JP2007227260A - Photoelectric converter and photovoltaic generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve photoelectric conversion efficiency by increasing the area of an effective photoelectric conversion region to incident light, and decreasing a non-photoelectric conversion region. <P>SOLUTION: A photoelectric converter 1 comprises: a substrate at a side where light operates, where a transparent conductive layer 3 and a porous oxide semiconductor layer 4 carrying a coloring matter are formed on one main surface of a light-transmitting substrate 2; and a substrate at a counter electrode side, where a counter electrode layer 8 is formed on one main surface of a conductive substrate 7, and a collector 13 is formed on the other. The photoelectric converter 1 allows the porous oxide semiconductor layer 4 to oppose the counter electrode layer 8, and has an electrolyte layer 6 between them. The photoelectric converter 1 comprises: a plurality of through-holes 10 that are formed at a fixed interval and reach the transparent conductive layer 3 through the conductive substrate 7, the counter electrode layer 8, the electrolyte layer 6, and the porous oxide semiconductor layer 4; and a conductor 12 that is formed at the center axis of the through-hole 10, and connects the transparent conductive layer 3 and the collector 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dye-sensitized photoelectric conversion device and a photovoltaic device such as a solar cell and a light receiving element that are excellent in photoelectric conversion efficiency.

  Conventionally, a dye-sensitized solar cell, which is a kind of photoelectric conversion device, does not require a vacuum device such as a vapor deposition device or a sputtering device for its production, and thus is considered to be a low-cost and low environmental load solar cell. R & D is actively underway.

  This dye-sensitized solar cell is usually provided with a porous titanium oxide layer having a thickness of about 10 μm obtained by sintering fine particles of titanium oxide having an average particle size of about 20 nm on a conductive glass substrate at about 450 ° C. A photoactive electrode substrate in which a single molecule of a dye is adsorbed on the surface of titanium oxide particles of the porous titanium oxide layer and a counter electrode substrate in which a counter electrode made of platinum or carbon is formed on a conductive glass substrate. The porous titanium oxide layer and the counter electrode are opposed to each other, a frame-shaped thermoplastic resin sheet is used as a spacer and sealing material, and both substrates are bonded together by hot pressing, and iodine / iodide is sandwiched between the substrates. It is obtained by injecting an electrolyte solution containing a redox couple. In the dye-sensitized solar cell thus obtained, the dye adsorbed on the porous titanium oxide layer as the porous oxide semiconductor layer absorbs the irradiated light energy, and the generated electrons are porous oxide. Moves to the semiconductor layer, then moves to the transparent conductive layer of the conductive glass substrate, moves through the external load circuit, moves the electrolyte as ions from the counter electrode, and then returns to the dye to be extracted as electrical energy (See Non-Patent Document 1 below).

  However, in the dye-sensitized solar cell, when the area of the counter electrode substrate is increased as well as the photo-active electrode substrate, the sheet resistance of the transparent conductive layer on the conductive glass substrate is about 10Ω / □ (square). Therefore, there is a problem that the photoelectric conversion efficiency is remarkably lowered. Therefore, since the counter electrode substrate is usually disposed on the light emitting side, it is possible to use a corrosion-resistant metal thin plate made of titanium, stainless steel, or the like instead of the conductive glass substrate. It is possible to reduce the photoelectric conversion efficiency (hereinafter also referred to as “conversion efficiency”) to some extent.

  However, since the light working electrode substrate is usually disposed on the light incident side, it is essential to use a transparent substrate made of glass or the like having a transparent conductive layer. In this case, since the sheet resistance of the transparent conductive layer is as large as about 10Ω / □, there is a problem that the conversion efficiency is greatly reduced.

  Therefore, a comb-shaped grid electrode made of a metal thin film or fine metal wire is provided on the surface of the transparent conductive layer, and wiring with a current collecting function is performed on the transparent conductive layer, so that the conversion efficiency can be improved even if the photoelectrode substrate becomes large. Ingenuity has been devised so as not to cause a decrease in the number of times. However, in the dye-sensitized solar cell, the corrosive electrolyte composed of iodine compound or bromine compound is used in the liquid state or gel state, so that the grid electrode is protected to prevent the grid electrode from being corroded. A structure that reliably protects the body was indispensable (see Non-Patent Document 2 below).

  An example of such a conventional photoelectric conversion device will be described below with reference to FIGS. In addition, in each figure, the same code | symbol is attached | subjected to the same member.

  A cross-sectional view of a conventional photoelectric conversion device 1G is shown in FIG. In the conventional photoelectric conversion device 1G of FIG. 9, a porous oxide semiconductor layer 4 carrying a transparent conductive layer 3, a grid electrode 15, a protector 16, and a dye (not shown) is formed on a translucent substrate 2. The counter electrode layer 8 is formed on the conductive substrate 7, the porous oxide semiconductor layer 4 and the counter electrode layer 8 are opposed to each other, and the electrolyte layer 6 is disposed therebetween. And the structure which formed the grid electrode 15 on the transparent conductive layer 3, and coat | covered this grid electrode 15 with the protective body 16, and the electrolyte 6 touched the grid electrode 15 and the grid electrode 15 was not corroded. It is.

  FIG. 10 is a cross-sectional view of this conventional photoelectric conversion device 1G taken along line AA ′ of FIG. In FIG. 10, the area of the grid electrode 15 and the protector 16 occupies a considerable proportion of the area of the transparent substrate 2 with respect to the area of the porous oxide semiconductor layer 4 supporting the dye. The width of the protective body 16 for preventing corrosion of the electrode 15 is wide and its area occupies about 30% of the area of the light working electrode of the translucent substrate 2. As described above, the light working electrode on the light incident side has a structure having not only the photoelectric conversion region composed of the porous oxide semiconductor layer 4 but also the non-photoelectric conversion region composed of the grid electrode 15 and the protector 16.

  Further, in FIG. 9, there is a portion for providing a metal wiring 17 (in the figure, substituted by the transparent conductive layer 3) provided inside the photoelectric conversion device 1 </ b> G in order to draw out the electric power generated in the photoelectric conversion device 1 </ b> G to the outside. Necessary. This further increases the non-power generation area. In FIG. 9, the sealing body 9 is for sealing the electrolyte 6.

  Further, Patent Document 1 includes a working electrode, a counter electrode, and an electrolyte layer formed between them. The working electrode includes a transparent substrate and a transparent conductive film formed on the transparent substrate. Is a photoelectric conversion element comprising a substrate and a conductive film formed on the substrate, wherein the photoelectric conversion element is electrically connected to the transparent conductive film or the conductive film to the transparent substrate forming the working electrode or the counter electrode, and the transparent substrate. Alternatively, a photoelectric conversion element provided with a conductor through which a current flows so as to penetrate the substrate is disclosed. Thus, in this photoelectric conversion element, the conductor is provided from the transparent conductive film constituting the working electrode to the outer surface of the transparent substrate, or the conductive film constituting the counter electrode is provided on the outer surface of the substrate. Therefore, the distance between the two poles can be narrowed, and the energy conversion efficiency is higher.

In Patent Document 2, a metal substrate having through holes at regular intervals is used as a first electrode, and an amorphous or polycrystalline semiconductor thin film and a second electrode are formed on one main surface of the metal substrate. In a thin film solar cell having a structure in which a certain transparent conductive film is sequentially folded, at least an insulating film and a metal film are sequentially folded on the other main surface of the metal substrate, and the metal film is transparent at least in the through hole. A thin film solar cell having a structure electrically connected to a film is disclosed. As a result, the power generated by the transparent conductive film as the second electrode is reduced by collecting the electric charge generated on the transparent electrode side through the through-hole provided in the metal substrate to the metal film on the back surface of the metal substrate. Can be made. In addition, if a large number of through holes are provided in the metal substrate at regular intervals in advance, the semiconductor thin film, the transparent conductive film, the insulating film on the back of the metal substrate, and the metal film are simply formed without alignment. Therefore, it is possible to provide a thin film solar cell that is low in cost, high in yield, low in loss, and easy to increase in area.
JP 2005-339882 A JP-A-8-64850 Published by Information Technology Co., Ltd. “Frontiers and Future Prospects of Dye-Sensitized Solar Cells and Solar Cells” P26-P27 Published by Information Technology Co., Ltd. “Optonews 2005 No.6“ Trends in dye-sensitized solar cell modules ”and the forefront and future prospects of solar cells” P23-P25

When the working electrode is made of a transparent substrate such as glass having a transparent conductive layer as in a conventional dye-sensitized solar cell, the sheet resistance of the transparent conductive layer is as large as about 10Ω / □, so the area of the working electrode When the value becomes larger than about 1 cm ^2, there is a problem that the conversion efficiency is greatly lowered.

