JP2009135395A - Photoelectric conversion device, photovoltaic generator, and photoelectric conversion module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve light utilization efficiency and photoelectric conversion efficiency of both photoelectric converters, in a stacked photoelectric conversion device where an amorphous silicon photoelectric converter and a dye-sensitized photoelectric converter are stacked. <P>SOLUTION: This photoelectric conversion device includes: the amorphous silicon photoelectric converter 31 having an amorphous silicon photoelectric conversion layer 30 and a translucent conductive layer (second translucent conductive layer) 16 formed on the amorphous silicon photoelectric conversion layer 30; and the dye-sensitized photoelectric converter 20 stacked on the second translucent conductive layer 16 side of the amorphous silicon photoelectric converter 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a stacked type (tandem type) photoelectric conversion device and photovoltaic device in which an amorphous silicon photoelectric conversion body and a dye-sensitized photoelectric conversion body are stacked, and has high photoelectric conversion efficiency and the like. The present invention relates to a photoelectric conversion device, a photovoltaic power generation device, and a photoelectric conversion module that can obtain excellent characteristics.

  A normal bulk crystal silicon solar cell using a silicon crystal plate has a problem of finite resources and material cost because the thickness of the silicon crystal plate is as thick as about 300 μm. Therefore, there is a problem of process cost that high temperature treatment at 1000 ° C. or higher is necessary. In addition, since there is a limit to the size (about 15 cm square) of the silicon crystal plate that constitutes one power generation cell, the assembly cost required for producing a large (meter-order size) module using a large number of power generation cells is reduced. Take it.

  On the other hand, a thin film type amorphous silicon solar cell using an amorphous silicon thin film is composed of a very thin amorphous silicon thin film having a thickness of about 0.3 μm, and a low temperature process (about 300 ° C.). The above-described problems can be almost eliminated by being able to form the substrate by using a substrate having a large free size.

Dye-sensitized solar cells are attracting attention as low-cost next-generation solar cells by using silicon and obtaining high efficiency, but still have problems in reliability. From this, a tandem structure as shown in Patent Document 1 has been proposed.
JP 2005-158620 A

  Conventionally, a tandem solar cell obtained by combining an amorphous silicon solar cell and a microcrystalline silicon solar cell is well known. These two solar cells have many similarities in physical properties, and there are few major problems when they are stacked. However, combining amorphous silicon solar cells and dye-sensitized solar cells in tandem type has various problems due to differences in their physical properties such as their refractive index. It is a big problem for new energy development.

  In particular, amorphous silicon solar cells have a problem in that light is greatly reflected on the back surface, making it difficult to transmit light to a dye-sensitized solar cell disposed below the amorphous silicon solar cell. It was an obstacle to improvement.

  The present invention has been completed in view of the above-described conventional problems, and an object of the present invention is a stacked type (tandem type) in which an amorphous silicon photoelectric conversion body and a dye-sensitized photoelectric conversion body are stacked. In the photoelectric conversion device, the light use efficiency of both photoelectric conversion bodies, the photoelectric conversion device with improved photoelectric conversion efficiency, and the photovoltaic device are obtained.

  The photoelectric conversion device of the present invention includes an amorphous silicon photoelectric conversion layer and an amorphous silicon photoelectric conversion body having a translucent conductive layer formed on the amorphous silicon photoelectric conversion layer, and the amorphous silicon. And a dye-sensitized photoelectric converter laminated on the translucent conductive layer side of the photoelectric converter.

  In the photoelectric conversion device of the present invention, preferably, the translucent conductive layer has a thickness of 0.07 to 0.12 μm.

  In the photoelectric conversion device of the present invention, preferably, a catalyst layer is formed on the translucent conductive layer, and the dye-sensitized photoelectric conversion body is opposed to the catalyst layer via a charge transport layer. Are arranged.

  In the photoelectric conversion device of the present invention, preferably, the dye-sensitized photoelectric converter has a porous semiconductor layer that is dye-sensitized.

  In the photoelectric conversion device of the present invention, preferably, the catalyst layer is made of platinum, palladium, rhodium, carbon, or polythiophene.

  In the photoelectric conversion device of the present invention, preferably, the amorphous silicon photoelectric conversion body and the dye-sensitized photoelectric conversion body are bonded via a transparent resin.

  In the photoelectric conversion device of the present invention, preferably, the amorphous silicon photoelectric conversion layer is formed on the first conductive amorphous silicon semiconductor layer and the first conductive amorphous silicon semiconductor layer. An intrinsic type amorphous silicon semiconductor layer and a second conductivity type amorphous silicon semiconductor layer formed on the intrinsic type amorphous silicon semiconductor layer.

  In the photoelectric conversion device of the present invention, preferably, the translucent conductive layer includes at least one of an indium oxide layer, a tin oxide layer, and an indium tin oxide layer.

  The photovoltaic device of the present invention uses the photoelectric conversion device of the present invention as power generation means, and supplies the generated power of the power generation means to a load.

  In the photoelectric conversion module of the present invention, a plurality of the photoelectric conversion devices of the present invention are arranged in the horizontal direction and are electrically connected.

  A photoelectric conversion device according to the present invention includes an amorphous silicon photoelectric conversion layer, an amorphous silicon photoelectric conversion body having a translucent conductive layer formed on the amorphous silicon photoelectric conversion layer, and an amorphous silicon photoelectric conversion A dye-sensitized photoelectric conversion body laminated on the translucent conductive layer side of the body, so that the translucent conductive layer does not contribute to power generation of the amorphous silicon photoelectric conversion body. Wavelength light (light having a wavelength of about 600 to 900 nm) can be incident on the dye-sensitized photoelectric conversion body without reducing reflection. As a result, short-wavelength light (light having a wavelength of about 300 to 600 nm) is efficiently absorbed and photoelectrically converted by the amorphous silicon photoelectric converter, and long-wavelength light is efficiently absorbed by the dye-sensitized photoelectric converter. The photoelectric conversion efficiency can be greatly improved.

  In the photoelectric conversion device of the present invention, preferably, the light-transmitting conductive layer has a thickness of 0.07 to 0.12 μm. Therefore, long-wavelength light (wavelength 600) that does not contribute to power generation of the amorphous silicon photoelectric conversion body. It is possible to more effectively make the light incident on the dye-sensitized photoelectric converter without reflection reduction.

  In the photoelectric conversion device of the present invention, preferably, a catalyst layer is formed on the translucent conductive layer, and the dye-sensitized photoelectric converter is disposed so as to face the catalyst layer via the charge transport layer. Therefore, the exchange of charges between the charge transport layer and the amorphous silicon photoelectric converter can be facilitated by the catalyst layer, and the overvoltage (voltage applied at the initial stage of driving the photoelectric conversion device) can be reduced. Can do. In addition, since the translucent conductive layer has conductivity, even if the amorphous silicon photoelectric converter is incorporated in the same cell as the dye-sensitized photoelectric converter, an extra electric field is generated in the charge transport layer (electrolyte layer). Generation | occurrence | production and it can suppress that a catalyst layer raise | generates peeling. As a result, the reliability of the catalyst layer can be increased, and the amorphous silicon photoelectric conversion body can be incorporated in the same cell as the dye-sensitized photoelectric conversion body.

