WO2010023867A1 - Thin-film solar cell and manufacturing method therefore and substrate for thin-film solar cell - Google Patents

Thin-film solar cell and manufacturing method therefore and substrate for thin-film solar cell Download PDF

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WO2010023867A1
WO2010023867A1 PCT/JP2009/004067 JP2009004067W WO2010023867A1 WO 2010023867 A1 WO2010023867 A1 WO 2010023867A1 JP 2009004067 W JP2009004067 W JP 2009004067W WO 2010023867 A1 WO2010023867 A1 WO 2010023867A1
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layer
refractive index
solar cell
film solar
thin film
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French (fr)
Japanese (ja)
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井野英二
渡邉亮
西村成史
保田真由子
高羽正明
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株式会社エバテック
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
    • H01L31/036—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
    • H01L31/0392—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
    • H01L31/03921—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate including only elements of Group IV of the Periodic Table
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0216—Coatings
    • H01L31/02161—Coatings for devices characterised by at least one potential jump barrier or surface barrier
    • H01L31/02167—Coatings for devices characterised by at least one potential jump barrier or surface barrier for solar cells
    • H01L31/02168—Coatings for devices characterised by at least one potential jump barrier or surface barrier for solar cells the coatings being antireflective or having enhancing optical properties for the solar cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H01L31/022466—Electrodes made of transparent conductive layers, e.g. TCO, ITO layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
    • H01L31/036—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
    • H01L31/0368—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including polycrystalline semiconductors
    • H01L31/03682—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including polycrystalline semiconductors including only elements of Group IV of the Periodic Table
    • H01L31/03685—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including polycrystalline semiconductors including only elements of Group IV of the Periodic Table including microcrystalline silicon, uc-Si
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers
    • H01L31/075—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers the potential barriers being only of the PIN type, e.g. amorphous silicon PIN solar cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
    • H01L31/1884—Manufacture of transparent electrodes, e.g. TCO, ITO
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/545—Microcrystalline silicon PV cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/548—Amorphous silicon PV cells

Definitions

  • the present invention relates to a thin film solar cell, a manufacturing method thereof, and a substrate for a thin film solar cell for supporting a photoelectric conversion layer of the thin film solar cell.
  • a type of solar cell is a thin film solar cell.
  • it has become difficult to obtain bulk silicon crystals, and therefore, the attention of thin film solar cells that do not require the use of bulk silicon crystals has increased.
  • Thin film solar cells include pin junctions (p-type semiconductor layer-intrinsic semiconductor layer-n-type semiconductor layer joined in this order), pn junctions (p-type semiconductor layer and n-type semiconductor layer joined), etc.
  • the transparent electrode side is supported by a transparent substrate in order to maintain the shape of the main body and to protect the light incident surface.
  • incident light passes through the transparent electrode from the transparent substrate side and enters the photoelectric conversion layer.
  • part of the incident light is reflected at the boundary between the two. Since the energy of the incident light reflected in this way is not converted into electric power, the efficiency of photoelectric conversion is lowered.
  • the texture structure means a structure in which irregularities are provided on the boundary surface between the transparent electrode and the photoelectric conversion layer so that the boundary surface is a non-flat surface as described in Patent Document 1, for example.
  • the texture structure reduces the reflectance at the boundary between the transparent electrode and the photoelectric conversion layer, and effectively increases the optical path length (light diffusion length) in the photoelectric conversion layer. Is provided to obtain. The reason why such an effect is obtained will be described with reference to FIG. FIG. 1 shows a part of a conventional thin film solar cell, in which a texture structure is formed on the boundary surface 94 between the transparent electrode 91 and the photoelectric conversion layer 92. A part of the incident light 951 incident on the boundary surface 94 through the transparent electrode 91 is reflected on the boundary surface 94 (first reflected light 952), and the remaining light passes through the boundary surface 94 and enters the photoelectric conversion layer 92. (First transmitted light 9531).
  • the optical path length of the second transmitted light 9532 in the photoelectric conversion layer 92 is longer than the optical path length of the first transmitted light 9531, so that the photoelectric conversion efficiency can be increased.
  • JP-A-61-288473 page 2, lower left column, lines 1-14, page 4, upper right column, lines 1-10, Fig. 1
  • a texture structure is provided at the boundary between the transparent electrode and the photoelectric conversion layer.
  • a photoelectric conversion layer is formed on a transparent electrode.
  • the direction of crystal growth is disturbed in the photoelectric conversion layer.
  • the photoelectric conversion layer is composed of a large number of microcrystals that are smaller than the unevenness of the texture structure, the crystal growth direction is determined by the direction of the boundary, so the crystal growth directions are uneven and the microcrystals collide with each other. Grain boundaries are formed in irregular directions. As a result, defects are generated in the microcrystal, and photoexcited carriers are captured by the defects.
  • Non-Patent Document 2 the inventor of the present application has found that when the growth direction of the microcrystals becomes uneven as described above, a short circuit occurs between adjacent microcrystals when the solar cell is used, thereby reducing the efficiency of photoelectric conversion. I found it.
  • the problem to be solved by the present invention is to provide a thin film solar cell that can increase the efficiency of photoelectric conversion, a method for producing the same, and a substrate for the thin film solar cell.
  • the thin film solar cell according to the present invention which has been made to solve the above problems, is a thin film solar cell that converts light energy in a predetermined wavelength range into electric power, a) an intensity holding layer capable of transmitting light in the predetermined wavelength range; b) a low-refractive-index layer provided on the intensity-holding layer and capable of transmitting light in the predetermined wavelength range and having a refractive index n L ; c) a high refractive index layer provided in contact with the upper surface of the low refractive index layer and capable of transmitting light in the predetermined wavelength range and having a refractive index n H higher than n L ; d) a transparent electrode provided on the high refractive index layer and capable of transmitting light in the predetermined wavelength range and having conductivity; e) a photoelectric conversion unit provided on the transparent electrode; It is characterized by providing.
  • the thin film solar cell according to the present invention by providing a double layer of a low refractive index layer and a high refractive index layer at the boundary between the transparent electrode and the photoelectric conversion unit, more light is taken into the photoelectric conversion unit from the transparent electrode. In addition, the light once incident on the photoelectric conversion unit can stay in the photoelectric conversion unit for a longer time. Thereby, the utilization efficiency of light can increase and the efficiency of photoelectric conversion of a thin film solar cell can be improved.
  • the reason will be described with reference to the conceptual diagram of FIG.
  • the thin-film solar cell 10 has a photoelectric conversion unit 15 formed on a thin-film solar cell substrate 10S including an intensity holding layer 11, a low refractive index layer 12, a high refractive index layer 13, and a transparent electrode 14. It is.
  • the light incident on the thin-film solar cell 10 first enters from the lower surface of the strength holding layer 11, passes through the strength holding layer 11, the low refractive index layer 12, the high refractive index layer 13, and the transparent electrode 14 and enters the photoelectric conversion unit 15. be introduced. A part of the light introduced into the photoelectric conversion unit 15 is converted into electric power, but the rest (returned light) is reflected at the upper end of the photoelectric conversion unit 15 and the like, and passes through the transparent electrode 14 and the high refractive index layer 13 to be high. The light enters the boundary B between the refractive index layer 13 and the low refractive index layer 12.
  • This return light has an incident angle ⁇ C at the boundary B of sin ⁇ C ⁇ (n L / n H ) (1), When satisfied, total reflection occurs at the boundary B.
  • n H > n L in the present invention the right side of equation (1) is less than 1, and equation (1) always has a solution.
  • all the return light having the incident angle ⁇ C satisfying the expression (1) again enters the photoelectric conversion unit 15 by total reflection. Further, part of the return light that does not satisfy the expression (1) and does not cause total reflection is reflected at the boundary B and is incident on the photoelectric conversion unit 15 again. With these reflected lights, the light can be kept in the photoelectric conversion unit 15 for a long time, whereby the efficiency of photoelectric conversion of the thin film solar cell 10 can be increased.
  • the light incident on the photoelectric conversion unit 15 from the intensity holding layer 11 is less likely to cause total reflection at the boundary B, so that more light can be taken into the photoelectric conversion unit 15. become.
  • the efficiency of photoelectric conversion can be increased without providing a texture structure at the boundary between the transparent electrode and the photoelectric conversion portion, the upper surface of the transparent electrode can be flattened.
  • disorder such as a defect
  • the present invention can increase the efficiency of photoelectric conversion.
  • the growth direction of the microcrystals is aligned, so that formation of defects that cause photoexcited carriers to be captured and short-circuiting between microcrystals are prevented. Since it can prevent, the effect by making the upper surface of a transparent electrode flat is remarkable.
  • a reflective part can be provided on the photoelectric conversion part, and a texture structure can be formed at the boundary between the photoelectric conversion part and the reflective part.
  • the texture structure provided above the photoelectric conversion unit does not cause disorder of crystal growth in the photoelectric conversion unit.
  • the reflection part having such a texture structure scatters the light (return light) introduced into the photoelectric conversion part, thereby increasing the probability of total reflection at the boundary between the high refractive index layer and the low refractive index layer.
  • a plasma-resistant layer made of a plasma-resistant material and having a flat upper surface may be provided on the transparent electrode.
  • the plasma is hydrogen plasma
  • TiO 2 or ZnO can be used as the plasma resistant material.
  • the thickness of the high refractive index layer is preferably (2k H ⁇ 1) ⁇ 0 / 4n H.
  • k H is a natural number
  • ⁇ 0 is a wavelength within the predetermined wavelength range.
  • the refractive index n M is higher than n L , and the thickness is (2k M ⁇ 1) ⁇ 0 / 4n M ( An intermediate layer of k M is a natural number) may be provided. Such an intermediate layer can suppress reflection of light having a wavelength ⁇ 0 from the intensity maintaining layer toward the low refractive index layer.
  • An antireflection layer may be provided below the strength holding layer.
  • the antireflection layer is made of, for example, SnO 2 in order from the strength holding layer side, and has a thickness of (2k 1 ⁇ 1) ⁇ 0 / 4n 1 (k 1 is a natural number, n 1 is the refractive index of SnO 2 ).
  • a thin film solar cell manufacturing method is a method of manufacturing a thin film solar cell that converts light energy in a predetermined wavelength range into electric power, a) producing a low refractive index layer made of SiO 2 on a glass substrate under a temperature condition of 100 ° C. to 240 ° C. by a sputtering method; b) forming a high refractive index layer made of TiO 2 on the low refractive index layer under a temperature condition of 100 ° C. to 240 ° C. by a sputtering method; c) producing a transparent electrode made of SnO 2 on the high refractive index layer by a sputtering method under a temperature condition of 100 ° C. to 240 ° C .; It is characterized by having.
  • a transparent electrode in the thin film solar cell When producing a transparent electrode in the thin film solar cell according to the present invention, if a method suitable for crystal growth, such as a CVD method, is used, or if the film formation temperature of the transparent electrode is too high, the transparent electrode is formed. Since the crystal grains grow and become too large, the flatness of the upper surface of the transparent electrode is deteriorated. Further, when the flatness of the upper surface of the low refractive index layer or the high refractive index layer is poor, the flatness of the upper surface of the transparent electrode formed thereon is also deteriorated.