  In addition, a comb-shaped grid electrode made of a metal thin film or thin metal wire is provided on the surface of the transparent substrate or the transparent conductive layer, which is the working electrode, and the transparent conductive layer is wired to have a current collecting function. A device has been devised so that the conversion efficiency does not decrease as much as possible even if the substrate becomes large. However, in this case, as described in Patent Document 1, since the metal grid electrode is exposed to a high temperature in the process of forming the porous oxide semiconductor layer, a material that is not denatured by heating must be used. In addition, the corrosive electrolyte may penetrate the transparent conductive layer and corrode the grid electrode. In addition, the distance between the working electrode and the counter electrode is increased, resulting in a problem that the conversion efficiency is remarkably lowered.

  Furthermore, in dye-sensitized solar cells, corrosive electrolytes composed of iodine compounds and bromine compounds are used in a liquid state or a gel state, so that the grid electrodes are protected from corrosion in order to prevent corrosion of the grid electrodes. I had to protect it with my body. Due to the formation of the protective body, the distance between the working electrode and the counter electrode is further increased, and there is a problem that the conversion efficiency is further reduced. In the working electrode having such a configuration, not only the photoelectric conversion region composed of the porous oxide semiconductor layer but also the non-photoelectric conversion region composed of the grid electrode and the protector, The area of the grid electrode and the protection body formation area (area of the non-photoelectric conversion area) occupies a significant proportion of the total area of the working electrode, and the area of the porous oxide semiconductor layer carrying the dye (photoelectric conversion) There was a problem that the area of the region) was significantly reduced.

  The grid electrode is a linear electrode with a large area, and it covers the porous oxide semiconductor layer, which is the surrounding photoelectric conversion region, in a one-dimensionally narrow (differentiated) manner, and the photocurrent from this narrow area is transparent. Since current is collected via the conductive layer, there is a problem that the amount of material used for the electrode member is increased as a design with a margin.

  In addition, since a portion for drawing out the electric power generated in the photoelectric conversion device is necessary, the non-power generation region is further increased, and the area of the porous oxide semiconductor layer (area of the photoelectric conversion region) is further reduced. There was a problem of becoming.

  Further, the photoelectric conversion device of Patent Document 1 has the following problems. That is, the through hole must be formed so as to penetrate the transparent substrate forming the working electrode or the substrate forming the counter electrode, but it is usually difficult to form the through hole because glass is used for the transparent substrate. Nevertheless, it is necessary to form through holes at intervals of about 1 cm, and a device having a size of several tens of centimeters to several meters, such as a solar cell, requires a large number of through holes, and is made of a transparent glass substrate. In addition, forming a large number of through holes with high reliability has a problem of productivity and a decrease in strength of glass. In addition, when the collector electrode (grid electrode) wiring is provided on the light incident side surface of the transparent substrate forming the working electrode, the collector electrode shields light, but the area occupied by the collector electrode with respect to the total area of the working electrode in plan view ( There is a problem that the area of the non-photoelectric conversion region occupies a considerable proportion and the effective area of the porous oxide semiconductor layer (the area of the effective photoelectric conversion region) is reduced.

  The photoelectric conversion device of Patent Document 2 relates to a thin film solar cell made of a compound semiconductor such as amorphous silicon or CIS (CuInS), and the transparent conductive film electrically connected through the through-hole is a translucent substrate. There is no description about the dye-sensitized solar cell, and there is no need to consider the electrolyte. Moreover, only an example in which the through holes are formed at regular intervals is disclosed.

  Accordingly, the present invention has been completed in view of the problems in the above-described conventional technology, and the object thereof is as follows.

(1) In the working electrode on the light incident side of the photoelectric conversion device, the area of the effective photoelectric conversion region of the porous oxide semiconductor layer carrying the dye is greatly increased, and the non-photoelectric conversion region comprising the grid electrode and its protector To significantly reduce the area.

(2) Even if the area of the effective photoelectric conversion region composed of the porous oxide semiconductor layer is greatly increased and the area of the non-photoelectric conversion region composed of the grid electrode and the protector is greatly reduced, the transparent conductive layer is changed to the collector electrode. Make sure that the current carrying resistance does not increase.

(3) The conversion efficiency is hardly lowered even if the area of the photoelectric conversion device is increased.

(4) The electrical resistance of the collector electrode and the transparent conductive layer should not increase even when the porous oxide semiconductor layer is treated at a high temperature.

(5) To increase the conversion efficiency by reducing the distance between the working electrode and the counter electrode.

  The photoelectric conversion device of the present invention includes a light working electrode side substrate in which a transparent conductive layer and a porous oxide semiconductor layer carrying a dye are formed on one main surface of a light-transmitting substrate, and a main surface of the conductive substrate. A counter electrode layer having a counter electrode layer formed on the other main surface and having a collector electrode formed on the other main surface, wherein the porous oxide semiconductor layer and the counter electrode layer are opposed to each other and an electrolyte layer is provided therebetween. In the conversion device, a plurality of through-holes formed at regular intervals through the conductive substrate, the counter electrode layer, the electrolyte layer, and the porous oxide semiconductor layer to reach the transparent conductive layer, and the through-holes And a conductor connecting the transparent conductive layer and the collector electrode.

  The photoelectric conversion device of the present invention is preferably characterized in that an insulating protective layer is formed on at least one of the inner surface of the through hole and the outer peripheral surface of the conductor.

  The photoelectric conversion device of the present invention is preferably characterized in that the plurality of through holes are formed at regular intervals in the vertical direction and the horizontal direction in plan view.

  Moreover, the photoelectric conversion device of the present invention is preferably characterized in that the plurality of through holes are formed so as to be positioned at the centers of a plurality of regular hexagons arranged in a close-packed manner in a plan view.

  The photoelectric conversion device of the present invention is preferably characterized in that a sealing member is formed from the outer peripheral portion of the working electrode side substrate to the outer peripheral portion of the counter electrode side substrate.

  The integrated photoelectric conversion device of the present invention is the photoelectric conversion device of the present invention described above, wherein the transparent conductive layer, the porous oxide semiconductor layer, the electrolyte layer, and the counter electrode layer are separated from each other. The partition wall portion is formed to prevent the electrolyte layer from continuing between the photoelectric conversion regions, and the plurality of photoelectric conversion regions are connected in series. It is characterized by being connected in parallel or in series and parallel.

  The photovoltaic power generation device of the present invention is characterized in that the photoelectric conversion device of the present invention is used as a power generation means, and the generated power of the power generation means is supplied to a load.

  The photoelectric conversion device of the present invention includes a light working electrode side substrate in which a transparent conductive layer and a porous oxide semiconductor layer carrying a dye are formed on one main surface of a light-transmitting substrate, and a main surface of the conductive substrate. A photoelectric conversion device having a counter electrode layer substrate on which a counter electrode layer is formed and a collector electrode formed on another main surface, the porous oxide semiconductor layer and the counter electrode layer facing each other, and an electrolyte layer provided therebetween In the structure, a plurality of through-holes formed at regular intervals through the conductive substrate, the counter electrode layer, the electrolyte layer, and the porous oxide semiconductor layer and the central axis portion of the through-hole are formed. By including the conductor connecting the transparent conductive layer and the collector electrode, the area of the non-photoelectric conversion region in plan view is very small as the area of the plurality of through holes, and the area of the photoelectric conversion region is The total area of the working electrode excluding the area of multiple through holes To become listening, high conversion efficiency even when the size of the photoelectric conversion device becomes large is obtained. That is, the energization by the conductor of the through-hole of the present invention covers the porous oxide semiconductor layer, which is the surrounding photoelectric conversion region, with a point electrode having a small area in a two-dimensional manner so that a photocurrent from a large area can be obtained. Is an energization through the transparent conductive layer, and is an effective energization.