  Moreover, the photoelectric conversion device of the present invention preferably has a dye-sensitized photoelectric converter having a dye-sensitized porous semiconductor layer. Therefore, a dye (sensitizing dye) is added to a porous semiconductor layer having a large surface area. ) Can be absorbed (adsorbed) more, so that long-wavelength light transmitted through the amorphous silicon photoelectric conversion body can be absorbed and photoelectrically converted without leakage. Therefore, the amorphous silicon photoelectric conversion body is excellent in short wavelength (about 300 to 600 nm) sensitivity, and the dye-sensitized photoelectric conversion body is excellent in long wavelength (about 600 to 900 nm) sensitivity. As a result, a wide wavelength range (300 to 900 nm). More efficient photoelectric conversion is possible.

  In the photoelectric conversion device of the present invention, preferably, the catalyst layer is made of platinum, palladium, rhodium, carbon, or polythiophene, so that charge exchange between the charge transport layer (electrolyte layer) and the amorphous silicon photoelectric converter is performed. The overvoltage (voltage applied at the initial stage of driving of the photoelectric conversion device) can be further reduced.

  In the photoelectric conversion device of the present invention, it is preferable that the amorphous silicon photoelectric conversion body and the dye-sensitized photoelectric conversion body are bonded via a transparent resin, so that the amorphous silicon having different operating voltages is used. The photoelectric conversion body and the dye-sensitized photoelectric conversion body can be stacked by separating them electrically and mechanically. Therefore, by incorporating the dye-sensitized photoelectric converter and the amorphous silicon photoelectric converter in the same cell, an extra electric field is generated in the charge transport layer (electrolyte layer), causing the catalyst layer to peel off, etc. Can be eliminated.

  In the photoelectric conversion device of the present invention, preferably, the amorphous silicon photoelectric conversion layer includes a first conductive type amorphous silicon semiconductor layer and an intrinsic type formed on the first conductive type amorphous silicon semiconductor layer. Since it comprises an amorphous silicon semiconductor layer and a second conductive type amorphous silicon semiconductor layer formed on the intrinsic type amorphous silicon semiconductor layer, the band gap of the amorphous silicon photoelectric conversion layer is 1. Since it becomes 8 eV and does not absorb long wavelength light having a wavelength of 650 nm or more, the amorphous silicon photoelectric conversion layer can transmit long wavelength light without loss. Therefore, it is suitable for a laminated structure (tandem structure) with a dye-sensitized photoelectric conversion body.

  In the photoelectric conversion device of the present invention, preferably, the translucent conductive layer includes at least one of an indium oxide layer, a tin oxide layer, and an indium tin oxide layer. The ohmic contact with the porous silicon photoelectric conversion layer can be ensured, and the light transmittance is sufficient. It is also possible to laminate a titanium oxide layer, a copper oxide layer, an organic conductive film, etc. on the indium oxide layer, etc. In this case, further improvement in light transmittance, dye-sensitized photoelectric converter and charge transport layer (electrolyte) Layer).

  Since 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, the photoelectric conversion characteristics are improved.

  In the photoelectric conversion module of the present invention, a plurality of photoelectric conversion devices of the present invention are arranged in the horizontal direction and are electrically connected, so that a plurality of photoelectric conversion devices having high photoelectric conversion efficiency are electrically connected. Since it is connected, it becomes a photoelectric conversion module with a large photocurrent output.

  Hereinafter, the photoelectric conversion device of this embodiment will be described in detail with reference to the drawings.

  1 and 2 are cross-sectional views showing examples of embodiments of the photoelectric conversion device of the present invention. In these figures, 1 is incident light, 2 is a translucent substrate made of glass or plastic, 3 is an ITO (tin-doped indium oxide: indium tin oxide) layer, FTO (fluorine-doped tin oxide) layer, etc. 1 is a first conductive type (for example, p-type) amorphous silicon semiconductor layer, 5 is an intrinsic type (i-type) amorphous silicon semiconductor layer, and 6 is a second conductive type (for example, n-type). Type) amorphous silicon semiconductor layer, 16 is a second light-transmitting conductive layer as the “light-transmitting conductive layer” in this embodiment, 7 is a catalyst layer, 8 is a sealing member, and 9 is a charge transport layer. (Electrolyte layer). 30 is an amorphous silicon photoelectric conversion layer, and 31 is an amorphous silicon photoelectric conversion body.

  Reference numeral 20 denotes a dye-sensitized photoelectric converter, and the dye-sensitized photoelectric converter 20 is represented by a translucent substrate 10, a translucent conductive layer 11, and a dye (sensitizing dye) 14 (shown by black dots in the figure). ) Consists of a porous semiconductor layer 13 adsorbed on the surface.

  In FIG. 2, the dye-sensitized photoelectric conversion body 20 includes a translucent substrate 10, a translucent conductive layer 11, a catalyst layer 12, a charge transport layer 9, a porous semiconductor layer 13, and a dye 14.

  1 includes an amorphous silicon photoelectric conversion layer 30 and a light-transmitting conductive layer (second light-transmitting conductive layer) formed on the amorphous silicon photoelectric conversion layer 30. Layer) 16, and a dye-sensitized photoelectric converter 20 stacked on the second light-transmissive conductive layer 16 side of the amorphous silicon photoelectric converter 31. is doing.

  Specifically, the photoelectric conversion device includes a translucent substrate 2 in which a first translucent conductive layer 3 is formed on one main surface, and an amorphous formed on the first translucent conductive layer 3. Amorphous silicon photoelectric conversion body 31 having porous silicon photoelectric conversion layer 30 and second translucent conductive layer 16 formed on amorphous silicon photoelectric conversion layer 30, and amorphous silicon photoelectric conversion body It is preferable to have the dye-sensitized photoelectric conversion body 20 laminated on 31. The thickness of the second translucent conductive layer 16 is preferably 0.07 to 0.12 μm.

  In the photoelectric conversion device of the present embodiment, the translucent substrate 2 may be omitted, and in that case, the amorphous silicon photoelectric conversion body 31 itself may be formed of a hard plate. Moreover, the 1st translucent conductive layer 3 does not need to be provided, and in that case, a collector electrode or the like may be provided at the end of the amorphous silicon photoelectric conversion body 31. Moreover, when there exists the translucent board | substrate 2 and the 1st translucent conductive layer 3, the translucent board | substrate 2 functions as a support body and light transmissive body of the amorphous silicon photoelectric conversion body 31, and a translucent conductive The layer 3 is suitable in that it functions as a translucent large-area electrode.

  The second light-transmitting conductive layer 16 does not reflect and reduce long wavelength light (light having a wavelength of about 600 to 900 nm) that does not contribute to power generation of the amorphous silicon photoelectric conversion body 31, and thus the dye-sensitized photoelectric conversion body. 20 is incident. As a result, short wavelength light (light having a wavelength of about 300 to 600 nm) is efficiently absorbed and photoelectrically converted by the amorphous silicon photoelectric converter 31, and long wavelength light is efficiently converted by the dye-sensitized photoelectric converter 20. Can be absorbed and photoelectrically converted, and the photoelectric conversion efficiency is greatly improved.

  That is, by forming the second translucent conductive layer 16, silicon having a refractive index of 3.5 and a refractive index of 1.3 are formed on the main surface of the amorphous silicon photoelectric converter 31 on the charge transport layer 9 side. The interface reflection of light due to the difference from the charge transport layer 9 is reduced from 35% when the second light-transmitting conductive layer 16 is absent to 5%. Therefore, it is possible to increase the amount of light that passes through the amorphous silicon photoelectric converter 31 and travels toward the charge transport layer 9. As a result, the photoelectric conversion device can maintain a high voltage, and high photoelectric conversion efficiency can be realized.