  • a method suitable for crystal growth such as a CVD method
  • the SiO 2 for the low refractive index layer, a TiO 2 in the high refractive index layer, the SnO 2 used in the transparent electrode that these layers of both 100 ° C. ⁇ 240 ° C. It is fabricated by sputtering under relatively low temperature conditions. Thereby, a low refractive index layer, a high refractive index layer and a transparent electrode having high flatness while suppressing crystal growth can be obtained.
  • a substrate (strength retaining layer) made of air-cooled tempered glass will crack when heated to about 250 ° C or higher and then rapidly cooled, and when heated to about 300 ° C or higher, it will crack only by heating.
  • the heating temperature is 100 ° C. to 240 ° C., so that a transparent electrode can be formed directly on the tempered glass.
  • the thin film solar cell substrate according to the present invention a part of the light introduced into the photoelectric conversion part of the thin film solar cell is reflected at the boundary between the high refractive index layer and the low refractive index layer, and particularly satisfies the above formula (1).
  • the reflected light is reintroduced into the photoelectric conversion unit, and the light use efficiency is increased. Thereby, the efficiency of photoelectric conversion of the thin film solar cell can be increased.
  • the thin film solar cell substrate according to the present invention does not need to use a texture structure, the upper surface of the transparent electrode can be flattened.
  • the photoelectric conversion part is formed on the upper surface of such a flat transparent electrode, it is possible to prevent the photoelectric conversion part from being disturbed such as defects, so that the efficiency of photoelectric conversion can be further increased.
  • the longitudinal cross-sectional view which shows the role of the texture structure in the conventional thin film solar cell.
  • the longitudinal cross-sectional view of the thin film solar cell 20 which concerns on 1st Example of this invention.
  • the longitudinal cross-sectional view which shows the manufacturing method of the thin film solar cell 20.
  • FIG. The longitudinal cross-sectional view of the thin film solar cell 30 which concerns on 2nd Example of this invention.
  • the thin film solar cell 20 which is the 1st Example of this invention is shown.
  • the thin film solar cell 20 of this example includes a thin film solar cell substrate 20S formed by sequentially laminating a strength holding layer 21, an intermediate layer 27, a low refractive index layer 22, a high refractive index layer 23, and a transparent electrode layer 24, and a thin film. It consists of a plasma-resistant layer 28, a photoelectric conversion layer 25, and a reflective electrode layer 26, which are sequentially stacked on the solar cell substrate 20S.
  • the strength retention layer 21 is made of tempered glass made of soda lime having a refractive index of 1.50, which has been widely used as a substrate for solar cells.
  • the intermediate layer 27 is made of SnO 2 (tin dioxide) having a refractive index n M of 2.00.
  • the low refractive index layer 22 is made of SiO 2 (silicon dioxide) having a refractive index n L of 1.45.
  • the high refractive index layer 23 is made of TiO 2 (titanium dioxide) having a refractive index n H of 2.45 to 2.92 (depending on the crystal structure).
  • the transparent electrode layer 24 is made of SnO 2 which has been conventionally used as a transparent electrode of a thin film solar cell.
  • the plasma-resistant layer 28 is made of TiO 2 .
  • the reflective electrode layer 26 is made of a silver vapor deposition film. Note that ZnO (zinc oxide) can be used instead of TiO 2 for the material of the plasma-resistant layer 28, and aluminum can be used for the reflective electrode layer 26 instead of silver.
  • the surface (upper surface) of the transparent electrode layer 24 is made as flat as possible. Thereby, it can prevent that the growth direction of the microcrystal (after-mentioned) of the photoelectric converting layer 25 formed above the transparent electrode layer 24 is disturbed, and can improve the efficiency of photoelectric conversion of a thin film solar cell.
  • the top surfaces of the high refractive index layer 23, the low refractive index layer 22 and the intermediate layer 27 below the transparent electrode layer 24 should be made as flat as possible. desirable.
  • Ra is one of the definitions of surface roughness stipulated by Japanese Industrial Standards.
  • Ra on the upper surface of the transparent electrode layer 24 is desirably set to 100 nm or less.
  • Ra on the upper surface of the plasma-resistant layer 28 is also set to 100 nm or less. Also for the high refractive index layer 23 and the low refractive index layer 22 below the transparent electrode layer 24, in order to prevent the flatness of the upper surface of the transparent electrode layer 24 from being impaired, it is desirable that the upper surface Ra is 100 nm or less.
  • the plasma resistant layer 28 is provided is as follows. If the photoelectric conversion layer 25 is fabricated directly on the upper surface of the transparent electrode layer 24 by a CVD method using hydrogen or silane gas, the surface of the transparent electrode layer 24 may be exposed to hydrogen plasma at the start of fabrication and may be reduced. . If such reduction occurs, the transparent electrode layer 24, which is an oxide film, changes in quality, resulting in a decrease in transparency and an increase in resistance value, so that it does not function as a transparent electrode. Therefore, in this embodiment, the plasma-resistant layer 28 is provided on the uppermost layer of the transparent electrode layer 24 to prevent the reduction action by hydrogen plasma from occurring.
  • a pin-type photoelectric conversion layer formed by stacking three layers of a p-type semiconductor, an intrinsic semiconductor, and an n-type semiconductor, or a pin tandem photoelectric conversion layer formed by stacking two pairs of pin-type photoelectric conversion layers is used.
  • the semiconductor of the photoelectric conversion layer an amorphous semiconductor or a microcrystalline semiconductor is used.
  • Three layers of 253 were laminated.
  • the upper surface of the plasma-resistant layer 28 has a flatness of Ra of 100 nm or less, the upper surface of the p-layer 251 formed on the plasma-resistant layer 28 can also be flattened. As a result, the growth direction of the microcrystals of the i layer 252 formed on the upper surface of the p layer 251 is aligned, and defects due to irregularly formed interfaces and electrical shorts between the microcrystals are prevented. Can do. Note that the crystal growth direction of the i layer 252 is perpendicular to the transparent electrode layer 24.
  • the upper ends of the microcrystals are unevenly arranged on the upper surface of the i layer 252.
  • the film becomes an uneven mirror. Accordingly, the boundary surface between the n layer 253 and the reflective electrode layer 26 is naturally uneven.
  • the thickness of the high refractive index layer 23 is set to 1/4 times the wavelength ⁇ 0 / n H in the light layer having the wavelength ⁇ 0 in vacuum, and the thickness of the intermediate layer 27 is ⁇ 0 / n. It was set to 1/4 times M. In this embodiment, since the reference wavelength lambda 0 was 550 nm, the thickness of the intermediate layer 27 is 69 nm, the thickness of the high refractive index layer 23 is 55 nm. The thicknesses of the other layers are determined regardless of the wavelength ⁇ 0.
  • the strength holding layer 21 is 1 to 10 ⁇ m
  • the low refractive index layer 22 is 32 ⁇ m
  • the transparent electrode layer 24 is about 0.5 to 1 ⁇ m.
  • the thin film solar cell 20 is produced as follows. First, while maintaining the soda-lime glass plate as a strength retention layer 21 to a temperature of 100 ° C. ⁇ 240 ° C., thereon, to prepare an intermediate layer 27 by forming a SnO 2 by sputtering (FIG. 4 (a), (b)). Similarly, the temperature by sputtering while maintaining in the above range, to prepare a low refractive index layer 22 by depositing SiO 2 (FIG. 4 (b), (c) ), the TiO 2 A high refractive index layer 23 is produced by film formation (FIGS. 4C and 4D), and a transparent electrode layer 24 is produced by depositing SnO 2 (FIGS. 4D and 4E). ).
  • a plasma-resistant layer 28 is formed by depositing TiO 2 by sputtering while maintaining the temperature within the above range (FIG. 4 (e)). Thereafter, the thin film solar cell 20 is obtained by fabricating the photoelectric conversion layer 25 by the plasma CVD method and the reflective electrode layer 26 by the sputtering method, respectively (FIG. 3).
  • the thickness of the intermediate layer 27 is 1/4 times ⁇ 0 / n M , reflection of light having a wavelength in the vicinity of ⁇ 0 at the boundary between the intensity holding layer 21 and the intermediate layer 27 and the intermediate layer 27. And reflection at the boundary of the low refractive index layer 22 are suppressed.
  • the low refractive index layer 22 in this embodiment has the following function in addition to the function of totally reflecting light because the material is SiO 2 . That is, when the strength holding layer 21 is soda glass, it has a function of preventing alkali ions eluted from the soda glass from entering the photoelectric conversion layer 25 and degrading the photoelectric conversion layer 25 (as an alkali ion permeation prevention film). Function of).
  • the intermediate layer 27 in the present embodiment, by the material is SnO 2, in addition to the function as an antireflection film, made of the strength retention layer 21 and the SiO 2 made of soda glass substrate low refractive index layer 22 It also has a function to relieve stress caused by the difference in thermal expansion coefficient between the two. When a layer made of SnO 2 is provided at the position of the intermediate layer 27 only for the purpose of stress relaxation function, the thickness of the layer does not need to be 1/4 times ⁇ 0 / n M.
  • FIG. 5 shows a longitudinal sectional view of a thin film solar cell 30 according to the second embodiment of the present invention.
  • the thin film solar cell 30 of the present embodiment is different from the thin film solar cell 20 of the first embodiment in that an antireflection layer 39 is provided on the lower surface of the strength holding layer 21, that is, the surface on which the light of the strength holding layer 21 is incident. That is.
  • the antireflection layer 39 includes three layers of a first layer 391, a second layer 392, and a third layer 393 in order from the strength holding layer 21 side.
  • the thin-film solar cell 30 of this example is similar to the thin-film solar cell 20 described above.
  • the intermediate layer 27, the low-refractive index layer 22, The high refractive index layer 23 and the transparent electrode layer 24 are manufactured, and then the first layer 391, the second layer 392, and the third layer 393 are formed below the strength holding layer 21 by sputtering under the same temperature conditions. Furthermore, it can manufacture by producing the photoelectric converting layer 25 and the reflective electrode layer 26 after that.
  • the light incident on the antireflection layer 39 then passes through the antireflection layer 39 with high transmittance and enters the strength holding layer 21.
  • Other operations are the same as those in the first embodiment.

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Abstract

The thin-film solar cell (20) has a strength-retention layer (21), a low refractive index layer (22) with the refractive index of nL that is provided above the strength-retention layer (21), a high refractive index layer (23) with the refractive index of nH higher than nL that is provided in contact with the upper surface of the low refractive index layer (22), a transparent electrode layer (24), and a photoelectric conversion layer (25). A portion of a light that is not photoelectrically converted from a light irradiated from the strength-retention layer (21) side to the photoelectric conversion layer (25) is totally reflected off at the boundary (B) between the low refractive index layer (22) and the high refractive index layer (23). Because the totally reflected light reenters the photoelectric conversion layer (25), the photoelectric conversion efficiency can be improved. Additionally, because no use of any texture is required, or preferably when the transparent electrode layer (24) is formed flat, crystallinity of the photoelectric conversion layer (25) can be improved, and thus the photoelectric conversion efficiency can be improved.

