WO2014002796A1 - Photoelectric conversion apparatus and method for manufacturing photoelectric conversion apparatus - Google Patents

Photoelectric conversion apparatus and method for manufacturing photoelectric conversion apparatus Download PDF

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Publication number
WO2014002796A1
WO2014002796A1 PCT/JP2013/066473 JP2013066473W WO2014002796A1 WO 2014002796 A1 WO2014002796 A1 WO 2014002796A1 JP 2013066473 W JP2013066473 W JP 2013066473W WO 2014002796 A1 WO2014002796 A1 WO 2014002796A1
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photoelectric conversion
semiconductor layer
electrode layer
film
conversion device
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PCT/JP2013/066473
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French (fr)
Japanese (ja)
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憲 西浦
塁 鎌田
英章 浅尾
計匡 梅里
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京セラ株式会社
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Priority to JP2014522543A priority Critical patent/JP5791802B2/en
Publication of WO2014002796A1 publication Critical patent/WO2014002796A1/en

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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
    • H01L31/03923—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 AIBIIICVI compound materials, e.g. CIS, CIGS
    • 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
    • H01L31/0256—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 the material
    • H01L31/0264—Inorganic materials
    • H01L31/032—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312
    • H01L31/0322—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312 comprising only AIBIIICVI chalcopyrite compounds, e.g. Cu In Se2, Cu Ga Se2, Cu In Ga Se2
    • 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
    • H01L31/042—PV modules or arrays of single PV cells
    • H01L31/0445—PV modules or arrays of single PV cells including thin film solar cells, e.g. single thin film a-Si, CIS or CdTe solar cells
    • H01L31/046—PV modules composed of a plurality of thin film solar cells deposited on the same substrate
    • 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 at least one potential-jump barrier or surface barrier
    • H01L31/072—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 at least one potential-jump barrier or surface barrier the potential barriers being only of the PN heterojunction type
    • H01L31/0749—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 at least one potential-jump barrier or surface barrier the potential barriers being only of the PN heterojunction type including a AIBIIICVI compound, e.g. CdS/CulnSe2 [CIS] heterojunction solar 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
    • Y02E10/541—CuInSe2 material 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a photoelectric conversion device using a semiconductor layer containing a group I-III-VI compound and a method for manufacturing the photoelectric conversion device.
  • a photoelectric conversion device used for solar power generation or the like there is a device using a semiconductor layer containing an I-III-VI group compound such as CIS or CIGS as a light absorption layer.
  • a photoelectric conversion device is described in, for example, Japanese Patent Application Laid-Open No. 2000-299486.
  • Such a photoelectric conversion device using a semiconductor layer containing an I-III-VI group compound has a configuration in which a plurality of photoelectric conversion cells are arranged side by side in a plane.
  • Each photoelectric conversion cell has a substrate such as glass, a lower electrode such as a metal electrode, a photoelectric conversion layer including a light absorption layer and a buffer layer, and an upper electrode such as a transparent electrode and a metal electrode in this order. It is constructed by stacking.
  • the plurality of photoelectric conversion cells are electrically connected in series by electrically connecting the upper electrode of one adjacent photoelectric conversion cell and the lower electrode of the other photoelectric conversion cell by a connecting conductor. Yes.
  • Such a semiconductor layer containing the I-III-VI group compound is formed by forming a film containing the raw material of the I-III-VI group compound on the lower electrode and heat-treating the film.
  • a salt or a complex of an element constituting the I-III-VI group compound is used as a raw material for the I-III-VI group compound.
  • a single source precursor single source source precursor in which Cu, Se and In or Ga are present in one organic compound is a compound of the I-III-VI group. It is described that it is used as a raw material.
  • This photoelectric conversion efficiency indicates the rate at which sunlight energy is converted into electric energy in the photoelectric conversion device.
  • the value of the electric energy output from the photoelectric conversion device is the amount of sunlight incident on the photoelectric conversion device. Divided by the value of energy and derived by multiplying by 100.
  • This invention aims at the improvement of the photoelectric conversion efficiency in a photoelectric conversion apparatus.
  • a photoelectric conversion device includes a semiconductor layer including a group 11 element, an indium element, a gallium element, a sulfur element, and a selenium element on an electrode layer, and the semiconductor layer includes the electrode.
  • the relative atomic number ratio of gallium element and the relative atomic number ratio of sulfur element to the total number of atoms of indium element and gallium element increase as the distance from the electrode layer increases.
  • a film containing a group 11 element and an indium element and containing a gallium element at least on the surface portion opposite to the electrode layer is formed on an electrode layer. And heating the film in an atmosphere containing sulfur element, and then heating the film in an atmosphere containing selenium element to form the film on the surface portion opposite to the electrode layer with indium element and gallium element. And a step of forming a semiconductor layer in which a relative atomic number ratio of gallium element and a relative atomic number ratio of sulfur element increase with increasing distance from the electrode layer.
  • Any embodiment of the present invention can provide a photoelectric conversion device with high photoelectric conversion efficiency.
  • FIG. 1 It is a perspective view which shows an example of embodiment of the photoelectric conversion apparatus produced using the manufacturing method of the photoelectric conversion apparatus which concerns on one Embodiment of this invention.
  • FIG. 1 It is sectional drawing of the photoelectric conversion apparatus of FIG. It is a graph which shows the composition distribution of the thickness direction of a 1st semiconductor layer.
  • FIG. 1 is a perspective view showing an example of a photoelectric conversion device 11 according to an embodiment of the present invention.
  • FIG. 2 is an XZ sectional view of the photoelectric conversion device 11 of FIG. 1 to 9 are provided with a right-handed XYZ coordinate system in which the arrangement direction of photoelectric conversion cells 10 (the horizontal direction in the drawing in FIG. 1) is the X-axis direction.
  • the photoelectric conversion device 11 has a configuration in which a plurality of photoelectric conversion cells 10 are arranged in parallel on a substrate 1.
  • a plurality of photoelectric conversion cells 10 are arranged in parallel on a substrate 1.
  • FIG. 1 only two photoelectric conversion cells 10 are shown for convenience of illustration, but an actual photoelectric conversion device 11 includes a large number of photoelectric conversion cells in the X-axis direction of the drawing or further in the Y-axis direction of the drawing.
  • the conversion cells 10 are arranged two-dimensionally (two-dimensionally).
  • Each photoelectric conversion cell 10 mainly includes a lower electrode layer 2, a first semiconductor layer 3, a second semiconductor layer 4, an upper electrode layer 5, and a collecting electrode 7.
  • the main surface on the side where the upper electrode layer 5 and the collecting electrode 7 are provided is a light receiving surface. Further, the photoelectric conversion device 11 is provided with three types of groove portions such as first to third groove portions P1, P2, and P3.
  • the substrate 1 supports the plurality of photoelectric conversion cells 10 and is made of, for example, a material such as glass, ceramics, resin, or metal.
  • a blue plate glass sina lime glass having a thickness of about 1 to 3 mm may be used as the substrate 1.
  • the lower electrode layer 2 is a conductive layer provided on one main surface of the substrate 1.
  • Mo molybdenum
  • Al aluminum
  • Ti titanium
  • Ta tantalum
  • Au gold
  • the lower electrode layer 2 has a thickness of about 0.2 to 1 ⁇ m and is formed by a known thin film forming method such as sputtering or vapor deposition.
  • the first semiconductor layer 3 as the light absorption layer is provided on a main surface (also referred to as one main surface) on the + Z side of the lower electrode layer 2 and has a first conductivity type (here, p-type conductivity type). And a thickness of about 1 to 3 ⁇ m.
  • the first semiconductor layer 3 is a semiconductor layer containing an I-III-VI group compound.
  • Group I-III-VI compounds are Group 11 elements (also referred to as Group IB elements in the former IUPAC system), Group 13 elements (also referred to as Group III-B elements), and Group 16 elements (Group VI-B). (Also referred to as an element).
  • the first semiconductor layer 3 has at least a surface portion 3a opposite to the lower electrode layer 2 (hereinafter referred to as a surface portion 3a opposite to the lower electrode layer 2 of the first semiconductor layer 3).
  • the surface portion 3a of the first semiconductor layer 3 includes at least an indium element (hereinafter also referred to as an In element) and a gallium element (hereinafter also referred to as a Ga element) as group 13 elements, and at least as a group 16 element. It contains selenium element (hereinafter also referred to as Se element) and sulfur element (hereinafter also referred to as S element).