  The preferred photoelectric conversion device shown in FIG. 2 has a configuration in which an amorphous silicon photoelectric conversion body 31 and a dye-sensitized photoelectric conversion body 20 are bonded via a transparent resin 32. With this configuration, the amorphous silicon photoelectric conversion body 31 and the dye-sensitized photoelectric conversion body 20 having different operating voltages can be separated electrically and mechanically and stacked. Accordingly, by incorporating the dye-sensitized photoelectric conversion body 20 and the amorphous silicon photoelectric conversion body 31 in the same cell, an extra electric field is generated in the charge transport layer (electrolyte layer) 9 and the catalyst layer 12 is peeled off. It is possible to eliminate various problems such as

  In FIG. 2, 2 ′ is an intermediate translucent substrate provided between the amorphous silicon photoelectric converter 31 and the dye-sensitized photoelectric converter 20, and 3 ′ is an intermediate translucent substrate 2 ′. It is an intermediate translucent conductive layer formed on the main surface on the dye-sensitized photoelectric conversion body 20 side.

  The transparent resin 32 is preferably made of vinyl chloride acetate (EVA), polyolefin resin, silicone resin, epoxy resin, polyimide resin, polycarbonate resin, or the like. In particular, those having high translucency with respect to long wavelength light (light having a wavelength of about 600 to 900 nm) are preferable, and in this respect, vinyl chloride acetate (EVA), polyolefin resin, silicone resin and the like are preferable. The thickness of the transparent resin 32 (interval between the second translucent conductive layer 16 and the intermediate translucent substrate 2 ′) is preferably about 5 to 1000 μm. By setting the thickness within this range, dust can be prevented from entering the transparent resin 32, and the amorphous silicon photoelectric converter 31 is inclined and sealed with respect to the dye-sensitized photoelectric converter 20. This can be suppressed. Further, the thickness of the transparent resin 32 is not excessively increased, which is suitable for resource saving.

  Moreover, it is preferable that the transparent resin 32 contains the absorber etc. which absorb short wavelength light (light with a wavelength of about 300-600 nm). In that case, it is possible to suppress the occurrence of a problem such that the short wavelength light enters the dye-sensitized photoelectric conversion body 20 and the dye 14 deteriorates. Examples of the absorber that absorbs short wavelength light (light having a wavelength of about 300 to 600 nm) include organic dyes such as dyes and pigments used in blue and green color filters, organic semiconductors, and the like.

  FIG. 5 is a cross-sectional view of a photoelectric conversion module obtained by modularizing the photoelectric conversion device of FIG.

  In the photoelectric conversion module of this embodiment, a plurality of the photoelectric conversion devices of this embodiment are arranged in the horizontal direction and are electrically connected. With this configuration, since a plurality of photoelectric conversion devices having high photoelectric conversion efficiency are electrically connected, a photoelectric conversion module having a large photocurrent output is obtained.

  The photoelectric conversion module in FIG. 5 has a configuration in which three photoelectric conversion devices are connected in series. The configuration of each photoelectric conversion device is the same as that shown in FIG. The upper electrode on the amorphous silicon photoelectric conversion body 31 side of the rightmost photoelectric conversion device passes through the partition wall between the adjacent second photoelectric conversion device from the right, and the second photoelectric conversion device is connected by the connection wiring 15. The dye-sensitized photoelectric conversion body 20 is electrically connected to the lower electrode. The same applies to the electrical connection between the second photoelectric conversion device and the third photoelectric conversion device. Note that the plurality of photoelectric conversion devices may be connected in parallel or in series and parallel.

  The connection wiring 15 may be a sintered metal paste. The metal paste contains metal particles made of a metal (including an alloy) containing at least one of Mo, Ag, Cu, Ni, W, and Sn. The method of sintering the metal paste may be a method of heating in a furnace. However, since amorphous silicon is altered at a high temperature of 200 ° C. or higher, the portion of the connection wiring 15 is locally heated and baked by laser light. It is preferable to tie. Low melting point metal particles made of a low melting point metal that is melted by laser light may be mixed in the metal paste. The low melting point metal particles are preferably particles made of, for example, solder or an indium alloy. In this case, the low molten metal is embedded in the gaps between the metal particles in the connection wiring 15, and the resistance of the connection wiring 15 is reduced.

  As described above, adjacent photoelectric conversion devices are connected in series to form a module, thereby eliminating the trouble of electrically connecting wirings by soldering as in a conventional photoelectric conversion device using a crystalline silicon substrate. Thus, the connection wiring 15 can be formed.

<Translucent substrate>
The translucent substrate 2 is a resin material such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), polyimide, polycarbonate, or an inorganic material such as blue plate glass, soda glass, borosilicate glass, alkali-free glass, or translucent ceramics. A material, a conductive resin material, an organic-inorganic hybrid material, or the like is preferable. The thickness is about 0.1 to 5 mm.

  When a glass material is used as the material of the translucent substrate 2, it is preferable to use tempered glass, in which case the mechanical strength of the photoelectric conversion device is increased. On the main surface opposite to the main surface on which the amorphous silicon photoelectric conversion layer 30 of the translucent substrate 2 is formed (upper surface in FIG. 1), an antireflection film with a controlled refractive index and porosity is provided. Alternatively, a design may be made by pasting a color film or the like.

  The 1st translucent conductive layer 3 consists of ITO, a tin oxide, etc., and thickness is good about 0.3-2 micrometers. By setting the thickness within the range, the sheet resistance can be reduced, the series resistance of the photoelectric conversion device can be reduced, and deterioration of the FF characteristics can be suppressed. Further, the unevenness of the surface of the first light-transmissive conductive layer 3 becomes smaller than the thickness of the first conductive amorphous silicon semiconductor layer 4, and the first conductive amorphous silicon semiconductor layer 4 makes the first transparent The entire surface of the photoconductive layer 3 can be stably covered. The first translucent conductive layer 3 is formed by a CVD method, a sputtering method, a spray method or the like.

  In general, in the photoelectric conversion device using the amorphous silicon semiconductor layer 4, the first light-transmitting conductive layer 3 in which the surface reflection is reduced by forming a fine uneven structure (texture structure) on the surface is used. In many cases, the surface of the first light-transmitting conductive layer 3 is preferably a flat surface in the present embodiment. In this case, the amorphous silicon photoelectric conversion layer 30 sandwiched between the first light-transmitting conductive layer 3 and the second light-transmitting conductive layer 16 has the interface with the first light-transmitting conductive layer 3 and the first light-transmitting conductive layer 3. Long-wavelength light (wavelength 600 to 900 nm) that does not contribute to power generation of the amorphous silicon photoelectric conversion body 31 by generating reflected light at the interface with the two translucent conductive layers 16 and expressing the light interference effect. Can be made incident on the dye-sensitized photoelectric conversion body 20 without reducing reflection. In this case, the arithmetic average roughness of the surface of the first translucent conductive layer 3 is preferably 0.05 μm or less.

  In order to reduce light reflection at the amorphous silicon photoelectric conversion layer 30, an Nb-doped titanium oxide layer may be inserted as an intermediate layer in the first light-transmissive conductive layer 3. In this case, the second translucent conductive layer 16 made of silicon having a refractive index of 3.5 and ITO having a refractive index of about 1.9 is provided by including the Nb-doped titanium oxide layer having a refractive index of about 2.6. The reflection of light generated between the two can be suppressed.