  In addition, since a plurality of conductors are formed so as to connect the transparent conductive layer and the collector electrode at regular intervals, the current-carrying resistance from the transparent conductive layer to the collector electrode is not increased, and the size of the photoelectric conversion device is reduced. High conversion efficiency can be obtained even when the size is increased.

  In addition, since the conductor of the through hole can be formed after the porous oxide semiconductor layer is sintered at high temperature, the electrical resistance of the collector electrode and the transparent conductive layer can be formed by heat treatment for forming the porous oxide semiconductor layer. Does not decrease the conversion efficiency.

  In addition, since there is no obstacle between the light working electrode side substrate made of a porous oxide semiconductor layer or the like and the counter electrode side substrate, the distance between the two electrodes can be formed small, so that the conversion efficiency is increased.

  In the photoelectric conversion device of the present invention, preferably, the insulating protective layer is formed on at least one of the inner surface of the through hole and the outer peripheral surface of the conductor, so that the intrusion of the electrolyte is prevented by the insulating protective layer. In addition, it is possible to prevent the corrosion of the working electrode and the short circuit between the working electrode and the counter electrode by the insulating protective layer, maintain high conversion efficiency, and improve the reliability.

  In the photoelectric conversion device of the present invention, preferably, the plurality of through holes are formed at regular intervals in the vertical direction and the horizontal direction in a plan view, thereby reducing the total number of through holes to be non-photoelectric conversion regions. Therefore, the area of the photoelectric conversion region can be increased, and the conversion efficiency can be increased. That is, when two-dimensionally uniform photocurrent is taken out from a continuous transparent conductive layer that is two-dimensionally uniform with a plurality of conductors, it is better to take out current at regular intervals in the vertical and horizontal directions in plan view. This is because the conduction current of each conductor becomes uniform, the design and arrangement of the conductor becomes easy, and the number of points is unavoidable. For example, if conductors are unevenly arranged, current concentrates on conductors that are spaced apart from adjacent ones, causing the conductors to heat up and burn or deteriorate, or vice versa. Since only a small current flows through a conductor with a small interval, the number of conductors becomes excessive and the electrode member is wasted.

  In the photoelectric conversion device of the present invention, preferably, the plurality of through holes are formed so as to be positioned at the centers of a plurality of regular hexagons arranged in a close-packed manner in a plan view. Since the total number of through-holes can be minimized, the area of the photoelectric conversion region can be increased and the conversion efficiency can be increased.

  In the photoelectric conversion device of the present invention, preferably, a sealing member is formed from the outer peripheral portion of the light working electrode side substrate to the outer peripheral portion of the counter electrode side substrate, thereby preventing electrolyte leakage and maintaining high conversion efficiency. And reliability can be improved.

  The integrated photoelectric conversion device of the present invention is the photoelectric conversion device of the present invention described above, wherein a plurality of independent photoelectric conversion regions in which the transparent conductive layer, the porous oxide semiconductor layer, the electrolyte layer, and the counter electrode layer are separated from each other are provided. And partition walls are formed to prevent electrolyte layers from continuing between the photoelectric conversion regions, and a plurality of photoelectric conversion regions are connected in series, parallel connection, or series-parallel connection. Thus, an integrated photoelectric conversion device that exhibits the above-described specific effects of the present invention in each photoelectric conversion region is obtained.

  The photovoltaic device of the present invention uses the photoelectric conversion device of the present invention as a power generation means and supplies the generated power of the power generation means to a load, thereby utilizing the operational effects of the photoelectric conversion device of the present invention. Even if the size is increased, the photovoltaic device has high conversion efficiency and high reliability.

  Embodiments of the photoelectric conversion device and the photovoltaic device according to the present invention will be described below in detail with reference to FIGS. In addition, in each figure, the same code | symbol is attached | subjected to the same member.

  1 and 2 are cross-sectional views of the photoelectric conversion device of the present invention. FIG. 3 is a cross-sectional view taken along the line AA ′ of FIGS. 3 is a sectional view taken along the line BB ′ of FIG. 3, and FIG. 2 is a sectional view taken along the line CC ′.

  The photoelectric conversion device 1 of FIGS. 1 and 2 includes a light working electrode side substrate in which a transparent conductive layer 3 and a porous oxide semiconductor layer 4 carrying a dye are formed on one main surface of a translucent substrate 2, and a conductive layer. A counter electrode layer 8 is formed on one main surface of the conductive substrate 7 and a collector electrode 13 is formed on the other main surface, and the porous oxide semiconductor layer 4 and the counter electrode layer 8 are opposed to each other. A plurality of through-holes formed at regular intervals, having an electrolyte layer 6 between them, penetrating the conductive substrate 7, the counter electrode layer 8, the electrolyte layer 6 and the porous oxide semiconductor layer 4 to reach the transparent conductive layer 3. The hole 10 and the conductor 12 formed at the central axis portion of the through hole 10 and connecting the transparent conductive layer 3 and the collector electrode 13 are provided. Further, an insulating protective layer 11 is provided between the through hole 10 and the conductor 12.

  FIG. 4 shows a cross-sectional view of another example of the embodiment of the photoelectric conversion device of the present invention. The difference between the photoelectric conversion device 1 in FIGS. 1 and 2 and the photoelectric conversion device 1A in FIG. 4 is that the collector electrode 13 is formed on the upper end of the through hole or on the conductive substrate 7 adjacent to the through hole. The difference lies in whether the portion is formed via the insulating film 14. In the case of the configuration of FIG. 4, since all of the collector electrode 13 can be formed in advance before the conductor 12 is formed, there is a degree of freedom in the method of forming the collector electrode 13 and the conductivity of the collector electrode 13 is increased. There is an advantage that

  In the photoelectric conversion device of the present invention, preferably, as shown in FIG. 3, the plurality of through holes 10 are formed at regular intervals in the vertical direction and the horizontal direction in plan view. In this case, the photocurrent from the two-dimensionally uniform porous oxide semiconductor layer 4 is taken out by the plurality of conductors 12 through the two-dimensionally uniform transparent conductive layer 3 at an equal current value. Therefore, it is possible to equalize the load of energization of the conductor 12, and to make a uniform design without waste in terms of arrangement of the conductor 12. As a result, there is no heat loss due to resistance loss or the like that occurs when the conductors 12 are non-uniformly arranged, and design is not wasted. Therefore, the total number of through-holes 10 serving as non-photoelectric conversion regions can be reduced.

  Further, in the photoelectric conversion device of the present invention, preferably, as shown in FIG. 5, the plurality of through holes 10 are formed so as to be positioned at the centers of a plurality of regular hexagons arranged in a close-packed manner in plan view. . In this case, the electrical resistance from the transparent conductive layer 3 to the conductor 12 is higher than that of the conductor 12 as shown in FIG. 3 as long as the number of the conductors 12 per area of the transparent conductive layer 3 is the same. The arrangement of the conductors 12 as described above is smaller, and the configuration of FIG. 5 can further increase the conversion efficiency.

  FIG. 6 is a plan view of the photoelectric conversion device 1 of FIG. 1 as viewed from above, and shows a preferred configuration in which the collector electrode 13 is formed by connecting a plurality of conductors 12. In this case, since the width of the collector electrode 13 can be increased, there is an effect that the electrical resistance can be reduced and the conversion efficiency can be increased.

  And the manufacturing method of the photoelectric conversion apparatus 1 of FIG. 1 is as follows. First, the transparent conductive layer 3 and the porous oxide semiconductor layer 4 are laminated on the translucent substrate 2, and the porous oxide semiconductor layer 4 is penetrated by a mask brush cutting method, a mask blasting method, a screen printing method, or the like. The hole 10 is formed, and then the substrate on the light working electrode side is immersed in a dye solution to adsorb (carry) the dye on the porous oxide semiconductor layer 4.