  • Examples of the I-III-VI group compound contained in the surface portion 3a include Cu (In, Ga) (Se, S) 2 (also referred to as diselen / copper indium / gallium / CIGSS).
  • the first semiconductor layer 3 has a portion 3b other than the surface portion 3a (hereinafter, the portion 3b other than the surface portion 3a of the first semiconductor layer 3 is also referred to as a remaining portion 3b of the first semiconductor layer 3).
  • the S element may or may not be contained.
  • the remaining portion 3b of the first semiconductor layer 3 contains at least an In element and a Ga element as group 13 elements and at least an Se element as group 16 elements.
  • Examples of the I-III-VI group compound contained in the remaining part 3b include Cu (In, Ga) Se 2 (also referred to as copper indium selenide / gallium, CIGS), CIGSS, and the like. That is, the first semiconductor layer 3 may be a layer containing CIGSS as a whole, or the surface portion 3a may contain CIGSS and the remaining portion 3b may contain CIGS.
  • the first semiconductor layer 3 has, on the surface portion 3a, the relative atomic number ratio Ga / (In + Ga) of the Ga element to the total atomic number of the In element and the Ga element and the relative atomic number ratio S / (In + Ga) of the S element. ) Increases as the distance from the lower electrode layer 2 increases.
  • the conduction band is shifted to the high energy side and the valence band is shifted to the low energy side in the surface portion 3a of the first semiconductor layer 3 that forms a pn junction with the second semiconductor layer 4. Since the band gap can be increased, the pn junction can be improved to suppress interface recombination, and the open circuit voltage can be increased.
  • the composition distribution in the thickness direction of the first semiconductor layer 3 is expressed, for example, as shown in FIG.
  • the composition distribution in the thickness direction of the first semiconductor layer 3 can be measured by various elemental analysis methods. For example, for the Ga element and the S element, elemental analysis is performed by X-ray electron spectroscopy (XPS) while the first semiconductor layer 3 is shaved in the thickness direction by sputtering or the like, or a cross section of the first semiconductor layer 3 is obtained. Can be measured by elemental analysis by energy dispersive X-ray analysis (EDS) using a transmission electron microscope (TEM). Further, the oxygen element can be measured by elemental analysis by secondary ion mass spectrometry (SIMS) while cutting the first semiconductor layer 3 in the thickness direction by sputtering or the like.
  • XPS X-ray electron spectroscopy
  • EDS energy dispersive X-ray analysis
  • TEM transmission electron microscope
  • SIMS secondary ion mass spectrometry
  • the thickness of the surface portion 3a of the first semiconductor layer 3 in which the relative atomic number ratio of Ga element and the relative atomic number ratio of S element increases as the distance from the lower electrode layer 2 increases. It is sufficient that the thickness is about 0.15 to 0.5 times the total thickness.
  • the relative atomic number ratio of Ga element to the total number of In elements and Ga element in the surface portion 3a of the first semiconductor layer 3 is a portion on the second semiconductor layer 4 side in the surface portion 3a (first semiconductor layer 3a). In the vicinity of the interface between the semiconductor layer 3 and the second semiconductor layer 4, it is 0.1 to 0.5, and the portion on the lower electrode layer 2 side in the surface portion 3 a (in the case of FIG. In a portion where the number ratio is minimal, it may be 0.05 to 0.4.
  • the relative atomic number ratio of the S element to the total number of In elements and Ga elements in the surface portion 3a of the first semiconductor layer 3 is a portion on the second semiconductor layer 4 side in the surface portion 3a (first semiconductor layer 3a). It is 0.05 to 1 in the vicinity of the interface between the semiconductor layer 3 and the second semiconductor layer 4, and the portion on the lower electrode layer 2 side in the surface portion 3 a (in the case of FIG. 3, the relative atomic number ratio of Ga element) In the region where the minimum is 0), it may be 0 to 0.05.
  • the relative atomic number ratio of Ga element to the total atomic number of In element and Ga element may increase as it approaches the lower electrode layer 2. With such a configuration, charge transfer can be made better, and the photoelectric conversion efficiency of the photoelectric conversion device 11 becomes higher.
  • Such a composition distribution of the remaining portion 3b is expressed as shown in FIG. 3, for example.
  • the relative atomic number ratio of the Ga element to the total number of In elements and Ga elements in the remaining part 3b of the first semiconductor layer 3 is a part on the second semiconductor layer 4 side in the remaining part 3b (in the case of FIG. 3). Is 0.05 to 0.4 at the portion where the relative atomic number ratio of Ga element is minimized, and the portion on the lower electrode layer 2 side (the first semiconductor layer 3 and the lower electrode layer 2) in the remaining portion 3b. In the vicinity of the interface, it may be 0.1 to 0.7.
  • the first semiconductor layer 3 may further contain an oxygen element at least in the surface portion 3a.
  • the oxygen element enters lattice defects in the first semiconductor layer 3, and charge recombination can be reduced.
  • the number of oxygen atoms contained per unit volume in the surface portion 3a may be about 10 18 to 10 22 atms / cm 3 .
  • the content of the oxygen element may increase as the distance from the lower electrode layer 2 increases as in the case of the Ga element and the S element. That is, as the Ga element and S element increase, the oxygen element also increases.
  • the content (number of atoms) at each site in the thickness direction of the oxygen element may be, for example, about 5 to 30% of the S element at each site.
  • the second semiconductor layer 4 is a semiconductor layer provided on one main surface of the first semiconductor layer 3.
  • the second semiconductor layer 4 has a conductivity type (here, n-type conductivity type) different from that of the first semiconductor layer 3.
  • a conductivity type here, n-type conductivity type
  • positive and negative carriers generated by photoelectric conversion in the first semiconductor layer 3 are well separated.
  • semiconductors having different conductivity types are semiconductors having different main conductive carriers.
  • the conductivity type of the second semiconductor layer 4 may be i-type instead of n-type.
  • the second semiconductor layer 4 includes, for example, cadmium sulfide (CdS), indium sulfide (In 2 S 3 ), zinc sulfide (ZnS), zinc oxide (ZnO), indium selenide (In 2 Se 3 ), In (OH , S), (Zn, In) (Se, OH), and (Zn, Mg) O. From the viewpoint of reducing current loss, the second semiconductor layer 4 can have a resistivity of 1 ⁇ ⁇ cm or more.
  • the second semiconductor layer 4 is formed by, for example, a chemical bath deposition (CBD) method or the like.
  • the second semiconductor layer 4 has a thickness in the normal direction of one main surface of the first semiconductor layer 3. This thickness is set to, for example, 10 to 200 nm.
  • the upper electrode layer 5 is a transparent conductive film provided on the second semiconductor layer 4 and is an electrode for extracting charges generated in the first semiconductor layer 3.
  • the upper electrode layer 5 is made of a material having a lower resistivity than the second semiconductor layer 4.
  • the upper electrode layer 5 includes what is called a window layer, and when a transparent conductive film is further provided in addition to the window layer, these may be regarded as an integrated upper electrode layer 5.
  • the upper electrode layer 5 mainly includes a material having a wide forbidden band, transparent, and low resistance.
  • a metal oxide semiconductor such as ZnO, In 2 O 3 and SnO 2 can be adopted.
  • These metal oxide semiconductors may contain any element of Al, B, Ga, In, F, and the like.
  • Specific examples of the metal oxide semiconductor containing such an element include, for example, AZO (Aluminum Zinc Oxide), GZO (Gallium Zinc Oxide), IZO (Indium Zinc Oxide), ITO (Indium Tin Oxide), FTO ( Fluorine tin Oxide).
  • the upper electrode layer 5 is formed to have a thickness of 0.05 to 3 ⁇ m by sputtering, vapor deposition, chemical vapor deposition (CVD), or the like.
  • the upper electrode layer 5 has a resistivity of less than 1 ⁇ ⁇ cm and a sheet resistance of 50 ⁇ / ⁇ or less. Can do.
  • the second semiconductor layer 4 and the upper electrode layer 5 may be made of a material having a property (also referred to as light transmission property) that allows light to easily pass through the wavelength region of light absorbed by the first semiconductor layer 3. Thereby, a decrease in light absorption efficiency in the first semiconductor layer 3 caused by providing the second semiconductor layer 4 and the upper electrode layer 5 is reduced.
  • a property also referred to as light transmission property
  • the upper electrode layer 5 can have a thickness of 0.05 to 0.5 ⁇ m. Further, from the viewpoint of reducing light reflection loss at the interface between the upper electrode layer 5 and the second semiconductor layer 4, the absolute refractive index between the upper electrode layer 5 and the second semiconductor layer 4 is substantially equal. It can be made the same.
