JP4710291B2 - Photoelectric conversion element container, photoelectric conversion unit, and photoelectric conversion module - Google Patents

Description

  The present invention relates to a container suitable for use in a photoelectric conversion element such as a dye-sensitized solar cell, a photoelectric conversion unit in which the photoelectric conversion element is accommodated in the container, and a photoelectric conversion module including the photoelectric conversion unit. It is about.

  The dye-sensitized solar cell proposed by Gretzell et al. In 1991 has been attracting attention because it operates by a mechanism different from that of a silicon semiconductor pn junction and exhibits high conversion efficiency. A dye-sensitized solar cell realizes photoelectric conversion by injecting excited electrons generated by a dye by collecting light into a semiconductor. Therefore, it is important that a large amount of a sensitizing dye is supported on the semiconductor in order to increase the light collecting ability, and further that electrons are injected from the sensitizing dye into the semiconductor as soon as possible. This new dye-sensitized solar cell, also referred to as a Gretzel cell, solves this problem by supporting a ruthenium complex, which is a sensitizing dye, on a porous film made of ultrafine titanium oxide (for example, non-particles). Patent Document 1).

  The Gretzel cell can be assembled by simply applying a paste in which ultrafine particles of titanium oxide are dispersed to a transparent electrode to carry a sensitizing dye and filling an electrolyte between the counter electrode. Therefore, compared with the conventional solar cell, it can be manufactured with a simple device, and is attracting attention as one of the next generation solar cells.

  The output voltage of a single-cell dye-sensitized solar cell is about 0.7 V. To drive various devices with a dye-sensitized solar cell, for example, an output voltage of 1.5 V or 4 V or more is required. Therefore, it is necessary to increase the output voltage by connecting dye-sensitized solar cells in series. Under such circumstances, a technique for producing a module in which dye-sensitized solar cells are connected in series has been proposed (see, for example, Patent Document 1).

Gratzel, 1 other, “Nature” (UK), Oct. 24, 1991, volume 353, p. 737-740 JP 2004-119902 A

  Since the conventional solar cell is supplied by a module that outputs a predetermined rated voltage and rated current, a converter or the like has to be used to obtain a voltage and current desired by the user. Therefore, the power generated by the solar cell is lost by the converter drive power. Especially when using a solar cell as the power source for power-saving devices, the converter power loss cannot be ignored. is there.

  The present invention has been made in view of the above circumstances, and its purpose is to freely provide a photoelectric conversion element to provide a user with a photoelectric conversion element that supplies an appropriate voltage and current to a power saving device. A photoelectric conversion element container that can be connected in series and / or in parallel and that facilitates electrical connection between the photoelectric conversion elements, and a photoelectric conversion unit that contains the photoelectric conversion element in the container, Another object is to provide a photoelectric conversion module in which a plurality of the photoelectric conversion units are connected.

  The container of the photoelectric conversion element of the present invention that can achieve the above object (hereinafter sometimes simply referred to as “container”) is accommodated in the container body outside the container body and the side surface of the container body. Each of the positive electrode and the negative electrode of the photoelectric conversion element has two electrodes for electrical connection via a conductor, and the container body has a substantially quadrangular planar shape, and the two electrodes Are in contact with each other so as to face each other across the container body at locations corresponding to three sides of the substantially quadrangular shape that are adjacent to each other on the outside of the side surface of the container body. It is characterized by being arranged without any problems.

  The present invention also includes a photoelectric conversion unit in which a photoelectric conversion element is housed in the photoelectric conversion element container, and a photoelectric conversion module in which a plurality of the photoelectric conversion units are connected in series and / or in parallel. The

  According to the photoelectric conversion unit of the present invention in which the photoelectric conversion element is housed in the container of the present invention, the electrical connection between the photoelectric conversion elements is facilitated. Therefore, when connecting a plurality of photoelectric conversion elements, series connection and / or Parallel connection can be arbitrarily set, and the photoelectric conversion module of the present invention having a desired output voltage and output current can be easily provided.

  That is, the photoelectric conversion module of the present invention can easily change the connection configuration of the photoelectric conversion elements (photoelectric conversion units), and can easily secure a desired output voltage and output current.

  The container of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing an example of the container of the present invention. In FIG. 1, 1 is a container main body, 2 and 3 are electrodes. As shown in FIG. 1, the container of the present invention has a substantially quadrilateral planar shape (a shape in a plan view of the upper part of the container), and is housed in the container body 1 outside the side surface of the container body 1. Electrodes 2 and 3 for electrical connection via a conductor are disposed on each of the positive electrode and the negative electrode of the photoelectric conversion element.

  The two electrodes 2 and 3 are opposed to each other across the container body 1 at locations corresponding to three sides of the substantially quadrangular shape that are adjacent to each other on the outside of the side surface of the container body 1. And arranged without contacting each other. In other words, in the container of the present invention, for example, when the container body 1 is formed of a hexahedron having a quadrilateral top surface and a bottom surface and four side surfaces connecting the top surface and the bottom surface, the two electrodes 2 and 3 are These are arranged so as to face each other across the container main body 1 and not in contact with each other over three side surfaces adjacent to each other among the four side surfaces.