  Next, a counter electrode layer 8 is formed on one main surface of the conductive substrate 7 in which the through holes 10 are formed by a press method or the like, and an insulating film is formed on the other main surface. Next, the translucent substrate 2 and the conductive substrate 7 are formed. The sealing member 9 is formed on the outer peripheral portions of both substrates while maintaining a gap for forming the electrolyte layer 6, and the inner wall of the through hole 10 is covered with the insulating protective layer 11. At this time, when the insulating protective layer 11 is made of a silicone resin having a high viscosity, the insulating protective layer 11 can be connected to the gap without any problem even if the gap (about 5 to 50 μm) is present. The upper and lower through-holes 10 can be made continuous and dropped so as to seal the inner space. Next, the conductor 12 is formed inside the insulating protective layer 11 of the through hole 10.

  Next, the collector electrode 13 is formed on the insulating film on the other main surface of the conductive substrate 7, the upper end of the conductor 12, and the insulating protective layer 11 around the upper end of the conductor 12. The electrolyte solution 6 is then injected into the gap from the injection port (not shown) formed in the conductive substrate 7 or the sealing member 9 to form the electrolyte layer 6, and the injection port is sealed.

  Moreover, the manufacturing method of 1 A of photoelectric conversion apparatuses of FIG. 4 is as follows. First, the transparent conductive layer 3 and the porous oxide semiconductor layer 4 are laminated on the translucent substrate 2, and then the counter electrode layer 8 is formed on one main surface of the conductive substrate 7 in which the through holes 10 are formed by a pressing method or the like. Then, an insulating film is formed on the other main surface, and then the translucent substrate 2 and the conductive substrate 7 are bonded to each other by forming a sealing member 9 on the outer peripheral portions of both substrates while maintaining a gap.

  Next, through holes 10 are formed in the porous oxide semiconductor layer 4 through the through holes 10 of the conductive substrate 7 by a mask brush cutting method, a mask blasting method, or the like, or a mask brush cutting method or a mask blasting process is performed in advance. Through holes 10 are formed in the porous oxide semiconductor layer 4 by a method, a screen printing method, or the like. Next, a base layer made of gold, aluminum or the like for forming the conductor 12 is formed on the surface of the transparent conductive layer 3 in the collector electrode 13 and the through hole 10 by vapor deposition or the like, and then in the through hole 10 A conductor 12 is formed from the surface of the transparent conductive layer 3 to the collector electrode 13 by a metal wire bonder method or the like.

  Next, both bonded substrates are immersed in the dye solution, and the dye is adsorbed to the porous oxide semiconductor layer 4 through the through holes 10, and then the inner walls of the through holes 10 are covered with the insulating protective layer 11. At this time, as described above, when the insulating protective layer 11 is made of a silicone resin or the like having a high viscosity, the insulating protective layer 11 can be used in the gap even if the gap (about 5 to 50 μm) is present. The upper and lower through-holes 10 can be made continuous and dropped so as to seal the inner space. Next, an electrolyte solution is injected from an injection port (not shown) opened in the conductive substrate 7 or the sealing member 9 into the gap to form the electrolyte layer 6, and the injection port is sealed.

  Next, each element which comprises the photoelectric conversion apparatus 1 mentioned above is demonstrated in detail.

<Translucent substrate>
As the translucent substrate 2, a substrate made of a translucent inorganic material such as white plate glass, soda glass, borosilicate glass, ceramics, or the like, or polycarbonate (PC), acrylic, polyethylene terephthalate (PET), polyethylene naphthalate. A substrate made of a resin material such as phthalate (PEN) or polyimide is preferable. Among them, glass made of white plate glass, soda glass, borosilicate glass, etc. is inexpensive and can withstand the firing temperature of the porous oxide semiconductor layer 4, resulting in high conversion efficiency. Especially good.

  The thickness of the translucent substrate 2 is 0.01 to 8 mm, preferably 0.1 to 4 mm in terms of mechanical strength and translucency.

<Transparent conductive layer>
As the transparent conductive layer 3, one made of a metal oxide doped with fluorine or metal can be used. For example, impurities (F, Sb, etc.) doped tin oxide film (SnO ₂ film), impurities (Ga, Al, etc.) doped zinc oxide film (ZnO film), tin doped indium oxide film (ITO film), impurity doped oxidation An indium film (In ₂ O ₃ film), a niobium-doped titanium oxide film, or the like may be used.

Among them, a fluorine-doped tin dioxide film (SnO ₂ : F film) formed by a thermal CVD method or a spray pyrolysis method is best because it has heat resistance and an inexpensive material cost. As a method for forming the transparent conductive layer 3, there are a thermal CVD method, a spray pyrolysis method, a sputtering method, a vacuum deposition method, an ion plating method, a dip coating method, a solution growth method, a sol-gel method, and the like.

Further, as the transparent conductive layer 3, a film in which a tin-doped indium oxide film (ITO film) film and an impurity (F, Sb, etc.)-Doped tin oxide film (SnO ₂ film) are laminated has low sheet resistance and chemical resistance. Is high and preferable.

  In addition, the transparent conductive layer 3 may be an extremely thin metal film such as Au, Pd, or Al formed by a vacuum deposition method or a sputtering method. Further, these metal films may be laminated and used in various combinations. For example, the transparent conductive layer 3 may be a layer in which a Ti layer, an ITO layer, and a Ti layer are sequentially stacked, resulting in a stacked film with improved adhesion and corrosion resistance.

  The thickness of the transparent conductive layer 3 is 0.001 to 10 μm, preferably 0.05 to 2 μm. When the thickness is less than 0.001 μm, the resistance of the transparent conductive layer 3 increases, and when it exceeds 10 μm, the film formation cost increases.

<Porous oxide semiconductor layer>
The porous oxide semiconductor layer 4 is preferably a porous n-type oxide semiconductor layer made of titanium dioxide or the like. The porous oxide semiconductor layer 4 is formed on the translucent substrate 2 and the transparent conductive layer 3.

The material and composition of the porous oxide semiconductor layer 4 is optimally titanium oxide (TiO ₂ ), and other materials are titanium (Ti), zinc (Zn), tin (Sn), niobium (Nb). , Indium (In), yttrium (Y), lanthanum (La), zirconium (Zr), tantalum (Ta), hafnium (Hf), strontium (Sr), barium (Ba), calcium (Ca), vanadium (V) Metal oxide semiconductors of at least one metal element such as tungsten (W) are preferable, and nitrogen (N), carbon (C), fluorine (F), sulfur (S), chlorine (Cl), phosphorus ( You may contain 1 or more types of nonmetallic elements, such as P). Titanium oxide or the like is preferable because it has an electron energy band gap in the range of 2 to 5 eV, which is larger than the energy of visible light. The porous oxide semiconductor layer 4 is preferably an n-type semiconductor whose conduction band is lower than the conduction band of the dye at the electron energy level.

  In the porous oxide semiconductor layer 4, the average particle diameter of primary particles before sintering may be 1 to 40 nm, and more preferably 5 to 30 nm. Here, if the lower limit value (1 nm) in the average particle size is less than this, the material cannot be refined, and if the upper limit value (40 nm) is more than this, the junction area with respect to the transparent conductive layer 3 is reduced, and the photocurrent is reduced. Is due to the extremely small.

  The porous oxide semiconductor layer 4 is prepared by using the oxide semiconductor fine particles, which are fine primary particles, as a dispersed phase, and preparing a paste using an aqueous or non-aqueous solution as a dispersion medium. It is formed by coating and baking. As a paste application method, various methods such as a bar coater application method, a spin coater method, a screen printing method, and a spray method can be used.

