JP4411955B2 - Photoelectric conversion element module - Google Patents

Description

  The present invention relates to a photoelectric conversion element module, and more particularly, easily and reliably electrically connecting a working electrode of one photoelectric conversion element and a counter electrode of the other photoelectric conversion element among adjacent photoelectric conversion elements. The present invention also relates to a photoelectric conversion element module having high exchange efficiency.

In practical use of photoelectric conversion elements, in order to increase the voltage that can be output, in many cases, photoelectric conversion elements are connected in series to form a photoelectric conversion element module, but a method of connecting the photoelectric conversion elements in series For example, the following proposals have been made. In the photoelectric conversion element module 1 shown in FIG. 2, the inside of the sealing part 11 (that is, the sealing part 11.2 and the sealing part 11.3 between the adjacent photoelectric conversion elements 2.1 and 2.2). The counter electrode 9.1 and the working electrode 5.2 of adjacent photoelectric conversion elements are electrically connected by the conductive material 12 (Patent Document 1).
WO96 / 29716

  In the photoelectric conversion element module 1 described in Patent Document 1, the working electrodes 5.1 to 5.2 and the counter electrodes 9.1 to 9.2 are provided on different substrates 3 and 7, respectively. When electrically connecting the counter electrode 9.1 and the working electrode 5.2 between the matching photoelectric conversion elements with the conductive material 12, there is no liquid junction between the adjacent photoelectric conversion elements, and the distance between the two substrates There is a problem that it is necessary to carry out the control simultaneously and it is difficult to assemble.

Further, in the photoelectric conversion element module shown in FIG. 3, the working electrode 5.1 and the counter electrode 9.2 between adjacent photoelectric conversion elements are directly electrically connected, and then the entire sealing is performed with the laminate material 14. (Patent Document 2).
WO 97/16838

  In the photoelectric conversion element module shown in FIG. 3, the process of electrically connecting the working electrode and the counter electrode of adjacent photoelectric conversion elements as in the photoelectric conversion element module shown in FIG. Although it is not necessary to carry out the process at the same time, there is a problem that it is difficult to assemble because the counter electrode 9.2 must be manufactured and electrically connected to the working electrode 5.1 of the adjacent photoelectric conversion element.

  For these connection methods, after preparing an electrode for electrically connecting a working electrode and a counter electrode between adjacent photoelectric conversion elements, a working electrode and a counter electrode between adjacent photoelectric conversion elements on the electrode are provided. In the manufacturing method, the working electrode and the counter electrode between adjacent photoelectric conversion elements can be easily and reliably electrically connected. As an example, Patent Document 1 proposes a photoelectric conversion element module as shown in FIG.

  That is, in the photoelectric conversion element module shown in FIG. 4, one of the photoelectric conversion elements 2.1 and 2.2 adjacent to the transparent electrode 8.1 formed on the one substrate 7. One counter electrode 9.1 and the working electrode 5.2 of the other photoelectric conversion element 2.2 are formed, and the adjacent photoelectric conversion element 2.2 on the transparent electrode 4.2 formed on the other substrate 3. 2.3, the counter electrode 9.2 of one photoelectric conversion element 2.2 and the working electrode 5.3 of the other photoelectric conversion element 2.3 are formed.

  Therefore, in the photoelectric conversion element module having the structure shown in FIG. 4, one of the adjacent photoelectric conversion elements has a structure in which light that reaches the working electrode reaches after passing through the counter electrode. The effect of light loss could not be avoided.

  As described above, in the conventional photoelectric conversion element module, it is difficult to easily and surely connect the working electrode and the counter electrode between adjacent photoelectric conversion elements or to realize high conversion efficiency. .

  The present invention solves the problems of the conventional photoelectric conversion element module as described above, makes it possible to easily and surely connect the working electrode and the counter electrode of adjacent photoelectric conversion elements, and to achieve high conversion. It aims at providing the photoelectric conversion element module which can implement | achieve efficiency.

The present invention includes at least a working electrode having a semiconductor layer supporting a sensitizing dye, a counter electrode facing the working electrode, an electrolyte disposed between the working electrode and the counter electrode, and contact between the electrolyte and the outside air In a photoelectric conversion element module in which a plurality of photoelectric conversion elements each having a sealing portion for blocking are connected in series, the photoelectric conversion element module is independent from any substrate of the working electrode and the counter electrode, has conductivity, and partially has a through hole The above-mentioned problem is solved by providing a sheet-like conductive material with a working electrode of one of the adjacent photoelectric conversion elements and a counter electrode of the other photoelectric conversion element.
The sheet-like conductive material preferably has a structure in which a conductive film or layer is provided on a porous support.
It is also preferable that the sheet-like conductive material has a conductive porous film inside the through hole, and the semiconductor layer of the working electrode is provided on one surface of the conductive material. In this case, it is preferable that the sheet-like conductive material is formed by plugging conductive particles in a mesh-like void having conductivity.

  That is, in the photoelectric conversion element module of the present invention, after preparing a conductive material for electrically connecting a working electrode and a counter electrode between adjacent photoelectric conversion elements, among the adjacent photoelectric conversion elements on the conductive material Since the working electrode of one of the photoelectric conversion elements and the counter electrode of the other photoelectric conversion element are provided, the working electrode and the counter electrode between adjacent photoelectric conversion elements can be easily and reliably electrically connected, Further, since all the working electrodes are positioned on the light receiving surface side of the counter electrode, there is no light transmission loss due to the counter electrode or the electrolyte, and high conversion efficiency can be achieved.

  According to the present invention, a working electrode and a counter electrode between adjacent photoelectric conversion elements can be easily and reliably electrically connected, and high conversion efficiency can be achieved.