Description

薄膜太陽電池及びその製造方法、並びに薄膜太陽電池用基板Thin film solar cell, method for manufacturing the same, and substrate for thin film solar cell
　本発明は、薄膜太陽電池及びその製造方法、並びに薄膜太陽電池の光電変換層を支持するための薄膜太陽電池用基板に関する。 The present invention relates to a thin film solar cell, a manufacturing method thereof, and a substrate for a thin film solar cell for supporting a photoelectric conversion layer of the thin film solar cell.
　太陽電池の一種に薄膜太陽電池がある。近年、太陽電池の需要の増加に伴いバルクのシリコン結晶が入手困難となってきたため、バルクシリコン結晶を使用する必要のない薄膜太陽電池の注目度が増している。 A type of solar cell is a thin film solar cell. In recent years, with the increase in demand for solar cells, it has become difficult to obtain bulk silicon crystals, and therefore, the attention of thin film solar cells that do not require the use of bulk silicon crystals has increased.
　薄膜太陽電池は、pin接合体（p型半導体層-真性半導体層-n型半導体層をこの順で接合したもの）やpn接合体（p型半導体層とn型半導体層を接合したもの）等から成る光電変換層を透明電極と反射電極層で挟んだ本体を有する。本体は通常、その形状の保持のため及び光の入射面の保護のために、透明電極側が透明基板によって支持されている。このような薄膜太陽電池では、入射光は透明基板側から透明電極を通過して光電変換層に入射する。しかし、透明電極と光電変換層の屈折率の違いにより、入射光の一部は両者の境界で反射される。このように反射された入射光のエネルギーは電力に変換されないため、光電変換の効率が低下する。 Thin film solar cells include pin junctions (p-type semiconductor layer-intrinsic semiconductor layer-n-type semiconductor layer joined in this order), pn junctions (p-type semiconductor layer and n-type semiconductor layer joined), etc. A main body sandwiched between a transparent electrode and a reflective electrode layer. In general, the transparent electrode side is supported by a transparent substrate in order to maintain the shape of the main body and to protect the light incident surface. In such a thin film solar cell, incident light passes through the transparent electrode from the transparent substrate side and enters the photoelectric conversion layer. However, due to the difference in refractive index between the transparent electrode and the photoelectric conversion layer, part of the incident light is reflected at the boundary between the two. Since the energy of the incident light reflected in this way is not converted into electric power, the efficiency of photoelectric conversion is lowered.
　そこで、従来の薄膜太陽電池では、透明電極と光電変換層の境界にいわゆる「テクスチャ構造」が採用されている。テクスチャ構造とは、例えば特許文献１に記載のように、透明電極と光電変換層の境界面に凹凸を設けて前記境界面を非平坦面状にした構造をいう。 Therefore, in the conventional thin film solar cell, a so-called “texture structure” is adopted at the boundary between the transparent electrode and the photoelectric conversion layer. The texture structure means a structure in which irregularities are provided on the boundary surface between the transparent electrode and the photoelectric conversion layer so that the boundary surface is a non-flat surface as described in Patent Document 1, for example.
　非特許文献１によれば、テクスチャ構造は透明電極と光電変換層の境界における反射率を低下させると共に、光電変換層内の光路長（光拡散長）を実効的に増加させる、という２つの効果を得るために設けられている。図１を用いて、そのような効果が得られる理由を説明する。図１は、従来の薄膜太陽電池の一部を示しており、透明電極９１と光電変換層９２の境界面９４にテクスチャ構造が形成されている。透明電極９１を通って境界面９４に入射した入射光９５１は、その一部が境界面９４において反射され（第１反射光９５２）、残りが境界面９４を透過して光電変換層９２に入射する（第１透過光９５３１）。また、第１反射光９５２の一部は境界面９４の別の部位に入射し、その一部は再度反射され、残りは境界面９４を透過し、光電変換層９２に入射する（第２透過光９５３２）。このとき、光電変換層９２内における第２透過光９５３２の光路長は第１透過光９５３１の光路長よりも長くなることから、光電変換効率を高めることができる。 According to Non-Patent Document 1, the texture structure reduces the reflectance at the boundary between the transparent electrode and the photoelectric conversion layer, and effectively increases the optical path length (light diffusion length) in the photoelectric conversion layer. Is provided to obtain. The reason why such an effect is obtained will be described with reference to FIG. FIG. 1 shows a part of a conventional thin film solar cell, in which a texture structure is formed on the boundary surface 94 between the transparent electrode 91 and the photoelectric conversion layer 92. A part of the incident light 951 incident on the boundary surface 94 through the transparent electrode 91 is reflected on the boundary surface 94 (first reflected light 952), and the remaining light passes through the boundary surface 94 and enters the photoelectric conversion layer 92. (First transmitted light 9531). In addition, a part of the first reflected light 952 is incident on another part of the boundary surface 94, a part thereof is reflected again, and the remaining part is transmitted through the boundary surface 94 and incident on the photoelectric conversion layer 92 (second transmission). Light 9532). At this time, the optical path length of the second transmitted light 9532 in the photoelectric conversion layer 92 is longer than the optical path length of the first transmitted light 9531, so that the photoelectric conversion efficiency can be increased.
特開昭61-288473号公報（第2頁左下欄1～14行目、第4頁右上欄1～10行目、第1図）JP-A-61-288473 (page 2, lower left column, lines 1-14, page 4, upper right column, lines 1-10, Fig. 1)
　しかし、透明電極と光電変換層の境界にテクスチャ構造を設けると以下のような問題が生じる。薄膜太陽電池を作製するときは、透明電極の上に光電変換層を形成する。このとき、透明電極の表面にテクスチャ構造が存在すると、光電変換層内で結晶成長の方向性に乱れが生じる。特に、テクスチャ構造の凹凸よりも小さい多数の微結晶から光電変換層が成る場合、結晶の成長方向が境界の向きにより定まるため、各微結晶の成長方向が不揃いとなり、微結晶同士が衝突して不規則な方向に粒界が形成される。これにより微結晶内に欠陥が生じ、光励起キャリアが欠陥に捕獲される結果、内部電界が低下して光電変換の効率が低下する（非特許文献２参照）。また、本願発明者は、上述のように微結晶の成長方向が不揃いになることにより、太陽電池の使用時に、隣接する微結晶間で短絡が生じ、それにより光電変換の効率が低下することを見出した。 However, if a texture structure is provided at the boundary between the transparent electrode and the photoelectric conversion layer, the following problems occur. When producing a thin film solar cell, a photoelectric conversion layer is formed on a transparent electrode. At this time, if a texture structure is present on the surface of the transparent electrode, the direction of crystal growth is disturbed in the photoelectric conversion layer. In particular, when the photoelectric conversion layer is composed of a large number of microcrystals that are smaller than the unevenness of the texture structure, the crystal growth direction is determined by the direction of the boundary, so the crystal growth directions are uneven and the microcrystals collide with each other. Grain boundaries are formed in irregular directions. As a result, defects are generated in the microcrystal, and photoexcited carriers are captured by the defects. As a result, the internal electric field is reduced and the efficiency of photoelectric conversion is reduced (see Non-Patent Document 2). Further, the inventor of the present application has found that when the growth direction of the microcrystals becomes uneven as described above, a short circuit occurs between adjacent microcrystals when the solar cell is used, thereby reducing the efficiency of photoelectric conversion. I found it.
　本発明が解決しようとする課題は、光電変換の効率を高めることができる薄膜太陽電池、その製造方法及び薄膜太陽電池用基板を提供することである。 The problem to be solved by the present invention is to provide a thin film solar cell that can increase the efficiency of photoelectric conversion, a method for producing the same, and a substrate for the thin film solar cell.
　上記課題を解決するために成された本発明に係る薄膜太陽電池は、所定の波長域の光のエネルギーを電力に変換する薄膜太陽電池であって、
　a) 前記所定波長域の光を透過可能な強度保持層と、
　b) 前記強度保持層の上部に設けられた、前記所定波長域の光を透過可能であって屈折率nLを有する低屈折率層と、
　c) 前記低屈折率層の上面に接して設けられた、前記所定波長域の光を透過可能であってnLよりも高い屈折率nHを有する高屈折率層と、
　d) 前記高屈折率層の上部に設けられた、前記所定波長域の光を透過可能であって導電性を有する透明電極と、
　e) 前記透明電極の上部に設けられた光電変換部と、
を備えることを特徴とする。 The thin film solar cell according to the present invention, which has been made to solve the above problems, is a thin film solar cell that converts light energy in a predetermined wavelength range into electric power,
a) an intensity holding layer capable of transmitting light in the predetermined wavelength range;
b) a low-refractive-index layer provided on the intensity-holding layer and capable of transmitting light in the predetermined wavelength range and having a refractive index n L ;
c) a high refractive index layer provided in contact with the upper surface of the low refractive index layer and capable of transmitting light in the predetermined wavelength range and having a refractive index n H higher than n L ;
d) a transparent electrode provided on the high refractive index layer and capable of transmitting light in the predetermined wavelength range and having conductivity;
e) a photoelectric conversion unit provided on the transparent electrode;
It is characterized by providing.
　本願では、各層の位置関係を説明するために、便宜上、「上」及び「下」という語を用いたに過ぎず、これら「上」及び「下」は、重力の向きについての「上」及び「下」を意味するものではない。 In this application, in order to explain the positional relationship of each layer, only the words “upper” and “lower” are used for convenience, and these “upper” and “lower” are “upper” and “lower” with respect to the direction of gravity. It does not mean “under”.
　本発明に係る上記薄膜太陽電池では、透明電極と光電変換部の境界に低屈折率層と高屈折率層の２重層を設けることにより、より多くの光を透明電極から光電変換部に取り込むことができるとともに、一旦光電変換部に入射した光がより長く光電変換部内に留まるようにすることができる。これにより、光の利用効率が高まり、薄膜太陽電池の光電変換の効率を高めることができる。以下、その理由を、図２の概念図を用いて説明する。本発明に係る薄膜太陽電池１０は、強度保持層１１、低屈折率層１２、高屈折率層１３及び透明電極１４を備える薄膜太陽電池用基板１０Ｓの上に光電変換部１５が形成されたものである。 In the thin film solar cell according to the present invention, by providing a double layer of a low refractive index layer and a high refractive index layer at the boundary between the transparent electrode and the photoelectric conversion unit, more light is taken into the photoelectric conversion unit from the transparent electrode. In addition, the light once incident on the photoelectric conversion unit can stay in the photoelectric conversion unit for a longer time. Thereby, the utilization efficiency of light can increase and the efficiency of photoelectric conversion of a thin film solar cell can be improved. Hereinafter, the reason will be described with reference to the conceptual diagram of FIG. The thin-film solar cell 10 according to the present invention has a photoelectric conversion unit 15 formed on a thin-film solar cell substrate 10S including an intensity holding layer 11, a low refractive index layer 12, a high refractive index layer 13, and a transparent electrode 14. It is.