  Thus, the average particle diameter of the secondary particles constituting the porous oxide semiconductor layer 4 formed by firing the primary particles is preferably 10 to 500 nm, and more preferably 20 to 200 nm. Thereby, light with a wide wavelength such as sunlight can be well confined and absorbed and photoelectrically converted. If the average particle size of the secondary particles is less than 10 nm, the light confinement effect for short wavelength light is lost, and if it exceeds 500 nm, the light confinement effect for long wavelength light is lost.

  In addition, when the average particle size of the secondary particles is small within the above range of the average particle size of the secondary particles, the surface area of the porous oxide semiconductor layer 4 as the light working electrode layer can be increased. As a result, the amount of adsorbed dye increases, and short wavelength light is well confined to absorb light of short wavelength light, so that conversion efficiency can be increased and electron conduction can be performed efficiently. Further, when the average particle size of the secondary particles is large, the long wavelength light is well confined and the long wavelength light is absorbed well, so that the conversion efficiency can be increased and the electron conduction can be performed efficiently. Further, when the average particle size of the secondary particles is the intermediate size, the intermediate wavelength light is well confined and the intermediate wavelength light is well absorbed, so that the conversion efficiency can be increased and the electron conduction can be performed efficiently.

  Therefore, the porous oxide semiconductor layer 4 is formed into a multilayer structure, and the porous oxide semiconductor layer 4 having a small average particle size of secondary particles (about 10 to 60 nm) is formed on the light incident side, and the light emitting side is formed. It is preferable to form the porous oxide semiconductor layer 4 having a large secondary particle (about 30 to 200 nm), and can absorb light of a wider wavelength more effectively and can significantly improve the conversion efficiency.

  In order to enlarge the secondary particles of the porous oxide semiconductor layer 4, for example, primary particles larger than the primary particles are mixed within a range of 1% to 50% by weight, and a paste is applied. It is good to fire. Further, as another method, it is preferable to stir a paste composed of primary particles with a shaker or the like so as to include bubbles to form a coating, or to include bubbles when forming a coating, such as a spray coating method. Furthermore, as another method, a method using PEG (polyethylene glycol) flakes or spherical fine particles of an acrylic resin (methacrylic ester copolymer) as an additive to the primary particles is good, and the additive vaporizes during firing. As a result, the pore size increases, and as a result, the secondary particles increase.

  The evaluation of the light confinement effect of the porous oxide semiconductor layer 4 is performed by forming the porous oxide semiconductor layer 4 made of titanium oxide or the like on the translucent substrate 2 with the transparent conductive layer 3 such as FTO glass, and about 300 to 1100 nm. It is possible to measure the light transmittance by scanning the wavelength of the light of the wavelength. Further, the surface and fracture surface of the porous oxide semiconductor layer 4 are observed with a scanning electron microscope (SEM), a surf test device (stylus type surface roughness measuring device), an atomic force microscope ( When the arithmetic average roughness Ra is measured with an AFM (Atomic Force Microscope), a laser microscope, or the like, the value of Ra substantially corresponds to the size of the secondary particles, and therefore the size of the secondary particles can be specified.

  The thickness of the porous oxide semiconductor layer 4 is preferably 1 to 100 μm, and more preferably 5 to 30 μm. If it is less than 1 μm, the amount of dye adsorbed is reduced and high conversion efficiency cannot be obtained. If it exceeds 100 μm, the porous oxide semiconductor layer 4 is cracked or peeled off to form the porous oxide semiconductor layer 4. I can't do it well.

In addition, when the porous surface of the porous oxide semiconductor layer 4 is treated with TiCl ₄ , that is, immersed in a TiCl ₄ solution for about 10 hours, washed with water, and baked at 450 ° C. for 30 minutes, the electronic conductivity is increased. It becomes better and the conversion efficiency increases.

  In addition, an extremely thin (thickness of about several tens to several hundreds of nanometers) dense layer made of an n-type oxide semiconductor may be inserted between the porous oxide semiconductor layer 4 and the conductive substrate 2 to suppress reverse current. Conversion efficiency increases because it can.

  In order to form the through holes 10 in the porous oxide semiconductor layer 4, the paste can be applied to the pattern of the through holes 10 by screen printing. Alternatively, after forming the porous oxide semiconductor layer 4 on the entire surface of the transparent conductive layer 3, the through holes 10 may be formed by mechanical cutting. Alternatively, the conductive substrate 7 having the through holes 10 may be used as a mask, and the through holes 10 may be formed in the porous oxide semiconductor layer 4 by a mechanical cutting or blasting removal method. At this time, the porous oxide semiconductor layer 4 can be easily formed by coating the entire surface and calcining (100 to 200 ° C.) and then forming the through hole 10 before firing.

<Dye>
Examples of the sensitizing dye include a ruthenium-tris, ruthenium-bis, osmium-tris, osmium-bis transition metal complex, a polynuclear complex, or a ruthenium-cis-diaqua-bipyridyl complex, or a phthalocyanine or porphyrin. Xanthene dyes such as polycyclic aromatic compounds and rhodamine B are preferred.

  In order to adsorb the dye to the porous oxide semiconductor layer 4, it is effective that the dye has at least one carboxyl group, sulfonyl group, hydroxamic acid group, alkoxy group, aryl group, phosphoryl group as a substituent. is there. Here, the substituent is not particularly limited as long as it can firmly adsorb the dye itself to the porous oxide semiconductor layer 4 and can easily transfer the charge from the excited dye to the porous oxide semiconductor layer 4.

  As a method of adsorbing the dye to the porous oxide semiconductor layer 4, for example, a method of immersing the porous oxide semiconductor layer 4 formed on the transparent substrate 2 with the transparent conductive layer 3 in a solution in which the dye is dissolved. Is mentioned.

Examples of the solvent of the solution in which the dye is dissolved include a mixture of one or more alcohols such as ethanol, ketones such as acetone, ethers such as diethyl ether, nitrogen compounds such as acetonitrile, and the like. The dye concentration in the solution is preferably about 5 × 10 ⁻⁵ to 2 × 10 ⁻³ mol / l (l: liter (1000 cm ³ )).

  When the translucent substrate 2 with the transparent conductive layer 3 on which the porous oxide semiconductor layer 4 is formed is immersed in a solution in which a dye is dissolved, the temperature conditions of the solution and the atmosphere are not particularly limited. For example, the conditions for heating the light-transmitting substrate 3 under atmospheric pressure or in vacuum, room temperature, or the like. The immersion time can be appropriately adjusted depending on the type of the dye and the solution, the concentration of the solution, and the like. Thereby, the dye can be adsorbed to the porous oxide semiconductor layer 4.

<Conductive substrate>
The conductive substrate 7 is preferably a metal having a low electrical resistance and excellent corrosion resistance, such as a substrate made of titanium, stainless steel, nickel, carbon or the like, a sheet, a foil, or the like.

  The conductive substrate 7 may be a substrate in which a metal layer or a transparent conductive layer is formed on an insulating substrate. The insulating substrate may be non-translucent or translucent. When the conductive substrate 7 has translucency, light can be incident from either of the main surfaces of the photoelectric conversion device 1, so that light can be incident from both main surfaces to increase conversion efficiency. .

  Insulating substrate materials include white plate glass, soda glass, borosilicate glass, etc., inorganic materials such as ceramics, polyethylene terephthalate (PET), polycarbonate (PC), acrylic, polyethylene naphthalate (PEN), polyimide, etc. Materials, organic-inorganic hybrid materials, etc. are preferable.

  The metal layer formed on the insulating substrate is preferably a thin film made of titanium, stainless steel, nickel or the like formed by a vacuum deposition method or a sputtering method.

As the transparent conductive layer formed on the insulating substrate, impurities (F, Sb, etc.) doped tin oxide film (SnO ₂ film), impurities (Ga, Al, etc.) doped zinc oxide film (ZnO film), etc. are heat resistant. It is particularly good.

  What laminated | stacked the metal layer and the transparent conductive layer on the insulated substrate may improve the corrosion resistance of a metal layer.

  Further, a laminated film in which three layers of a Ti layer, an ITO layer, a Ti layer, etc. are laminated on an insulating substrate may be formed, resulting in a laminated film with improved adhesion and corrosion resistance.