<Amorphous silicon photoelectric conversion layer>
The amorphous silicon photoelectric conversion layer 30 is preferably a thin film photoelectric conversion layer such as a thin film type amorphous silicon semiconductor layer, and more specifically formed on the first light-transmissive conductive layer 3. The first conductive type amorphous silicon semiconductor layer 4, the intrinsic type amorphous silicon semiconductor layer 5 formed on the first conductive type amorphous silicon semiconductor layer 4, and the intrinsic type amorphous silicon semiconductor layer 5 The second conductive type amorphous silicon semiconductor layer 6 is formed thereon. In this case, the band gap of the amorphous silicon photoelectric conversion layer 30 is 1.8 eV, and since the amorphous silicon photoelectric conversion layer 30 does not absorb long wavelength light having a wavelength of 650 nm or more, it can transmit long wavelength light. Thus, it is suitable for a laminated structure (tandem structure) with the dye-sensitized photoelectric conversion body 20.

  When the intrinsic type amorphous silicon semiconductor layer 5 is amorphous, at least one of the first conductive type amorphous silicon semiconductor layer 4 and the second conductive type amorphous silicon semiconductor layer 6 has microcrystals Or a hydrogenated amorphous silicon alloy based layer. For example, it is more preferable that the first conductive type amorphous silicon semiconductor layer 4 on the light incident side is made of hydrogenated amorphous silicon carbide because it can improve translucency and reduce light loss.

  Further, the first conductive type amorphous silicon semiconductor layer 4, the intrinsic type amorphous silicon semiconductor layer 5, and the second conductive type amorphous silicon semiconductor layer 6 are continuously formed under respective film forming conditions by chemical vapor deposition. Can be deposited.

For example, the first conductivity type amorphous silicon semiconductor layer 4 is a p-type a-Si: H (H-doped amorphous silicon) layer, and in the case of forming a film, SiH ₄ gas, H ₂ gas, B ₂ H are used as source gases. ₆ gases (diluted to 500 ppm with H ₂ ) are used, and the flow rates of these gases are optimized. The thickness of the p-type a-Si: H layer is preferably in the range of 50 to 200 mm, more preferably 80 to 120 mm. By setting it within the range of 50 to 200 cm, an internal electric field can be formed in the amorphous silicon photoelectric conversion layer 30 and an increase in light loss can be suppressed.

Further, for example, the intrinsic type amorphous silicon semiconductor layer 5 is an i-type a-Si: H layer, and when forming a film, SiH ₄ gas and H ₂ gas are used as source gases, and the flow rates of these gases are optimized. Turn into. The thickness of the i-type a-Si: H layer is preferably in the range of 500 to 10000 (0.05 μm to 1 μm), more preferably 2000 to 8000 (0.2 μm to 0.8 μm). By setting it within the range of 500 to 10,000 mm, a sufficient photocurrent can be obtained, and light can be easily transmitted to the dye-sensitized photoelectric conversion body 20 on the rear side.

Further, for example, the second conductivity type amorphous silicon semiconductor layer 6 is an n-type a-Si: H layer, and in the case of film formation, SiH ₄ gas, H ₂ gas, PH ₃ gas (in H ₂ ) These are diluted to 1000 ppm) and the flow rates of these gases are optimized. The thickness of the n-type a-Si: H layer is preferably in the range of 50 to 200 mm, more preferably 80 to 120 mm. By setting it within the range of 50 to 200 cm, an internal electric field can be formed in the amorphous silicon photoelectric conversion layer 30 and an increase in optical loss can be suppressed.

  The temperature of the translucent substrate 2 when the first conductive type amorphous silicon semiconductor layer 4, the intrinsic type amorphous silicon semiconductor layer 5, and the second conductive type amorphous silicon semiconductor layer 6 are formed may be any layer. Also in this case, the range of 150 ° C to 300 ° C is preferable, and 180 ° C to 240 ° C is more preferable. By setting the temperature within the range of 150 ° C. to 300 ° C., the amorphous silicon photoelectric conversion layer 30 having suitable characteristics can be obtained.

<Second translucent conductive layer>
The second light transmissive conductive layer 16 is formed on the amorphous silicon photoelectric conversion layer 30. The second translucent conductive layer 16 preferably includes at least one of an indium oxide layer, a tin oxide layer, and an indium tin oxide (ITO) layer, and more specifically, an ITO layer, a tin oxide layer, or the like. And formed by a CVD method, a sputtering method, a spray method or the like. Alternatively, a titanium oxide layer, an organic conductive layer, or the like may be laminated on an ITO layer, a tin oxide layer, or the like.

  The thickness of the second translucent conductive layer 16 is preferably about 0.07 to 0.12 μm. By setting the thickness within the range of about 0.07 to 0.12 μm, the peak of light transmittance improvement by the second light-transmissive conductive layer 16 is close to the wavelength of light absorbed by the amorphous silicon photoelectric conversion layer 30. By suppressing this, it is possible to increase the transmittance of light having a long wavelength of 700 nm or more that is transmitted to the dye-sensitized photoelectric conversion body 20 side. In addition, it is effective for power generation of the dye-sensitized photoelectric conversion body 20 so that the peak of transmittance improvement by the second light-transmitting conductive layer 16 does not exceed the wavelength of about 900 nm of light absorbed by the dye 14. Light in the wavelength band can be increased.

  The thickness range of the second translucent conductive layer 16 is such that the refractive index of the amorphous silicon photoelectric conversion layer 30 is about 3.5, and the refractive index of the second translucent conductive layer 16 made of ITO or the like. This is particularly effective when is about 1.9.

  FIG. 3 is a graph showing the relationship between the wavelength of light and the transmittance of the amorphous silicon photoelectric conversion layer 30 in the absence of the second light-transmissive conductive layer 16, and FIG. 4 is a graph showing the relationship between the wavelength of light and the transmittance of an amorphous silicon photoelectric conversion layer 30 when the conductive conductive layer 16 is formed. Compared with the graph of FIG. 3, in the graph of FIG. 4, the transmittance | permeability (light transmittance of the amorphous silicon photoelectric conversion layer 30) of 600-1000 nm which is the power generation wavelength range of the dye-sensitized photoelectric conversion body 20 is large. It has improved. 3 and 4, the amorphous silicon photoelectric conversion layer 30 has a thickness of 0.63 μm and a refractive index of 3.5, and the second translucent conductive layer 16 has a thickness of 100 nm and a refractive index of 1.. A case of 9 ITO layers is shown.

<Catalyst layer>
The catalyst layer 7 is formed in a plurality of island shapes on the second light-transmitting conductive layer 16, and the thickness is preferably about 0.5 to 20 nm. By setting the thickness within the range of about 0.5 to 20 nm, the distance between the island-shaped catalyst layers 7 can be reduced, and an effective catalytic effect can be obtained. Further, the decrease in the amount of transmitted light is suppressed so that the entire surface of the second conductivity type amorphous silicon semiconductor layer 6 is not covered with the catalyst layer (metal layer) 7 made of Pt or the like. A short circuit with the amorphous silicon semiconductor layer 6 can be avoided. The catalyst layer 7 is formed by a sputtering method or the like. However, in order to form a plurality of islands, it can be realized by performing an operation of forming an extremely thin thickness as described above.