  • the current collecting electrodes 7 are spaced apart in the Y-axis direction, and each extend in the X-axis direction.
  • the collector electrode 7 is an electrode having conductivity, and is made of a metal such as silver (Ag), for example.
  • the collecting electrode 7 plays a role of collecting charges generated in the first semiconductor layer 3 and taken out in the upper electrode layer 5. If the current collecting electrode 7 is provided, the upper electrode layer 5 can be thinned.
  • connection conductor 6 is constituted by a portion extending in the Y-axis direction of the current collecting electrode 7 as shown in FIG.
  • connection conductor 6 is not limited to this, You may be comprised by the extension part of the upper electrode layer 5.
  • the current collecting electrode 5 has a width of 50 to 400 ⁇ m so that good conductivity is ensured and a decrease in the light receiving area that affects the amount of light incident on the first semiconductor layer 3 is minimized. Can be.
  • FIGS. 4 to 9 are cross-sectional views each schematically showing a state during the manufacture of the photoelectric conversion device 11.
  • Each of the cross-sectional views shown in FIGS. 4 to 9 shows a state in the middle of manufacturing a portion corresponding to the cross-section shown in FIG.
  • a lower electrode layer 2 made of Mo or the like is formed on substantially the entire surface of the cleaned substrate 1 using a sputtering method or the like. Then, the first groove portion P1 is formed from the linear formation target position along the Y direction on the upper surface of the lower electrode layer 2 to the upper surface of the substrate 1 immediately below the formation position.
  • the first groove portion P1 can be formed, for example, by laser scribing, in which groove processing is performed by irradiating the formation target position while scanning with laser light from a YAG laser or the like.
  • FIG. 5 is a diagram illustrating a state after the first groove portion P1 is formed.
  • the surface region containing the group 11 element and the In element on the lower electrode layer 2 and at least opposite to the lower electrode layer 2 (hereinafter, opposite to the lower electrode layer 2 of the film)
  • the surface region on the side is also simply referred to as the surface region of the film) to prepare a film containing Ga element.
  • the film is heated and sulfurized in an atmosphere containing S element, and then heated in an atmosphere containing Se element to selenize the film.
  • This makes it possible to easily control the content ratios of Ga element and S element in the surface portion 3a of the first semiconductor layer 3, and in the surface portion 3a on the side opposite to the lower electrode layer 2, the In element and Ga element.
  • the first semiconductor layer 3 in which the relative atomic number ratio of Ga element and the relative atomic number ratio of S element with respect to the total number of atoms with the element increases as the distance from the lower electrode layer 2 increases easily and stably. can do.
  • Ga element when a film containing Ga element is formed at least on the surface as described above, and this film is sulfurized and then selenized, first, in sulfide, Ga element produces sulfide crystals rather than In element. It tends to be easy. For this reason, the Ga element and the S element react and crystallize at the surface portion of the film where the reaction with the S element in the atmosphere is likely to occur, and the less reactive In element moves to the lower electrode layer 2 side. Then, by selenizing the film, the first semiconductor layer 3 having a configuration in which the relative atomic number ratio of the Ga element and the S element becomes higher as the distance from the lower electrode layer 2 in the surface portion 3a is easily manufactured. Is possible.
  • each element of group 11 element, In element, and Ga element in the film may be uniformly mixed in the film, but a state in which a plurality of elements exist in separate layers (specific elements are It may be present only in a part of the thickness direction of the film. This is because, in the case of a film having a thickness of several ⁇ m to several tens of ⁇ m, even when a plurality of elements are present in separate layers, each element diffuses when the film is heat-treated, This is because each element can react with each other.
  • the coating can be produced using a raw material containing any one or more of group 11 elements, In elements and Ga elements.
  • the film can be formed by applying a raw material solution containing the above raw materials, or by sputtering, vapor deposition, or the like.
  • the film may be a laminate composed of a plurality of layers.
  • Each element of group 11 element, In element, and Ga element may be present in the film in any state of a compound, an alloy, and a simple substance. From the viewpoint that the reactivity with the S element in the atmosphere is increased and the relative atomic number ratio of the Ga element in the surface portion of the first semiconductor layer 3 to be generated can be more easily increased, each of the above elements has an organic coordination. It may be present in the film in the state of an organic complex coordinated by a child. In particular, from the viewpoint of increasing the reactivity and improving the crystallinity, as the organic complex, an organic chalcogen compound is coordinated as an organic ligand to at least one of group 11 element, In element and Ga element. A thing may be used.
  • An organic chalcogen compound is an organic compound containing a chalcogen element, and is an organic compound having a covalent bond between a carbon element and a chalcogen element.
  • chalcogen element Se element or S element can be used.
  • organic chalcogen compound for example, thiol, sulfide, disulfide, selenol, selenide, diselenide and the like can be used.
  • an organic complex in which an organic chalcogen compound is coordinated include an organic complex in which an organic chalcogen compound is coordinated with a group 11 element such as a Cu element or an Ag element, an organic complex in which an organic chalcogen compound is coordinated with an In element, Ga
  • An organic complex in which an organic chalcogen compound is coordinated to an element, or an organic chalcogen compound is coordinated to both a group 11 element and a group 13 element and has a group 11 element, a group 13 element, and a chalcogen element in one molecule A single source organic complex (see Patent Document 2) or the like can be used.
  • the organic complex containing any of the group 11 element, In element and Ga element as described above is dissolved in an organic solvent such as pyridine or aniline to obtain a raw material solution. Then, this raw material solution is deposited in the form of a film on the first electrode layer 2 by, for example, a spin coater, screen printing, dipping, spraying, a die coater, etc., and the solvent is removed by drying to form a film. Can do.
  • membrane is good also as a laminated body of two or more layers by repeating the said film formation process.
  • the produced film is then sulfided by heating at 300 to 650 ° C. for 10 to 120 minutes in an atmosphere containing S element as sulfur vapor or hydrogen sulfide. Thereafter, this film is selenized by heating at 400 to 650 ° C. for 10 to 120 minutes in an atmosphere containing Se element as selenium vapor or hydrogen selenide.
  • sulfidation stage in such a heating process sulfidation of Ga element in the film is particularly facilitated by S element in the atmosphere, and the ratio of Ga element and S element in the surface portion increases.
  • the subsequent selenization step selenization proceeds inside and below the film where the sulfidation of the film is not completed, and the Ga element easily moves to the lower electrode layer 2 side.
  • the Ga element reacted at the time of sulfidation of the surface portion hardly moves during selenization.
  • the first semiconductor layer in which the relative atomic number ratio of the Ga element and the relative atomic number ratio of the S element with respect to the total number of atoms of the In element and the Ga element increase as the distance from the lower electrode layer 2 increases. 3 can be obtained.
  • the film is sulfidized, if the film is heated to a temperature of 400 ° C. or higher, which is the crystallization temperature of the first semiconductor layer 3, the film is sulfidized satisfactorily. The concentration distribution of elements can be maintained better.
  • the concentration distribution of S element and the concentration distribution of Ga element in the first semiconductor layer 3 can be easily changed. For example, as the heating temperature at the time of sulfiding is increased or the heating time is increased, the thickness of the surface portion 3a in the first semiconductor layer 3 increases or the surface portion 3a of the first semiconductor layer 3 increases. There is a tendency that the change rate of the relative atomic number ratio of the Ga element or the S element increases (that is, the slope of the distribution of the Ga element or the slope of the distribution of the S element increases in the surface portion of the graph of FIG. 3).
  • the rate of change of the relative atomic number ratio of Ga element in the remaining portion 3b of the first semiconductor layer increases (that is, in FIG. There is a tendency for the slope of the Ga element distribution in the remainder of the graph to increase.
  • multiple heating steps may be performed.
  • sulfiding may be performed at 500 to 600 ° C. after sulfiding at 300 to 450 ° C.
  • selenization may be performed at 500 to 600 ° C. after performing selenization at 350 to 450 ° C.
  • selenization may be performed at 450 to 550 ° C. after performing selenization at 500 to 600 ° C.
  • oxygen may be included in the atmosphere, for example, 1 to 100 ppmv at a partial pressure ratio.
  • the oxygen element can be included in the surface portion so as to increase as the distance from the lower electrode layer 2 is increased, similarly to the Ga element and the S element.
  • efficiency reduction due to carrier recombination can be reduced. Can be suppressed.
