, 0. 7: 1.

In the module assembly 31, the area of the upper layer 2 side surface of the semiconductor layer 4 of the lower layer 3 is larger than the area of the lower layer 3 side surface of the connection portion 15 of the upper layer 2. When viewed in plan from the upper layer 2 side, it becomes easy to dispose the connection portion 15 of the upper layer 2 and the semiconductor layer 4 of the lower layer 3 so that the connection portion 15 of the upper layer 2 is accommodated in the semiconductor layer 4 of the lower layer 3. .
(Embodiment 4)

  FIG. 9 shows another example of the module assembly of the present invention. 9, constituent members having the same functions as those shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted. In FIG. 9, a portion surrounded by a dotted line and marked with dots is a structure 17.

  As shown in FIG. 9, the module assembly 41 of the present embodiment is different from the module assembly 21 of the second embodiment (see FIG. 7) in that the semiconductor layer 4 of the upper layer 2 is on the first electrode 6 side. Is the ratio of the area of the upper surface 2 to the area of the upper layer 2 side of the lower semiconductor layer 4. In the module assembly 21 of the second embodiment, the ratio is, for example, 1: 1 (see FIG. 7), whereas in the module assembly 41 of the present embodiment, the ratio is, for example, 2 : 1. Further, in the module assembly of the second embodiment, the upper layer 2 and the lower layer 3 are electrically connected in series, whereas in the module assembly 41 of the present embodiment, the upper layer 2 and the lower layer 3 are the extraction electrodes. 14 are electrically connected in parallel by wiring (not shown) connected to 14.

When the upper layer 2 and the lower layer 3 are electrically connected in parallel, in order to increase the current value of the module assembly 41, the light receiving side surface of the semiconductor layer 4 included in the module that can receive the most light It is preferable to increase the area. As shown in FIG. 9, for example, if the area of the semiconductor layer 4 of the upper layer 2 on the first electrode 6 side is larger than the area of the upper layer 2 side of the semiconductor layer 4 of the lower layer 3, the module assembly The output of the body 41 can be improved.
(Embodiment 5)

  FIG. 10 shows another example of the module assembly of the present invention. 10, constituent members having the same functions as those shown in FIG. 1 are given the same symbols, and descriptions thereof are omitted. In FIG. 10, a portion surrounded by a dotted line and attached with a dot is the structure 17.

  As shown in FIG. 10, the module assembly 51 of the present embodiment is different from the module of the second embodiment in that the conductor 12, the first electrode part 6 a included in the connection portion 15, and the first 2 is a joint structure with a part 7a of the electrode 2 (see FIG. 7). In the module assembly 21 of the second embodiment, the entire surface of one main surface of the conductor 12 and the part 6a of the first electrode are joined, and the entire surface of the other main surface of the conductor 12 and the second electrode are joined. Is joined to a part 7a (see FIG. 7). On the other hand, in the module assembly 51 of the present embodiment, the cut surface of the conductor 12 when cut in a direction orthogonal to the main surfaces of the substrates 8 and 9 so as to cross the photoelectric conversion unit 5 and the connection unit 15. Is substantially Z-shaped, a part of one main surface of the conductor 12 and a part 6a of the first electrode are joined, and a part of the other main surface of the conductor 12 and the second electrode Part 7a is joined. The joint portion between the conductor portion 12 and the first electrode portion 6a and the joint portion between the conductor 12 and the second electrode portion 7a are displaced in the surface direction.

In the module assembly of the second embodiment, the thickness of the conductor 12 and the distance between the first electrode portion 6a and the second electrode portion 7a (distance in the direction perpendicular to the substrate) are small. If they are different, good electrical connection cannot be realized. Therefore, in the module assembly manufacturing process, the thickness of the conductor 12 and the distance between the first electrode part 6a and the second electrode part 7a (substrate) High accuracy is required for the distance in the direction perpendicular to On the other hand, the module assembly 51 includes the joint structure in which the first electrode part 6a and the second electrode part 7a and the conductor 12 are partly joined. 9 and 9, the distance between the first electrode part 6 a and the second electrode part 7 a (distance in the direction perpendicular to the substrate) varies in the plurality of connection portions 15. However, the module assembly 51 with good connection stability can be realized.
(Embodiment 6)

  FIG. 11 shows another example of the module assembly of the present invention. 11, constituent members having the same functions as those shown in FIG. 1 are given the same symbols, and descriptions thereof are omitted. In FIG. 11, a portion surrounded by a dotted line and attached with a dot is the structure 17.