　薄膜太陽電池１０に入射する光は、まず強度保持層１１の下面から入射し、強度保持層１１、低屈折率層１２、高屈折率層１３、透明電極１４を通過して光電変換部１５に導入される。光電変換部１５に導入された光の一部は電力に変換されるが、残り（戻り光）は光電変換部１５の上端などにおいて反射され、透明電極１４及び高屈折率層１３を通って高屈折率層１３と低屈折率層１２の境界Ｂに入射する。 The light incident on the thin-film solar cell 10 first enters from the lower surface of the strength holding layer 11, passes through the strength holding layer 11, the low refractive index layer 12, the high refractive index layer 13, and the transparent electrode 14 and enters the photoelectric conversion unit 15. be introduced. A part of the light introduced into the photoelectric conversion unit 15 is converted into electric power, but the rest (returned light) is reflected at the upper end of the photoelectric conversion unit 15 and the like, and passes through the transparent electrode 14 and the high refractive index layer 13 to be high. The light enters the boundary B between the refractive index layer 13 and the low refractive index layer 12.
　この戻り光は、境界Ｂにおいて、入射角θCが
　　sinθC≧(nL/nH)　　…(1)、
を満たす時、境界Ｂにおいて全反射する。ここで、本発明ではnH>nLであることから、(1)式の右辺は1未満になり、(1)式は必ず解を持つ。このように、入射角θCが(1)式を満たす戻り光は全て、全反射により再び光電変換部１５に入射する。また、(1)式を満たさず全反射が生じない戻り光も、その一部は境界Ｂにおいて反射され、再び光電変換部１５に入射する。これらの反射光により、光を光電変換部１５内に長く留めることができ、それにより薄膜太陽電池１０の光電変換の効率を高めることができる。
　また、強度保持層１１から光電変換部１５に入射してくる光については、逆に、境界Ｂにおいてより全反射が生じにくくなるため、より多くの光を光電変換部１５に取り込むことができるようになる。 This return light has an incident angle θ C at the boundary B of sin θ C ≧ (n L / n H ) (1),
When satisfied, total reflection occurs at the boundary B. Here, since n H > n L in the present invention, the right side of equation (1) is less than 1, and equation (1) always has a solution. As described above, all the return light having the incident angle θ C satisfying the expression (1) again enters the photoelectric conversion unit 15 by total reflection. Further, part of the return light that does not satisfy the expression (1) and does not cause total reflection is reflected at the boundary B and is incident on the photoelectric conversion unit 15 again. With these reflected lights, the light can be kept in the photoelectric conversion unit 15 for a long time, whereby the efficiency of photoelectric conversion of the thin film solar cell 10 can be increased.
On the contrary, the light incident on the photoelectric conversion unit 15 from the intensity holding layer 11 is less likely to cause total reflection at the boundary B, so that more light can be taken into the photoelectric conversion unit 15. become.
　このように、本発明では透明電極と光電変換部の境界にテクスチャ構造を設けることなく光電変換の効率を高めることができるため、透明電極の上面を平坦にすることができる。これにより、透明電極の上側に形成される光電変換部１５に欠陥等の乱れが生じることを防ぐことができる。この点においても、本発明により光電変換の効率を高めることができる。特に、多数の半導体微結晶から成る層を有する光電変換部を用いた場合に、微結晶の成長方向が揃うため、光励起キャリアが捕獲される原因となる欠陥の形成や、微結晶間の短絡を防ぐことができるため、透明電極の上面を平坦にすることによる効果が顕著である。 Thus, in the present invention, since the efficiency of photoelectric conversion can be increased without providing a texture structure at the boundary between the transparent electrode and the photoelectric conversion portion, the upper surface of the transparent electrode can be flattened. Thereby, disorder, such as a defect, can be prevented from occurring in the photoelectric conversion unit 15 formed on the upper side of the transparent electrode. Also in this respect, the present invention can increase the efficiency of photoelectric conversion. In particular, in the case of using a photoelectric conversion part having a layer made of a large number of semiconductor microcrystals, the growth direction of the microcrystals is aligned, so that formation of defects that cause photoexcited carriers to be captured and short-circuiting between microcrystals are prevented. Since it can prevent, the effect by making the upper surface of a transparent electrode flat is remarkable.
　本発明では、光電変換部の上部に反射部を設け、前記光電変換部と前記反射部の境界にテクスチャ構造を形成することができる。透明電極と光電変換部の境界に設けられるテクスチャ構造とは異なり、光電変換部の上部に設けられたテクスチャ構造は光電変換部に結晶成長の乱れを生じさせることがない。このようなテクスチャ構造を有する反射部により、光電変換部に導入された光（戻り光）は散乱し、それにより高屈折率層と低屈折率層の境界において全反射する確率を高めることができる。 In the present invention, a reflective part can be provided on the photoelectric conversion part, and a texture structure can be formed at the boundary between the photoelectric conversion part and the reflective part. Unlike the texture structure provided at the boundary between the transparent electrode and the photoelectric conversion unit, the texture structure provided above the photoelectric conversion unit does not cause disorder of crystal growth in the photoelectric conversion unit. The reflection part having such a texture structure scatters the light (return light) introduced into the photoelectric conversion part, thereby increasing the probability of total reflection at the boundary between the high refractive index layer and the low refractive index layer. .
　透明電極の上部に、耐プラズマ材料から成り上面が平坦な耐プラズマ層を設けてもよい。これにより、プラズマを用いて透明電極の上に光電変換部を作製する場合に、透明電極がプラズマに侵されて平坦性を失うことを防ぐことができる。上記プラズマが水素プラズマの場合には、耐プラズマ材料にはTiO2又はZnOを用いることができる。 A plasma-resistant layer made of a plasma-resistant material and having a flat upper surface may be provided on the transparent electrode. Thereby, when producing a photoelectric conversion part on a transparent electrode using plasma, it can prevent that a transparent electrode is invaded by plasma and loses flatness. When the plasma is hydrogen plasma, TiO 2 or ZnO can be used as the plasma resistant material.
　高屈折率層の厚みは(2kH-1)λ0/4nHとすることが望ましい。ここで、kHは自然数、λ0は前記所定波長域内にある波長である。これにより、高屈折率層は、低屈折率層から光電変換部に向かう波長λ0の光の反射を抑えることができる。波長λ0は真空内における光の波長で定義される。 The thickness of the high refractive index layer is preferably (2k H −1) λ 0 / 4n H. Here, k H is a natural number, and λ 0 is a wavelength within the predetermined wavelength range. Thereby, the high refractive index layer can suppress reflection of light having a wavelength λ 0 from the low refractive index layer toward the photoelectric conversion unit. The wavelength λ 0 is defined by the wavelength of light in a vacuum.
　強度保持層と低屈折率層の間に、波長λ0の光を透過可能であり、nLよりも高い屈折率nMを有し、厚みが(2kM-1)λ0/4nM（kMは自然数）である中間層を設けてもよい。このような中間層は、強度保持層から低屈折率層に向かう波長λ0の光の反射を抑えることができる。 Between the intensity maintaining layer and the low refractive index layer, light having a wavelength λ 0 can be transmitted, the refractive index n M is higher than n L , and the thickness is (2k M −1) λ 0 / 4n M ( An intermediate layer of k M is a natural number) may be provided. Such an intermediate layer can suppress reflection of light having a wavelength λ 0 from the intensity maintaining layer toward the low refractive index layer.
　前記強度保持層の下部には反射防止層を設けてもよい。前記反射防止層は、例えば、強度保持層側から順に、SnO2から成り、厚みが(2k1-1)λ0/4n1（k1は自然数、n1はSnO2の屈折率）である第１層と、TiO2から成り、厚みが(2k2-1)λ0/2n2（k2は自然数、n2はTiO2の屈折率）である第２層と、SiO2から成り、厚みが(2k3-1)λ0/4n3（k3は自然数、n3はSiO2の屈折率）である第３層とから構成することができる。 An antireflection layer may be provided below the strength holding layer. The antireflection layer is made of, for example, SnO 2 in order from the strength holding layer side, and has a thickness of (2k 1 −1) λ 0 / 4n 1 (k 1 is a natural number, n 1 is the refractive index of SnO 2 ). A first layer composed of TiO 2 , a thickness of (2k 2 −1) λ 0 / 2n 2 (k 2 is a natural number, n 2 is the refractive index of TiO 2 ), and SiO 2 And a third layer having a thickness of (2k 3 −1) λ 0 / 4n 3 (k 3 is a natural number and n 3 is a refractive index of SiO 2 ).
　本発明に係る薄膜太陽電池製造方法は、所定の波長域の光のエネルギーを電力に変換する薄膜太陽電池を製造する方法であって、
　a) ガラス製の基板の上に、スパッタリング法により100℃～240℃の温度条件で、SiO2から成る低屈折率層を作製する工程と、
　b) 前記低屈折率層の上に、スパッタリング法により100℃～240℃の温度条件で、TiO2から成る高屈折率層を作製する工程と、
　c) 前記高屈折率層の上に、スパッタリング法により100℃～240℃の温度条件で、SnO2から成る透明電極を作製する工程と、
　を有することを特徴とする。 A thin film solar cell manufacturing method according to the present invention is a method of manufacturing a thin film solar cell that converts light energy in a predetermined wavelength range into electric power,
a) producing a low refractive index layer made of SiO 2 on a glass substrate under a temperature condition of 100 ° C. to 240 ° C. by a sputtering method;
b) forming a high refractive index layer made of TiO 2 on the low refractive index layer under a temperature condition of 100 ° C. to 240 ° C. by a sputtering method;
c) producing a transparent electrode made of SnO 2 on the high refractive index layer by a sputtering method under a temperature condition of 100 ° C. to 240 ° C .;
It is characterized by having.
　本発明に係る薄膜太陽電池において透明電極を作製する際に、CVD法等のように結晶成長に適した方法を用いたり、透明電極の成膜温度を高くし過ぎたりすると、透明電極を構成する結晶粒が成長して大きくなり過ぎるため、透明電極上面の平坦性が悪化する。また、低屈折率層や高屈折率層の上面の平坦性が悪いと、その上に形成される透明電極上面の平坦性も悪くなる。そこで、本発明に係る薄膜太陽電池製造方法では、低屈折率層にSiO2を、高屈折率層にTiO2を、透明電極にSnO2を用い、これら各層をいずれも100℃～240℃という比較的低い温度条件下でスパッタリング法により作製する。これにより、結晶成長を抑えつつ高い平坦性を有する低屈折率層、高屈折率層及び透明電極を得ることができる。 When producing a transparent electrode in the thin film solar cell according to the present invention, if a method suitable for crystal growth, such as a CVD method, is used, or if the film formation temperature of the transparent electrode is too high, the transparent electrode is formed. Since the crystal grains grow and become too large, the flatness of the upper surface of the transparent electrode is deteriorated. Further, when the flatness of the upper surface of the low refractive index layer or the high refractive index layer is poor, the flatness of the upper surface of the transparent electrode formed thereon is also deteriorated. Therefore, in the thin-film solar cell manufacturing method according to the present invention, the SiO 2 for the low refractive index layer, a TiO 2 in the high refractive index layer, the SnO 2 used in the transparent electrode, that these layers of both 100 ° C. ~ 240 ° C. It is fabricated by sputtering under relatively low temperature conditions. Thereby, a low refractive index layer, a high refractive index layer and a transparent electrode having high flatness while suppressing crystal growth can be obtained.