  • the film is heated in an atmosphere containing no chalcogen element, for example, at 50 to 350 ° C. to thermally decompose organic components in the film. It may be left. Thereby, it can reduce that an organic component remains in the 1st semiconductor layer 3, and can improve the photoelectric conversion efficiency of the 1st semiconductor layer 3 more.
  • an oxidizing gas such as water vapor or oxygen may be contained in the atmosphere at a partial pressure ratio of about 50 to 300 ppmv. Thereby, an oxygen element can be contained in the first semiconductor layer 3. As a result, the recombination of charges can be reduced by the oxygen element entering the lattice defects of the first semiconductor layer 3.
  • Se element may be included in the above film.
  • Se element may be included in the above film.
  • the degree of sulfidation can be easily controlled, and the concentration distribution of S element on the surface portion can be easily made desired.
  • an organic selenium compound may be used as the organic chalcogen compound as described above.
  • the film may be selenized to such an extent that the film is not completely selenized by heating in the Se atmosphere before heating the film in the S element atmosphere.
  • the second semiconductor layer 4 can be formed by a solution growth method (also referred to as a CBD method). For example, cadmium acetate and thiourea are dissolved in ammonia water, and the substrate 1 that has been formed up to the formation of the first semiconductor layer 3 is immersed in the second semiconductor layer 3 so as to contain the second CdS on the first semiconductor layer 3.
  • the semiconductor layer 4 can be formed.
  • the upper electrode layer 5 is a transparent conductive film containing, for example, indium oxide (ITO) containing Sn as a main component, and can be formed by a sputtering method, a vapor deposition method, a CVD method, or the like.
  • FIG. 7 is a view showing a state after the second semiconductor layer 4 and the upper electrode layer 5 are formed.
  • ITO indium oxide
  • the second groove portion P ⁇ b> 2 is formed from the linear formation target position along the Y direction on the upper surface of the upper electrode layer 5 to the upper surface of the lower electrode layer 2 immediately below it.
  • the second groove portion P2 can be formed by, for example, mechanical scribing using a scribe needle.
  • FIG. 8 is a diagram illustrating a state after the second groove portion P2 is formed.
  • the second groove portion P2 is formed at a position slightly deviated in the X direction (+ X direction in the drawing) from the first groove portion P1.
  • the collecting electrode 7 and the connecting conductor 6 are formed.
  • a conductive paste also referred to as a conductive paste
  • a metal powder such as Ag is dispersed in a resin binder is printed in a desired pattern and heated.
  • FIG. 9 is a view showing a state after the current collecting electrode 7 and the connection conductor 6 are formed.
  • the third groove portion P ⁇ b> 3 is formed from the linear formation target position on the upper surface of the upper electrode layer 5 to the upper surface of the lower electrode layer 2 immediately below it.
  • the width of the third groove portion P3 can be set to about 40 to 1000 ⁇ m, for example.
  • the 3rd groove part P3 can be formed by a mechanical scribing process similarly to the 2nd groove part P2. In this way, the photoelectric conversion device 11 shown in FIGS. 1 and 2 is manufactured by forming the third groove portion P3.
  • Substrate 2 Lower electrode layer 3: First semiconductor layer 3a: Surface portion 3b: Remaining portion 4: Second semiconductor layer 5: Upper electrode layer 6: Connection conductor 7: Current collecting electrode 10: Photoelectric conversion cell 11: Photoelectric conversion device

Abstract

The purpose of the present invention is to improve photoelectric conversion efficiency of a photoelectric conversion apparatus. A photoelectric conversion apparatus (11) is provided with a semiconductor layer (3) on an electrode layer (2), said semiconductor layer containing a group 11 element, indium element, gallium element, sulfur element, and selenium element. In the surface portion (3a) of the semiconductor layer (3), said surface portion being on the reverse side of the electrode layer (2), the relative number of atoms of the gallium element, and the relative number of atoms of the sulfur element with respect to the total number of atoms of the indium element and the gallium element increase toward the side away from the electrode layer (2).

Description

光電変換装置および光電変換装置の製造方法Photoelectric conversion device and method for manufacturing photoelectric conversion device
　本発明は、Ｉ－III－VI族化合物を含む半導体層を用いた光電変換装置およびその製造方法に関するものである。 The present invention relates to a photoelectric conversion device using a semiconductor layer containing a group I-III-VI compound and a method for manufacturing the photoelectric conversion device.
　太陽光発電等に使用される光電変換装置として、ＣＩＳやＣＩＧＳ等のＩ－III－VI族化合物を含む半導体層を光吸収層に用いたものがある。このような光電変換装置は、例えば、特開２０００－２９９４８６号公報に記載されている。 As a photoelectric conversion device used for solar power generation or the like, there is a device using a semiconductor layer containing an I-III-VI group compound such as CIS or CIGS as a light absorption layer. Such a photoelectric conversion device is described in, for example, Japanese Patent Application Laid-Open No. 2000-299486.
　このようなＩ－III－VI族化合物を含む半導体層を用いた光電変換装置は、複数の光電変換セルが平面的に並設された構成を有する。各光電変換セルは、ガラス等の基板の上に、金属電極等の下部電極と、光吸収層やバッファ層等からなる光電変換層と、透明電極や金属電極等の上部電極とが、この順に積層されて構成される。また、複数の光電変換セルは、隣り合う一方の光電変換セルの上部電極と他方の光電変換セルの下部電極とが接続導体によって電気的に接続されることで、電気的に直列に接続されている。 Such a photoelectric conversion device using a semiconductor layer containing an I-III-VI group compound has a configuration in which a plurality of photoelectric conversion cells are arranged side by side in a plane. Each photoelectric conversion cell has a substrate such as glass, a lower electrode such as a metal electrode, a photoelectric conversion layer including a light absorption layer and a buffer layer, and an upper electrode such as a transparent electrode and a metal electrode in this order. It is constructed by stacking. In addition, the plurality of photoelectric conversion cells are electrically connected in series by electrically connecting the upper electrode of one adjacent photoelectric conversion cell and the lower electrode of the other photoelectric conversion cell by a connecting conductor. Yes.
　このようなＩ－III－VI族化合物を含む半導体層は、下部電極上にＩ－III－VI族化合物の原料を含む皮膜が形成され、この皮膜が熱処理されることによって形成される。 Such a semiconductor layer containing the I-III-VI group compound is formed by forming a film containing the raw material of the I-III-VI group compound on the lower electrode and heat-treating the film.
　Ｉ－III－VI族化合物の原料としては、Ｉ－III－VI族化合物を構成する元素の塩や錯体等が用いられる。例えば米国特許第６９９２２０２号明細書には、１つの有機化合物内にＣｕと、Ｓｅと、ＩｎもしくはＧａとを存在させた単一源前駆体（Single Source Precursor）がＩ－III－VI族化合物の原料として用いられることが記載されている。 As a raw material for the I-III-VI group compound, a salt or a complex of an element constituting the I-III-VI group compound is used. For example, in US Pat. No. 6,992,202, a single source precursor (single source source precursor) in which Cu, Se and In or Ga are present in one organic compound is a compound of the I-III-VI group. It is described that it is used as a raw material.
　Ｉ－III－VI族化合物を含む半導体層を用いた光電変換装置には、光電変換効率の向上が常に要求される。この光電変換効率は、光電変換装置において太陽光のエネルギーが電気エネルギーに変換される割合を示し、例えば、光電変換装置から出力される電気エネルギーの値が、光電変換装置に入射される太陽光のエネルギーの値で除されて、１００が乗じられることで導出される。 Improvement in photoelectric conversion efficiency is always required for a photoelectric conversion device using a semiconductor layer containing a group I-III-VI compound. This photoelectric conversion efficiency indicates the rate at which sunlight energy is converted into electric energy in the photoelectric conversion device. For example, the value of the electric energy output from the photoelectric conversion device is the amount of sunlight incident on the photoelectric conversion device. Divided by the value of energy and derived by multiplying by 100.
　本発明は、光電変換装置における光電変換効率の向上を目的とする。 This invention aims at the improvement of the photoelectric conversion efficiency in a photoelectric conversion apparatus.