As shown in FIG. 11, the module assembly 61 of the present embodiment is different from the module 1 of the first embodiment in that the connecting portion 15 does not include the conductor 12, and the substrate 8 and the substrate 9 are in the plane direction. It is the point which has shifted | deviated and joined. Further, by joining the substrate 8 and the substrate 9 while being shifted in the surface direction, a part of the first electrode 6 and the second electrode 7 is exposed to the outside, and wirings connected to the exposed part (see FIG. The plurality of photoelectric conversion units 5 are electrically connected to each other (not shown) (see FIG. 1). Since the module assembly 61 does not include the conductor 12, it is preferable in that the light transmission loss due to the conductor 12 can be suppressed.
(Embodiment 7)

  FIG. 12 shows another example of the module assembly of the present invention. 12, constituent members having the same functions as those shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted. In FIG. 12, a portion surrounded by a dotted line and provided with a dot is the structure 17.

  As shown in FIG. 12, the module assembly 71 of the present embodiment is different from the module 1 of the first embodiment in that the conductor 12 (see FIG. 7) is not included, and a part 6a of the first electrode is included. A pair of adjacent photoelectric conversions on the outside of the connection portion 15, including a first extraction electrode 14 a bonded to the first electrode 14 a and a second extraction electrode 14 b bonded to a portion 7 a of the second electrode. The part 5 is electrically connected by a wiring (not shown) joined to the first extraction electrode 14a and the second extraction electrode 14b. A part of the first extraction electrode 14 a and a part of the second extraction electrode 14 b are embedded in the sealing resin 13.

  A part of the first extraction electrode 14 a and a part of the second extraction electrode 14 b embedded in the sealing resin 13 have a plurality of holes through which light incident perpendicularly to the main surface of the substrate 8 is transmitted. It is preferable that the porous body is included. If a part of the first extraction electrode 14a and a part of the second extraction electrode 14b include the porous body, a part of the light can pass through the hole, so that the translucency of the connecting portion 15 is ensured. it can. As the porous body, the same material as the conductor 12 (see FIG. 1) described in Embodiment 1 can be used, and the same material can be used. When a part of the first extraction electrode 14a and the second extraction electrode 14b contain the above material, the resistance loss can be reduced.

  Next, based on an Example, this invention is demonstrated more concretely. However, the present invention is not limited to the following examples.

  In Example 1, the module assembly 1 shown in FIG. 1 was produced.

One surface fluorine-doped SnO ₂ glass substrate coated with the film (manufactured by Asahi Glass Co., surface resistance 10 [Omega / sq, thickness 1.1 mm) was prepared, a portion of the fluorine-doped SnO ₂ film, using a laser Removed. Subsequently, the glass substrate and the fluorine-doped SnO ₂ film were immersed and washed in an aqueous titanium chloride solution for 30 minutes, taken out from the aqueous titanium chloride solution, and dried.

Next, a high-purity titanium oxide powder having an average primary particle diameter of 20 nm was dispersed in ethyl cellulose to prepare a screen printing paste. The mixing ratio of the high purity titanium oxide powder and ethyl cellulose was 2: 1 by weight. This paste was applied onto a fluorine-doped SnO ₂ film and dried, and the obtained dried product was baked in air at 450 ° C. for 30 minutes to form a porous titanium oxide film having a thickness of 8 μm. Subsequently, the glass substrate, the fluorine-doped SnO ₂ film and the porous titanium oxide film were washed by immersing in an aqueous titanium chloride solution for 30 minutes, taken out from the aqueous titanium chloride solution and dried. Next, after heating them at 450 ° C. for 30 minutes, they were cooled to about 80 ° C. by leaving them in the air to obtain a semiconductor layer 4 (light receiving area 5 cm ² ). The glass substrate is one of the pair of substrates 8, and the fluorine-doped SnO ₂ layer is the first electrode 6.

Next, the semiconductor layer 4 is immersed in a solution containing a dye represented by [Ru (4,4′-dicarboxyl-2,2′-bipyridine) _2- (NCS) ₂ ] and then taken out from the solution. The pigment was adsorbed to the semiconductor layer 4 by allowing it to stand at room temperature for 12 hours in a dark place. The solution was prepared by dissolving the dye in a mixed solvent obtained by mixing acetonitrile and t-butanol at a volume ratio of 50:50 so that the concentration was 3 × 10 ⁻⁴ mol / dm ^−3. Was used.

On the other hand, one surface fluorine-doped SnO ₂ glass substrate coated with the film (manufactured by Asahi Glass Co., surface resistance 10 [Omega / sq, thickness 1.1 mm) was prepared, the laser part of the fluorine-doped SnO ₂ film Subsequently, 5 × 10 ⁻⁶ l / cm ^{2 of} 5 mmol / dm ³ H ₂ PtCl ₆ solution (solvent isopropyl alcohol) was applied to the fluorine-doped SnO ₂ film. Next, these were heated at 450 ° C. for 15 minutes to produce a substrate 9 provided with the second electrode 7 on one main surface.