  Next, an embodiment of the photoelectric conversion element module of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing one embodiment of a photoelectric conversion element module of the present invention. In the figure, reference numeral 1 denotes a photoelectric conversion element module. In FIG. 1, three photoelectric conversion elements 2.1, 2.2, and 2.3 among the photoelectric conversion elements constituting the photoelectric conversion element module 1 are shown. These photoelectric conversion elements 2.1 to 2.3 have working electrodes 5.1 to 5.3 having a semiconductor layer supporting at least a sensitizing dye, and the working electrodes 5.1 to 5.3. Counter electrodes 9.1 to 9.3 facing each other, electrolytes 10.1 to 10.3 disposed between the working electrodes 5.1 to 5.3 and the counter electrodes 9.1 to 9.3, and The sealing portions 11.1 to 11.4 for blocking the contact between the electrolytes 10.1 to 10.3 and the outside air.

  In addition, in this photoelectric conversion element module 1, the reference numerals regarding a plurality of members are simply indicated by only integer numbers when the plurality of members are indicated generically, and these members are individually indicated. When there is a need to indicate the number, the number for identification between the members is added after the number of the integer place, with a period added. For example, when the photoelectric conversion elements are generically indicated, only “2” is indicated. When the photoelectric conversion elements need to be indicated individually, “2.1”, “2.2”, “2.3” ". Such a way of indication is the same for other members provided.

  And in this photoelectric conversion element module 1, between the adjacent photoelectric conversion element 2.1 and the photoelectric conversion element 2.2, the working electrode 5.1 of the photoelectric conversion element 2.1 and the counter electrode of the photoelectric conversion element 2.2 9.2 is provided on the conductive material 12.2, and between the adjacent photoelectric conversion element 2.2 and photoelectric conversion element 2.3, the working electrode 5.2 of the photoelectric conversion element 2.2 and the photoelectric conversion element The counter electrode 9.3 of 2.3 is provided on the conductive material 12.3.

  The conductive material 12.2 passes through the sealing portion 11.2 between the photoelectric conversion element 2.1 and the photoelectric conversion element 2.2, and the conductive material 12.3 is the photoelectric conversion element 2.2 and the photoelectric conversion element. It penetrates the sealing part 11.3 between 2.3. In this photoelectric conversion element module 1, the counter electrode 9.1 of the photoelectric conversion element 2.1 located at the left end is provided on the conductive material 12.1, and the conductive material 12.1 passes through the sealing portion 11.1. Although not shown, the working electrode of the photoelectric conversion element located on the left side of the photoelectric conversion element 2.1 is provided at the left end thereof.

  Moreover, in this photoelectric conversion element module 1, the working electrode 5.3 of the photoelectric conversion element 2.1 located at the right end is provided on the conductive material 12.4, and this conductive material 12.4 has the sealing portion 11.4. Although not shown in the figure, a counter electrode of the photoelectric conversion element located further to the right of the photoelectric conversion element 2.3 is provided at the right end thereof. However, what is necessary is just to provide either the working electrode 5 or the counter electrode 9 in the electrically conductive material 12 in the edge part of the whole photoelectric conversion element module 1 also including the part which is not shown in figure.

  The conductive material 12 is not formed on the substrates 3 and 7 like the transparent electrode in the conventional photoelectric conversion element module (usually, the transparent electrode is formed of a transparent conductive film). However, the conductive material 12 has a through hole in a part thereof, and the part having the through hole is disposed in a part where the working electrode 5 is provided. The

  The working electrode in the conventional photoelectric conversion element includes a semiconductor layer carrying a sensitizing dye and a collecting electrode for efficiently taking out electrons from the semiconductor layer (usually a transparent electrode formed on a substrate is used as the collecting electrode). In the present invention, since the conductive material 12 also functions as the current collecting electrode, the working electrode 5 can be composed only of a semiconductor layer carrying a sensitizing dye. However, if necessary, the working electrode 5 may be configured by providing a collecting electrode. In addition, an insulating layer 13 is provided on the surface opposite to the surface on which the working electrode 5 of the conductive material 12 is provided so as to avoid contact with the counter electrode 9 in the same photoelectric conversion element 2. This insulating layer 13 is not essential.

  Next, each component of the photoelectric conversion element module 1 will be described. As the substrate 3 and the substrate 7, transparent glass or plastic can be used. Because plastic is flexible, it is suitable for applications that require flexibility. Moreover, the transparent electrode comprised with a transparent conductive film as a collector electrode may be formed in the board | substrates 3 and 7, and it does not need to be formed.

  In the photoelectric conversion element module 1 of the said embodiment, it is preferable that the thickness of the semiconductor layer which carry | supported the sensitizing dye which comprises the working electrode 5 exists in the range of 0.1-100 micrometers. If the thickness of the semiconductor layer is less than 0.1 μm, a sufficient photoelectric conversion effect may not be obtained, and if the thickness is more than 100 μm, it is transparent to visible light and near infrared light. There is a risk of inconvenience such as a marked deterioration. A more preferable range of the thickness of the semiconductor layer is 1 to 50 μm, a further preferable range is 5 to 30 μm, and a most preferable range is 10 to 20 μm.

Examples of the material constituting the semiconductor layer include Nb, Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, and Ga. , Si, Cr oxides, perovskites such as SrTiO ₃ , CaTiO ₃ , or 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 sulfide, CdSe, In ₂ Se ₃ , WSe ₂ , HgSe, PbSe, CdTe metal chalcogenide, GaAs, Si, Se, Cd ₃ P ₂ , Zn ₃ P ₂ , InP, AgBr, PbI ₂ , HgI ₂ , BiI _{3 and the} like are preferable. Also, a composite containing at least one selected from the semiconductor materials, for example, 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 ₃₂ , CdS / CdSeCd _y Zn _1-y S, CdS / HgS / CdS, and the like can also be suitably used as the material constituting the semiconductor layer.