　本発明の一実施形態に係る光電変換装置は、電極層上に、１１族元素、インジウム元素、ガリウム元素、硫黄元素およびセレン元素を含む半導体層を具備しており、該半導体層は、前記電極層とは反対側の表面部において、インジウム元素とガリウム元素との合計原子数に対するガリウム元素の相対原子数比および硫黄元素の相対原子数比が、前記電極層から離れるに従って増加している。 A photoelectric conversion device according to an embodiment of the present invention includes a semiconductor layer including a group 11 element, an indium element, a gallium element, a sulfur element, and a selenium element on an electrode layer, and the semiconductor layer includes the electrode. In the surface portion opposite to the layer, the relative atomic number ratio of gallium element and the relative atomic number ratio of sulfur element to the total number of atoms of indium element and gallium element increase as the distance from the electrode layer increases.
　本発明の他の実施形態に係る光電変換装置の製造方法は、電極層上に、１１族元素およびインジウム元素を含むとともに少なくとも前記電極層とは反対側の表面部にガリウム元素を含む皮膜を作製する工程と、該皮膜を硫黄元素を含む雰囲気で加熱した後、セレン元素を含む雰囲気で加熱することによって、前記皮膜を、前記電極層とは反対側の表面部において、インジウム元素とガリウム元素との合計原子数に対するガリウム元素の相対原子数比および硫黄元素の相対原子数比が、前記電極層から離れるに従って増加している半導体層にする工程とを具備する。 In a method for manufacturing a photoelectric conversion device according to another embodiment of the present invention, a film containing a group 11 element and an indium element and containing a gallium element at least on the surface portion opposite to the electrode layer is formed on an electrode layer. And heating the film in an atmosphere containing sulfur element, and then heating the film in an atmosphere containing selenium element to form the film on the surface portion opposite to the electrode layer with indium element and gallium element. And a step of forming a semiconductor layer in which a relative atomic number ratio of gallium element and a relative atomic number ratio of sulfur element increase with increasing distance from the electrode layer.
　本発明のいずれの実施形態によっても、光電変換効率の高い光電変換装置を提供することができる。 Any embodiment of the present invention can provide a photoelectric conversion device with high photoelectric conversion efficiency.
本発明の一実施形態に係る光電変換装置の製造方法を用いて作製した光電変換装置の実施の形態の一例を示す斜視図である。It is a perspective view which shows an example of embodiment of the photoelectric conversion apparatus produced using the manufacturing method of the photoelectric conversion apparatus which concerns on one Embodiment of this invention. 図１の光電変換装置の断面図である。It is sectional drawing of the photoelectric conversion apparatus of FIG. 第１の半導体層の厚み方向の組成分布を示すグラフである。It is a graph which shows the composition distribution of the thickness direction of a 1st semiconductor layer. 光電変換装置の製造途中の様子を模式的に示す断面図である。It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. 光電変換装置の製造途中の様子を模式的に示す断面図である。It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. 光電変換装置の製造途中の様子を模式的に示す断面図である。It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. 光電変換装置の製造途中の様子を模式的に示す断面図である。It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. 光電変換装置の製造途中の様子を模式的に示す断面図である。It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus. 光電変換装置の製造途中の様子を模式的に示す断面図である。It is sectional drawing which shows typically the mode in the middle of manufacture of a photoelectric conversion apparatus.
　以下、本発明の一実施形態に係る光電変換装置およびその製造方法について、図面を参照しながら説明する。なお、図面においては同様な構成および機能を有する部分については同一符号を付しており、下記説明では重複説明を省略する。また、図面は模式的に示したものであり、各図における各種構造のサイズおよび位置関係等は正確に図示されたものではない。 Hereinafter, a photoelectric conversion device and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, parts having similar configurations and functions are denoted by the same reference numerals, and redundant description is omitted in the following description. Further, the drawings are schematically shown, and the sizes and positional relationships of various structures in the drawings are not accurately illustrated.
　＜（１）光電変換装置の構成＞
　図１は、本発明の一実施形態に係る光電変換装置１１の一例を示す斜視図である。図２は、図１の光電変換装置１１のＸＺ断面図である。なお、図１から図９には、光電変換セル１０の配列方向（図１の図面視左右方向）をＸ軸方向とする右手系のＸＹＺ座標系を付している。 <(1) Configuration of photoelectric conversion device>
FIG. 1 is a perspective view showing an example of a photoelectric conversion device 11 according to an embodiment of the present invention. FIG. 2 is an XZ sectional view of the photoelectric conversion device 11 of FIG. 1 to 9 are provided with a right-handed XYZ coordinate system in which the arrangement direction of photoelectric conversion cells 10 (the horizontal direction in the drawing in FIG. 1) is the X-axis direction.
　光電変換装置１１は、基板１の上に複数の光電変換セル１０が並設された構成を有している。図１では、図示の都合上、２つの光電変換セル１０のみが示されているが、実際の光電変換装置１１には、図面のＸ軸方向、或いはさらに図面のＹ軸方向に、多数の光電変換セル１０が平面的に（二次元的に）配列されている。 The photoelectric conversion device 11 has a configuration in which a plurality of photoelectric conversion cells 10 are arranged in parallel on a substrate 1. In FIG. 1, only two photoelectric conversion cells 10 are shown for convenience of illustration, but an actual photoelectric conversion device 11 includes a large number of photoelectric conversion cells in the X-axis direction of the drawing or further in the Y-axis direction of the drawing. The conversion cells 10 are arranged two-dimensionally (two-dimensionally).
　各光電変換セル１０は、下部電極層２、第１の半導体層３、第２の半導体層４、上部電極層５、および集電電極７を主に備えている。光電変換装置１１では、上部電極層５および集電電極７が設けられた側の主面が受光面となっている。また、光電変換装置１１には、第１～３溝部Ｐ１，Ｐ２，Ｐ３といった３種類の溝部が設けられている。 Each photoelectric conversion cell 10 mainly includes a lower electrode layer 2, a first semiconductor layer 3, a second semiconductor layer 4, an upper electrode layer 5, and a collecting electrode 7. In the photoelectric conversion device 11, the main surface on the side where the upper electrode layer 5 and the collecting electrode 7 are provided is a light receiving surface. Further, the photoelectric conversion device 11 is provided with three types of groove portions such as first to third groove portions P1, P2, and P3.
　基板１は、複数の光電変換セル１０を支持するものであり、例えば、ガラス、セラミックス、樹脂、または金属等の材料で構成されている。例えば、基板１として、１～３ｍｍ程度の厚さを有する青板ガラス（ソーダライムガラス）が用いられてもよい。 The substrate 1 supports the plurality of photoelectric conversion cells 10 and is made of, for example, a material such as glass, ceramics, resin, or metal. For example, a blue plate glass (soda lime glass) having a thickness of about 1 to 3 mm may be used as the substrate 1.
　下部電極層２は、基板１の一主面の上に設けられた導電層であり、例えば、モリブデン（Ｍｏ）、アルミニウム（Ａｌ）、チタン（Ｔｉ）、タンタル（Ｔａ）または金（Ａｕ）等の金属、あるいはこれらの金属の積層構造体からなる。また、下部電極層２は、０．２～１μｍ程度の厚さを有し、例えば、スパッタリング法または蒸着法等の公知の薄膜形成方法によって形成される。 The lower electrode layer 2 is a conductive layer provided on one main surface of the substrate 1. For example, molybdenum (Mo), aluminum (Al), titanium (Ti), tantalum (Ta), gold (Au), etc. Or a laminated structure of these metals. The lower electrode layer 2 has a thickness of about 0.2 to 1 μm and is formed by a known thin film forming method such as sputtering or vapor deposition.