　風冷強化ガラス製の基板（強度保持層）は約250℃以上に加熱した後に急冷すると割れが生じ、約300℃以上に加熱すると、加熱しただけで割れが生じる。本発明に係る薄膜太陽電池製造方法では加熱温度が100℃～240℃であるため、強化ガラス上に直接透明電極を形成することができる。 A substrate (strength retaining layer) made of air-cooled tempered glass will crack when heated to about 250 ° C or higher and then rapidly cooled, and when heated to about 300 ° C or higher, it will crack only by heating. In the method for producing a thin film solar cell according to the present invention, the heating temperature is 100 ° C. to 240 ° C., so that a transparent electrode can be formed directly on the tempered glass.
　本発明に係る薄膜太陽電池用基板は、薄膜太陽電池の光電変換部に導入された光の一部が高屈折率層と低屈折率層の境界において反射され、特に上記(1)式を満たす場合には全反射されることから、それら反射光が再度光電変換部に導入され、光の利用効率が高まる。これにより、薄膜太陽電池の光電変換の効率を高めることができる。 In the thin film solar cell substrate according to the present invention, a part of the light introduced into the photoelectric conversion part of the thin film solar cell is reflected at the boundary between the high refractive index layer and the low refractive index layer, and particularly satisfies the above formula (1). In this case, since the light is totally reflected, the reflected light is reintroduced into the photoelectric conversion unit, and the light use efficiency is increased. Thereby, the efficiency of photoelectric conversion of the thin film solar cell can be increased.
　また、本発明に係る薄膜太陽電池用基板はテクスチャ構造を用いる必要がないため、透明電極の上面を平坦にすることができる。このような平坦な透明電極の上面に光電変換部を形成した場合には、光電変換部に欠陥等の乱れが生じることを防ぐことができるため、光電変換の効率をより高めることができる。 Moreover, since the thin film solar cell substrate according to the present invention does not need to use a texture structure, the upper surface of the transparent electrode can be flattened. In the case where the photoelectric conversion part is formed on the upper surface of such a flat transparent electrode, it is possible to prevent the photoelectric conversion part from being disturbed such as defects, so that the efficiency of photoelectric conversion can be further increased.
従来の薄膜太陽電池におけるテクスチャ構造の役割を示す縦断面図。The longitudinal cross-sectional view which shows the role of the texture structure in the conventional thin film solar cell. 本発明に係る薄膜太陽電池用基板において光の利用効率が高まる理由を説明するための概念図。The conceptual diagram for demonstrating the reason for the utilization efficiency of light increasing in the board | substrate for thin film solar cells which concerns on this invention. 本発明の第１実施例に係る薄膜太陽電池２０の縦断面図。The longitudinal cross-sectional view of the thin film solar cell 20 which concerns on 1st Example of this invention. 薄膜太陽電池２０の製造方法を示す縦断面図。The longitudinal cross-sectional view which shows the manufacturing method of the thin film solar cell 20. FIG. 本発明の第２実施例に係る薄膜太陽電池３０の縦断面図。The longitudinal cross-sectional view of the thin film solar cell 30 which concerns on 2nd Example of this invention.
　図３～図５を用いて、本発明に係る薄膜太陽電池の実施例を説明する。 Examples of the thin film solar cell according to the present invention will be described with reference to FIGS.
　図３に、本発明の第１の実施例である薄膜太陽電池２０の縦断面図を示す。
　本実施例の薄膜太陽電池２０は、強度保持層２１、中間層２７、低屈折率層２２、高屈折率層２３、透明電極層２４が順に積層されて成る薄膜太陽電池用基板２０Ｓと、薄膜太陽電池用基板２０Ｓの上に順に積層された耐プラズマ層２８、光電変換層２５及び反射電極層２６から成る。 In FIG. 3, the longitudinal cross-sectional view of the thin film solar cell 20 which is the 1st Example of this invention is shown.
The thin film solar cell 20 of this example includes a thin film solar cell substrate 20S formed by sequentially laminating a strength holding layer 21, an intermediate layer 27, a low refractive index layer 22, a high refractive index layer 23, and a transparent electrode layer 24, and a thin film. It consists of a plasma-resistant layer 28, a photoelectric conversion layer 25, and a reflective electrode layer 26, which are sequentially stacked on the solar cell substrate 20S.
　上記各層は以下の材料が用いられている。強度保持層２１は、従来より太陽電池用の基板として広く用いられている、屈折率が1.50のソーダ石灰製の強化ガラスから成る。中間層２７は屈折率nMが2.00であるSnO2（二酸化スズ）から成る。低屈折率層２２は屈折率nLが1.45であるSiO2（二酸化珪素）から成る。高屈折率層２３は屈折率nHが2.45～2.92（結晶構造により異なる）であるTiO2（二酸化チタン）から成る。透明電極層２４は、従来から薄膜太陽電池の透明電極として用いられているSnO2から成る。耐プラズマ層２８はTiO2から成る。反射電極層２６は銀の蒸着膜から成る。なお、耐プラズマ層２８の材料にはTiO2の代わりにZnO（酸化亜鉛）を、反射電極層２６には銀の代わりにアルミニウムを、それぞれ用いることもできる。 The following materials are used for each of the above layers. The strength retention layer 21 is made of tempered glass made of soda lime having a refractive index of 1.50, which has been widely used as a substrate for solar cells. The intermediate layer 27 is made of SnO 2 (tin dioxide) having a refractive index n M of 2.00. The low refractive index layer 22 is made of SiO 2 (silicon dioxide) having a refractive index n L of 1.45. The high refractive index layer 23 is made of TiO 2 (titanium dioxide) having a refractive index n H of 2.45 to 2.92 (depending on the crystal structure). The transparent electrode layer 24 is made of SnO 2 which has been conventionally used as a transparent electrode of a thin film solar cell. The plasma-resistant layer 28 is made of TiO 2 . The reflective electrode layer 26 is made of a silver vapor deposition film. Note that ZnO (zinc oxide) can be used instead of TiO 2 for the material of the plasma-resistant layer 28, and aluminum can be used for the reflective electrode layer 26 instead of silver.
　透明電極層２４の表面（上面）はできるだけ平坦にする。これにより、透明電極層２４の上側に形成される光電変換層２５の微結晶（後述）の成長方向が乱れることを防ぐことができ、薄膜太陽電池の光電変換の効率を高めることができる。なお、透明電極層２４の表面の平坦性を高めるためには、透明電極層２４よりも下にある高屈折率層２３、低屈折率層２２及び中間層２７の上面をできるだけ平坦にすることが望ましい。 The surface (upper surface) of the transparent electrode layer 24 is made as flat as possible. Thereby, it can prevent that the growth direction of the microcrystal (after-mentioned) of the photoelectric converting layer 25 formed above the transparent electrode layer 24 is disturbed, and can improve the efficiency of photoelectric conversion of a thin film solar cell. In order to improve the flatness of the surface of the transparent electrode layer 24, the top surfaces of the high refractive index layer 23, the low refractive index layer 22 and the intermediate layer 27 below the transparent electrode layer 24 should be made as flat as possible. desirable.
　透明電極層２４等の平坦性を示す指標の１つに「算術平均粗さ」（「中心線平均粗さ」とも呼ばれる）Raがある。Raは日本工業規格で定められた表面粗さの定義の１つであり、長さLの範囲内で測定により得られる粗さ曲線と平均線（粗さ曲線を平均化した直線）の差f(x)を用いて以下の式により求められる。
Figure JPOXMLDOC01-appb-M000001
 光電変換層２５の微結晶の成長方向が乱れることを防ぐために、透明電極層２４の上面のRaは100nm以下とすることが望ましい。また、本実施例では光電変換層２５に接するのは耐プラズマ層２８であるため、耐プラズマ層２８の上面のRaも100nm以下とする。透明電極層２４の下にある高屈折率層２３や低屈折率層２２についても、透明電極層２４の上面の平坦性を損ねることを防ぐために、上面のRaを100nm以下とすることが望ましい。 One of indexes indicating flatness of the transparent electrode layer 24 and the like is “arithmetic average roughness” (also referred to as “centerline average roughness”) Ra. Ra is one of the definitions of surface roughness stipulated by Japanese Industrial Standards. The difference between the roughness curve obtained by measurement within the range of length L and the average line (a straight line obtained by averaging the roughness curve) f Using (x), the following equation is obtained.
Figure JPOXMLDOC01-appb-M000001
 In order to prevent the growth direction of the microcrystals of the photoelectric conversion layer 25 from being disturbed, Ra on the upper surface of the transparent electrode layer 24 is desirably set to 100 nm or less. In this embodiment, since the plasma-resistant layer 28 is in contact with the photoelectric conversion layer 25, Ra on the upper surface of the plasma-resistant layer 28 is also set to 100 nm or less. Also for the high refractive index layer 23 and the low refractive index layer 22 below the transparent electrode layer 24, in order to prevent the flatness of the upper surface of the transparent electrode layer 24 from being impaired, it is desirable that the upper surface Ra is 100 nm or less.
　耐プラズマ層２８を設けた理由は以下の通りである。仮に、透明電極層２４の上面に直接、水素やシランガスを用いたCVD法により光電変換層２５を作製すると、作製開始時に透明電極層２４の表面が水素プラズマに晒され、還元されるおそれがある。このような還元が生じれば、酸化膜である透明電極層２４は変質し、透明度の低下や抵抗値の上昇が生じるため、透明電極としての機能を果たさなくなる。そこで、本実施例では透明電極層２４の一番上側の層に耐プラズマ層２８を設け、水素プラズマによる還元作用が生じるのを防止した。 The reason why the plasma resistant layer 28 is provided is as follows. If the photoelectric conversion layer 25 is fabricated directly on the upper surface of the transparent electrode layer 24 by a CVD method using hydrogen or silane gas, the surface of the transparent electrode layer 24 may be exposed to hydrogen plasma at the start of fabrication and may be reduced. . If such reduction occurs, the transparent electrode layer 24, which is an oxide film, changes in quality, resulting in a decrease in transparency and an increase in resistance value, so that it does not function as a transparent electrode. Therefore, in this embodiment, the plasma-resistant layer 28 is provided on the uppermost layer of the transparent electrode layer 24 to prevent the reduction action by hydrogen plasma from occurring.