  The semiconductor material is usually used in a particle shape, and the particle size of the semiconductor particles at that time is preferably in the range of 5 nm to 1 μm. When the particle size of the semiconductor particles is smaller than 5 nm, the pore diameter in the semiconductor layer becomes smaller than 5 nm, and it becomes difficult to move the redox substance in the electrolyte, and the obtained photocurrent is likely to be lowered. In addition, when the particle size of the semiconductor particles is larger than 1 μm, the surface area of the semiconductor layer is not sufficiently increased, so that the amount of the sensitizing dye supported is reduced, and there is a possibility that a sufficient photocurrent cannot be obtained. A particularly preferable range of the particle diameter of the semiconductor particles is 10 to 100 nm.

  In the formation of the semiconductor layer, the conductive material is dispersed by a known and commonly used method such as a doctor blade or a bar coater, a spray method, a dip coating method, a screen printing method, a spin coating method, or the like. After being applied to the portion having the through-holes and dried, it is fixed by applying pressure or heating as necessary. And about the thickness of this semiconductor layer, it can be set as desired thickness by repeating the said application | coating and pressurization or a heating process.

  In addition, by controlling the thickness of the semiconductor layer, the roughness factor (ratio of the actual area inside the porous body to the substrate area) can be determined. The roughness factor is preferably 20 or more, more preferably 150 or more. When the roughness factor is less than 20, the amount of the sensitizing dye carried becomes insufficient, and it becomes difficult to improve the photoelectric conversion characteristics. The upper limit of the roughness factor is generally about 5000. The roughness factor increases as the thickness of the semiconductor layer increases, and the surface area of the semiconductor layer increases, and an increase in the amount of sensitizing dye supported can be expected. However, if the thickness becomes too thick, the effects of light transmittance and resistance loss of the semiconductor layer begin to appear. If the porosity in the semiconductor layer is increased, the roughness factor can be increased without increasing the thickness, but if the porosity is too high, the contact area between the semiconductor particles decreases. Thus, the effect of resistance loss must be taken into account. For these reasons, the porosity of the semiconductor layer is preferably 50% or more, and the upper limit is generally about 80%. The porosity of the semiconductor layer can be calculated from the measurement result of the adsorption-desorption isotherm curve of nitrogen gas or krypton gas under liquid nitrogen temperature.

As the sensitizing dye, any dye that has been conventionally used in dye-sensitized photoelectric conversion elements can be used. Among such dyes, examples of inorganic dyes include RuL ₂ (H ₂ O) ₂ type ruthenium-cis-diaqua-bipyridyl complex or ruthenium-tris (RuL ₃ ), ruthenium-bis (RuL ₂ ), osmium. -Tris (OsL ₃ ), osnium-bis (OsL ₂ ) type transition metal complex, or zinc-tetra (4-carboxyphenyl) porphyrin, iron-hexocyanide complex, phthalocyanine and the like. Examples of organic dyes include 9-phenylxanthene dyes, coumarin dyes, acridine dyes, triphenylmethane dyes, tetraphenylmethane dyes, quinone dyes, azo dyes, indigo dyes, cyanine dyes, Examples include merocyanine dyes and xanthene dyes. Of these, a ruthenium-bis (RuL ₂ ) derivative is particularly preferable.

The amount of the sensitizing dye supported on the semiconductor layer is preferably 10 ⁻⁸ to 10 ⁻⁶ mol / cm ² , particularly preferably 0.1 to 9.0 × 10 ⁻⁷ mol / cm ² . When the loading amount of the sensitizing dye is less than 10 ⁻⁸ mol / cm ² , the effect of improving the photoelectric conversion efficiency is insufficient, and when the loading amount of the sensitizing dye is more than 10 ⁻⁶ mol / cm ² , The effect of improving the conversion efficiency is saturated and only uneconomical.

  Examples of the method for supporting the sensitizing dye on the semiconductor layer include a method of immersing the conductive material on which the semiconductor layer is formed in a solution in which the sensitizing dye is dissolved. Any solvent can be used as the solvent for the solution as long as it can dissolve sensitizing dyes such as water, alcohol, toluene, and dimethylformamide. In addition, as a dipping method, it is also effective to add heating reflux or apply ultrasonic waves while the conductive material on which the semiconductor layer is formed is dipped in the solution in which the sensitizing dye is dissolved. It is.

  The counter electrode functions as the positive electrode of the photoelectric conversion element (therefore, the working electrode functions as the negative electrode), and the counter electrode is the other end of the conductive material provided with the working electrode of the adjacent photoelectric conversion element at one end. For example, it is provided by depositing platinum, graphite, polyethylenedioxythiophene, or the like having a catalytic action for imparting electrons to the electrolyte reductant. However, the material for forming the counter electrode is not limited to the above examples.

  An electrolyte exists between a working electrode having a semiconductor layer carrying a sensitizing dye and a counter electrode. The electrolyte used for constituting the electrolyte is not particularly limited as long as a pair of redox constituents composed of an oxidant and a reductant is contained in the solvent, but the oxidant and the reductant are not limited. Redox constituents having the same charge are preferred. In this specification, the redox-system constituent substance means a pair of substances that are present reversibly in the form of an oxidant and a reductant in an oxidation-reduction reaction. Examples of such a redox component include chlorine compound-chlorine, iodine compound-iodine, bromine compound-bromine, 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 ion-permanganate ion, ferricyanide-ferrocyanide, quinone-hydroquinone, fumaric acid-succinic acid and the like can be mentioned. However, other redox constituents can also be used. Among them, iodine compound-iodine is preferable. Examples of the iodine compound include metal iodides such as lithium iodide and potassium iodide, quaternary ammonium iodide compounds such as tetraalkylammonium iodide and pyridinium iodide, and iodide. Particularly preferred are diimidazolium iodide compounds such as dimethylpropylimidazolium.