  The catalyst layer 7 is preferably made of platinum, palladium, rhodium, carbon or polythiophene. In this case, charge exchange between the charge transport layer (electrolyte layer) 9 and the amorphous silicon photoelectric converter 31 can be facilitated, and an overvoltage (voltage applied at the initial stage of driving of the photoelectric conversion device) can be further increased. Can be small.

  As shown in FIG. 1, the catalyst layer 7 is formed on the second light-transmissive conductive layer 16, and the dye-sensitized photoelectric conversion body 20 is opposed to the catalyst layer 7 via the charge transport layer 9. Is preferably arranged. In this case, the exchange of charges between the charge transport layer 9 and the amorphous silicon photoelectric conversion body 31 can be facilitated by the catalyst layer 7 and the overvoltage (voltage applied at the initial stage of driving of the photoelectric conversion device) can be reduced. be able to. Further, since the second light-transmitting conductive layer 16 has conductivity, even if the amorphous silicon photoelectric converter 31 is incorporated in the same cell as the dye-sensitized photoelectric converter 20, the charge transport layer (electrolyte layer) It is possible to suppress the occurrence of an extra electric field in 9 and the catalyst layer 7 from peeling or the like. As a result, the reliability of the catalyst layer 7 can be increased, and the amorphous silicon photoelectric conversion body 31 can be incorporated in the same cell as the dye-sensitized photoelectric conversion body 20.

  Further, as shown in FIG. 2, the dye-sensitized photoelectric conversion body 20 may have another catalyst layer 12 on the light-transmitting conductive layer 11 formed on the light-transmitting substrate 10. . In this case, the output of the dye-sensitized photoelectric conversion body 20 can be efficiently taken out to the translucent conductive layer 11 through the other catalyst layer 12.

  In the configuration of FIG. 2, when the translucent substrate 10 has the translucent conductive layer 11 formed on the surface, an ITO layer, a tin oxide layer, or the like is formed on the translucent substrate 10 made of glass or plastic. What formed the translucent conductive layer 11 which consists of can be used. Instead of the translucent substrate 10, a conductive substrate made of metal may be used. When the conductive substrate is made of a metal, one made of titanium, molybdenum, tungsten, nickel or the like can be used.

<Sealing member>
The sealing member 8 may have a thickness (height) of about 0.06 to 1000 μm. By setting the thickness within the range of about 0.06 to 1000 μm, the thickness of the sealing member 8 is made larger than the thickness of the amorphous silicon photoelectric conversion layer 30, and the charge transport layer 9 together with the dye-sensitized photoelectric conversion body 20. In addition, it is possible to prevent the photoelectric conversion efficiency of the photoelectric conversion device from decreasing due to the charge transport layer 9 becoming too thick and the internal resistance increasing.

  The sealing member 8 is made of a resin adhesive such as polyethylene, polypropylene, epoxy resin, fluororesin or silicone resin, or an inorganic adhesive such as glass frit or ceramics.

  The sealing member 8 includes a first translucent conductive layer 3, a first conductive amorphous silicon semiconductor layer 4, an intrinsic amorphous silicon semiconductor layer 5, a second conductive amorphous silicon semiconductor layer 6, The sealing member 8 made of resin or the like is installed in a frame shape surrounding the amorphous silicon photoelectric conversion layer 30 on the one principal surface of the translucent substrate 2 on which the catalyst layer 7 is formed on one principal surface. It can be formed by a method of curing.

  Since the charge transport layer 9 is sealed by the sealing member 8, the durability and reliability of the photoelectric conversion device against light irradiation and high-temperature heating can be effectively maintained. That is, it is possible to effectively suppress the charge transport layer 9 from leaking out of the photoelectric conversion device due to light irradiation and high-temperature heating.

<Charge transport layer>
The charge transport layer 9 is preferably a liquid electrolyte or a gel electrolyte. Photoelectric conversion efficiency is improved by using a liquid electrolyte or a gel electrolyte excellent in charge transport characteristics. The charge transport layer 9 is made of a solid electrolyte such as a polymer electrolyte, a conductive polymer such as polythiophene / polypyrrole or polyphenylene vinylene, or an organic molecular electron transport agent such as a fullerene derivative, a pentacene derivative, a perylene derivative, or a triphenyldiamine derivative. It may be a thing.

  The charge transport layer 9 includes iodine / iodide salt, bromine / bromide salt, cobalt complex, potassium ferrocyanide, and the like. The notation “iodine / iodide salt” indicates that the charge transport layer 9 reversibly changes into iodine and iodide salt.

  The thickness of the charge transport layer 9 is preferably about 0.01 to 500 μm. By setting it within the range of about 0.01 to 500 μm, it is possible to suppress a short circuit due to contact between the positive electrode side (amorphous silicon photoelectric converter 31 side) and the counter electrode side (dye sensitized photoelectric converter 20 side). In addition, it is possible to suppress a decrease in photoelectric conversion efficiency due to an increase in the charge transport layer 9 which is a resistance component, and further, when the charge transport layer 9 is a liquid electrolyte, it is possible to suppress the occurrence of a sealing defect due to an increase in the liquid portion.

<Porous semiconductor layer>
Further, the dye-sensitized photoelectric converter 20 preferably includes a dye-sensitized photoelectric converter 20 having a dye-sensitized porous semiconductor layer 13 as shown in FIG. In this case, since the porous semiconductor layer 13 having a large surface area can carry (adsorb) more dye (sensitizing dye) 14, the long-wavelength light transmitted through the amorphous silicon photoelectric converter 31 is not leaked. It can absorb and photoelectrically convert. Therefore, the amorphous silicon photoelectric conversion body 31 is excellent in sensitivity for short wavelengths (about 300 to 600 nm), and the dye-sensitized photoelectric conversion body 20 is excellent in sensitivity for long wavelengths (about 600 to 900 nm). More efficient photoelectric conversion can be performed over about 900 nm).

  That is, the photoelectric conversion device of FIG. 1 is a stacked type (tandem type) photoelectric conversion device in which an amorphous silicon photoelectric conversion body 31 and a dye-sensitized photoelectric conversion body 20 are stacked.

As the material and composition of the porous semiconductor layer 13, titanium oxide (TiO ₂ ) is optimal,
Other materials include 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), tungsten (W) and the like, and at least one metal oxide semiconductor is preferable. N), carbon (C), fluorine (F), sulfur (S), chlorine (Cl), phosphorus (P), or other nonmetallic elements may be contained. 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 semiconductor layer 13 is preferably an n-type semiconductor whose conduction band is lower than the conduction band of the dye 14 at the electron energy level.

  The porous semiconductor layer 13 is made of titanium dioxide or the like and contains a large number of fine pores (having a pore diameter of preferably about 10 to 40 nm, and a peak in photoelectric conversion efficiency at 22 nm). A porous n-type oxide semiconductor layer or the like is preferable.

  When the pore diameter of the porous semiconductor layer 10 is 10 nm or more, the penetration and adsorption of the dye 14 are promoted, and a sufficient adsorption amount of the dye 14 is easily obtained, and the diffusion of the electrolyte proceeds and the diffusion resistance is reduced. As a result, the photoelectric conversion efficiency is improved.

  When the pore diameter of the porous semiconductor layer 10 is 40 nm or less, the specific surface area of the porous semiconductor layer 13 increases, so that it is not necessary to increase the thickness in order to secure the amount of adsorption of the dye 14. It is possible to suppress a decrease in light transmittance when the thickness is too large and a decrease in light absorption of the dye 14. In addition, the loss due to charge recombination can be reduced by shortening the moving distance of charges injected into the porous semiconductor layer 13. Furthermore, since the diffusion distance of the electrolyte is shortened to reduce the diffusion resistance, the photoelectric conversion efficiency is improved.