  In addition, as the conductive substrate 7, a surface of an insulating substrate or the like formed with a resin layer or conductive resin layer impregnated with metal fine particles or fine lines, or the surface of the insulating substrate or the like is corroded by an electrolyte. For prevention, a titanium layer, a stainless steel layer, a conductive metal oxide layer or the like may be coated.

When light reflectivity is imparted to the conductive substrate 7, a glossy thin metal substrate such as nickel, titanium, stainless steel, aluminum, silver, or copper is used alone, or SnO ₂ : What covered the transparent conductive layer etc. which consist of impurity-doped metal oxide layers, such as F layer, is good.

  The thickness of the conductive substrate 7 is preferably 0.005 to 5 mm, more preferably 0.01 to 2 mm in terms of mechanical strength. When the conductive substrate 7 has a conductive layer formed on an insulating substrate, the thickness of the conductive layer is preferably 0.001 to 10 μm, more preferably 0.05 to 2 μm.

<Counter electrode layer>
The counter electrode layer 8 is preferably an ultrathin film (thickness of about 10 to 100 nm) made of platinum, carbon or the like having a catalytic function. In addition, an electrodeposited ultrathin film such as gold (Au) or palladium (Pd) can be used. Moreover, the thin film which consists of electroconductive organic materials, such as PEDOT (polyethylene dioxythiophene), is mentioned. In addition, a porous film made of fine particles of these materials, for example, a porous film of carbon fine particles is preferable. In this case, the surface area of the counter electrode layer 8 is increased, and the electrolyte can be contained in the pores, thereby increasing the conversion efficiency. be able to.

<Conductor>
The conductor 12 in FIG. 1 is formed by forming solder (such as Kuroda Techno Sales, product name “Cerasolzer”, etc.) as a point electrode on the surface of the transparent conductive layer 3 in the through hole 10 by an ultrasonic soldering method. Good.

  1 may be formed as a point electrode by dropping a conductive paste onto the surface of the transparent conductive layer 3 in the through hole 10. This point electrode is formed by applying and baking a conductive paste composed of conductive particles such as silver, aluminum, nickel, titanium, copper, tin, and carbon, an epoxy resin that is an organic matrix, and a curing agent. . As this conductive paste, silver paste, aluminum paste, and titanium paste are particularly good, and any of low-temperature paste and high-temperature paste can be used.

  Moreover, the conductor 12 of FIG. 4 can form the wire-like conductor 12 which consists of gold | metal | money, aluminum, etc. from the transparent conductive layer 3 to the collector electrode 13 by an ultrasonic wire bond method, and can connect them. In this case, since the conductor 12 can be miniaturized, the density of the number of conductors 12 formed can be increased.

  The pitch of the formation pattern of the through holes 10 and the conductors 12 shown in FIGS. 3 and 5 is preferably 1 to 40 mm, and preferably 5 to 30 mm. If it is less than 1 mm, the non-photoelectric conversion region increases and the photoelectric conversion region becomes narrow and high photoelectric conversion efficiency cannot be obtained. If it exceeds 30 mm, the resistance of the transparent conductive layer 3 increases and high photoelectric conversion efficiency cannot be obtained.

<Insulating protective layer>
The insulating protective layer 11 can be formed either before or after the conductor 12 is formed in the through hole 10, and the order of formation can be changed. When the insulating protective layer 11 is formed after the conductor 12 is formed in the through hole 10, an insulating material such as an organic resin may be filled around the conductor 12 in the through hole 10. When the insulating protective layer 11 is formed before forming the conductor 12 in the through hole 10, a process of forming a hollow portion using a mold or the like corresponding to the shape of the conductor 12 is performed.

  Materials for the insulating protective layer 11 are silicone resin, epoxy resin, UV curable resin, urethane resin, ethylene vinyl acetate copolymer resin (EVA), polyvinyl butyral (PVB), ethylene-ethyl acrylate copolymer (EEA). , Fluorine resin, Acrylic resin, Saturated polyester resin, Amino resin, Phenol resin, Polyamideimide resin, Silicon polyester resin, High weather resistance polyester resin, Polycarbonate resin, PET (polyethylene terephthalate) resin, Saturated polyester resin, etc. A potting resin or the like used for sealing is preferable.

<Collecting electrode>
When the conductive substrate 7 is made of a metal substrate or the like, the collector electrode 13 is preferably formed on the main surface of the conductive substrate 7 with an insulating film 14 interposed therebetween as shown in FIG. Further, the collector electrode 13 can be formed so as to be in direct contact with the conductor 12 as shown in FIG.

  As this metal film, a thin film (thickness of about 0.1 to 10 μm) made of silver, copper, aluminum, tin, titanium, stainless steel, nickel or the like is preferably formed by masking using a vacuum deposition method, a sputtering method, or the like. In addition, as this metal film, a conductive paste composed of conductive particles such as gold, silver, aluminum, titanium, nickel, copper, tin, and carbon, an epoxy resin that is an organic matrix, and a curing agent, It may be applied and baked by a screen printing method or the like. As this conductive paste, silver paste and aluminum paste are particularly inexpensive and may have low resistance, and can be used for both low-temperature fired paste and high-temperature fired paste.

  The collector electrode 13 is formed by forming a conductive layer such as a metal layer on the insulating substrate, and the other main surface of the conductive substrate 7 is a surface where the insulating substrate is exposed. A metal film may be directly formed on the surface without the insulating film 14 interposed therebetween. The formation material, the formation method, and the like may be the same as described above.

<Sealing member>
The sealing member 9 is provided in order to prevent the electrolyte from leaking to the outside and reinforce the mechanical strength of the photoelectric conversion device 1 and to prevent the electrolyte from directly contacting the external environment and deteriorating the photoelectric conversion function.

  The material of the sealing member 9 is preferably a material having a moisture absorption preventing function and sufficient adhesive strength, such as ethylene vinyl acetate copolymer resin (EVA), polyvinyl butyral (PVB), ethylene-ethyl acrylate copolymer ( EEA), fluorine resin, epoxy resin, acrylic resin, saturated polyester resin, amino resin, phenol resin, polyamideimide resin, UV curable resin, silicone resin, fluorine resin, urethane resin, silicone polyester resin, highly weather resistant polyester resin, polycarbonate Resins, PET (polyethylene terephthalate) resins, saturated polyester resins, coating resins used for metal roofs, and the like are preferable.

  In addition, shading, heat insulation, heat resistance, antibacterial, antifungal, antiglare, wear resistance, antistatic, snow sliding, low contamination, design, high workability, far infrared radiation, corrosion resistance, By imparting acid resistance, environmental compatibility, and the like to the sealing member 9, reliability and merchantability can be further improved.

<Electrolyte layer>
Examples of the material for the electrolyte layer 6 include electrolyte solutions, gel electrolytes, ion conductive electrolytes such as solid electrolytes, and organic hole transport agents.

  As the electrolyte solution, a quaternary ammonium salt, a Li salt, or the like is used. As the composition of the electrolyte solution, for example, a solution prepared by mixing tetrapropylammonium iodide, lithium iodide, iodine or the like with ethylene carbonate, acetonitrile, methoxypropionitrile, or the like can be used.

  Gel electrolytes are roughly classified into chemical gels and physical gels. A chemical gel is a gel formed by a chemical bond by a cross-linking reaction or the like, and a physical gel is gelled near room temperature by a physical interaction. The gel electrolyte is a gel obtained by mixing a host polymer such as polyethylene oxide, polyacrylonitrile, polyvinylidene fluoride, polyvinyl alcohol, polyacrylic acid, or polyacrylamide into acetonitrile, ethylene carbonate, propylene carbonate, or a mixture thereof. An electrolyte is preferred. When a gel electrolyte or a solid electrolyte is used, a low-viscosity precursor is contained in the porous oxide semiconductor layer 4, and a two-dimensional or three-dimensional crosslinking reaction is performed by means such as heating, ultraviolet irradiation, or electron beam irradiation. It can be gelled or solidified by causing it to occur.