  In addition, the substantially quadrilateral planar shape of the container body 1 includes, for example, various quadrilaterals such as a square, a rectangle, and a parallelogram, and some or all of the corners of each quadrilateral are curved or notched. The thing which becomes is included.

  The container of the present invention has two electrodes arranged as described above. Therefore, the photoelectric conversion element is accommodated in the container body 1, and the positive electrode of the photoelectric conversion element is connected to one electrode 2 or 3 of the container, and the negative electrode of the photoelectric conversion element is connected to the other electrode 3 or 2 via a conductor. A plurality of photoelectric conversion units are prepared, and these are connected vertically and horizontally as shown in FIG. 2, FIG. 3, or FIG. 4, for example, and a plurality of photoelectric conversion elements are connected in series (FIG. 2) and connected in parallel. (FIG. 3) or series-parallel connection (FIG. 4) can be achieved.

  When the two electrodes are not arranged without being in contact with each other, the photoelectric conversion element housed in the container body cannot be short-circuited to generate power. Further, if the two electrodes are not arranged so as to face each other, even in the outer side of the side surface of the container body, at the positions corresponding to the three sides adjacent to each other of the substantially quadrangular shape representing the planar shape of the container body. Even if two electrodes are arranged, for example, as shown in FIG. 5, it is difficult to realize serial connection and / or parallel connection between the photoelectric conversion units. Further, the two electrodes are located on the outer side of the side surface of the container main body at locations corresponding to three non-adjacent sides of the substantially quadrilateral representing the planar shape of the container main body, or one side or two sides of the substantially quadrilateral. Or when arranged in the place corresponding to four sides, a series connection and / or a parallel connection may not be realized only by connecting a container arbitrarily vertically and horizontally.

  Note that the two electrodes 2 and 3 do not have to be continuous on the outside of the side surface of the container body, for example, as shown in FIG. The outer side surface of the container body may be divided.

  Thus, the container of the present invention can be easily connected in series and / or easily by arranging a plurality of containers vertically and horizontally without using an external connection terminal such as a battery holder due to the presence of the two electrodes. Electrical connection can be ensured so as to realize parallel connection.

  Further, in the container of the present invention, mechanical engagement can be easily achieved in addition to electrical connection between the photoelectric conversion elements by providing the engagement means as described below. Therefore, in the photoelectric conversion module of the present invention formed by connecting a plurality of photoelectric conversion units of the present invention in which the photoelectric conversion element is housed in the container of the present invention, a support for maintaining the mechanical structure is used. It does not have to be.

  Examples of the engaging means include (1) an engaging means that uses the action of magnetic force, and (2) an engaging means that uses a fitting between a concave portion and a convex portion, such as a side-to-side hole relationship. Can be mentioned. In addition to these engaging means, for example, engaging means such as hooks or fasteners can be employed.

  Specifically, the engaging means of (1) includes arranging a magnet and a magnetic body on the side surface of the container body. In order to arrange these, for example, a magnet is disposed at a position corresponding to any one side of the substantially quadrilateral representing the planar shape of the container in the side surface of the container main body, and faces the one side of the substantially quadrilateral It is recommended that a magnetic material is disposed at a position corresponding to one side, and that these magnets and magnetic materials are disposed so as to face the magnetic materials and magnets disposed in a container adjacent to the container.

  Further, the magnetic body combined with the magnet may be a magnet arranged so as to have a different polarity from the magnet, and by using this, an error in electrical connection between the photoelectric conversion elements can be prevented. . That is, if a photoelectric conversion element (photoelectric conversion unit) is to be connected between incorrect poles, the magnet poles of the containers become the same, and therefore the connection cannot be made by repulsive magnetic action.

  Examples of the engaging means (2) include providing a convex portion and a concave portion having a shape capable of fitting the convex portion on the side surface portion of the container main body. In order to provide these, for example, among the side surfaces of the container main body, a convex portion is provided at a position corresponding to any one side of the substantially quadrilateral representing the planar shape of the container, and one side facing the one side of the substantially quadrilateral It is recommended that a concave portion is provided at a position corresponding to, and that the convex portion and the concave portion are provided so as to face the concave portion and the convex portion provided in the container adjacent to the container.

  Further, for a plurality of containers, for example, the side connected to the electrode side connected to the positive electrode of the photoelectric conversion element to be accommodated is a convex portion, and the side connected to the electrode side connected to the negative electrode is a concave portion. Moreover, erroneous electrical connection can be prevented by separating the shape of the convex concave portion for each polarity to be connected.

  In order to simply prevent erroneous electrical connection, for example, a positive or negative mark may be engraved on the container.

  From the viewpoint of ensuring electrical connection between the photoelectric conversion elements (that is, photoelectric conversion units), it is desirable that at least one of the two electrodes according to the container of the present invention has elasticity. In order to give the electrode elasticity, for example, the electrode itself has a spring structure, or a conductive spring is retrofitted to the material constituting the electrode to form an electrode as a whole, or a conductive substance such as metal powder or graphite is used. An elastic body such as rubber may be attached to the material constituting the electrode to form the electrode as a whole.

  Each of the two electrodes arranged on the side surface portion of the container of the present invention is electrically connected to one of the positive electrode and the negative electrode of the photoelectric conversion element housed in the container body via a conductor. The conductor is not particularly limited as long as it has conductivity, and a conductive wire, metal foil, metal mesh, conductive tape, conductive sheet, conductive film, and the like can be used.