　光吸収層としての第１の半導体層３は、下部電極層２の＋Ｚ側の主面（一主面ともいう）の上に設けられた、第１の導電型（ここではｐ型の導電型）を有する半導体層であり、１～３μｍ程度の厚さを有している。第１の半導体層３はＩ－III－VI族化合物を含む半導体層である。Ｉ－III－VI族化合物とは、１１族元素（旧ＩＵＰＡＣ方式ではＩ－Ｂ族元素ともいう）と、１３族元素（III－Ｂ族元素ともいう）と、１６族元素（VI－Ｂ族元素ともいう）とを含んだ化合物である。そして、第１の半導体層３は、少なくとも下部電極層２とは反対側の表面部３ａ（以下、第１の半導体層３の下部電極層２とは反対側の表面部３ａのことを、単に第１の半導体層３の表面部３ａともいう）において、１３族元素として少なくともインジウム元素（以下、Ｉｎ元素ともいう）およびガリウム元素（以下、Ｇａ元素ともいう）を含むとともに、１６族元素として少なくともセレン元素（以下、Ｓｅ元素ともいう）および硫黄元素（以下、Ｓ元素ともいう）を含んでいる。表面部３ａに含まれるＩ－III－VI族化合物としては、例えば、Ｃｕ（Ｉｎ，Ｇａ）（Ｓｅ，Ｓ）２（二セレン・イオウ化銅インジウム・ガリウム、ＣＩＧＳＳともいう）等が挙げられる。また、第１の半導体層３は、表面部３ａ以外の部位３ｂ（以下、第１の半導体層３の表面部３ａ以外の部位３ｂのことを、第１の半導体層３の残部３ｂともいう）においては、Ｓ元素は含まれていても、含まれていなくてもよい。この第１の半導体層３の残部３ｂは、１３族元素として少なくともＩｎ元素およびＧａ元素を含むとともに、１６族元素として少なくともＳｅ元素を含んでいる。残部３ｂに含まれるＩ－III－VI族化合物としては、Ｃｕ（Ｉｎ，Ｇａ）Ｓｅ２（二セレン化銅インジウム・ガリウム、ＣＩＧＳともいう）やＣＩＧＳＳ等が挙げられる。つまり、第１の半導体層３は、全体がＣＩＧＳＳを含む層であってもよく、あるいは表面部３ａがＣＩＧＳＳを含むとともに残部３ｂがＣＩＧＳを含む層であってもよい。 The first semiconductor layer 3 as the light absorption layer is provided on a main surface (also referred to as one main surface) on the + Z side of the lower electrode layer 2 and has a first conductivity type (here, p-type conductivity type). And a thickness of about 1 to 3 μm. The first semiconductor layer 3 is a semiconductor layer containing an I-III-VI group compound. Group I-III-VI compounds are Group 11 elements (also referred to as Group IB elements in the former IUPAC system), Group 13 elements (also referred to as Group III-B elements), and Group 16 elements (Group VI-B). (Also referred to as an element). The first semiconductor layer 3 has at least a surface portion 3a opposite to the lower electrode layer 2 (hereinafter referred to as a surface portion 3a opposite to the lower electrode layer 2 of the first semiconductor layer 3). The surface portion 3a of the first semiconductor layer 3 includes at least an indium element (hereinafter also referred to as an In element) and a gallium element (hereinafter also referred to as a Ga element) as group 13 elements, and at least as a group 16 element. It contains selenium element (hereinafter also referred to as Se element) and sulfur element (hereinafter also referred to as S element). Examples of the I-III-VI group compound contained in the surface portion 3a include Cu (In, Ga) (Se, S) 2 (also referred to as diselen / copper indium / gallium / CIGSS). The first semiconductor layer 3 has a portion 3b other than the surface portion 3a (hereinafter, the portion 3b other than the surface portion 3a of the first semiconductor layer 3 is also referred to as a remaining portion 3b of the first semiconductor layer 3). In S, the S element may or may not be contained. The remaining portion 3b of the first semiconductor layer 3 contains at least an In element and a Ga element as group 13 elements and at least an Se element as group 16 elements. Examples of the I-III-VI group compound contained in the remaining part 3b include Cu (In, Ga) Se 2 (also referred to as copper indium selenide / gallium, CIGS), CIGSS, and the like. That is, the first semiconductor layer 3 may be a layer containing CIGSS as a whole, or the surface portion 3a may contain CIGSS and the remaining portion 3b may contain CIGS.
　また、第１の半導体層３は、表面部３ａにおいて、Ｉｎ元素とＧａ元素との合計原子数に対するＧａ元素の相対原子数比Ｇａ／（Ｉｎ＋Ｇａ）およびＳ元素の相対原子数比Ｓ／（Ｉｎ＋Ｇａ）が、下部電極層２から離れるに従って増加している。このような構成により、第２の半導体層４とｐｎ接合を行なう第１の半導体層３の表面部３ａにおいて、伝導帯を高エネルギー側へシフトさせるとともに価電子帯を低エネルギー側へシフトさせてバンドギャップを大きくすることができるため、ｐｎ接合性を良好にして界面再結合を抑制することができるとともに、開放電圧を大きくすることができる。その結果、光電変換装置１１の光電変換効率を高めることができる。第１の半導体層３の厚み方向の組成分布は、例えば図３に示すように表わされる。なお、第１の半導体層３の厚み方向の組成分布は、種々の元素分析法によって測定できる。例えば、Ｇａ元素およびＳ元素については、第１の半導体層３をスパッタリング法等によって厚み方向に削りながらＸ線電子分光分析法（ＸＰＳ）で元素分析したり、あるいは第１の半導体層３の断面を、透過電子顕微鏡（ＴＥＭ）を用いたエネルギー分散型Ｘ線分析法（ＥＤＳ）で元素分析したりすることによって測定できる。また、酸素元素については、第１の半導体層３をスパッタリング法等によって厚み方向に削りながら２次イオン質量分析法（ＳＩＭＳ）で元素分析することによって測定できる。 Further, the first semiconductor layer 3 has, on the surface portion 3a, the relative atomic number ratio Ga / (In + Ga) of the Ga element to the total atomic number of the In element and the Ga element and the relative atomic number ratio S / (In + Ga) of the S element. ) Increases as the distance from the lower electrode layer 2 increases. With such a configuration, the conduction band is shifted to the high energy side and the valence band is shifted to the low energy side in the surface portion 3a of the first semiconductor layer 3 that forms a pn junction with the second semiconductor layer 4. Since the band gap can be increased, the pn junction can be improved to suppress interface recombination, and the open circuit voltage can be increased. As a result, the photoelectric conversion efficiency of the photoelectric conversion device 11 can be increased. The composition distribution in the thickness direction of the first semiconductor layer 3 is expressed, for example, as shown in FIG. The composition distribution in the thickness direction of the first semiconductor layer 3 can be measured by various elemental analysis methods. For example, for the Ga element and the S element, elemental analysis is performed by X-ray electron spectroscopy (XPS) while the first semiconductor layer 3 is shaved in the thickness direction by sputtering or the like, or a cross section of the first semiconductor layer 3 is obtained. Can be measured by elemental analysis by energy dispersive X-ray analysis (EDS) using a transmission electron microscope (TEM). Further, the oxygen element can be measured by elemental analysis by secondary ion mass spectrometry (SIMS) while cutting the first semiconductor layer 3 in the thickness direction by sputtering or the like.
　このようなＧａ元素の相対原子数比およびＳ元素の相対原子数比が下部電極層２から離れるに従って増加している第１の半導体層３の表面部３ａの厚みは、第１の半導体層３の全体の厚みの０．１５～０．５倍程度であればよい。また、第１の半導体層３の表面部３ａにおけるＩｎ元素とＧａ元素との合計原子数に対するＧａ元素の相対原子数比は、表面部３ａにおける第２の半導体層４側の部位（第１の半導体層３と第２の半導体層４との界面付近）においては０．１～０．５であり、表面部３ａにおける下部電極層２側の部位（図３の場合は、Ｇａ元素の相対原子数比が極小となる部位）においては０．０５～０．４であればよい。また、第１の半導体層３の表面部３ａにおけるＩｎ元素とＧａ元素との合計原子数に対するＳ元素の相対原子数比は、表面部３ａにおける第２の半導体層４側の部位（第１の半導体層３と第２の半導体層４との界面付近）においては０．０５～１であり、表面部３ａにおける下部電極層２側の部位（図３の場合は、Ｇａ元素の相対原子数比が極小となる部位）においては０～０．０５であればよい。 The thickness of the surface portion 3a of the first semiconductor layer 3 in which the relative atomic number ratio of Ga element and the relative atomic number ratio of S element increases as the distance from the lower electrode layer 2 increases. It is sufficient that the thickness is about 0.15 to 0.5 times the total thickness. In addition, the relative atomic number ratio of Ga element to the total number of In elements and Ga element in the surface portion 3a of the first semiconductor layer 3 is a portion on the second semiconductor layer 4 side in the surface portion 3a (first semiconductor layer 3a). In the vicinity of the interface between the semiconductor layer 3 and the second semiconductor layer 4, it is 0.1 to 0.5, and the portion on the lower electrode layer 2 side in the surface portion 3 a (in the case of FIG. In a portion where the number ratio is minimal, it may be 0.05 to 0.4. Moreover, the relative atomic number ratio of the S element to the total number of In elements and Ga elements in the surface portion 3a of the first semiconductor layer 3 is a portion on the second semiconductor layer 4 side in the surface portion 3a (first semiconductor layer 3a). It is 0.05 to 1 in the vicinity of the interface between the semiconductor layer 3 and the second semiconductor layer 4, and the portion on the lower electrode layer 2 side in the surface portion 3 a (in the case of FIG. 3, the relative atomic number ratio of Ga element) In the region where the minimum is 0), it may be 0 to 0.05.