  As the ion conductive solid electrolyte, a solid electrolyte having a polymer chain such as polyethylene oxide, polyethylene oxide or polyethylene having a salt such as sulfonimidazolium salt, tetracyanoquinodimethane salt or dicyanoquinodiimine salt is preferable. As the molten salt of iodide, an iodide such as an imidazolium salt, a quaternary ammonium salt, an isoxazolidinium salt, an isothiazolidinium salt, a pyrazolidium salt, a pyrrolidinium salt, or a pyridinium salt can be used.

  Examples of the molten salt of iodide include 1,1-dimethylimidazolium iodide, 1, methyl-3-ethylimidazolium iodide, 1-methyl-3-pentylimidazolium iodide, 1-methyl- 3-isopentylimidazolium iodide, 1-methyl-3-hexylimidazolium iodide, 1-methyl-3-ethylimidazolium iodide, 1,2-dimethyl-3-propylimidazole iodide, 1-ethyl- Examples thereof include 3-isopropylimidazolium iodide and pyrrolidinium iodide.

  The integrated photoelectric conversion device 1B of FIG. 7 is formed by forming a plurality of independent photoelectric conversion regions in which the transparent conductive layer 3, the porous oxide semiconductor layer 4, the electrolyte layer 6 and the counter electrode layer 8 are separated from each other. In addition, a partition wall 18 that prevents the electrolyte layer 6 from continuing between the photoelectric conversion regions is formed, and a plurality of photoelectric conversion regions are connected in series, parallel, or series-parallel. It is. That is, the transparent conductive layer 3 on the translucent substrate 2 is composed of a plurality of transparent conductive layers 3a and 3b that are electrically separated. Similarly, the counter electrode layer 8 formed on one main surface of the conductive substrate 7 is also electrically connected. A plurality of counter electrode layers 8a and 8b separated from each other, a partition wall 18 for separating the electrolyte layer 6 is provided between the separated parts, and a photoelectric conversion element 19a composed of a pair of a working electrode and a counter electrode, A plurality of 19b are formed, and these photoelectric conversion elements 19a and 19b are connected in series, in parallel or in series-parallel.

  The partition wall portion 18 is made of the same material as the sealing member 9 and can be formed by a method in which a resin is dropped into a linear shape with a dispenser and solidified.

  A photoelectric conversion device 1C having a module structure in FIG. 8 is configured by arranging a plurality of photoelectric conversion devices 1a and 1b in a plane and connecting these photoelectric conversion devices 1a and 1b in series, parallel connection, or series-parallel connection. In this case, each of the photoelectric conversion devices 1a and 1b exhibits the above-described effects of the present invention, and even if the size of the entire photoelectric conversion device is increased, the photoelectric conversion devices 1a and 1b have a high resistance and low resistance outside the photoelectric conversion devices 1a and 1b. Since conductive connection is possible, a photoelectric conversion device having a module structure with high conversion efficiency and high reliability is obtained.

  The photoelectric conversion apparatus 1 can be used as a power generation means, and a photovoltaic power generation apparatus configured to supply generated power from the power generation means to a load can be obtained. In other words, when one or a plurality of the photoelectric conversion devices 1 are used, a series, parallel or series-parallel connection is used as a power generation means, and the generated power is directly supplied from this power generation means to the DC load. May be. In addition, after the photovoltaic power generation means converts the generated power into appropriate AC power via power conversion means such as an inverter, the generated power can be supplied to an AC load such as a commercial power system or various electric devices. It is good also as a possible electric power generating apparatus. Furthermore, it is also possible to use such a power generation device as a photovoltaic power generation device such as a solar power generation system of various aspects by installing it in a building with good sunlight, and thereby high conversion efficiency and durability. A photovoltaic device can be provided.

  Further, the photovoltaic power generation apparatus of the present invention uses the photoelectric conversion apparatus 1 of the present invention as a power generation means and supplies the generated power of the power generation means to a load. It has the effects of increasing the reliability, increasing the application, expanding the use, and facilitating the manufacturing and reducing the cost. Moreover, the photoelectric conversion apparatus 1 of this invention is not limited to a solar cell as the use, It can apply if it has a photoelectric conversion function, and can also apply it to various light receiving elements, an optical sensor, etc.

  Example 1 of the photoelectric conversion device of the present invention will be described below. A photoelectric conversion device 1 having the configuration shown in FIG. 1 was produced as follows.

  First, as the conductive substrate 7, the main surface has vertical and horizontal intervals of 20 mm, four 5 mmφ (diameter) through-holes 10 vertically and four horizontally, a total of 16 in a grid pattern. A metal titanium sheet (length 10 cm × width 10 cm × thickness 50 μm) punched with a punch (hole punch) was produced.

Then, as the light-transmitting substrate 2 and the transparent conductive layer 3, a glass substrate (vertical 10 cm × width 10 cm × thickness 4 mm) made of fluorine-doped tin oxide (FTO) and having a transparent conductive layer 3 is used. A porous oxide semiconductor layer 4 made of titanium (TiO ₂ ) was formed. This porous oxide semiconductor layer 4 was formed as follows. First, acetylacetone was added to TiO ₂ anatase powder, and then kneaded with deionized water to prepare a liquid paste of titanium dioxide stabilized with a surfactant. This liquid paste is gently dropped onto the FTO film on the glass substrate, applied by a spinner coating method (900 rpm, 25 seconds), baked at 480 ° C. for 30 minutes in the atmosphere, and a porous oxide having a thickness of about 9 μm. A semiconductor layer 4 was formed. Next, the perforated conductive substrate 7 is placed on the porous oxide semiconductor layer 4 of the glass substrate with the FTO film, and the porous oxide semiconductor layer 4 is formed with a metal brush using the conductive substrate 7 as a mask. The through holes 10 were formed in the porous oxide semiconductor layer 4.

  Next, the glass substrate with an FTO film in which the through holes 10 were formed in the porous oxide semiconductor layer 4 was immersed in the dye solution for about 12 hours to adsorb the dye to the porous oxide semiconductor layer 4. The dye solution is a ruthenium complex dye N719 (manufactured by Solaronics S.A., product name “Ruthenium 535-bisTBA”) dissolved in acetonitrile and t-butanol (1: 1 by volume) as solvents (0.3 m). Mol / l) was used.

  A platinum layer as a counter electrode layer (catalyst layer) 8 is deposited with a thickness of 50 nm on one main surface of a metal titanium sheet as the conductive substrate 7 by sputtering, and an insulating film 14 made of polyimide is formed on the other main surface in FIG. Like the collector electrode pattern shown, it was formed by screen printing excluding the perforated region.

  Then, these optical working electrode side substrate and counter electrode side substrate are arranged so that the porous oxide semiconductor layer 4 and the counter electrode layer 8 face each other, and are formed in a frame shape on the outer peripheral portions of the opposing main surfaces of both substrates. The sealing member 9 made of an olefin-based resin (made by Mitsui DuPont Polychemical Co., Ltd., trade name “HIMILAN”) is sandwiched between the two substrates and heated to cure and seal the sealing member 9. did.

  Thus, a through hole 10 penetrating the porous oxide semiconductor layer 4, the counter electrode layer 8, and the conductive substrate 7 was formed on the FTO film on the glass substrate.

  Next, a silicone resin was dropped onto the inner wall surface of the through hole 10 to coat it, and the insulating protective layer 11 was formed continuously.

  Further, a conductive paste (Ag paste) is dropped into the through hole 10 to form the conductor 12, and the conductive paste (Ag paste) is collected on the insulating film 14 made of a polyimide resin film as shown in FIG. The collector electrode 13 connected to the conductor 12 was formed by dripping like an electrode pattern.

Next, an electrolyte was injected from the injection hole. In Example 1, the electrolyte was a liquid electrolyte, and was prepared using iodine (I ₂ ), lithium iodide (LiI), and an acetonitrile solution. Thereafter, the injection hole was sealed with an ultraviolet curable resin.

When the photoelectric conversion characteristics of the photoelectric conversion device 1 thus obtained were evaluated, the conversion efficiency was 4.1% at AM 1.5 and 100 mW / cm ² .