  The porous semiconductor layer 13 is a porous body that is a granular body, or a linear body such as a needle-shaped body, a tubular body, or a columnar body, or a collection of these various linear bodies. By this, the surface area which adsorb | sucks the pigment | dye 14 increases and a photoelectric conversion efficiency can be improved. The porous semiconductor layer 13 is preferably a porous body having a porosity of 20 to 80%, more preferably 40 to 60%. By making porous, the surface area as the light working electrode layer can be increased by 1000 times or more compared to the case of a dense body, and light absorption, photoelectric conversion, and electron conduction can be performed efficiently.

The porosity of the porous semiconductor layer 13 is obtained by obtaining an isothermal adsorption curve of a sample by a nitrogen gas adsorption method using a gas adsorption measuring device, and using a BJH (Barrett-Joyner-Halenda) method or a CI (Chemical Ionization) method. , DH (Dollimore-Heal) method or the like can be used to determine the pore volume and obtain it from the particle density of the sample.

  The shape of the porous semiconductor layer 13 is preferably a shape having a large surface area and a small electric resistance, and is preferably composed of fine particles or fine linear bodies, for example. The average particle diameter or average wire diameter is preferably 5 to 500 nm, and more preferably 10 to 200 nm. By setting the thickness within the range of 5 to 500 nm, the material can be miniaturized, and the junction area can be increased to increase the photocurrent.

  Further, by forming the porous semiconductor layer 13 as a porous body, the surface of the dye-sensitized photoelectric conversion body 20 formed by adsorbing the dye 14 to the porous body becomes uneven, thereby providing a light confinement effect and photoelectric conversion. Efficiency can be further increased.

  The thickness of the porous semiconductor layer 13 is preferably 0.1 to 50 μm, more preferably 1 to 20 μm. By setting the thickness within the range of 0.1 to 50 μm, the photoelectric conversion action can be largely maintained, and the light can be easily incident while maintaining the light transmittance.

When the porous semiconductor layer 13 is made of titanium oxide, it is formed as follows. First, acetylacetone is added to TiO ₂ anatase powder, and then kneaded with deionized water to prepare a titanium oxide paste stabilized with a surfactant. The prepared paste is applied at a constant speed onto the light-transmitting conductive layer 11 on the light-transmitting substrate 10 by a doctor blade method, a bar coating method, or the like, and is 300 to 600 ° C., preferably 400 to 500 ° C. in the atmosphere. The porous semiconductor layer 13 is formed by heat treatment for 10 to 60 minutes, preferably 20 to 40 minutes. This method is simple and preferable.

As a low temperature growth method of the porous semiconductor layer 13, an electrodeposition method, an electrophoretic electrodeposition method, a hydrothermal synthesis method and the like are preferable. As a post-treatment for improving electron transport properties, a microwave treatment and a CVD method are used. A UV treatment such as plasma treatment or thermal catalyst treatment is preferable. The porous semiconductor layer 13 formed by the low temperature growth method is preferably composed of a porous ZnO layer formed by the electrodeposition method, a porous TiO ₂ layer formed by the electrophoretic electrodeposition method, and the like.

Further, the surface of the porous body of the porous semiconductor layer 13 may be treated with TiCl ₄ , that is, immersed in a TiCl ₄ solution for 13 hours, washed with water, and baked at 450 ° C. for 30 minutes. It improves and the photoelectric conversion efficiency increases.

  In addition, an ultrathin (thickness of about 5 μm) dense layer made of an n-type oxide semiconductor may be inserted between the porous semiconductor layer 13 and the translucent conductive layer 11, and the reverse current can be suppressed, so that the photoelectric conversion efficiency Will increase.

  The porous semiconductor layer 13 is preferably composed of a sintered body of oxide semiconductor fine particles, and the average particle diameter of the oxide semiconductor fine particles is preferably gradually smaller in the thickness direction than the translucent substrate 10 side. For example, the porous semiconductor layer 13 is preferably composed of a two-layer laminate in which the average particle diameter of the oxide semiconductor fine particles is different. Specifically, by using oxide semiconductor fine particles having a large average particle diameter on the light-transmitting substrate 10 side and using oxide semiconductor fine particles (scattering particles) having a small average particle diameter on the catalyst layer 7 side, the average particle diameter is determined. The porous semiconductor layer 13 having a large thickness produces a light confinement effect due to light scattering and light reflection, and can increase the photoelectric conversion efficiency.

  More specifically, as oxide semiconductor fine particles having a small average particle diameter, 100 wt% (wt%) having an average particle diameter of about 20 nm is used, and as the oxide semiconductor fine particles having a large average particle diameter, the average particle diameter is What is necessary is just to use 70 wt% of about 20 nm and 30 wt% of those having an average particle diameter of about 180 nm. By changing the weight ratio, the average particle diameter, and the respective film thicknesses, an optimum light confinement effect can be obtained. Further, by increasing the number of stacked layers from two layers to three or more layers, or by coating and forming such that these boundaries do not occur, the average particle size is gradually decreased in the thickness direction from the translucent substrate 10 side. Can be formed.

<Dye>
Examples of the dye 14 include ruthenium-tris, ruthenium-bis, osmium-tris, osmium-bis transition metal complexes, polynuclear complexes, ruthenium-cis-diaqua-bipyridyl complexes, phthalocyanines, porphyrins, and polycyclic aromatics. A xanthene dye such as a compound or rhodamine B is preferable.

  In order to adsorb the dye 14 to the porous semiconductor layer 13, the dye 14 has at least one carboxyl group, sulfonyl group, hydroxamic acid group, alkoxy group, aryl group, phosphoryl group or the like as a substituent. It is valid. Here, the substituent may be any as long as it can strongly adsorb the dye 14 itself to the porous semiconductor layer 13 and can easily transfer the charge from the excited dye 14 to the porous semiconductor layer 13.

  As a method for adsorbing the dye 14 to the porous semiconductor layer 13, for example, there is a method of immersing the porous semiconductor layer 13 formed on the translucent substrate 10 in a solution in which the dye 14 is dissolved.

Solvents for dissolving the dye 14 when adsorbing the dye 14 to the porous semiconductor layer 13 include alcohols such as ethanol, ketones such as acetone, ethers such as diethyl ether, nitrogen compounds such as acetonitrile, and the like. May be one or a mixture of two or more. The concentration of the dye 14 in the solution is preferably about 5 × 10 ⁻⁵ to 2 × 10 ⁻³ mol / l (l (liter): 1000 cm ³ ).

  When adsorb | sucking the pigment | dye 14 to the porous semiconductor layer 13, the conditions of the temperature of a solution and atmosphere are not specifically limited, For example, the conditions of room temperature or heating under atmospheric pressure or a vacuum are mentioned. The time required for adsorption of the dye 14 can be appropriately adjusted depending on the kind of the dye 14 and the solution, the concentration of the solution, the circulation amount of the solution of the dye 14 and the like. Thereby, the dye 14 can be adsorbed to the porous semiconductor layer 13.

  The photovoltaic device of the present embodiment has a configuration in which the photoelectric conversion device of the present embodiment is used as a power generation means, and the generated power of the power generation means is supplied to a load. Specifically, a photovoltaic device is a structure having a load such as a photoelectric conversion device, an inverter device that converts a direct current output from the photoelectric conversion device into an alternating current, an electric motor, a lighting device, and the like. Used as a solar cell or the like installed on the roof or wall.