　また、第１の半導体層３は、さらに残部３ｂにおいて、Ｉｎ元素とＧａ元素との合計原子数に対するＧａ元素の相対原子数比が、下部電極層２に近づくに従って増加していてもよい。このような構成により、電荷移動をより良好にすることができ、光電変換装置１１の光電変換効率がより高くなる。このような残部３ｂの組成分布は、例えば図３に示すように表わされる。 Further, in the first semiconductor layer 3, in the remaining part 3 b, the relative atomic number ratio of Ga element to the total atomic number of In element and Ga element may increase as it approaches the lower electrode layer 2. With such a configuration, charge transfer can be made better, and the photoelectric conversion efficiency of the photoelectric conversion device 11 becomes higher. Such a composition distribution of the remaining portion 3b is expressed as shown in FIG. 3, for example.
　このような第１の半導体層３の残部３ｂにおけるＩｎ元素とＧａ元素との合計原子数に対するＧａ元素の相対原子数比は、残部３ｂにおける第２の半導体層４側の部位（図３の場合はＧａ元素の相対原子数比が極小となる部位）においては０．０５～０．４であり、残部３ｂにおける下部電極層２側の部位（第１の半導体層３と下部電極層２との界面付近）においては０．１～０．７であればよい。 The relative atomic number ratio of the Ga element to the total number of In elements and Ga elements in the remaining part 3b of the first semiconductor layer 3 is a part on the second semiconductor layer 4 side in the remaining part 3b (in the case of FIG. 3). Is 0.05 to 0.4 at the portion where the relative atomic number ratio of Ga element is minimized, and the portion on the lower electrode layer 2 side (the first semiconductor layer 3 and the lower electrode layer 2) in the remaining portion 3b. In the vicinity of the interface, it may be 0.1 to 0.7.
　また、第１の半導体層３は、少なくとも表面部３ａにおいて酸素元素をさらに含んでいてもよい。これにより、酸素元素が第１の半導体層３の格子欠陥に入り、電荷の再結合を低減することができる。その結果、光電変換装置１１の光電変換効率がより高くなる。表面部３ａにおける単位体積当たりに含まれる酸素の原子数は、１０１８～１０２２ａｔｍｓ/ｃｍ３程度であればよい。また、表面部３ａにおいて、酸素元素の含有量は、Ｇａ元素およびＳ元素と同様に下部電極層２から離れるに従って増加していてもよい。つまり、Ｇａ元素とＳ元素の増加に伴って酸素元素も増加している。このような構成により、Ｇａ元素やＳ元素の含有率が高まるにつれて生じやすい欠陥に対し、Ｇａ元素やＳ元素の含有率に応じた最適な酸素量を供給することで、キャリア再結合に起因した効率低下を抑制できる。酸素元素の厚み方向における各部位での含有量（原子数）は、例えば各部位におけるＳ元素の５～３０％程度であってもよい。 The first semiconductor layer 3 may further contain an oxygen element at least in the surface portion 3a. As a result, the oxygen element enters lattice defects in the first semiconductor layer 3, and charge recombination can be reduced. As a result, the photoelectric conversion efficiency of the photoelectric conversion device 11 becomes higher. The number of oxygen atoms contained per unit volume in the surface portion 3a may be about 10 18 to 10 22 atms / cm 3 . Further, in the surface portion 3a, the content of the oxygen element may increase as the distance from the lower electrode layer 2 increases as in the case of the Ga element and the S element. That is, as the Ga element and S element increase, the oxygen element also increases. With such a configuration, it is caused by carrier recombination by supplying an optimal amount of oxygen corresponding to the content ratio of Ga element or S element to defects that are likely to occur as the content ratio of Ga element or S element increases. Efficiency reduction can be suppressed. The content (number of atoms) at each site in the thickness direction of the oxygen element may be, for example, about 5 to 30% of the S element at each site.
　第２の半導体層４は、第１の半導体層３の一主面の上に設けられた半導体層である。この第２の半導体層４は、第１の半導体層３の導電型とは異なる導電型（ここではｎ型の導電型）を有している。第１の半導体層３と第２の半導体層４との接合によって、第１の半導体層３で光電変換されて生じた正負のキャリアが良好に分離される。なお、導電型が異なる半導体とは、主要な伝導担体（キャリア）が異なる半導体のことである。また、上記のように第１の半導体層３の導電型がｐ型である場合には、第２の半導体層４の導電型は、ｎ型でなくｉ型であっても良い。さらに、第１の半導体層３の導電型がｎ型またはｉ型であり、第２の半導体層４の導電型がｐ型である態様も有り得る。 The second semiconductor layer 4 is a semiconductor layer provided on one main surface of the first semiconductor layer 3. The second semiconductor layer 4 has a conductivity type (here, n-type conductivity type) different from that of the first semiconductor layer 3. By joining the first semiconductor layer 3 and the second semiconductor layer 4, positive and negative carriers generated by photoelectric conversion in the first semiconductor layer 3 are well separated. Note that semiconductors having different conductivity types are semiconductors having different main conductive carriers. Further, when the conductivity type of the first semiconductor layer 3 is p-type as described above, the conductivity type of the second semiconductor layer 4 may be i-type instead of n-type. Furthermore, there may be a mode in which the conductivity type of the first semiconductor layer 3 is n-type or i-type and the conductivity type of the second semiconductor layer 4 is p-type.
　第２の半導体層４は、例えば、硫化カドミウム（ＣｄＳ）、硫化インジウム（Ｉｎ２Ｓ３）、硫化亜鉛（ＺｎＳ）、酸化亜鉛（ＺｎＯ）、セレン化インジウム（Ｉｎ２Ｓｅ３）、Ｉｎ（ＯＨ，Ｓ）、（Ｚｎ，Ｉｎ）（Ｓｅ，ＯＨ）、および（Ｚｎ，Ｍｇ）Ｏ等の化合物半導体によって構成されている。そして、電流の損失が低減される観点から言えば、第２の半導体層４は、１Ω・ｃｍ以上の抵抗率を有するものとすることができる。なお、第２の半導体層４は、例えばケミカルバスデポジション（ＣＢＤ）法等で形成される。 The second semiconductor layer 4 includes, for example, cadmium sulfide (CdS), indium sulfide (In 2 S 3 ), zinc sulfide (ZnS), zinc oxide (ZnO), indium selenide (In 2 Se 3 ), In (OH , S), (Zn, In) (Se, OH), and (Zn, Mg) O. From the viewpoint of reducing current loss, the second semiconductor layer 4 can have a resistivity of 1 Ω · cm or more. The second semiconductor layer 4 is formed by, for example, a chemical bath deposition (CBD) method or the like.
　また、第２の半導体層４は、第１の半導体層３の一主面の法線方向に厚さを有する。この厚さは、例えば１０～２００ｎｍに設定される。 Further, the second semiconductor layer 4 has a thickness in the normal direction of one main surface of the first semiconductor layer 3. This thickness is set to, for example, 10 to 200 nm.
　上部電極層５は、第２の半導体層４の上に設けられた透明導電膜であり、第１の半導体層３において生じた電荷を取り出す電極である。上部電極層５は、第２の半導体層４よりも低い抵抗率を有する物質によって構成されている。上部電極層５には、いわゆる窓層と呼ばれるものも含まれ、この窓層に加えてさらに透明導電膜が設けられる場合には、これらが一体の上部電極層５とみなされてもよい。 The upper electrode layer 5 is a transparent conductive film provided on the second semiconductor layer 4 and is an electrode for extracting charges generated in the first semiconductor layer 3. The upper electrode layer 5 is made of a material having a lower resistivity than the second semiconductor layer 4. The upper electrode layer 5 includes what is called a window layer, and when a transparent conductive film is further provided in addition to the window layer, these may be regarded as an integrated upper electrode layer 5.