  The electrolyte is usually prepared by dissolving an electrolytic substance such as the redox constituent in a solvent. As the solvent for dissolving the electrolytic substance, either an aqueous solvent or an organic solvent can be used. However, in order to further stabilize the oxidation-reduction component, an organic solvent 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, 1,2- Ether compounds such as dimethoxyethane, 1,3-dioxolane, tetrahydrofuran and 2-methyl-tetrahydrofuran, heterocyclic compounds such as 3-methyl-2-oxazodilinone and 2-methylpyrrolidone, and nitriles such as acetonitrile, methoxyacetonitrile and propionitrile Examples thereof include aprotic polar compounds such as compounds, sulfolane, didimethyl sulfoxide and dimethylformamide. These can be used alone or in combination of two or more. Among them, carbonate compounds such as ethylene carbonate and propylene carbonate, heterocyclic compounds such as 3-methyl-2-oxazozirinone and 2-methylpyrrolidone, acetonitrile, methoxyacetonitrile, propionitrile, 3-methoxypropionitrile, valeric acid Nitrile compounds such as nitrile are particularly preferred. In addition, the electrolyte is not limited to a liquid one, and other types can be used. For example, the electrolyte may be used in a gel state by holding a liquid electrolyte in a polymer matrix. As such a polymer matrix, polymerizable monomers such as vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene, trifluoroethylene, ethylene, propylene, acrylonitrile, vinylidene chloride, methyl acrylate, ethyl acrylate, methyl methacrylate, and styrene are used. A homopolymer obtained by polymerizing alone or a copolymer obtained by copolymerizing two or more of these monomers can be used.

  Examples of the base material of the sealing material constituting the sealing portion include silicone resin, polyolefin, butyl rubber, ethylene-vinyl acetate copolymer, ethylene / α-olefin copolymer, and 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, polystyrene, polyolefin, At least one selected from polydiene-based, polyester-based, polyurethane-based, fluororesin-based, polyamide-based elastomers and the like can be used. Among them, silicone resin, ionomer resin, epoxy resin, olefin resin, butyl rubber, fluorine Resin containing is preferred . In addition, when a nitrile solvent or a carbonate solvent is used as the electrolyte solvent, a silicone resin, an ionomer resin, an olefin resin, a thermosetting olefin resin, or the like having low compatibility with those solvents is preferable.

  Moreover, in order to improve the weather resistance of the sealing material, a crosslinking agent, an ultraviolet absorber and the like can be mixed as appropriate, and a silane coupling agent and a titanate are used to increase the adhesive strength with the substrate. A coupling agent or the like may be added. In addition, wet cleaning, chemical cleaning, plasma cleaning, ozone processing, ultraviolet irradiation processing, ultrasonic processing, surface polishing processing, or the like may be performed on the substrate in advance to perform surface cleaning or surface activation. Among these, activation of the surface of the transparent substrate by plasma treatment is particularly preferable.

  In the present invention, it is a sheet-like conductive material that electrically connects one of the adjacent photoelectric conversion elements and the counter electrode of the other photoelectric conversion element. Of the conductive material, the portion where the working electrode is provided needs to have a through hole in order to secure a path for the electrolytic substance in the electrolyte to move. Other portions that are in contact with the sealing material and portions where the counter electrode is provided may or may not have through holes.

  The sheet-like conductive material may be a net-like or porous metal material, and the net-like or porous metal material is fixed to a heat-resistant perforated structure such as a ceramic, inorganic oxide, or glass fiber filter. You may have done. A conductive porous film made of a net-like or porous metal material used as the sheet-like conductive material is formed by applying a conductive fine particle and then firing, or by a film forming method such as vapor deposition, sputtering, or ion plating. can do. As a constituent material of the conductive porous film, a metal is preferable from the viewpoint of conductivity and light reflectivity, a metal such as Au, Pt, Ag, Cu, Al, Ni, Zn, Ti or Cr, or a metal of these metals. Alloys are preferably used.

  In the case of forming a conductive porous film composed of a sintered body by firing conductive fine particles, specifically, a paste in which conductive fine particles are dispersed is formed into a net-like, porous metal material, ceramic, or inorganic oxide. A method of applying to a heat-resistant porous structure such as a glass fiber filter, and sintering after drying may be employed. The particle diameter of the conductive fine particles used at this time is preferably in the range of 5 nm to 20 μm. Within this range, the conductive fine particles are unlikely to aggregate, so a uniform film is easily formed, a film having uniform resistance is formed, the characteristics of the photoelectric conversion element are stabilized, and the film thickness is also uniform. So that it is not short-circuited with the counter electrode. The conductive fine particles may be composed of particles having a uniform particle diameter, or may be a mixture of particles having different particle diameters.

  In the formation of the conductive porous film, when a thin film forming method such as vapor deposition, sputtering, or ion plating is adopted, the semiconductor layer is porous and has irregularities on its surface. A thin film formed on a heat-resistant porous structure such as an inorganic oxide or a glass fiber filter is also a porous film.

  The thickness of the conductive porous membrane is not particularly limited, but is preferably 10 nm or more in order to have good conductivity, and 1 μm or less at maximum in order not to inhibit the ionic conductivity of the electrolyte. Is preferred.

Furthermore, it is also effective to provide a film made of an oxide semiconductor on the surface of a portion having a through hole of the sheet-like conductive material (hereinafter referred to as “effective portion”). By providing an oxide semiconductor film, it is possible to prevent the effective portion of the conductive material from being altered and to prevent the same reduction reaction that occurs at the counter electrode from occurring on the surface of the effective portion of the conductive material. it can. As a method of forming a film of an oxide semiconductor on the surface of an effective portion of a conductive material for such a purpose, for example, a method such as electrolytic plating, electroless plating, liquid phase deposition method, titanium tetrachloride deposition method or the like is used. Can be adopted. As oxide semiconductors for covering the surface of the effective portion of the conductive material, in addition to titanium oxide, tungsten pentoxide, strontium tungstic acid, strontium titanate, niobium pentoxide, cadmium sulfide, cadmium oxide, zinc oxide, tin oxide Indium trioxide, ZnSb ₂ O ₆ , CdIn ₂ O ₄ , MgIn ₂ O ₄ , Zn ₂ SnO ₄ , GaInO ₃ , Cd ₂ SnO ₃ , CdSnO ₃ , In ₂ TeO ₆ , InGaMgO ₄ , InGaZnO ₄ , Zn ₂ In _{One or more of 2} O ₅ , AgSO ₃ , Cd ₂ Sb ₂ O ₇ , Cd ₂ GeO ₄ , and ZnSnO ₃ can be used. In addition, the surface of the effective portion of the conductive material is coated with Ti, Nb, Zn, Sn, In, Cd by a method such as vapor deposition, sputtering, or ion plating, and an oxide film formed on the surface in contact with the semiconductor layer is Ti, It is effective to form an oxide film of Nb, Zn, Sn, In, and Cd.