  Hereinafter, examples of the photoelectric conversion device of this embodiment will be described. A photoelectric conversion device having the configuration of FIG. 1 was produced as follows.

  As the translucent substrate 2, a glass substrate (size 1 cm × 2 cm) in which the first translucent conductive layer 3 (ITO layer, thickness 350 nm, sheet resistance 10Ω / □) was formed on one main surface was prepared. First, using a plasma CVD apparatus, a p-type a-Si: H layer as the first conductive type amorphous silicon semiconductor layer 4 on the first transparent conductive layer 3 of the transparent substrate 2, an intrinsic type. An i-type a-Si: H layer as the amorphous silicon semiconductor layer 5 and an n-type a-Si: H layer as the second conductivity type amorphous silicon semiconductor layer 6 are successively deposited in a vacuum. It was.

SiH ₄ gas and B ₂ H ₆ gas (diluted with H ₂ ) are used as source gases for forming the p-type a-Si: H layer, and the flow rates of these gases are set to 2.7 sccm and 9 sccm, respectively. , And a thickness of 100 mm (0.01 μm).

Next, SiH ₄ gas and H ₂ gas are used as source gases for forming the i-type a-Si: H layer, and the flow rates of these gases are 5 sccm and 20 sccm, respectively, and the thickness is 6000 mm (0.6 μm). It was deposited with.

Next, SiH ₄ gas, H ₂ gas, and PH ₃ gas (diluted with H ₂ ) are used as source gases for forming the n-type a-Si: H layer, and the flow rates of these gases are 2 respectively. The film was deposited to a thickness of 200 cm (0.02 μm) as 0.7 sccm, 37 sccm, and 2.8 sccm.

  Note that the temperature of the glass substrate was 200 ° C. in any of the formation of the p-type a-Si: H layer, the i-type a-Si: H layer, and the n-type a-Si: H layer.

  As described above, amorphous silicon photoelectric conversion comprising a p-type a-Si: H layer, an i-type a-Si: H layer, and an n-type a-Si: H layer having a thickness of 0.63 μm and a refractive index of 3.5. Layer 30 was formed.

  Next, an ITO layer having a refractive index of 1.9 was formed as the second translucent conductive layer 16 with a thickness of 100 nm. Before the film formation, the transmittance characteristic shown in the graph of FIG. 3 becomes the transmittance characteristic shown in the graph of FIG. 4 after the second light-transmitting conductive layer 16 is formed, and the wavelength is 600 to 1200 nm. The transmittance was significantly improved. The transmittance was measured with an ultraviolet-visible near-infrared spectrophotometer V-600 manufactured by JASCO.

  Next, using a sputtering apparatus, a Pt layer as the catalyst layer 7 was deposited on the ITO layer as the second light-transmitting conductive layer 16 to a thickness of 0.01 μm. At this time, since the Pt layer was thin, the resistance was high, and the sheet resistance of the Pt layer separately formed on the glass substrate in the same manner could not be measured.

Next, as the translucent substrate 10 on the dye-sensitized photoelectric conversion body 20 side, a translucent conductive layer 11 (SnO ₂ : F (FTO layer), thickness 800 nm, sheet resistance 10Ω / □) is formed on one main surface. A formed glass substrate (size 1 cm × 2 cm) was prepared. A titanium dioxide layer as a porous semiconductor layer 13 was formed on the translucent conductive layer 11 of the glass substrate. The titanium dioxide layer as an electron transporter was formed as follows. First, acetylacetone was added to TiO ₂ anatase powder, and then kneaded with deionized water to prepare a titanium dioxide paste stabilized with a surfactant. Next, the prepared paste was applied at a constant speed onto the light-transmitting conductive layer 11 by a doctor blade method, and baked at 450 ° C. for 20 minutes in the air to form a porous titanium dioxide layer.

  Next, a glass in which a titanium dioxide layer is formed using a black dye (made by Solaronics) as the dye 14, acetonitrile and t-butanol (1: 1 by volume) as a solvent used to dissolve the dye 14. The substrate was immersed in a solution in which the dye 14 was dissolved, and the dye 14 was supported on the titanium dioxide layer. The immersion time was 24 hours, and the temperature of the glass substrate at that time was 24 ° C.

Next, the outer peripheral part of one main surface in which the amorphous silicon photoelectric conversion body 31 of the translucent substrate 2 is formed, and the one main surface in which the dye-sensitized photoelectric conversion body 20 of the translucent substrate 10 is formed. The outer peripheral part of the film was adhered and hermetically sealed through a thermoplastic adhesive (trade name “Bynel 4164”, manufactured by DuPont) which is a film-like sealing member 8. The distance between the translucent substrate 2 and the translucent substrate 10 (corresponding to the thickness of the charge transport layer 9) was 30 μm. At this time, the translucent substrate 2 and the translucent substrate 10 were bonded to each other through the sealing member 8 in a state in which the following liquid electrolyte was contained in the titanium dioxide layer, thereby producing a stacked photoelectric conversion device. The charge transport layer (electrolyte) 9 was prepared by adding an acetonitrile solution and tertiary butyl pyridine (TBP) to iodine (I ₂ ) and lithium iodide (LiI), which are liquid electrolytes. With respect to this stacked photoelectric conversion device, characteristics such as photoelectric conversion efficiency were evaluated.

The obtained stacked photoelectric conversion device exhibited a relatively high short-circuit current density of 10.4 mA / cm ² and a high open-circuit voltage (1.50 V) at 100 mW / cm ² under AM 1.5. Fill factor (
The FF (Fill Factor) was 0.53, and the photoelectric conversion efficiency was 8.3%.

  As described above, in Example 1, high photoelectric conversion efficiency could be realized.

  A photoelectric conversion device having the configuration of FIG. 2 was produced as follows.

  As the translucent substrate 2, a glass substrate (size 1 cm × 2 cm) in which the first translucent conductive layer 3 (ITO layer, thickness 350 nm, sheet resistance 10Ω / □) was formed on one main surface was prepared. First, using a plasma CVD apparatus, a p-type a-Si: H layer as the first conductive amorphous silicon semiconductor layer 4 is formed on the first light-transmitting conductive layer 3 of the glass substrate. An i-type a-Si: H layer as the silicon semiconductor layer 5 and an n-type a-Si: H layer as the second conductivity type amorphous silicon semiconductor layer 6 were successively deposited in a vacuum.

SiH ₄ gas and B ₂ H ₆ gas (diluted with H ₂ ) are used as source gases for forming the p-type a-Si: H layer, and the flow rates of these gases are 2.7 sccm and 18 sccm, respectively. , And a thickness of 100 mm (0.01 μm).

Next, SiH ₄ gas and H ₂ gas are used as source gases for forming the i-type a-Si: H layer, the flow rates of these gases are 5 sccm and 20 sccm, respectively, and the film thickness is 6000 mm (0.6 μm). ).

Next, SiH ₄ gas, H ₂ gas and PH ₃ gas (diluted with H ₂ ) are used as source gases for forming the n-type a-Si: H layer, and the flow rates of these gases are 3 sccm, respectively. , 30 sccm, 6 sccm, with a thickness of 200 mm (0.02 μm).

  Note that the temperature of the glass substrate was 200 ° C. in any of the formation of the p-type a-Si: H layer, the i-type a-Si: H layer, and the n-type a-Si: H layer.