　光電変換層２５には、例えばp型半導体－真性半導体－n型半導体の３層を積層して成るpin型光電変換層、あるいはpin型光電変換層を２組積層したpinタンデム型光電変換層を用いることができる。光電変換層の半導体には、アモルファス半導体や微結晶半導体が用いられる。本実施例では、透明電極層２４の上面に、アモルファス又は微結晶のp型Si半導体から成るp層２５１、微結晶の真性Si半導体から成るi層２５２、アモルファスのn型Si半導体から成るn層２５３の３層を積層した。上述したように、耐プラズマ層２８の上面はRaが100nm以下という平坦性を有するため、耐プラズマ層２８の上に形成されるp層２５１の上面も平坦にすることができる。この結果、p層２５１の上面に形成されるi層２５２の微結晶の成長方向が揃い、不規則な向きに界面が形成されることによる欠陥や、微結晶間の電気的な短絡を防ぐことができる。なお、i層２５２の微結晶の成長方向は透明電極層２４に垂直な方向になる。 For the photoelectric conversion layer 25, for example, a pin-type photoelectric conversion layer formed by stacking three layers of a p-type semiconductor, an intrinsic semiconductor, and an n-type semiconductor, or a pin tandem photoelectric conversion layer formed by stacking two pairs of pin-type photoelectric conversion layers is used. Can be used. As the semiconductor of the photoelectric conversion layer, an amorphous semiconductor or a microcrystalline semiconductor is used. In this embodiment, on the upper surface of the transparent electrode layer 24, a p layer 251 made of an amorphous or microcrystalline p-type Si semiconductor, an i layer 252 made of a microcrystalline intrinsic Si semiconductor, and an n layer made of an amorphous n-type Si semiconductor. Three layers of 253 were laminated. As described above, since the upper surface of the plasma-resistant layer 28 has a flatness of Ra of 100 nm or less, the upper surface of the p-layer 251 formed on the plasma-resistant layer 28 can also be flattened. As a result, the growth direction of the microcrystals of the i layer 252 formed on the upper surface of the p layer 251 is aligned, and defects due to irregularly formed interfaces and electrical shorts between the microcrystals are prevented. Can do. Note that the crystal growth direction of the i layer 252 is perpendicular to the transparent electrode layer 24.
　一方、i層２５２の各微結晶の成長速度が異なることにより、i層２５２の上面には微結晶の上端が不揃いに並ぶ。このような不揃いが生じた面の上に（n層２５３を挟んで）銀あるいはアルミニウムを成膜すると、その膜が凹凸のある鏡となる。これにより、n層２５３と反射電極層２６の境界面が自然に凹凸状となる。 On the other hand, since the growth rates of the microcrystals of the i layer 252 are different, the upper ends of the microcrystals are unevenly arranged on the upper surface of the i layer 252. When silver or aluminum is formed on the surface where such irregularities occur (with the n layer 253 sandwiched), the film becomes an uneven mirror. Accordingly, the boundary surface between the n layer 253 and the reflective electrode layer 26 is naturally uneven.
　また、高屈折率層２３の厚みは、真空中で波長λ0を持つ光の層内での波長λ0/nHの1/4倍に設定し、中間層２７の厚みはλ0/nMの1/4倍に設定した。本実施例では、基準波長λ0を550nmとしたため、中間層２７の厚みは69nm、高屈折率層２３の厚みは55nmである。その他の層の厚みは波長λ0とは関係なく定められており、強度保持層２１は1～10μm、低屈折率層２２は32μm、透明電極層２４は約0.5～1μmである。 The thickness of the high refractive index layer 23 is set to 1/4 times the wavelength λ 0 / n H in the light layer having the wavelength λ 0 in vacuum, and the thickness of the intermediate layer 27 is λ 0 / n. It was set to 1/4 times M. In this embodiment, since the reference wavelength lambda 0 was 550 nm, the thickness of the intermediate layer 27 is 69 nm, the thickness of the high refractive index layer 23 is 55 nm. The thicknesses of the other layers are determined regardless of the wavelength λ 0. The strength holding layer 21 is 1 to 10 μm, the low refractive index layer 22 is 32 μm, and the transparent electrode layer 24 is about 0.5 to 1 μm.
　薄膜太陽電池２０は、以下のように作製する。まず、強度保持層２１であるソーダ石灰ガラス板を100℃～240℃の温度に維持しつつ、その上に、スパッタ法を用いてSnO2を成膜して中間層２７を作製する（図４(a),(b)）。同様に、温度を上記範囲内に維持したままでスパッタ法を用いて、SiO2を成膜することにより低屈折率層２２を作製し（図４(b),(c)）、TiO2を成膜することにより高屈折率層２３を作製し（図４(c),(d)）、SnO2を成膜することにより透明電極層２４を作製する（図４(d),(e)）。更に、温度を上記範囲内に維持したままスパッタ法でTiO2を成膜することにより耐プラズマ層２８を作製する（図４(e)）。その後、プラズマCVD法により光電変換層２５を、スパッタ法により反射電極層２６を、それぞれ作製することにより、薄膜太陽電池２０が得られる（図３）。 The thin film solar cell 20 is produced as follows. First, while maintaining the soda-lime glass plate as a strength retention layer 21 to a temperature of 100 ° C. ~ 240 ° C., thereon, to prepare an intermediate layer 27 by forming a SnO 2 by sputtering (FIG. 4 (a), (b)). Similarly, the temperature by sputtering while maintaining in the above range, to prepare a low refractive index layer 22 by depositing SiO 2 (FIG. 4 (b), (c) ), the TiO 2 A high refractive index layer 23 is produced by film formation (FIGS. 4C and 4D), and a transparent electrode layer 24 is produced by depositing SnO 2 (FIGS. 4D and 4E). ). Furthermore, a plasma-resistant layer 28 is formed by depositing TiO 2 by sputtering while maintaining the temperature within the above range (FIG. 4 (e)). Thereafter, the thin film solar cell 20 is obtained by fabricating the photoelectric conversion layer 25 by the plasma CVD method and the reflective electrode layer 26 by the sputtering method, respectively (FIG. 3).
　本実施例の薄膜太陽電池２０の動作を説明する。光は強度保持層２１の下面から当該強度保持層２１に入射し、中間層２７、低屈折率層２２、高屈折率層２３、透明電極層２４及び耐プラズマ層２８を通過して光電変換層２５に到達する。光電変換層２５内では、一部の光のエネルギーが電力（電気エネルギー）に変換され、残りの光は反射電極層２６で反射される。ここで、反射電極層２６の反射面（反射電極層２６と光電変換層２５の境界面）には多数の凹凸が存在するため、反射電極層２６で反射される光は散乱され、光電変換層２５を通過し、戻り光として高屈折率層２３と低屈折率層２２の境界Ｂに入射する（なお、戻り光は光電変換層２５を通過しているので短波長の光が弱く、主成分は長波長の光である。）。
　境界Ｂに入射する戻り光のうち、入射角θCが次の式
　　sinθC≧nL/nH=1.45/2.52、
（なお、nHはアナターゼ構造のTiO2における値を用いた）を満たすもの、即ち、入射角θCが35.1°よりも大きい戻り光は全反射され、35.1°よりも小さい戻り光は一部が反射される。こうして反射された光は再び光電変換層２５に入射する。そのため、本実施例の薄膜太陽電池２０では光の利用効率を高めることができ、それにより光電変換効率を高めることができる。 Operation | movement of the thin film solar cell 20 of a present Example is demonstrated. Light enters the intensity holding layer 21 from the lower surface of the intensity holding layer 21, passes through the intermediate layer 27, the low refractive index layer 22, the high refractive index layer 23, the transparent electrode layer 24, and the plasma-resistant layer 28, and the photoelectric conversion layer. Reach 25. In the photoelectric conversion layer 25, a part of light energy is converted into electric power (electric energy), and the remaining light is reflected by the reflective electrode layer 26. Here, since many irregularities exist on the reflective surface of the reflective electrode layer 26 (the boundary surface between the reflective electrode layer 26 and the photoelectric conversion layer 25), the light reflected by the reflective electrode layer 26 is scattered, and the photoelectric conversion layer 25, and enters the boundary B between the high-refractive index layer 23 and the low-refractive index layer 22 as return light (note that since the return light passes through the photoelectric conversion layer 25, short-wavelength light is weak, and the main component Is long wavelength light.)
Of the return light incident on the boundary B, the incident angle θ C has the following formula: sin θ C ≧ n L / n H = 1.45 / 2.52,
(In this case, n H is a value in TiO 2 having an anatase structure), that is, return light having an incident angle θ C larger than 35.1 ° is totally reflected, and part of return light smaller than 35.1 ° is partially reflected Is reflected. The light thus reflected is incident on the photoelectric conversion layer 25 again. Therefore, in the thin film solar cell 20 of a present Example, the utilization efficiency of light can be improved and, thereby, photoelectric conversion efficiency can be improved.
　また、中間層２７の厚みをλ0/nMの1/4倍に設定したことにより、λ0付近の波長を有する光の、強度保持層２１と中間層２７の境界における反射及び中間層２７と低屈折率層２２の境界における反射が抑制される。同様に、高屈折率層２３についても、λ0付近の波長を有する光の、高屈折率層２３と低屈折率層２２の境界における反射及び高屈折率層２３と透明電極層２４の境界における反射が抑制される。つまり、強度保持層２１に入射してから光電変換層２５に到達するまでの間に、λ0付近の波長を有する光が、各層の境界で反射されることを抑制できる。このため、光電変換層２５に到達する光の強度を強くすることができ、光電変換の効率を一層高めることができる。 Further, by setting the thickness of the intermediate layer 27 to 1/4 times λ 0 / n M , reflection of light having a wavelength in the vicinity of λ 0 at the boundary between the intensity holding layer 21 and the intermediate layer 27 and the intermediate layer 27. And reflection at the boundary of the low refractive index layer 22 are suppressed. Similarly, with respect to the high refractive index layer 23, reflection of light having a wavelength near λ 0 at the boundary between the high refractive index layer 23 and the low refractive index layer 22 and at the boundary between the high refractive index layer 23 and the transparent electrode layer 24. Reflection is suppressed. That is, it is possible to prevent light having a wavelength in the vicinity of λ 0 from being reflected at the boundary between the layers after entering the intensity holding layer 21 and reaching the photoelectric conversion layer 25. For this reason, the intensity | strength of the light which reaches | attains the photoelectric converting layer 25 can be strengthened, and the efficiency of photoelectric conversion can be improved further.
　本実施例における低屈折率層２２は、その材料がSiO2であることにより、光を全反射させる機能の他に、次の機能を併せ持つ。つまり、強度保持層２１がソーダガラスである場合に、ソーダガラスから溶出するアルカリイオンが光電変換層２５に侵入して光電変換層２５を劣化させることを防ぐ機能を併せ持つ（アルカリイオン浸透防止膜としての機能）。また、本実施例における中間層２７は、その材料がSnO2であることにより、反射防止膜としての機能の他に、ソーダガラス基板から成る強度保持層２１とSiO2から成る低屈折率層２２の間で生じる熱膨張率の差による応力を緩和する機能を併せ持つ。なお、応力緩和機能のみを目的として中間層２７の位置にSnO2から成る層を設ける場合には、その層の厚みをλ0/nMの1/4倍にする必要はない。 The low refractive index layer 22 in this embodiment has the following function in addition to the function of totally reflecting light because the material is SiO 2 . That is, when the strength holding layer 21 is soda glass, it has a function of preventing alkali ions eluted from the soda glass from entering the photoelectric conversion layer 25 and degrading the photoelectric conversion layer 25 (as an alkali ion permeation prevention film). Function of). The intermediate layer 27 in the present embodiment, by the material is SnO 2, in addition to the function as an antireflection film, made of the strength retention layer 21 and the SiO 2 made of soda glass substrate low refractive index layer 22 It also has a function to relieve stress caused by the difference in thermal expansion coefficient between the two. When a layer made of SnO 2 is provided at the position of the intermediate layer 27 only for the purpose of stress relaxation function, the thickness of the layer does not need to be 1/4 times λ 0 / n M.