  A mesh (copper wire diameter 15 μm, aperture ratio 60%, length 50 mm, width 1 mm, thickness 0.3 mm) prepared using a copper wire as the conductor 12 was prepared, and a copper wire was used as the extraction electrode 14. Two pieces of meshes (copper wire diameter 15 μm, aperture ratio 60%, length 50 mm, width 4 mm, thickness 0.3 mm) were prepared.

  Next, the sealing resin 13 and the substrate 9 provided with the second electrode 7 are stacked in this order on the substrate 8 provided with the first electrode 6, and the laminate is formed at 150 ° C. at 60 ° C. The substrate 8 provided with the first electrode 6 and the substrate 9 provided with the second electrode 7 were bonded together by applying pressure while heating for seconds. As the sealing resin 13, a hot melt sheet (manufactured by DuPont, “High Milan”, thickness 20 μm) having an opening at a predetermined position was used. Further, when the substrate 8 and the substrate 9 were bonded together, the conductor 12 and the extraction electrode 14 were embedded at predetermined positions in the sealing resin 13.

  Next, the charge transporter 10 was filled between the first electrode 6 and the second electrode 7. The charge transporter 10 was injected by a reduced pressure injection method from an injection port having a diameter of 1 mm formed so as to penetrate the substrate 9 and the second electrode 7. After injecting the charge transporter 10, the injection port was sealed with a cover glass having a thickness of 500 μm to obtain a module in which a plurality of photoelectric conversion units 5 were electrically connected in series.

The cover glass was bonded to the substrate 9 using an adhesive resin (DuPont, “Binnel”). The charge carriers 10, 3-methoxy propionitrile, dimethylpropyl imidazolium iodides ^{0.6mol / dm 3, 0.1mol / dm} 3 of iodine, the N- methylbenzimidazole 0.5 mol / dm ³ The dissolved one was used.

  In the same manner as described above, another module was produced, and the two modules 2 and 3 were joined using (DuPont, “Binell”). The thickness of the joining part 11 was 0.6 mm. At the time of joining, the connection part 15 of the module 2 and the semiconductor layer 4 of the module 3 were arranged along the direction orthogonal to the main surface of the substrate 8.

  In order to measure the light transmittance of the structure 17, the module 2 produced in Example 1 and the substrate 8 provided with the first electrode 6 used for producing the module 3 were prepared, and these were prepared as DuPont. Bonding was performed using “Binell” manufactured by Komatsu. When the light transmittance of the structure 17 in the obtained laminate was measured as follows, the light transmittance was 50%, and the structure 17 was translucent. It could be confirmed.

  [Transmittance] After masking the surface of the laminate on the module 2 side so that only the structure is irradiated with light, the structure is irradiated with light having a wavelength of 550 nm along the direction orthogonal to the substrate 8. The amount of light transmitted through the structure was measured using a spectrophotometer. The light transmittance of the structure 17 was calculated from the following equation.

(Formula 1)
Transmittance = (amount of light transmitted through the structure) × 100 / (amount of light incident on the structure)
(Comparative Example 1)

  A module was produced in the same manner as in Example 1.

For the module assembly of Example 1 and the module of Comparative Example 1, the photoelectric conversion efficiency ((output / light incident energy) × 100) is obtained using pseudo sunlight (100 mW / cm ² , AM1.5) as a light source. As a result, the module aggregate of Example 1 was 8%, and the module alone of Comparative Example 1 was 5%.

  From the above results, in the module assembly of Example 1, the semiconductor layer 4 of the lower layer 3 is disposed immediately below the connecting portion 15 of the upper layer 2, and the structure 17 disposed immediately above the semiconductor layer 4 is translucent. Therefore, when the upper layer 2 side of the module assembly is the light receiving side, the light transmitted through the connection portion 15 of the upper layer 2 can be photoelectrically converted by the lower semiconductor layer 4, and the photoelectric conversion efficiency ((maximum output / It was confirmed that the irradiated light energy) × 100) was higher than that of the module alone. In the module assembly of Example 1, the structure 17 includes a pair of substrates 8 and 9 in the upper layer 2, a connection portion 15 in the upper layer 2, a bonding portion 11, and a substrate on the upper layer 2 side in the lower layer 3. 8 and the first electrode 6 of the lower layer 3.

  In the module assembly of the present invention, a plurality of modules are stacked, and when an outermost module of one of the stacked modules is an upper layer and a module arranged adjacent to the upper layer is a lower layer, the upper layer Since the light transmitted through the connecting portion can be photoelectrically converted by the lower semiconductor layer, the photoelectric conversion efficiency is high and useful.