  In addition, as the sheet-like conductive material, a material in which conductive particles are clogged in a void such as a conductive mesh may be used. In particular, when the resistance loss during the movement of electrons injected into the semiconductor layer to the perforated portion of the conductive material for current collection is large, the effect of reducing the resistance loss can be obtained by doing so. As described above, the sheet-like conductive material may be composed of one type of conductive material, or may be configured by combining a plurality of types of conductive materials.

  Furthermore, the part which provides the working electrode of the said sheet-like electroconductive material may be devised to collect incident light on the photoelectric conversion layer by configuring it with a high reflectance. In addition, it is also preferable to have a structure in which a working electrode having a semiconductor layer carrying a dye is multilayered to absorb incident light efficiently.

  In forming the insulating layer, for example, zirconium oxide, silica, aluminum oxide, tantalum oxide, or the like is used.

  Next, an Example is given and this invention is demonstrated more concretely. However, this invention is not limited only to those Examples.

Example 1
Tin oxide powder having an average primary particle size of 20 nm was dispersed in ethyl cellulose to prepare a screen printing paste. The obtained paste was filled in 80 mesh mesh made of titanium and dried. The sheet-like material thus obtained was pressed with a force of 100 t / cm ² . As a result, the tin oxide particles mechanically destroyed the natural oxide film formed on the surface of the titanium mesh, making contact between titanium and tin oxide, and reducing the interfacial resistance. Next, this sheet-like material was baked at 500 ° C. for 30 minutes and then washed with an aqueous nitric acid solution to remove the oxide film formed on the titanium surface to obtain a sheet-like conductive material.

  A counter electrode was provided by forming a Pt (platinum) film on a part of the surface of the sheet-like conductive material by sputtering. Next, a titanium oxide powder having an average primary particle size of 20 nm was dispersed in ethyl cellulose to prepare a screen printing paste. The obtained paste was applied to a portion where no Pt film was formed, and dried to provide a semiconductor layer. Next, zirconium oxide powder having an average primary particle size of 50 nm was dispersed in ethyl cellulose to prepare a paste for screen printing. The obtained paste was applied to the opposite side of the surface of the sheet-like conductive material on which titanium oxide was applied, and dried to provide an insulating layer. And the sheet-like electrically conductive material in which this counter electrode, the semiconductor layer, and the insulating layer were formed was baked in the air for 30 minutes at 500 degreeC.

Next, the sheet-like conductive material after firing is immersed in a sensitizing dye solution represented by [Ru (4,4′-dicarboxyl-2,2′-bipyridine) _2- (NCS) ₂ ], and the room temperature The working electrode was constructed by allowing the semiconductor layer to carry a sensitizing dye by allowing it to stand for 24 hours. As the sensitizing dye solution, a solution in which the sensitizing dye was contained at a concentration of 3 × 10 ⁻⁴ mol / dm ^{−3 in} a 50:50 volume ratio of acetonitrile and t-butanol was used. The above sensitizing dye was supported on the semiconductor layer by immersing it in a sensitizing dye solution at room temperature for 24 hours. In this way, the sensitizing dye was supported on the semiconductor layer, and the working electrode was provided on the sheet-like conductive material.

Next, the sheet-like conductive material provided with the working electrode and the counter electrode is overlapped in half between two substrates made of a transparent glass plate and filled with an electrolytic solution (liquid electrolyte). A photoelectric conversion element module having a structure as shown in FIG. 1 was prepared using a thermoplastic resin (trade name: bynel 4164). Here, the photoelectric conversion element module of Example 1 will be described with reference to FIG. 1. The substrates 3 and 7 are each made of a transparent glass plate, and the working electrodes 5.1 to 5.3 are made of a titanium oxide film. It is constituted by carrying a sensitizing dye on a semiconductor layer, the counter electrodes 9.1 to 9.3 are constituted by Pt films, the electrolytes 10.1 to 10.3 are 3-methoxypropionitrile, dimethylpropylimidazolium. the iodide 0.6 mol / dm ^-3, consists of iodine 0.1 mol / dm ^-3, liquid electrolyte comprising a N- methylbenzimidazole from those dissolving 0.5 mol / dm ^-3 (electrolyte), sealed Stops 11.1 to 11.4 are made of bynel (supra), conductive materials 12.1 to 12.4 are made of titanium mesh, and insulating layers 13.1 to 13.3 are made of zirconium oxide. Is There.

Example 2
A titanium film was formed on one surface of the glass fiber filter by vapor deposition. Next, the glass fiber filter on which the titanium film is formed is washed with a nitric acid aqueous solution, the oxide film formed on the titanium surface is removed to form a sheet-like conductive material, and a Pt film is formed on a part of the surface of the sheet-like conductive material. A counter electrode was formed by sputtering. Next, a titanium oxide powder having an average primary particle size of 20 nm was dispersed in ethyl cellulose to prepare a screen printing paste. The obtained paste was applied to the portion of the sheet-like conductive material where the Pt film was not formed, and dried to form a semiconductor layer. Next, the sheet-like conductive material on which the counter electrode and the semiconductor layer were formed was pressed with a force of 100 t / cm ² . As a result, the titanium oxide particles are pressed against the surface of the porous titanium film on the glass fiber filter, thereby mechanically destroying the natural oxide film formed on the surface of the titanium film. Was able to be reduced. And the sheet-like electrically conductive material in which this counter electrode and the semiconductor layer were formed was baked in the air for 30 minutes at 500 degreeC.