　図５に、本発明の第２の実施例である薄膜太陽電池３０の縦断面図を示す。本実施例の薄膜太陽電池３０が、第１実施例の薄膜太陽電池２０と異なる点は、強度保持層２１の下面、即ち強度保持層２１の光が入射する面に反射防止層３９を設けたことである。 FIG. 5 shows a longitudinal sectional view of a thin film solar cell 30 according to the second embodiment of the present invention. The thin film solar cell 30 of the present embodiment is different from the thin film solar cell 20 of the first embodiment in that an antireflection layer 39 is provided on the lower surface of the strength holding layer 21, that is, the surface on which the light of the strength holding layer 21 is incident. That is.
　反射防止層３９は、強度保持層２１側から順に第１層３９１、第２層３９２、第３層３９３の３つの層から成る。第１層３９１はSnO2から成り、厚みがλ0/4n1（n1=2.00）である。第２層３９２はTiO2から成り、厚みがλ0/2n2（n1=2.45～2.92）である。第３層３９３はSiO2から成り、厚みがλ0/4n3（n3=1.45）である。このように1/4波長分－1/2波長分－1/4波長分の厚みを持つ３つの層を重ねたものは、２つの波長で反射率が極小値を持ち、これら２つの波長間で低い反射率を有する反射防止膜として機能することが知られている（例えば、李正中著、「光学薄膜と成膜技術」、アグネ技術センター発行、97-98頁参照）。 The antireflection layer 39 includes three layers of a first layer 391, a second layer 392, and a third layer 393 in order from the strength holding layer 21 side. The first layer 391 is made of SnO 2 and has a thickness of λ 0 / 4n 1 (n 1 = 2.00). The second layer 392 is made of TiO 2 and has a thickness of λ 0 / 2n 2 (n 1 = 2.45 to 2.92). The third layer 393 is made of SiO 2 and has a thickness of λ 0 / 4n 3 (n 3 = 1.45). In this way, three layers with thicknesses of 1/4 wavelength-1/2 wavelength-1/4 wavelength overlap, and the reflectance is minimal at the two wavelengths. It is known to function as an antireflection film having a low reflectivity (see, for example, Lee Masanaka, “Optical thin film and film formation technology”, published by Agne Technology Center, pages 97-98).
　本実施例の薄膜太陽電池３０は、上述の薄膜太陽電池２０と同様に、強度保持層２１の上に100℃～240℃の温度でスパッタ法を用いて中間層２７、低屈折率層２２、高屈折率層２３及び透明電極層２４を作製し、その後に、同じ温度条件でスパッタ法により強度保持層２１の下側に第１層３９１、第２層３９２、第３層３９３を作製する。さらに、その後に光電変換層２５と反射電極層２６を作製することにより製造することができる。 The thin-film solar cell 30 of this example is similar to the thin-film solar cell 20 described above. The intermediate layer 27, the low-refractive index layer 22, The high refractive index layer 23 and the transparent electrode layer 24 are manufactured, and then the first layer 391, the second layer 392, and the third layer 393 are formed below the strength holding layer 21 by sputtering under the same temperature conditions. Furthermore, it can manufacture by producing the photoelectric converting layer 25 and the reflective electrode layer 26 after that.
　本実施例の薄膜太陽電池３０では、反射防止層３９に入射した光は、その後、反射防止層３９を高い透過率で通過し、強度保持層２１に入射する。それ以外の動作は第１実施例の場合と同様である。 In the thin film solar cell 30 of the present embodiment, the light incident on the antireflection layer 39 then passes through the antireflection layer 39 with high transmittance and enters the strength holding layer 21. Other operations are the same as those in the first embodiment.
１０、２０、３０…薄膜太陽電池
１０Ｓ、２０Ｓ、３０Ｓ…薄膜太陽電池用基板
１１、２１…強度保持層
１２、２２…低屈折率層
１３、２３…高屈折率層
１４…透明電極
２４…透明電極層
１５…光電変換部
２５、９２…光電変換層
２５１…p層
２５２…i層
２５３…n層
２６…反射電極層
２７…中間層
２８…耐プラズマ層
３９…反射防止層
　３９１…第１層
　３９２…第２層
　３９３…第３層
９１…透明電極
９４…テクスチャ境界
９５１…入射光
９５２…第１反射光
９５３１…第１透過光
９５３２…第２透過光 DESCRIPTION OF SYMBOLS 10, 20, 30 ... Thin film solar cell 10S, 20S, 30S ... Thin film solar cell substrate 11, 21 ... Strength retention layer 12, 22 ... Low refractive index layer 13, 23 ... High refractive index layer 14 ... Transparent electrode 24 ... Transparent Electrode layer 15 ... photoelectric conversion part 25, 92 ... photoelectric conversion layer 251 ... p layer 252 ... i layer 253 ... n layer 26 ... reflective electrode layer 27 ... intermediate layer 28 ... plasma-resistant layer 39 ... antireflection layer 391 ... first layer 392 ... Second layer 393 ... Third layer 91 ... Transparent electrode 94 ... Texture boundary 951 ... Incident light 952 ... First reflected light 9531 ... First transmitted light 9532 ... Second transmitted light

Claims (21)

  1. 　所定の波長域の光のエネルギーを電力に変換する薄膜太陽電池であって、
    　a) 前記所定波長域の光が透過可能な強度保持層と、
    　b) 前記強度保持層の上部に設けられた、前記所定波長域の光が透過可能であって屈折率nLを有する低屈折率層と、
    　c) 前記低屈折率層の上面に接して設けられた、前記所定波長域の光が透過可能であってnLよりも高い屈折率nHを有する高屈折率層と、
    　d) 前記高屈折率層の上部に設けられた、前記所定波長域の光が透過可能であって導電性を有する透明電極と、
    　e) 前記透明電極の上部に設けられた光電変換部と、
    を備えることを特徴とする薄膜太陽電池。     A thin-film solar cell that converts light energy in a predetermined wavelength range into electric power,
    a) an intensity holding layer capable of transmitting light in the predetermined wavelength range;
    b) a low-refractive-index layer provided on the intensity-holding layer and capable of transmitting light in the predetermined wavelength range and having a refractive index n L ;
    c) a high refractive index layer provided in contact with the upper surface of the low refractive index layer, capable of transmitting light in the predetermined wavelength range and having a refractive index n H higher than n L ;
    d) a transparent electrode provided on the high refractive index layer and capable of transmitting light in the predetermined wavelength range and having conductivity;
    e) a photoelectric conversion unit provided on the transparent electrode;
    A thin film solar cell comprising:
  2. 　前記透明電極の上面が平坦であり、前記光電変換部が多数の半導体微結晶から成る層を有することを特徴とする請求項１に記載の薄膜太陽電池。 The thin film solar cell according to claim 1, wherein the transparent electrode has a flat upper surface, and the photoelectric conversion part has a layer made of a large number of semiconductor microcrystals.
  3. 　前記透明電極上面の算術平均粗さRaが100nm以下であることを特徴とする請求項２に記載の薄膜太陽電池。 The thin film solar cell according to claim 2, wherein the arithmetic average roughness Ra of the upper surface of the transparent electrode is 100 nm or less.
  4. 　前記光電変換部の上部に設けられた反射部を備え、前記光電変換部と前記反射部の境界がテクスチャ構造を有することを特徴とする請求項１～３のいずれかに記載の薄膜太陽電池。 The thin-film solar cell according to any one of claims 1 to 3, further comprising a reflection portion provided on an upper portion of the photoelectric conversion portion, wherein a boundary between the photoelectric conversion portion and the reflection portion has a texture structure.
  5. 　前記高屈折率層の厚みが(2kH-1)λ0/4nH（kHは自然数、λ0は前記所定波長域内の波長）であることを特徴とする請求項１～４のいずれかに記載の薄膜太陽電池。 5. The thickness of the high refractive index layer is (2k H −1) λ 0 / 4n H (where k H is a natural number and λ 0 is a wavelength within the predetermined wavelength range). The thin film solar cell according to 1.
  6. 　前記低屈折率層がSiO2から成り、前記高屈折率層がTiO2から成ることを特徴とする請求項１～５のいずれかに記載の薄膜太陽電池。 6. The thin film solar cell according to claim 1, wherein the low refractive index layer is made of SiO 2 and the high refractive index layer is made of TiO 2 .
  7. 　前記強度保持層と前記低屈折率層の間に設けられた、前記所定波長域の光が透過可能な中間層を備え、
    　前記中間層が、nLよりも高い屈折率nMを有し、厚みが(2kM-1)λ0/4nM（kMは自然数、λ0は前記所定波長域内にある波長）であることを特徴とする請求項１～６のいずれかに記載の薄膜太陽電池。     An intermediate layer provided between the strength maintaining layer and the low refractive index layer and capable of transmitting light in the predetermined wavelength range;
    The intermediate layer has a refractive index n M higher than n L and a thickness (2k M −1) λ 0 / 4n M (k M is a natural number, and λ 0 is a wavelength within the predetermined wavelength range). The thin-film solar cell according to any one of claims 1 to 6, wherein
  8. 　前記中間層がSnO2から成ることを特徴とする請求項７に記載の薄膜太陽電池。 The thin film solar cell according to claim 7, wherein the intermediate layer is made of SnO 2 .
  9. 　前記強度保持層の下部に設けられた、前記所定波長域内の少なくとも一部の波長域の光の反射を防止する反射防止層を備えることを特徴とする請求項１～８のいずれかに記載の薄膜太陽電池。 9. The antireflection layer according to claim 1, further comprising an antireflection layer that is provided below the intensity holding layer and prevents reflection of light in at least a part of the predetermined wavelength range. Thin film solar cell.