  As described above, in Example 1, the photoelectric conversion device 1 can be easily manufactured, and high conversion efficiency can be realized in a relatively large area.

  A photoelectric conversion device 1A having the configuration shown in FIG. 4 was produced as follows.

  First, as the conductive substrate 7, a chemical etching method is performed in a grid pattern in which the main surface has vertical and horizontal intervals of 20 mm, four 2 mmφ through-holes 10 vertically and four horizontally, a total of 16 holes. A stainless steel sheet (length 10 cm × width 10 cm × thickness 50 μm) perforated was prepared.

Then, as the light-transmitting substrate 2 and the transparent conductive layer 3, a glass substrate (vertical 10 cm × width 10 cm × thickness 4 mm) made of fluorine-doped tin oxide (FTO) and having a transparent conductive layer 3 is used. A porous oxide semiconductor layer 4 made of titanium (TiO ₂ ) was formed. This porous oxide semiconductor layer 4 was formed as follows. First, acetylacetone was added to TiO ₂ anatase powder, and then kneaded with deionized water to prepare a liquid paste of titanium dioxide stabilized with a surfactant. This liquid paste is gently dropped onto the transparent conductive layer 3 of the glass substrate, applied by a spinner coating method (900 rpm, 25 seconds), baked in the atmosphere at 480 ° C. for 30 minutes, and a porous material having a thickness of about 9 μm. An oxide semiconductor layer 4 was formed.

Next, a platinum layer as a counter electrode layer (catalyst layer) 8 is deposited with a thickness of 50 nm on one main surface of the stainless steel sheet in which the through holes 10 are formed by sputtering, and a TiO ₂ film is sputtered on the other main surface. Formed with.

  Then, these optical working electrode side substrate and counter electrode side substrate are arranged so that the porous oxide semiconductor layer 4 and the counter electrode layer 8 face each other, and are formed in a frame shape on the outer peripheral portions of the opposing main surfaces of both substrates. The sealing member 9 made of an olefin-based resin (made by Mitsui DuPont Polychemical Co., Ltd., trade name “HIMILAN”) is sandwiched between the two substrates and heated to cure and seal the sealing member 9. did.

  Next, using the perforated stainless steel sheet as a mask, the porous oxide semiconductor layer 4 was scraped off with a metal brush to form through holes 10 in the porous oxide semiconductor layer 4.

Next, a collector electrode 13 made of an Au film is formed on the TiO ₂ film formed on the other main surface of the conductive substrate 7 by a sputtering method so as to be about 8 mm beside the through hole 10 as in the collector electrode pattern shown in FIG. Mask vapor deposition was performed at the width. At the same time, an Au film was deposited on the transparent conductive layer 3 in the through hole 10 at the same time.

  Next, the conductive layer 12 was formed by connecting the transparent conductive layer 3 and the collector electrode 13 with an Au wire (25 μmφ) by wire bonding.

  Next, a dye solution was injected from the through hole 10 to adsorb the dye to the porous oxide semiconductor layer 4. The dye solution is a ruthenium complex dye N719 (manufactured by Solaronics S.A., product name “Ruthenium 535-bisTBA”) dissolved in acetonitrile and t-butanol (1: 1 by volume) as solvents (0.3 m). Mol / l) was used.

  Next, a silicone resin was dropped into the inside of the through hole 10 and filled, and the insulating protective layer 11 was formed continuously.

Next, an electrolyte was injected into the conductive substrate 7 through an injection hole that was previously opened simultaneously with the through hole 10. In Example 2, the electrolyte was a liquid electrolyte, and was prepared using iodine (I ₂ ), lithium iodide (LiI), and an acetonitrile solution. Thereafter, the injection hole was sealed with an ultraviolet curable resin.

When the photoelectric conversion characteristics of the photoelectric conversion device 1A thus obtained were evaluated, the conversion efficiency was 4.5% at AM 1.5 and 100 mW / cm ² .

  As described above, in Example 2, the photoelectric conversion device 1A can be easily manufactured, and high conversion efficiency can be realized with a relatively large area.

  Further, in the second embodiment, since the wire bonding wire having a small electric resistance is used as the conductor 12, the diameter of the through hole 10 is made larger than that when the thick conductor 12 made of the conductive paste of the first embodiment is used. Since it can be made smaller, the non-photoelectric conversion region becomes narrower, and the conversion efficiency can be further increased.

An example of embodiment is shown about the photoelectric conversion apparatus of this invention, and it is sectional drawing in the BB 'line of FIG. 3 (FIG. 5). An example of embodiment is shown about the photoelectric conversion apparatus of this invention, and is sectional drawing in CC 'line of FIG. An example of embodiment is shown about the photoelectric conversion apparatus of this invention, and it is a top view in the AA 'line cross section of the part of the porous oxide semiconductor layer of FIG. 1, FIG. It is sectional drawing which shows the other example of embodiment about the photoelectric conversion apparatus of this invention. The photoelectric conversion apparatus of this invention is shown the other examples of embodiment, and is the top view in the AA 'line cross section of the part of the porous oxide semiconductor layer of FIG. 1, FIG. It is a top view which shows the other example of embodiment about the photoelectric conversion apparatus of this invention. It is sectional drawing which shows an example of embodiment about the integrated photoelectric conversion apparatus of this invention. It is sectional drawing which shows an example of embodiment about the module type photoelectric conversion apparatus of this invention. FIG. 11 shows an example of a conventional photoelectric conversion device and is a cross-sectional view taken along line BG-BG ′ in FIG. 10. FIG. 10 shows an example of a conventional photoelectric conversion device and is a plan view of a cross section taken along line AG-AG ′ of FIG. 9.

Explanation of symbols

1: Photoelectric conversion device 2: Translucent substrate 3: Transparent conductive layer 4: Porous oxide semiconductor layer 6: Electrolyte layer 7: Conductive substrate
8: Counter electrode layer 9: Sealing member 10: Through hole 11: Insulating protective layer 12: Conductor 13: Collector

Claims (7)

  A light-working electrode side substrate in which a transparent conductive layer and a porous oxide semiconductor layer carrying a dye are formed on one main surface of a translucent substrate, and a counter electrode layer is formed on one main surface of the conductive substrate. In the photoelectric conversion device having a counter electrode side substrate having a collector electrode formed on a surface thereof, wherein the porous oxide semiconductor layer and the counter electrode layer are opposed to each other, and an electrolyte layer is provided therebetween, the conductive substrate A plurality of through-holes formed at regular intervals through the counter electrode layer, the electrolyte layer and the porous oxide semiconductor layer to reach the transparent conductive layer, and a central axis portion of the through-hole. A photoelectric conversion device comprising: a conductor connecting the transparent conductive layer and the collector electrode.   The photoelectric conversion device according to claim 1, wherein an insulating protective layer is formed on at least one of an inner surface of the through hole and an outer peripheral surface of the conductor.   The photoelectric conversion device according to claim 1, wherein the plurality of through holes are formed at regular intervals in a vertical direction and a horizontal direction in a plan view.   3. The photoelectric conversion device according to claim 1, wherein the plurality of through holes are formed so as to be positioned at the centers of a plurality of regular hexagons arranged in a close-packed manner in a plan view.   5. The photoelectric conversion device according to claim 1, wherein a sealing member is formed from an outer peripheral portion of the working electrode side substrate to an outer peripheral portion of the counter electrode side substrate.   6. The photoelectric conversion device according to claim 1, wherein the transparent conductive layer, the porous oxide semiconductor layer, the electrolyte layer, and the counter electrode layer form a plurality of independent photoelectric conversion regions. And partition walls are formed between the photoelectric conversion regions to prevent the electrolyte layer from continuing, and the plurality of photoelectric conversion regions are connected in series, in parallel, or in series-parallel connection. An integrated photoelectric conversion device characterized by that. 7. A photovoltaic power generation apparatus, wherein the photoelectric conversion apparatus according to claim 1 is used as a power generation means, and the power generated by the power generation means is supplied to a load.

Images