  In the container of the present invention, it is desirable that the container body is made of an insulating material in order to prevent a short circuit between the two electrodes. Specifically, as long as it is an insulating material, it is not particularly limited, and wood, ceramics, and the like can be used, but plastics that are easy to mold and cut containers are preferable. Suitable plastics include, for example, acrylic resin, acrylonitrile-butadiene-styrene resin, acrylonitrile-styrene resin, polystyrene, polyvinyl chloride, polyamide, polycarbonate, polyacetal, polyphenylene sulfide, polyethylene, polypropylene, fluororesin, phenol resin, A polyester resin etc. can be illustrated.

  Moreover, as a raw material of two electrodes, if it has electroconductivity, it will not specifically limit, A conducting wire, metal foil, a metal mesh, a conductive tape, a conductive sheet, a conductive film etc. can be used.

  Further, in the container of the present invention, from the viewpoint of efficiently generating the photoelectric conversion element housed therein, a portion that takes light into the container body in order to irradiate the photoelectric conversion element with light, for example, the upper surface portion of the container body It is preferable that at least one of the bottom portion and the bottom portion is constituted by a cover having a portion having a total light transmittance of 80% or more. In consideration of only light capture, it is possible to provide nothing on the top surface or bottom surface of the container body, but in this case, the photoelectric conversion element may come off from the container and may be damaged. It is desirable to provide a cover. The material of the cover is not particularly limited as long as it has translucency and can achieve the above-mentioned total light transmittance. For example, glass; regenerated cellulose, diacetate cellulose, triacetate cellulose, tetraacetyl cellulose, polyethylene, polypropylene , Polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, polycarbonate, polyethylene naphthalate, polyethersulfone, polyetheretherketone, polysulfone, polyetherimide, polyimide, polyarylate, cycloolefin polymer, norbornene resin, And plastics such as polystyrene, hydrochloric acid rubber, nylon, polyacrylate, polyvinyl fluoride, and polytetrafluoroethylene.

  In addition, the total light transmittance of the said cover attaches the integrating sphere apparatus for jewelry measurement made from JASCO Corporation to the ultraviolet visible spectrophotometer "V-570" made by JASCO Corporation, and the sample in wavelength 380-780 nm is attached. The scattering rate data and the total light transmittance data were measured and calculated with a haze value calculation program manufactured by JASCO Corporation. This program consists of JIS K 7105: 1981 Plastic Optical Properties Test Method, JIS K 7136: 2000 Plastic-Transparent Material Haze Determination Method, and JIS K 7361: 1997 Plastic-Transparent Material Total Light Transmittance Test Method. In accordance with the test method described in.

  Moreover, in order to prevent deterioration of photoelectric conversion characteristics due to ultraviolet rays, the cover preferably has an ultraviolet cut function. A method for imparting an ultraviolet cut function to the cover is not particularly limited, and various conventionally known methods (for example, a known ultraviolet cut agent is contained in the plastic constituting the cover) can be applied.

  The container of the present invention contains a photoelectric conversion element. Not only a single cell (single element) of a photoelectric conversion element, but also a module in which photoelectric conversion elements are connected in series and / or in parallel. Can be stored. Moreover, the container of this invention can be used as a container of photoelectric conversion elements of all kinds, such as a silicon type solar cell, a compound semiconductor type solar cell, a thin film type solar cell, and an organic type solar cell.

  The container of the present invention is also suitable as a container for a dye-sensitized solar cell that is promising as a drive power source for a power-saving device. A schematic cross-sectional view showing an example of the dye-sensitized solar cell is shown in FIG. A dye-sensitized solar cell (photoelectric conversion element) 10 in FIG. 6 has a transparent electrode 12 (first electrode) formed on one surface of a transparent substrate 11. A semiconductor layer 16 carrying a sensitizing dye is formed on the surface opposite to the 11 side. Further, a counter electrode 14 (second electrode) is present facing the semiconductor layer 16 carrying the sensitizing dye. The counter electrode 14 is formed on one surface of another substrate 15. An electrolyte layer 17 exists between the semiconductor layer 16 and the counter electrode 14. That is, the photoelectric conversion element 10 of FIG. 6 includes a first substrate 11 including a first electrode 12 having a semiconductor layer 16 supporting a dye, and a second electrode 14 facing the semiconductor layer 16. The second substrate 15 is opposed to the second substrate 15 in a state where an electrolyte (electrolyte layer 17) is held between the semiconductor layer 16 and the second electrode 14. And the sealing material 18 is arrange | positioned so that the electrolyte layer 17 may be hold | maintained between the semiconductor layer 16 and the 2nd electrode 14, and the area | region where the electrolyte layer 17 exists is sealed.

  In the photoelectric conversion element 10, the conductive terminal 13 is preferably attached to each of the first electrode 12 and the second electrode 14. Since the presence of the conductive terminal 13 can improve the contact with the conductor for electrically connecting the two electrodes according to the container of the present invention, the current generated by the photoelectric conversion element 10 can be more reliably taken out. Will be able to.