  10. 　前記反射防止層が、前記強度保持層側から順に設けられた第１層、第２層、第３層を備え、
    　前記第１層は、SnO2から成り、厚みが(2k1-1)λ1/4n1（k1は自然数、n1はSnO2の屈折率、λ1は前記所定波長域内にある波長）であり、
    　前記第２層は、TiO2から成り、厚みが(2k2-1)λ1/2n2（k2は自然数、n2はTiO2の屈折率）であり、
    　前記第３層は、SiO2から成り、厚みが(2k3-1)λ1/4n3（k3は自然数、n3はSiO2の屈折率）であることを特徴とする請求項９に記載の薄膜太陽電池。     The antireflection layer includes a first layer, a second layer, and a third layer provided in order from the strength holding layer side,
    The first layer is made of SnO 2 and has a thickness of (2k 1 −1) λ 1 / 4n 1 (k 1 is a natural number, n 1 is a refractive index of SnO 2 , and λ 1 is a wavelength within the predetermined wavelength range) And
    The second layer is made of TiO 2 and has a thickness of (2k 2 −1) λ 1 / 2n 2 (k 2 is a natural number, n 2 is a refractive index of TiO 2 ),
    The third layer is made of SiO 2 and has a thickness of (2k 3 -1) λ 1 / 4n 3 (k 3 is a natural number and n 3 is a refractive index of SiO 2 ). The thin film solar cell described.
  11. 　前記透明電極と前記光電変換部の間に設けられた、耐プラズマ材料から成り上面が平坦な耐プラズマ層を備えることを特徴とする請求項１～１０のいずれかに記載の薄膜太陽電池。 The thin-film solar cell according to any one of claims 1 to 10, further comprising a plasma-resistant layer made of a plasma-resistant material and having a flat upper surface provided between the transparent electrode and the photoelectric conversion unit.
  12. 　所定の波長域の光のエネルギーを電力に変換する光電変換層を支持する基板であって、
    　a) 前記所定波長域の光が透過可能な強度保持層と、
    　b) 前記強度保持層の上部に設けられた、前記所定波長域の光が透過可能であって屈折率nLを有する低屈折率層と、
    　c) 前記低屈折率層の上面に接して設けられた、前記所定波長域の光が透過可能であってnLよりも高い屈折率nHを有する高屈折率層と、
    　d) 前記高屈折率層の上部に設けられた、前記所定波長域の光が透過可能であって導電性を有する透明電極と、
    　を備えることを特徴とする薄膜太陽電池用基板。     A substrate that supports a photoelectric conversion layer that converts light energy in a predetermined wavelength range into electric power,
    a) an intensity holding layer capable of transmitting light in the predetermined wavelength range;
    b) a low-refractive-index layer provided on the intensity-holding layer and capable of transmitting light in the predetermined wavelength range and having a refractive index n L ;
    c) a high refractive index layer provided in contact with the upper surface of the low refractive index layer, capable of transmitting light in the predetermined wavelength range and having a refractive index n H higher than n L ;
    d) a transparent electrode provided on the high refractive index layer and capable of transmitting light in the predetermined wavelength range and having conductivity;
    A thin film solar cell substrate comprising:
  13. 　前記透明電極の上面が平坦であることを特徴とする請求項１２に記載の薄膜太陽電池用基板。 The thin film solar cell substrate according to claim 12, wherein an upper surface of the transparent electrode is flat.
  14. 　前記透明電極上面の算術平均粗さRaが100nm以下であることを特徴とする請求項１３に記載の薄膜太陽電池用基板。 14. The thin film solar cell substrate according to claim 13, wherein the arithmetic average roughness Ra of the upper surface of the transparent electrode is 100 nm or less.
  15. 　前記高屈折率層の厚みが(2kH-1)λ0/4nH（kHは自然数、λ0は前記所定波長域内の波長）であることを特徴とする請求項１２～１４のいずれかに記載の薄膜太陽電池用基板。 The thickness of the high refractive index layer is (2k H -1) λ 0 / 4n H (k H is a natural number, λ 0 is a wavelength within the predetermined wavelength range), A substrate for a thin film solar cell according to 1.
  16. 　前記低屈折率層がSiO2から成り、前記高屈折率層がTiO2から成ることを特徴とする請求項１２～１５のいずれかに記載の薄膜太陽電池用基板。 The thin film solar cell substrate according to any one of claims 12 to 15, wherein the low refractive index layer is made of SiO 2 and the high refractive index layer is made of TiO 2 .
  17. 　前記強度保持層と前記低屈折率層の間に設けられた、前記所定波長域の光が透過可能な中間層を備え、
    　前記中間層は、nLよりも高い屈折率nMを有し、厚みが(2kM-1)λ0/4nM（kMは自然数、λ0は前記所定波長域内にある波長）である中間層を備えることを特徴とする請求項１２～１６のいずれかに記載の薄膜太陽電池用基板。     An intermediate layer provided between the strength maintaining layer and the low refractive index layer and capable of transmitting light in the predetermined wavelength range;
    The intermediate layer has a refractive index n M higher than n L and a thickness of (2k M −1) λ 0 / 4n M (k M is a natural number, and λ 0 is a wavelength within the predetermined wavelength range). The thin film solar cell substrate according to any one of claims 12 to 16, further comprising an intermediate layer.
  18. 　前記中間層がSnO2から成ることを特徴とする請求項１７に記載の薄膜太陽電池用基板。 The thin film solar cell substrate according to claim 17, wherein the intermediate layer is made of SnO 2 .
  19. 　前記強度保持層の下部に設けられた、前記所定波長域内の少なくとも一部の波長域の光の反射を防止する反射防止層を備えることを特徴とする請求項１２～１８のいずれかに記載の薄膜太陽電池用基板。 The antireflection layer for preventing reflection of light in at least a part of the wavelength range within the predetermined wavelength range, which is provided below the intensity maintaining layer, is provided. Thin film solar cell substrate.
  20. 　前記反射防止層が、前記強度保持層側から順に設けられた第１層、第２層、第３層を備え、
    　前記第１層は、SnO2から成り、厚みが(2k1-1)λ1/4n1（k1は自然数、n1はSnO2の屈折率、λ1は前記所定波長域内にある波長）であり、
    　前記第２層は、TiO2から成り、厚みが(2k2-1)λ1/2n2（k2は自然数、n2はTiO2の屈折率）であり、
    　前記第３層は、SiO2から成り、厚みが(2k3-1)λ1/4n3（k3は自然数、n3はSiO2の屈折率）であることを特徴とする請求項１９に記載の薄膜太陽電池用基板。     The antireflection layer includes a first layer, a second layer, and a third layer provided in order from the strength holding layer side,
    The first layer is made of SnO 2 and has a thickness of (2k 1 −1) λ 1 / 4n 1 (k 1 is a natural number, n 1 is a refractive index of SnO 2 , and λ 1 is a wavelength within the predetermined wavelength range) And
    The second layer consists of TiO 2, a thickness of (2k 2 -1) λ 1 / 2n 2 (k 2 is a natural number, n 2 is the refractive index of TiO 2),
    The third layer is made of SiO 2 and has a thickness of (2k 3 -1) λ 1 / 4n 3 (k 3 is a natural number and n 3 is a refractive index of SiO 2 ). The board | substrate for thin film solar cells of description.
  21. 　所定の波長域の光のエネルギーを電力に変換する薄膜太陽電池を製造する方法において、
    　a) ガラス製の基板の上に、スパッタリング法により100℃～240℃の温度条件で、SiO2から成る低屈折率層を作製する工程と、
    　b) 前記低屈折率層の上に、スパッタリング法により100℃～240℃の温度条件で、TiO2から成る高屈折率層を作製する工程と、
    　c) 前記高屈折率層の上に、スパッタリング法により100℃～240℃の温度条件で、SnO2から成る透明電極を作製する工程と、
    　を有することを特徴とする薄膜太陽電池製造方法。     In a method of manufacturing a thin-film solar cell that converts light energy in a predetermined wavelength range into electric power,
    a) producing a low refractive index layer made of SiO 2 on a glass substrate under a temperature condition of 100 ° C. to 240 ° C. by a sputtering method;
    b) forming a high refractive index layer made of TiO 2 on the low refractive index layer by a sputtering method under a temperature condition of 100 ° C. to 240 ° C .;
    c) producing a transparent electrode made of SnO 2 on the high refractive index layer by a sputtering method under a temperature condition of 100 ° C. to 240 ° C .;
    A method for producing a thin film solar cell, comprising:
PCT/JP2009/004067 2008-08-25 2009-08-24 Thin-film solar cell and manufacturing method therefore and substrate for thin-film solar cell WO2010023867A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013175690A (en) * 2012-02-27 2013-09-05 Yamagata Univ Method of assisting manufacturing multilayer substrate, method of manufacturing multilayer substrate, method of identifying failure cause, manufacture assisting program for multilayer substrate, and multilayer substrate
EP2530722A3 (en) * 2011-05-31 2014-12-17 First Solar Malaysia SDN.BHD Refractive index matching of thin film layers for photovoltaic devices and methods of their manufacture

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61159771A (en) * 1985-01-07 1986-07-19 Sanyo Electric Co Ltd Photovoltaic device
JPS61218178A (en) * 1985-03-25 1986-09-27 Komatsu Ltd Amorphous silicon solar cell
JPS62209872A (en) * 1986-03-11 1987-09-16 Fuji Electric Corp Res & Dev Ltd Photoelectric conversion element
JPH05206490A (en) * 1992-01-27 1993-08-13 Sharp Corp Photoelectric conversion device
JPH06181331A (en) * 1992-12-14 1994-06-28 Kanegafuchi Chem Ind Co Ltd Amorphous semiconductor solar cell
JPH07321362A (en) * 1994-05-24 1995-12-08 Sanyo Electric Co Ltd Photovoltaic device
JP2003098348A (en) * 2001-09-21 2003-04-03 Konica Corp Polarizing plate and liquid crystal display device using the same

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61159771A (en) * 1985-01-07 1986-07-19 Sanyo Electric Co Ltd Photovoltaic device
JPS61218178A (en) * 1985-03-25 1986-09-27 Komatsu Ltd Amorphous silicon solar cell
JPS62209872A (en) * 1986-03-11 1987-09-16 Fuji Electric Corp Res & Dev Ltd Photoelectric conversion element
JPH05206490A (en) * 1992-01-27 1993-08-13 Sharp Corp Photoelectric conversion device
JPH06181331A (en) * 1992-12-14 1994-06-28 Kanegafuchi Chem Ind Co Ltd Amorphous semiconductor solar cell
JPH07321362A (en) * 1994-05-24 1995-12-08 Sanyo Electric Co Ltd Photovoltaic device
JP2003098348A (en) * 2001-09-21 2003-04-03 Konica Corp Polarizing plate and liquid crystal display device using the same

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
JUNPEI TSUJIUCHI ET AL., SAISHIN KOGAKU GIJUTSU HANDBOOK, 20 September 2002 (2002-09-20), pages 525 - 527 *
TAKASHI HAYAKAWA ET AL.: "Silicon Kessho Usumaku Taiyo Denchi", SHARP TECHNICAL JOURNAL, no. 15, 83, August 2002 (2002-08-01), pages 45 - 48 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2530722A3 (en) * 2011-05-31 2014-12-17 First Solar Malaysia SDN.BHD Refractive index matching of thin film layers for photovoltaic devices and methods of their manufacture
JP2013175690A (en) * 2012-02-27 2013-09-05 Yamagata Univ Method of assisting manufacturing multilayer substrate, method of manufacturing multilayer substrate, method of identifying failure cause, manufacture assisting program for multilayer substrate, and multilayer substrate

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