Sectional drawing which shows the outline of an example of the module assembly of this invention (A) (b) is a top view which shows the outline of the module used for the module shown in FIG. 1, (c) is a top view which shows the outline of the module assembly of this invention. The top view which shows the outline of the other example of the module assembly of this invention The top view which shows the outline of the other example of the module assembly of this invention The top view which shows the outline of the other example of the module assembly of this invention The top view which shows the outline of the other example of the module assembly of this invention Sectional drawing which shows the outline of the other example of the module assembly of this invention Sectional drawing which shows the outline of the other example of the module assembly of this invention Sectional drawing which shows the outline of the other example of the module assembly of this invention Sectional drawing which shows the outline of the other example of the module assembly of this invention (A) The perspective view which shows the outline of the other example of the module assembly of this invention, (b) is AA 'sectional drawing of (a). Sectional drawing which shows the outline of the other example of the module assembly of this invention

Explanation of symbols

1, 21, 31, 41, 51, 61, 71 Module assembly 2 modules (upper layer)
3 modules (lower layer)
DESCRIPTION OF SYMBOLS 4 Semiconductor layer 5 Photoelectric conversion part 6 1st electrode 6a Part of 1st electrode 7 2nd electrode 7a Part of 2nd electrode 8,9 Substrate 10 Charge transporter 11 Junction part 12 Conductor 13 Sealing Resin 14 Extraction electrode 14a First extraction electrode 14b Second extraction electrode 15 Connection portion

Claims (14)

It includes a pair of substrates, a plurality of photoelectric conversion units, and a plurality of connection units, and the photoelectric conversion units and the connection units are alternately arranged between the substrates in a direction parallel to the main surface of the substrate. Contains two or more modules,
The two or more modules are stacked in a direction perpendicular to the main surface of the substrate;
The photoelectric conversion unit is disposed in contact with a first electrode provided on one of the pair of substrates and a surface opposite to the surface of the first electrode on the one substrate side. A supported semiconductor layer; a second electrode provided on the other of the pair of substrates; and a charge transporter disposed between the first electrode and the second electrode. Including
The connection portion includes a sealing resin filled between the pair of substrates,
When an outermost module of one of the stacked modules is an upper layer, and a module disposed adjacent to the upper layer is a lower layer, the lower layer is directly below at least a part of the connection portion of the upper layer. At least a portion of the semiconductor layer is disposed;
The pair of substrates in the upper layer, the connection portion in the upper layer, the substrate on the upper layer in the lower layer, and the first electrode in the lower layer, which are disposed immediately above at least a part of the semiconductor layer A module assembly in which the structure including the light transmitting property.   The module assembly according to claim 1, wherein the connection portion of the upper layer is accommodated in the semiconductor layer of the lower layer when viewed in plan from the upper layer side. Wherein disposed between the upper layer and the lower layer, further saw including a joint portion for joining the said lower layer and said upper layer, module assembly according to claim 1, wherein the joining portion has a light-transmitting property.   The module assembly according to claim 1, wherein the substrate on the lower layer side of the upper layer also serves as the substrate on the upper layer side of the lower layer.   The connection part includes a part of a first electrode extended from one photoelectric conversion part of a pair of adjacent photoelectric conversion parts, and a part of a second electrode extended from the other photoelectric conversion part. The module assembly according to claim 1, further comprising:   The connection portion further includes a conductor disposed between a part of the first electrode and a part of the second electrode, and a part of the first electrode via the conductor The module assembly according to claim 5, wherein a part of the second electrode is electrically connected.   The cut surface of the conductor is substantially Z-shaped when cut in a direction orthogonal to the main surface of the substrate so as to cross the photoelectric conversion portion and the connection portion, and one surface of the conductor The module assembly according to claim 6, wherein a part of the first electrode and a part of the first electrode are joined, and a part of the other surface of the conductor and a part of the second electrode are joined. .   The module assembly according to claim 6, wherein the conductor includes a porous body.   The connection portion further includes a first extraction electrode joined to a part of the first electrode, and a second extraction electrode joined to a part of the second electrode, The module assembly according to claim 5, wherein a part of the extraction electrode and a part of the second extraction electrode are embedded in the sealing resin.   The module assembly according to claim 9, wherein a part of the first extraction electrode and a part of the second extraction electrode include a porous body.   The module assembly according to claim 8 or 10, wherein the porous body contains at least one material selected from the group consisting of Au, Pt, Ag, Cu, Al, Ni, Zn, Ti, and Cr.   The module assembly according to claim 8 or 10, wherein the porous body is a mesh, a foam, or a punching metal.   The module assembly according to claim 1, wherein the number of modules included in the module assembly is two.   The upper layer and the lower layer are electrically connected in parallel, and the area of the upper electrode side surface of the upper semiconductor layer is larger than the area of the upper layer side surface of the lower semiconductor layer The module assembly according to claim 13, which is large.

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