Next, the sheet-like conductive material after firing is immersed in a sensitizing dye solution represented by [Ru (4,4′-dicarboxyl-2,2′-bipyridine) _2- (NCS) ₂ ], and the room temperature The working electrode was constructed by allowing the semiconductor layer to carry a sensitizing dye by allowing it to stand for 24 hours. As the sensitizing dye solution, as in Example 1, the sensitizing dye was contained in a mixed solvent of acetonitrile and t-butanol in a volume ratio of 50:50 at a concentration of 3 × 10 ⁻⁴ mol / dm ^−3. The solution was used. The above sensitizing dye was supported on the conductive material layer by immersing it in a sensitizing dye solution at room temperature for 24 hours. In this way, the sensitizing dye was supported on the semiconductor layer, and the working electrode was provided on the sheet-like conductive material.

  Next, the sheet-like conductive material provided with the working electrode and the counter electrode is overlapped in half between two substrates made of a transparent glass plate, and the same electrolytic solution as in Example 1 is filled. A photoelectric conversion element module having a structure as shown in FIG. 1 was produced using a thermoplastic resin (trade name: bynel 4164) manufactured by the company as a sealing material. The photoelectric conversion element module of Example 2 is almost the same as the photoelectric conversion element module of Example 1 except that a glass fiber filter having a titanium film formed thereon is used as the base material of the conductive materials 12.1 to 12.4. It is constituted similarly.

Comparative Example 1
A part of the transparent conductive film of a glass plate with a transparent conductive film 1.1 mm thick (F-SnO ₂ , 10Ω / sq, manufactured by Asahi Glass Co., Ltd.) was removed in a stripe shape by etching treatment to obtain a transparent electrode. Next, a titanium oxide powder having an average primary particle size of 20 nm was dispersed in ethyl cellulose to prepare a screen printing paste. The obtained paste was apply | coated on the transparent electrode which consists of a transparent conductive film of the said glass plate with a transparent conductive film, and it dried. Next, tin oxide powder having an average primary particle size of 20 nm was dispersed in ethyl cellulose to prepare a screen printing paste. The obtained paste was applied to the end of the transparent conductive film in a line shape and dried. The dried material thus obtained was baked in air at 500 ° C. for 30 minutes, a semiconductor layer composed of a porous titanium oxide film having a thickness of 10 μm and a thickness of 35 μm on the transparent electrode of the substrate composed of the glass plate. And a conductive portion made of a tin oxide film.

Next, a substrate having a semiconductor layer composed of the porous titanium oxide film and the tin oxide film is represented by [Ru (4,4′-dicarboxyl-2,2′-bipyridine) _2- (NCS) ₂ ]. It was immersed in a sensitizing dye solution and allowed to stand at room temperature for 24 hours to form a working electrode. As the sensitizing dye solution, a solution in which the sensitizing dye was contained at a concentration of 3 × 10 ⁻⁴ mol / dm ^{−3 in} a 50:50 volume ratio of acetonitrile and t-butanol was used. The above sensitizing dye was supported on the semiconductor layer by immersing it in a sensitizing dye solution at room temperature for 24 hours. Thus, the sensitizing dye was supported on the semiconductor layer, and the working electrode was provided on the transparent electrode of the substrate.

For the counter electrode, a portion of the transparent conductive film of a glass plate with a transparent conductive film 1.1 mm thick (F-SnO ₂ , 10Ω / sq, manufactured by Asahi Glass Co., Ltd.) is removed in a stripe shape by etching treatment, 20 nm thick Pt was sputtered on the transparent electrode, and 5 mmol / dm ^-3 H ₂ PtCl ₆ solution (solvent: isopropyl alcohol) was applied on the Pt film at a rate of 10 μl / cm ^2. A counter electrode was formed by heat treatment at 15 ° C. for 15 minutes.

  In this manner, a thermoplastic resin (trade name: bynel 4164) manufactured by DuPont was used for bonding the substrate provided with the working electrode and the substrate provided with the counter electrode. The thermoplastic resin was heated at 150 ° C. for 30 seconds. The injection of the electrolytic solution is performed by a reduced pressure injection method from an injection port having a diameter of 1 mm provided on the counter electrode, and the injection port is sealed by fixing a cover glass of 500 μm thickness by bynel (described above). A photoelectric conversion element module having the structure shown was manufactured. Here, the photoelectric conversion element module of Comparative Example 1 will be described with reference to FIG. 2. The working electrodes 5.1 to 5.2 are respectively formed on the transparent electrodes 4.1 to 4.2 provided on the substrate 3. The counter electrodes 9.1 to 9.2 are formed on the transparent electrodes 8.1 to 8.2 provided on the substrate 7, respectively. And although the said transparent electrodes 8.1-8.2 are comprised by the transparent conductive film and the electrically conductive material 12 is comprised by the tin oxide, the other member, ie, the board | substrate 3, the board | substrate 7, and the working electrode 5.1. To 5.2, counter electrodes 9.1 to 9.2, electrolytes 10.1 to 10.2, sealing parts 11.1 to 11.4 and the like are the same as in the case of Example 1. And although the circumference | surroundings of this photoelectric conversion element module are not shown in figure, the sealing seal made from Anelva company was apply | coated and the improvement of sealing strength was aimed at.