  The material of the conductive terminal 13 is not particularly limited as long as it has conductivity. For example, any metal can be used, but it is desirable to select a material that has a small increase in contact resistance due to oxidation or the like. Specifically, for example, nickel, copper, brass, phosphor bronze, beryllium copper, white, aluminum, stainless steel, nickel plated copper alloy, nickel plated steel, and gold plating, silver plating, solder plating or palladium plating are applied to these. It is preferable to include at least one selected from the group consisting of the above.

  Although the material which comprises the transparent substrate 11 will not be specifically limited if it has translucency, Usually, glass and a transparent resin film are used. Moreover, the higher the light transmittance of the transparent substrate 11, the better. The preferable light transmittance is 50% or more, more preferably 80% or more, in terms of the total light transmittance measured by the same method as the cover according to the container of the present invention.

  The first electrode 12 functions as a negative electrode in the photoelectric conversion element 10. The first electrode 12 is desirably excellent in light transmission as well as conductivity. Examples of the material of the first electrode 12 include zinc oxide, indium-tin composite oxide (ITO), and a conductive layer in which ITO and silver are laminated. Examples thereof include a body layer, antimony-doped tin oxide, and fluorine-doped tin oxide. Of these, tin oxide doped with fluorine is preferred from the viewpoints of conductivity and light transmittance.

  The lower the surface resistance of the first electrode 12, the better. The range of the surface resistance is preferably 50Ω / □ or less, more preferably 30Ω / □ or less. The lower limit of the surface resistance is not particularly limited, but is usually 0.1Ω / □.

  The higher the light transmittance, the better the first electrode 12 is. A preferable light transmittance is 50% or more, more preferably 80% or more in terms of the total light transmittance measured by the same method as the cover according to the container of the present invention. The thickness of the first electrode 12 is preferably 0.1 to 10 μm. This is because an electrode film having a uniform thickness can be formed with such a thickness, and light transmittance is not lowered, and sufficient light can be incident on the semiconductor layer 16. In this case, light is preferably incident from the side of the transparent substrate 11 having the first electrode 12, and the light is stored in the container so that the side of the transparent substrate 11 is the cover side.

  In the formation of the semiconductor layer 16, a dispersion coating of semiconductor particles, for example, a coating method using a doctor blade or a bar coater, a spray method, a dip coating method, a screen printing method, a gravure printing method, a spin coating method, an electrodeposition method, etc. Thus, it is preferable to apply a layer on the surface of the first electrode 12 to form a layer, and then to perform a fixing treatment of the semiconductor layer 16 as necessary.

  Examples of the immobilization treatment include heat treatment and pressure treatment. As the heat treatment, a heating method using an electric furnace, a hot plate, a microwave, an electron beam or the like is preferable, and the heating temperature is preferably about 400 to 600 ° C. when a glass substrate is used as the transparent substrate 11. Further, when a resin film such as polyethylene naphthalate (PEN) is used as the transparent substrate 11, if the semiconductor layer 16 is heat-treated at a temperature within the above range, the resin film may be deformed or the first film such as ITO may be used. The electrode 12 may peel from the resin film. Therefore, when a resin film is used, heat treatment is performed at a temperature of 200 ° C. or lower, and further, pressure is applied to the semiconductor layer 16 to suppress deformation of the resin film and peeling of the first electrode 12. Is desirable. Examples of the method for pressurizing the semiconductor layer 16 include a method using a press or a calendar.

  The thickness of the semiconductor layer 16 is preferably 0.1 μm or more and 100 μm or less. This is because such a thickness provides a sufficient photoelectric conversion effect and does not deteriorate the light transmittance with respect to visible light and near-infrared light. The thickness of the semiconductor layer 16 is more preferably 1 μm or more, further preferably 5 μm or more, particularly preferably 10 μm or more, more preferably 50 μm or less, still more preferably 30 μm or less, and particularly preferably 20 μm or less.

Examples of the semiconductor material used for forming the semiconductor layer 16 include Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, and Sr. Metal oxides such as Ga, Si, Cr, etc .; Perovskites such as SrTiO ₃ , CaTiO ₃ ; CdS, ZnS, In ₂ S ₃ , PbS, Mo ₂ S, WS ₂ , Sb ₂ S ₃ , Bi ₂ S ₃ , Sulfides such as ZnCdS ₂ and Cu ₂ S; Metal chalcogenides such as CdSe, In ₂ Se ₃ , WSe ₂ , HgS, PbSe, and CdTe; GaAs; Si; Se; Cd ₂ P _3; Zn ₂ P ₃ ; InP; AgBr PbI ₂ ; HgI ₂ ; BiI ₃ ; and the like, or a composite containing at least one selected from the above semiconductor materials, for example, CdS / Ti O ₂ , CdS / AgI, Ag ₂ S / AgI, CdS / ZnO, CdS / HgS, CdS / PbS, ZnO / ZnS, ZnO / ZnSe, CdS / HgS, CdS _x / CdSe _1-x , CS _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, etc. . Among these, TiO ₂ is preferable in terms of achieving avoidance of light dissolution in the electrolyte and ensuring high photoelectric conversion characteristics in the Gretzel cell (dye-sensitized solar cell).