  As described above, amorphous silicon photoelectric conversion comprising a p-type a-Si: H layer, an i-type a-Si: H layer, and an n-type a-Si: H layer having a thickness of 0.63 μm and a refractive index of 3.5. Layer 30 was formed.

  Next, an ITO layer having a thickness of 100 nm was formed as the second light-transmissive conductive layer 16 on the amorphous silicon photoelectric conversion layer 30.

  From the above, an amorphous silicon photoelectric conversion body 31 was produced.

Next, an intermediate translucent conductive layer 3 ′ (SnO ₂ : F (F
A glass substrate (size 1 cm × 2 cm) on which a TO layer), a thickness of 800 nm, and a sheet resistance of 10Ω / □ was formed was prepared. A porous titanium dioxide layer was formed on the intermediate translucent conductive layer 3 ′ of this glass substrate. The titanium dioxide layer as an electron transporter was formed as follows. First, acetylacetone was added to TiO ₂ anatase powder, and then kneaded with deionized water to prepare a titanium dioxide paste stabilized with a surfactant. The prepared paste was applied onto the intermediate translucent conductive layer 3 ′ at a constant speed by a doctor blade method, and baked at 450 ° C. for 20 minutes in the air to form a porous titanium dioxide layer.

  Next, a black dye (made by Solaronics) was used as the dye 14, an ethanol solution was used as a solvent used to dissolve the dye 14, and deoxycholic acid was added as a coadsorbent. The glass substrate on which the titanium dioxide layer was formed was immersed in a solution in which the dye 14 was dissolved, and the dye 14 was supported on the titanium dioxide layer. The immersion time was 24 hours, and the temperature of the glass substrate at that time was 24 ° C to 27 ° C.

  Next, a counter electrode side structure facing the porous semiconductor layer 13 was produced as follows. A glass substrate is prepared as a light-transmitting substrate 10 having a light-transmitting conductive layer 11 (FTO layer, thickness 800 nm, sheet resistance 10Ω / □) formed on one main surface, and a light-transmitting conductive material is formed using a sputtering apparatus. A Pt layer as the catalyst layer 12 was deposited on the layer 11 to a thickness of 0.01 μm.

Next, the intermediate translucent substrate 2 ′ on which the porous titanium dioxide layer carrying the dye 14 is formed and the translucent substrate 10 of the counter electrode side structure are bonded with a film-like sealing member 8. A certain thermoplastic adhesive (made by DuPont, trade name “Bynel 4164”) was bonded and hermetically sealed. The distance between the intermediate translucent substrate 2 ′ and the translucent substrate 10 (corresponding to the thickness of the charge transport layer 9) was 30 μm. At this time, the intermediate translucent substrate 2 ′ and the translucent substrate 10 are bonded via the sealing member 8 with the following liquid electrolyte contained in the titanium dioxide layer, and the dye-sensitized photoelectric conversion body 20. Was made. As the charge transport layer 9 (electrolyte layer), iodine (I ₂ ), lithium iodide (LiI), and dimethylpropylimidazolium iodide (D), which are liquid electrolytes, are used.
MPII) prepared by adding an acetonitrile solution and tertiary butylpyridine (TBP) was used.

  Next, a transparent resin 32 made of vinyl chloride (EVA) and having a thickness of 100 μm is interposed on the main surface opposite to the main surface on which the intermediate light-transmitting conductive layer 3 ′ is formed on the intermediate light-transmitting substrate 2 ′. The amorphous silicon photoelectric converter 31 was joined.

  From the above, a stacked photoelectric conversion device was manufactured. With respect to this stacked photoelectric conversion device, characteristics such as photoelectric conversion efficiency were evaluated.

The obtained stacked photoelectric conversion device showed a high open-circuit voltage (1.51 V) at 100 mW / cm ² under AM 1.5. The photoelectric conversion efficiency of the upper amorphous silicon photoelectric conversion body 31 is 4.8%, and the photoelectric conversion efficiency of the lower dye-sensitized photoelectric conversion body 20 is 6.1%. % Could be obtained.

  As described above, in Example 2, high photoelectric conversion efficiency could be realized.

It is sectional drawing which shows an example of the photoelectric conversion apparatus of this Embodiment. It is sectional drawing which shows the other example of the photoelectric conversion apparatus of this Embodiment. It is a graph which shows the transmittance | permeability characteristic by the light wavelength in the conventional photoelectric conversion apparatus. It is a graph which shows the transmittance | permeability characteristic by the light wavelength in the photoelectric conversion apparatus of this Embodiment. It is sectional drawing of the photoelectric conversion module using the photoelectric conversion apparatus of this Embodiment.

Explanation of symbols

1: incident light 2: translucent substrate 2 ′: intermediate translucent substrate 3: first translucent conductive layer 3 ′: intermediate translucent conductive layer 4: first conductive type (p-type) amorphous Silicon semiconductor layer 5: Intrinsic type (i-type) amorphous silicon layer 6: Second conductivity type (n-type) amorphous silicon semiconductor layer 7: Catalyst layer 8: Sealing member 9: Charge transport layer (electrolyte layer)
10: Translucent substrate 11: Translucent conductive layer 12: Catalyst layer 13: Porous semiconductor layer 14: Dye 15: Connection wiring 16: Second translucent conductive layer 20: Dye-sensitized photoelectric converter 30: Amorphous silicon photoelectric conversion layer 31: Amorphous silicon photoelectric conversion body

Claims (10)

  An amorphous silicon photoelectric conversion layer having an amorphous silicon photoelectric conversion layer and a translucent conductive layer formed on the amorphous silicon photoelectric conversion layer, and the translucency of the amorphous silicon photoelectric conversion body And a dye-sensitized photoelectric conversion body laminated on the conductive layer side.   The photoelectric conversion device according to claim 1, wherein the translucent conductive layer has a thickness of 0.07 to 0.12 μm.   The catalyst layer is formed on the said translucent conductive layer, The said dye-sensitized photoelectric conversion body is arrange | positioned so as to oppose the said catalyst layer through a charge transport layer. Photoelectric conversion device.   The photoelectric conversion device according to claim 1, wherein the dye-sensitized photoelectric conversion body includes a dye-sensitized porous semiconductor layer.   The photoelectric conversion device according to claim 1, wherein the catalyst layer is made of platinum, palladium, rhodium, carbon, or polythiophene.   The photoelectric conversion device according to claim 1, wherein the amorphous silicon photoelectric conversion body and the dye-sensitized photoelectric conversion body are bonded via a transparent resin.   The amorphous silicon photoelectric conversion layer includes a first conductive type amorphous silicon semiconductor layer, an intrinsic type amorphous silicon semiconductor layer formed on the first conductive type amorphous silicon semiconductor layer, and the intrinsic type. The photoelectric conversion device according to claim 1, further comprising: a second conductivity type amorphous silicon semiconductor layer formed on the type amorphous silicon semiconductor layer.   The photoelectric conversion device according to claim 1, wherein the translucent conductive layer includes at least one of an indium oxide layer, a tin oxide layer, and an indium tin oxide layer.   A photovoltaic device using the photoelectric conversion device according to any one of claims 1 to 8 as a power generation means, and supplying the generated power of the power generation means to a load.   A photoelectric conversion module in which a plurality of the photoelectric conversion devices according to claim 1 are arranged in a horizontal direction and are electrically connected to each other.