Comparative Example 2
A part of the transparent conductive film of a glass plate with a transparent conductive film 1.1 mm thick (F-SnO ₂ , 10Ω / sq, manufactured by Asahi Glass Co., Ltd.) was removed in a stripe shape by etching treatment to obtain a transparent electrode. Next, a titanium oxide powder having an average primary particle size of 20 nm was dispersed in ethyl cellulose to prepare a screen printing paste. The obtained paste was apply | coated on the transparent electrode of the glass plate with a transparent conductive film, and it dried and formed the semiconductor layer. Next, zirconium oxide powder having an average primary particle size of 200 nm was dispersed in ethyl cellulose to prepare a paste for screen printing. The obtained paste was applied onto a semiconductor layer made of a titanium oxide film and dried to form an insulating layer. Next, a carbon powder having an average primary particle size of 20 nm and a carbon powder of 200 nm were dispersed in ethyl cellulose to prepare a screen printing paste. The obtained paste was applied onto an insulating layer made of a zirconium oxide film and dried to form a counter electrode. The obtained dried product was baked in air at 500 ° C. for 30 minutes, and a semiconductor layer made of a porous titanium oxide film having a thickness of 10 μm and an insulating film made of a zirconium oxide film having a thickness of 30 μm were formed on a substrate made of a transparent glass plate. A counter electrode comprising a layer and a carbon film having a thickness of 200 μm was formed. The structure of each film was arranged as shown in FIG.

Next, a substrate on which a semiconductor layer made of such a porous titanium oxide film, an insulating layer made of a zirconium oxide film, and a counter electrode made of a carbon film is formed [Ru (4,4′-dicarboxyl-2,2 It was immersed in a sensitizing dye solution represented by '-bipyridine) _2- (NCS) ₂ ] and allowed to stand at room temperature for 24 hours to carry the sensitizing dye on the semiconductor layer to constitute a working electrode. As the sensitizing dye solution, a solution in which the sensitizing dye was contained at a concentration of 3 × 10 ⁻⁴ mol / dm ⁻³ in a mixed solvent of acetonitrile and t-butanol in a volume ratio of 50:50 was used. The above sensitizing dye was supported on the semiconductor layer by immersing it in a sensitizing dye solution at room temperature for 24 hours.

  Next, as shown in FIG. 3, a working material, a counter electrode, and the like are covered with a laminate material in which a DuPont thermoplastic resin (trade name: bynel 4164) is pasted on both surfaces of an aluminum thin film and sealed. . The electrolytic solution was injected by a reduced pressure injection method from an injection port having a diameter of 1 mm provided in the laminate material, and a thermoplastic resin manufactured by DuPont (trade name: bynel 4164) was used for sealing the injection port. In this way, a photoelectric conversion element module having the structure shown in FIG. 3 was produced.

  Here, the photoelectric conversion element module of Comparative Example 2 will be described with reference to FIG. 3. In the photoelectric conversion element module 1 of Comparative Example 2, only one substrate is used, and the transparent electrode on the substrate 3 is used. The working electrode 5.1 is formed on 4.1, and the working electrode 5.2 is formed on the transparent electrode 4.2 on the substrate 3. One end of the counter electrode 9.2 of the photoelectric conversion element 2.2 is connected to the transparent electrode 4.1, and the working electrode 5.1 of the photoelectric conversion element 2.1 is formed on the transparent electrode 4.1. Therefore, between the two adjacent photoelectric conversion elements 2.1 to 2.2, the working electrode 5.1 of one of the photoelectric conversion elements 2.1 and the counter electrode 9.2 of the photoelectric conversion element 2.2 are connected in series. Has been. The working electrodes 5.1 to 5.2, the counter electrodes 9.1 to 9.2, the electrolyte, the insulating layers 15.1 to 15.2, and the like are covered and sealed with the laminate material 14. The constituent materials such as working electrode 5.1 to 5.2, counter electrode 9.1 to 9.2, electrolyte, and insulating layers 15.1 to 15.2 are substantially the same as those in the first embodiment. In FIG. 3, the electrolyte is not shown, but the electrolyte is placed in the gaps of the working electrodes 5.1 to 5.2, the counter electrodes 9.1 to 9.2, and the insulating layers 15.1 to 15.2. It exists in a satisfied state.

Comparative Example 3
A part of the transparent conductive film of a glass plate with a transparent conductive film 1.1 mm thick (F-SnO ₂ , 10Ω / sq, manufactured by Asahi Glass Co., Ltd.) was removed in a stripe shape by etching treatment to obtain a transparent electrode. Next, a 5 mmol / dm ⁻³ H ₂ PtCl ₆ solution (solvent: isopropyl alcohol) was applied to a part of the transparent electrode at a rate of 10 μl / cm ² and dried. Next, a titanium oxide powder having an average primary particle size of 20 nm was dispersed in ethyl cellulose to prepare a screen printing paste. The obtained paste was applied onto the transparent electrode of the glass plate and dried. The obtained dried product was baked in air at 500 ° C. for 30 minutes, and a counter electrode was formed by depositing Pt in a stripe pattern with a semiconductor layer made of a porous titanium oxide film having a thickness of 10 μm on a substrate made of a glass plate. did.

Next, a substrate having a semiconductor layer made of a porous titanium oxide film and a counter electrode made of a Pt film is represented by [Ru (4,4′-dicarboxyl-2,2′-bipyridine) _2- (NCS) ₂ ]. The working electrode was constituted by immersing the film in a sensitizing dye solution and allowing the semiconductor layer to carry the sensitizing dye by allowing it to stand at room temperature for 24 hours. As the sensitizing dye solution, a solution in which the sensitizing dye was contained at a concentration of 3 × 10 ⁻⁴ mol / dm ^{−3 in} a 50:50 volume ratio of acetonitrile and t-butanol was used. The above sensitizing dye was supported on the semiconductor layer by immersing it in a sensitizing dye solution at room temperature for 24 hours.