  The semiconductor material is usually used in a particle shape, and the particle size of the semiconductor particles at that time is preferably preferably 5 to 1000 nm. With such a particle size, the pore size of the semiconductor layer 16 becomes appropriate, the oxidation-reduction substance in the electrolyte solution can easily move, and the photocurrent does not decrease, and the semiconductor layer 16 This is because a sufficient amount of dye can be obtained, and as a result, a large photocurrent can be obtained. The particle size of the semiconductor particles is particularly preferably 10 to 100 nm.

  By controlling the thickness of the semiconductor layer 16 and the particle size of the semiconductor particles, the roughness factor that is the ratio of the actual area inside the semiconductor layer to the support area of the semiconductor layer 16 can be determined. The roughness factor is preferably 20 or more, more preferably 150 or more. This is because within this range, the amount of the dye supported becomes sufficient and the photoelectric conversion characteristics can be improved. The upper limit of the roughness factor is generally about 5000. The roughness factor increases as the thickness of the semiconductor layer 16 increases, and the surface area of the semiconductor layer 16 increases, so that an increase in the amount of dye supported can be expected. However, if the thickness becomes too thick, an influence on the light transmittance and resistance loss of the semiconductor layer 16 starts to appear.

  Further, when the semiconductor layer 16 is formed, a surfactant, polyethylene glycol, a cellulose-based material, or the like is added, and the semiconductor layer 16 is made porous by burning them during the heat treatment of the semiconductor layer 16. The roughness factor can be increased without increasing the thickness by increasing the porosity of the semiconductor layer 16 by changing the particle size of the semiconductor layer 16. However, if the porosity becomes too high, the contact area between the semiconductor particles decreases, and the influence on the resistance loss must be taken into consideration. For this reason, the porosity of the semiconductor layer 16 is preferably 50% or more, and its upper limit is generally about 80%. The porosity of the semiconductor layer 16 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 to be carried on the semiconductor layer 16, any sensitizing dye commonly used in conventional dye-sensitized photoelectric conversion elements can be used. Examples of such a dye include a RuL ₂ (H ₂ O) ₂ type ruthenium-cis-diaqua-bipyridyl complex, ruthenium-tris (RuL ₃ ), ruthenium-bis (RuL ₂ ), and osmium-tris (OsL _3). ), Osmium-bis (OsL ₂ ) type transition metal complex (wherein “L” is 4,4′-dicarboxyl-2,2′-bipyridine), or zinc-tetra (4-carboxyl) Phenyl) porphyrin, iron-hexocyanide complex, phthalocyanine and the like. Also, 9-phenylxanthene dyes, coumarin dyes, acridine dyes, triphenylmethane dyes, tetraphenylmethane dyes, quinone dyes, azo dyes, indigo dyes, cyanine dyes, merocyanine dyes, xanthenes Organic dyes such as system dyes can also be used. Among these, ruthenium-bis (RuL ₂ ) derivatives are particularly preferable because they have a broad absorption spectrum in the visible light region.

  Examples of the method of supporting the sensitizing dye on the semiconductor layer 16 include a method of immersing the transparent substrate 11 having the first electrode 12 on which the semiconductor layer 16 is deposited in a solution in which the sensitizing dye is dissolved. The solvent of this solution may be any solvent that can dissolve the sensitizing dye, such as water, alcohol, toluene, and dimethylformamide. However, when the transparent substrate 11 is a resin film, the resin film is not deteriorated. It is desirable to choose one. Further, as a dipping method, when the transparent substrate 11 having the first electrode 12 having the semiconductor layer 16 adhered to the sensitizing dye solution is dipped for a certain time, heating reflux is applied or ultrasonic waves are applied. You can also In order to remove the sensitizing dye remaining on the semiconductor layer 16 without being supported after the dye is supported on the semiconductor layer 16, it is preferable to wash with a cleaning solution such as alcohol or acetonitrile.

  Furthermore, it is also preferable to coat the surface of a semiconductor particle on which no sensitizing dye is supported with t-butylpyridine. For this purpose, a solution in which t-butylpyridine is dissolved in a solvent such as alcohol or acetonitrile is used. It is also recommended to treat the surface. By performing such treatment, at the semiconductor particle / electrolyte interface, the surface of the semiconductor particle and the electrolyte can be separated by t-butylpyridine, so that leakage current can be suppressed, and the characteristics of the photoelectric conversion element can be reduced. This is because it can be remarkably improved.

The amount of the sensitizing dye supported on the semiconductor particles may be 1 × 10 ⁻⁸ to 1 × 10 ⁻⁶ mol / cm ² , particularly 0.1 × 10 ^{−7 to} 9.0 × 10 ⁻⁷ mol. / Cm ² is more preferable. This is because with such a loading amount, the effect of improving the photoelectric conversion efficiency can be obtained economically and sufficiently.

  The second electrode 14 functions as the positive electrode of the photoelectric conversion element 10. The second electrode 14 can be formed in the same manner as the first electrode. However, in order to efficiently function as the positive electrode of the photoelectric conversion element 10, the second electrode 14 is formed of a material having a catalytic action for supplying electrons to the electrolyte reductant. Is preferred. Examples of such a material include metals such as platinum, gold, silver, copper, aluminum, rhodium, and indium; graphite; conductive metal oxides such as ITO and fluorine-doped tin oxide; and the like. Of these, platinum and graphite are particularly preferred. The substrate 15 on the side on which the second electrode 14 is disposed can also have a transparent conductive film on the surface to which the second electrode 14 is attached (that is, between the second electrode 14 and the substrate 15) ( Not shown). This transparent conductive film can be formed of the same material as the first electrode 12, for example. In this case, the second electrode 14 is also preferably transparent.