  Two substrates with electrodes were produced by the above-mentioned process, and a thermoplastic resin (trade name: bynel 4164) manufactured by DuPont was used for bonding the two substrates with electrodes. Bynel (supra) was heated at 150 ° C. for 30 seconds. The electrolyte solution is injected by a reduced pressure injection method from a 1 mm diameter injection port formed on the substrate on the side provided with the counter electrode, and the injection port portion is sealed with a 500 μm thick cover glass made of DuPont's thermoplastic resin (trade name) : Bynel 4164). In this way, an optoelectronic conversion element module having the structure shown in FIG. 4 was produced. Here, the photoelectric conversion element module of Comparative Example 3 will be described with reference to FIG. 4. The constituent material itself of the photoelectric conversion element module of Comparative Example 4 is the photoelectric conversion element module of Example 1 and the photoelectric conversion element of Comparative Example 1. Although it is the same as that of a conversion element module etc., in the photoelectric conversion element module 1 of this comparative example 3, among the three photoelectric conversion elements 2.1, 2.2, and 2.3, the adjacent photoelectric conversion element 2.1. And 2.2, the counter electrode 9.1 of the photoelectric conversion element 2.1 and the working electrode 5.2 of the photoelectric conversion element 2.2 are formed on the same transparent electrode 8.1. The counter electrode 9.1 of the conversion element 2.1 and the working electrode 5.2 of the photoelectric conversion element 2.2 can be electrically connected in series, and the photoelectric conversion element 2.2 and the photoelectric conversion element 2.3 Of the photoelectric conversion element 2.2 Since the electrode 9.2 and the working electrode 5.3 of the photoelectric conversion element 2.3 are formed on the same transparent electrode 4.2, the counter electrode 9.2 of the photoelectric conversion element 2.1 and the photoelectric conversion element 2. The counter electrode 5.3 of 2 can be electrically connected in series, but in the photoelectric conversion element module of Comparative Example 3, one of the adjacent photoelectric conversion elements passes through the counter electrode. It becomes a structure that reaches after that. Although not shown in the photoelectric conversion element module of Comparative Example 4, a tall seal manufactured by Anelva Co. is applied around the photoelectric conversion element module to improve the sealing strength.

Each of the photoelectric conversion element modules of Example 1 and Comparative Examples 1 to 3 was prepared in a state where five photoelectric conversion elements were connected in series, and the open circuit voltage was less than 2 V under an illuminance of 100 mW / cm ² . Those above 2V were counted as successes. The failure rate during the production of the photoelectric conversion element module was defined as follows, and 100 photoelectric conversion element modules were produced and evaluated. Hereinafter, the photoelectric conversion element module may be simplified and referred to as “module”, and the failure rate at the time of manufacturing the photoelectric conversion element module may be simplified and referred to as “module manufacturing failure rate”.
(Module production failure rate) (%) =
[(Number of failed modules) / (number of fabricated modules)] × 100

In addition, the conversion efficiency of each module was measured under an illuminance of 100 mW / cm ² , and 5% or more was rated as ◯, and less than 5% as x. The results are shown in Table 1. Note that, as can be seen from the method of calculating the module production failure rate, the module production failure means a failure related to electrical connection in series.

  As is clear from the results shown in Table 1, Examples 1 and 2 have no module production failure and high conversion efficiency. The photoelectric conversion element module of the present invention is adjacent to the conventional photoelectric conversion element module. It was clear that electrical connection between the counter electrode and the working electrode of the matching photoelectric conversion element can be performed easily and reliably, and high conversion efficiency can be realized.

It is sectional drawing which shows roughly one Embodiment of the photoelectric conversion element module of this invention. It is sectional drawing which shows roughly one Embodiment of the conventional photoelectric conversion element module. It is sectional drawing which shows schematically other embodiment of the conventional photoelectric conversion element module. It is sectional drawing which shows schematically other embodiment of the conventional photoelectric conversion element module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoelectric conversion element module 2 (2.1-2.3) Photoelectric conversion element 3 Board | substrate 5 (5.1-5.3) Working electrode 7 Board | substrate 9 (9.1-9.3) Counter electrode 10 (10.1 To 10.3) Electrolyte 11 (11.1 to 11.4) Sealing part 12 (12.1 to 12.4) Conductive material

Claims (4)

At least a working electrode having a semiconductor layer carrying a sensitizing dye, a counter electrode facing the working electrode, an electrolyte disposed between the working electrode and the counter electrode, and a seal that blocks contact between the electrolyte and the outside air A photoelectric conversion element module formed by connecting a plurality of photoelectric conversion elements having stop portions in series, independent of any substrate of the working electrode and the counter electrode, and having conductivity and partially having a through hole. A sheet-like conductive material is provided with a working electrode of one of the adjacent photoelectric conversion elements and a counter electrode of the other photoelectric conversion element, and the sheet-like conductive material is porous. A photoelectric conversion element module having a structure having a conductive film or layer on the support . At least a working electrode having a semiconductor layer carrying a sensitizing dye, a counter electrode facing the working electrode, an electrolyte disposed between the working electrode and the counter electrode, and a seal that blocks contact between the electrolyte and the outside air A photoelectric conversion element module formed by connecting a plurality of photoelectric conversion elements having stop portions in series, independent of any substrate of the working electrode and the counter electrode, and having conductivity and partially having a through hole. A sheet-like conductive material is provided with a working electrode of one of the adjacent photoelectric conversion elements and a counter electrode of the other photoelectric conversion element, and the sheet-like conductive material has a through hole. porous membrane is present, the photoelectric conversion element module that characterized that you have the semiconductor layer of the working electrode is provided on one surface of the conductive material having conductivity in the interior of the. The photoelectric conversion element module according to claim 1 wherein the sheet of conductive material, characterized in it to contain the Ti, Cr, Cu, at least one selected from the group consisting of Ni and Al. The photoelectric conversion element module according to claim 2 , wherein the sheet-like conductive material is formed by clogging conductive particles in a mesh-like void having conductivity .

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