  Furthermore, in order to more reliably extract current from the first electrode 12 and the second electrode 14 through the conductive terminal 13, the first electrode 12 and the second electrode 14 are connected to copper, nickel, gold It is also recommended to apply single or multilayer plating.

  For the substrate 15, a metal or the like can be used in addition to the same glass or transparent resin film as the transparent substrate 11. The substrate 15 may be opaque, but is preferably transparent in that light can be incident on the photoelectric conversion element 10 not only from the transparent substrate 11 side but also from the substrate 15 side.

In the photoelectric conversion element 10, an electrolyte layer 17 exists between the semiconductor layer 16 and the second electrode 14. The electrolyte of the electrolyte layer is not particularly limited as long as the solvent contains a pair of redox constituents composed of an oxidant and a reductant, but the oxidant and the reductant have the same charge. The oxidation-reduction type | system | group substance which has is preferable. As used herein, the redox-based constituent material refers to a pair of substances that reversibly exist in the form of an oxidant and a reductant in an oxidation-reduction reaction. The oxidized form refers to an oxidized electrolyte (for example, I ³⁻ ), and the reduced form refers to a reduced state electrolyte (for example, I ⁻ ).

  Examples of the redox constituents that can be used in the electrolyte layer 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, but are not limited thereto. Among these, an iodine compound-iodine is 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 pyridium iodide; iodine such as dimethylpropylimidazolium iodide. Particularly preferred are diimidazolium fluoride compounds.

  The electrolyte is usually prepared by dissolving an electrolytic substance in a solvent. As the solvent used for dissolving the electrolytic substance, either an aqueous solvent or an organic solvent can be used, but an organic solvent is preferable in order to further stabilize the redox constituent. 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-oxozozirinone and 2-methylpyrrolidone; nitriles such as acetonitrile, methoxyacetonitrile and propionitrile Compounds; aprotic polar compounds such as sulfolane, dimethyl sulfoxide, dimethylformamide; and the like. These solvents can be used alone or in combination of two or more. Of these, carbonate compounds such as ethylene carbonate and propylene carbonate; heterocyclic compounds such as 3-methyl-2-oxozozirinone and 2-methylpyrrolidone; nitrile compounds such as acetonitrile, methoxyacetonitrile and propionitrile; are particularly preferable. .

  Further, 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 constituting the sealing material 18 include polyolefin (low density polyethylene, ethylene / α-olefin copolymer, etc.), butyl rubber, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid. Polymer (ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, etc.), acrylic resin, silicone resin (silicone resin) In addition to ionomer resins and polyisobutylene resins, polystyrene-based, polyolefin-based, polydiene-based, polyester-based, polyurethane-based, fluororesin-based, and polyamide-based elastomers can be used. Among these, silicone resins, ionomer resins, polyolefins, polyisobutylene resins, butyl rubber, fluororesin elastomers and the like are preferable. Also, when a nitrile solvent (nitrile compound) or a carbonate solvent (carbonate compound) is used as the electrolyte solvent, those having low compatibility with those solvents are preferable. For example, silicone resins, ionomer resins, polyisobutylene resins are used. Hot melt resins composed of resins, polyolefins, thermosetting olefin resins and the like are preferable. Moreover, in order to improve those weather resistance, the sealing material 18 can be mixed with a crosslinking agent, a ultraviolet absorber, etc. suitably.

  Furthermore, a silane coupling agent, a titanate coupling agent, or the like may be added to the sealing material 18 in order to increase the adhesive force between the first electrode 12 and the second electrode 14. In addition, the first electrode 12 and the second electrode 14 are previously subjected to wet cleaning, chemical cleaning, plasma processing, ozone processing, ultraviolet irradiation processing, ultrasonic processing, surface polishing processing, etc. Activation may be performed.

  The photoelectric conversion element 10 can be entirely covered with a fluororesin (not shown). Thereby, the intensity | strength and impact resistance of the photoelectric conversion element 10 can be improved. Since this fluororesin is used in the outermost layer of the photoelectric conversion element 10, it is preferable that it is excellent in gas barrier properties against water vapor and the like, light resistance against ultraviolet rays, transparency, strength, and weather resistance.

  Various photoelectric conversion elements as described above are accommodated in the container of the present invention, and the positive electrode and the negative electrode of the photoelectric conversion element are respectively connected to one of the two electrodes of the container to obtain the photoelectric conversion unit of the present invention. It is done. And the photoelectric conversion module of this invention by which the electrical connection was achieved by arranging the photoelectric conversion unit of this invention vertically and horizontally as shown, for example in FIG.2, FIG.3 and FIG.4 becomes.

  The shape and method of the external terminal for extracting current from the photoelectric conversion module of the present invention are not particularly limited as long as a desired output can be extracted. There is a method of connecting a conductive wire, a metal foil or the like to a container electrode with a conductive adhesive or a conductive tape. Further, if the rated voltage and the rated current are determined, the series number and the parallel number of photoelectric conversion elements (photoelectric conversion units) to be connected are determined, and as a result, a plurality of containers (photoelectric conversion units) are arranged vertically and horizontally. Since the arrangement is determined, the external terminal may be formed using a holder (battery holder) having a shape suitable for the arrangement. Of course, regardless of whether or not this battery holder is used, series connection and / or parallel connection between photoelectric conversion elements has already been achieved in the container (photoelectric conversion unit) of the present invention. It may be formed to devise a device that makes electrical connection between photoelectric conversion elements (photoelectric conversion units) more reliable.

  As described above, since the photoelectric conversion element container of the present invention facilitates electrical connection (and mechanical engagement) between the photoelectric conversion elements, the photoelectric conversion elements can be connected in series and / or in parallel. Since it can be set arbitrarily, it can contribute to a new application that cannot be applied to a module in which a single cell or standard is defined.

  Hereinafter, based on an Example, this invention is described in detail. However, the following examples are not intended to limit the present invention, and all modifications made without departing from the spirit of the preceding and following descriptions are included in the technical scope of the present invention.

Nippon Aerosil Co., Ltd. in a mixed solution (volume mixing ratio: water / acetylacetone = 20/1) of water and acetylacetone containing 0.01 g / dm ³ of a surfactant “Nonipol 100” (trade name) manufactured by Sanyo Kasei Co., Ltd. A slurry liquid was prepared by dispersing titanium oxide particles “P25” (trade name, average particle diameter 20 nm) manufactured by the company so that the concentration was 2% by mass. Next, conductive glass “F-SnO ₂ ” manufactured by Asahi Glass Co., Ltd. which is a glass substrate with a transparent electrode coated with SnO ₂ doped with fluorine on the surface to impart conductivity (trade name, thickness: 1. The slurry liquid was applied to a size of 2 cm × 4 cm on a transparent electrode having a thickness of 1 mm and a surface resistance of 10Ω / □, and dried. Thereafter, the obtained dried product was baked in the air at 500 ° C. for 30 minutes to form a titanium oxide film (semiconductor layer) having a thickness of 7 μm on the conductive glass. Subsequently, this substrate was treated with a sensitizing dye represented by [Ru (4,4′-dicarboxyl-2,2′-bipyridine) ₂ (NCS) ₂ ] at a concentration of 3 × 10 ⁻⁴ mol / dm ^3. A transparent electrode with a glass substrate was produced by immersing in the ethanol solution contained in the above and performing a dye adsorption treatment.

As the glass with board-to-electrode, the Asahi Glass Co., Ltd. of the conductive glass "F-SnO _2" was used platinum those deposited to a thickness of 20 nm.

Between the transparent electrode (first electrode) and the counter electrode (second electrode), a frame-shaped encapsulant with a width of 5 mm so as to surround the periphery of the titanium oxide film [DuPont Hot Melt resin “Bynel” (trade name)] was disposed and fused except for a portion (electrolyte injection portion) where the electrolyte was injected. Subsequently, an electrolyte solution was injected from the electrolyte injection portion by a reduced pressure injection method. After wiping off the excess electrolyte solution adhering to the electrolyte injection part, only this electrolyte injection part was fused, and the photoelectric conversion element was produced. As the electrolyte solution, a mixed solution of ethylene carbonate and acetonitrile containing 0.5 mol / dm ³ tetrapropylammonium iodide and 0.04 mol / dm ³ iodine (volume mixing ratio: ethylene carbonate / acetonitrile = 80). / 20) was used.

  A perspective view of the photoelectric conversion element manufactured by the above method is shown in FIG. After the copper and nickel multilayer plating was applied to the current collecting portion of the transparent electrode and the counter electrode, a metal terminal (terminal A) having a U-shaped cross section was attached. The current collection effect of the photoelectric conversion element was enhanced by plating and metal terminals. FIG. 8 shows a state in which the metal terminal is mounted. In FIG. 8, 13a is a metal terminal (terminal A), and other elements are the same as those in FIG.

  FIG. 9 is a perspective view of an acrylic container (container body 1) for containing the photoelectric conversion element 10 on which a U-shaped metal terminal (terminal A) 13a is mounted. A magnet 20a for engaging with an adjacent container and an iron piece 20b that can be engaged by a magnetic force at a corner facing the adjacent container are disposed at the corners of the side surface of the container body 1.

  Further, holes 21 provided in the vicinity of the four corners of the wall of the container body 1 shown in FIG. 9 are holes for inserting positioning pins for accurately positioning the container cover. Note that these holes do not necessarily have to be in the corners as in this embodiment, and the positions thereof may be appropriately selected in consideration of other components.

  FIG. 10 shows a perspective view of a state in which the photoelectric conversion element 10 is housed in the acrylic container (container body 1) and various terminal plates for electrical connection are mounted. The photoelectric conversion element 10 equipped with the metal terminal (terminal A) 13a was connected to U-shaped metal terminal plates (terminal B) 22a and 22b for enabling serial connection and parallel connection. And at least 1 side of this U-shaped metal terminal board (terminal B) 22a, 22b and the metal terminal board (terminal C) 23a, 23b, 23c which have elasticity were connected. Metal terminal plates (terminal D) 24a, 24b, and 24c are arranged on the sides facing the metal terminal plates (terminal C) 23a, 23b, and 23c in order to electrically connect the containers of the adjacent photoelectric conversion elements. . That is, the electrode composed of the metal terminal plates 22a, 23a, 23b, and 24b and the electrode composed of the metal terminal plates 22b, 23c, 24a, and 24c are the two electrodes (the electrodes in FIG. 2 and 3).

  Subsequently, as shown in FIG. 11, a container cover 25 including a transparent window 26 having a total light transmittance of 80% or more and a container lid 27 is attached to the container body 1 using the positioning pin hole 21. Attached. In addition, as shown in FIG. 11, each side of the container cover 25 is provided with uneven portions for ensuring mechanical engagement and preventing electrical misconnection. The photoelectric conversion unit 28 of the present invention produced as described above is shown in FIG.

  FIG. 13 shows a set of photoelectric conversion modules 29 in which four photoelectric conversion units 28 are produced, two of these containers are connected in series, and two of these containers are connected in parallel.

It is a schematic plan view which shows an example of the container of the photoelectric conversion element of this invention. It is a schematic plan view which shows a mode that four containers of FIG. 1 were connected in series. It is a schematic plan view which shows a mode that four containers of FIG. 1 were connected in parallel. It is a schematic plan view which shows a mode that the container of FIG. 1 was connected in 4 series 2 parallel. It is a general | schematic top view which shows an example of the container which does not correspond to this invention. It is a schematic sectional drawing which shows an example of the photoelectric conversion element which can be accommodated in the container of this invention. It is a general | schematic perspective view which shows the photoelectric conversion element produced in the Example. It is a general | schematic perspective view which shows the state which attached the metal terminal to the photoelectric conversion element of FIG. It is a general | schematic perspective view which shows the container of the photoelectric conversion element produced in the Example. FIG. 10 is a schematic perspective view showing a state where each terminal plate is mounted on the container of FIG. 9. It is a general | schematic perspective view which shows the container cover used in the Example. It is a schematic plan view which shows the photoelectric conversion unit produced in the Example. It is a schematic plan view which shows the photoelectric conversion module which connected the photoelectric conversion unit produced in the Example 2 series 2 parallel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Container body 2 Electrode 3 Electrode 10 Photoelectric conversion element 11 Transparent substrate 12 1st electrode 13 Conductive terminal 13a Metal terminal (terminal A)
14 Second electrode 15 Substrate 16 Semiconductor layer carrying sensitizing dye 17 Electrolyte layer 18 Sealing material 19 Light incident direction 20a Magnet 20b Iron piece 21 Pin hole 22a, 22b Metal terminal plate (terminal B)
23a, 23b, 23c Metal terminal board (terminal C)
24a, 24b, 24c Metal terminal board (terminal D)
25 Container Cover 26 Transparent Window 27 Container Lid 28 Photoelectric Conversion Unit 29 Photoelectric Conversion Module

Claims (12)

A container of photoelectric conversion elements,
The container includes two containers for electrically connecting via a conductor to each of a positive electrode and a negative electrode of a photoelectric conversion element housed in the container main body, outside the side surface of the container main body. Have electrodes,
The container body has a substantially quadrilateral planar shape,
The two electrodes are opposed to each other across the container body at locations corresponding to three sides of the substantially quadrangular shape that are adjacent to each other on the outside of the side surface of the container body, and A container for photoelectric conversion elements, which is arranged without being in contact with each other.   The container of the photoelectric conversion element of Claim 1 with which the magnet and magnetic body for engaging with the container adjacent to this container are distribute | arranged to the side part of the container main body in the said container.   The container of the photoelectric conversion element of Claim 1 or 2 with which the convex part and recessed part for engaging with the container adjacent to this container are provided in the side part of the container main body in the said container.   The container of the photoelectric conversion element according to claim 1, wherein at least one of the two electrodes has elasticity.   5. The photoelectric conversion element container according to claim 1, wherein at least one of the upper surface portion and the lower surface portion of the container body is configured by a cover having a portion having a total light transmittance of 80% or more. .   The container of the photoelectric conversion element according to claim 5, wherein the cover has an ultraviolet cut function.   The container of the photoelectric conversion element according to any one of claims 1 to 6, wherein the container body is made of an insulating material.   A photoelectric conversion unit comprising a photoelectric conversion element accommodated in the photoelectric conversion element container according to claim 1.   The photoelectric conversion element includes a first substrate provided with a first electrode having a semiconductor layer carrying a dye, and a second substrate provided with a second electrode facing the semiconductor layer. The photoelectric conversion unit according to claim 8, wherein the photoelectric conversion unit is opposed to each other while holding an electrolyte between the first electrode and the second electrode.   The photoelectric conversion unit according to claim 9, wherein a conductive terminal is attached to each of the first electrode and the second electrode.   The conductive terminal material is copper, brass, phosphor bronze, beryllium steel, white, aluminum, stainless steel, nickel-plated copper alloy, nickel-plated steel, and gold, silver, solder, or palladium plating. The photoelectric conversion unit according to claim 10, comprising at least one selected from the group consisting of: 12. A photoelectric conversion module comprising a plurality of photoelectric conversion units according to claim 8 connected in series and / or in parallel.

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