　上部電極層５は、禁制帯幅が広く且つ透明で低抵抗の材料を主に含んでいる。このような材料としては、例えば、ＺｎＯ、Ｉｎ２Ｏ３およびＳｎＯ２等の金属酸化物半導体等が採用され得る。これらの金属酸化物半導体には、Ａｌ、Ｂ、Ｇａ、ＩｎおよびＦ等のうちの何れかの元素が含まれても良い。このような元素が含まれた金属酸化物半導体の具体例としては、例えば、ＡＺＯ（Aluminum Zinc Oxide）、ＧＺＯ（Gallium Zinc Oxide）、ＩＺＯ（Indium Zinc Oxide）、ＩＴＯ（Indium Tin Oxide）、ＦＴＯ（Fluorine tin Oxide）等がある。 The upper electrode layer 5 mainly includes a material having a wide forbidden band, transparent, and low resistance. As such a material, for example, a metal oxide semiconductor such as ZnO, In 2 O 3 and SnO 2 can be adopted. These metal oxide semiconductors may contain any element of Al, B, Ga, In, F, and the like. Specific examples of the metal oxide semiconductor containing such an element include, for example, AZO (Aluminum Zinc Oxide), GZO (Gallium Zinc Oxide), IZO (Indium Zinc Oxide), ITO (Indium Tin Oxide), FTO ( Fluorine tin Oxide).
　上部電極層５は、スパッタリング法、蒸着法、または化学的気相成長（ＣＶＤ）法等によって、０．０５～３μｍの厚さを有するように形成される。ここで、第１の半導体層３から電荷が良好に取り出される観点から言えば、上部電極層５は、１Ω・ｃｍ未満の抵抗率と、５０Ω／□以下のシート抵抗とを有するものとすることができる。 The upper electrode layer 5 is formed to have a thickness of 0.05 to 3 μm by sputtering, vapor deposition, chemical vapor deposition (CVD), or the like. Here, from the viewpoint of good charge extraction from the first semiconductor layer 3, the upper electrode layer 5 has a resistivity of less than 1 Ω · cm and a sheet resistance of 50Ω / □ or less. Can do.
　第２の半導体層４および上部電極層５は、第１の半導体層３が吸収する光の波長領域に対して光を透過させ易い性質（光透過性ともいう）を有する素材によって構成され得る。これにより、第２の半導体層４と上部電極層５とが設けられることで生じる、第１の半導体層３における光の吸収効率の低下が低減される。 The second semiconductor layer 4 and the upper electrode layer 5 may be made of a material having a property (also referred to as light transmission property) that allows light to easily pass through the wavelength region of light absorbed by the first semiconductor layer 3. Thereby, a decrease in light absorption efficiency in the first semiconductor layer 3 caused by providing the second semiconductor layer 4 and the upper electrode layer 5 is reduced.
　また、光透過性が高められると同時に、光反射のロスが防止される効果と光散乱効果とが高められ、さらに光電変換によって生じた電流が良好に伝送される観点から言えば、上部電極層５は、０．０５～０．５μｍの厚さとなるようにすることができる。さらに、上部電極層５と第２の半導体層４との界面で光反射のロスが低減される観点から言えば、上部電極層５と第２の半導体層４との間で絶対屈折率が略同一となるようにすることができる。 In addition, from the viewpoint of improving the light transmission, the effect of preventing the loss of light reflection and the light scattering effect, and further transmitting the current generated by the photoelectric conversion, the upper electrode layer 5 can have a thickness of 0.05 to 0.5 μm. Further, from the viewpoint of reducing light reflection loss at the interface between the upper electrode layer 5 and the second semiconductor layer 4, the absolute refractive index between the upper electrode layer 5 and the second semiconductor layer 4 is substantially equal. It can be made the same.
　集電電極７は、Ｙ軸方向に離間して設けられ、それぞれがＸ軸方向に延在している。集電電極７は、導電性を有する電極であり、例えば、銀（Ａｇ）等の金属からなる。 The current collecting electrodes 7 are spaced apart in the Y-axis direction, and each extend in the X-axis direction. The collector electrode 7 is an electrode having conductivity, and is made of a metal such as silver (Ag), for example.
　集電電極７は、第１の半導体層３において発生して上部電極層５において取り出された電荷を集電する役割を担う。集電電極７が設けられれば、上部電極層５の薄層化が可能となる。 The collecting electrode 7 plays a role of collecting charges generated in the first semiconductor layer 3 and taken out in the upper electrode layer 5. If the current collecting electrode 7 is provided, the upper electrode layer 5 can be thinned.
　集電電極７および上部電極層５によって集電された電荷は、第２溝部Ｐ２に設けられた接続導体６を通じて、隣の光電変換セル１０に伝達される。接続導体６は、例えば、図２に示すように集電電極７のＹ軸方向への延在部分によって構成されている。これにより、光電変換装置１１においては、隣り合う光電変換セル１０の一方の下部電極層２と、他方の集電電極７とが、第２溝部Ｐ２に設けられた接続導体６を介して電気的に直列に接続されている。なお、接続導体６は、これに限定されず、上部電極層５の延在部分によって構成されていてもよい。 The electric charges collected by the current collecting electrode 7 and the upper electrode layer 5 are transmitted to the adjacent photoelectric conversion cell 10 through the connection conductor 6 provided in the second groove portion P2. For example, the connection conductor 6 is constituted by a portion extending in the Y-axis direction of the current collecting electrode 7 as shown in FIG. Thereby, in the photoelectric conversion apparatus 11, one lower electrode layer 2 of the adjacent photoelectric conversion cell 10 and the other collector electrode 7 are electrically connected via the connection conductor 6 provided in the second groove portion P2. Connected in series. In addition, the connection conductor 6 is not limited to this, You may be comprised by the extension part of the upper electrode layer 5. FIG.
　集電電極５は、良好な導電性が確保されつつ、第１の半導体層３への光の入射量を左右する受光面積の低下が最小限にとどめられるように、５０～４００μｍの幅を有するものとすることができる。 The current collecting electrode 5 has a width of 50 to 400 μm so that good conductivity is ensured and a decrease in the light receiving area that affects the amount of light incident on the first semiconductor layer 3 is minimized. Can be.
　＜（２）光電変換装置の製造方法＞
　図４から図９は、光電変換装置１１の製造途中の様子をそれぞれ模式的に示す断面図である。なお、図４から図９で示される各断面図は、図２で示された断面に対応する部分の製造途中の様子を示す。 <(2) Method for Manufacturing Photoelectric Conversion Device>
4 to 9 are cross-sectional views each schematically showing a state during the manufacture of the photoelectric conversion device 11. Each of the cross-sectional views shown in FIGS. 4 to 9 shows a state in the middle of manufacturing a portion corresponding to the cross-section shown in FIG.
　まず、図４に示すように、洗浄された基板１の略全面に、スパッタリング法等を用いて、Ｍｏ等からなる下部電極層２を成膜する。そして、下部電極層２の上面のうちのＹ方向に沿った直線状の形成対象位置からその直下の基板１の上面にかけて、第１溝部Ｐ１を形成する。第１溝部Ｐ１は、例えば、ＹＡＧレーザー等によるレーザー光を走査しつつ形成対象位置に照射することで溝加工を行なう、レーザースクライブ加工によって形成することができる。図５は、第１溝部Ｐ１を形成した後の状態を示す図である。 First, as shown in FIG. 4, a lower electrode layer 2 made of Mo or the like is formed on substantially the entire surface of the cleaned substrate 1 using a sputtering method or the like. Then, the first groove portion P1 is formed from the linear formation target position along the Y direction on the upper surface of the lower electrode layer 2 to the upper surface of the substrate 1 immediately below the formation position. The first groove portion P1 can be formed, for example, by laser scribing, in which groove processing is performed by irradiating the formation target position while scanning with laser light from a YAG laser or the like. FIG. 5 is a diagram illustrating a state after the first groove portion P1 is formed.
　第１溝部Ｐ１を形成した後、下部電極層２の上に、１１族元素およびＩｎ元素を含むとともに少なくとも下部電極層２とは反対側の表面領域（以下、皮膜の下部電極層２とは反対側の表面領域のことを単に皮膜の表面領域ともいう）にＧａ元素を含む皮膜を作製する。そして、この皮膜をＳ元素を含む雰囲気で加熱して硫化した後、Ｓｅ元素を含む雰囲気で加熱して皮膜をセレン化する。これにより、第１の半導体層３の表面部３ａにおけるＧａ元素およびＳ元素の含有率を容易に制御することが可能となり、下部電極層２とは反対側の表面部３ａにおいて、Ｉｎ元素とＧａ元素との合計原子数に対するＧａ元素の相対原子数比およびＳ元素の相対原子数比が、下部電極層２から離れるに従って増加している第１の半導体層３を容易に、かつ安定して作製することができる。 After the formation of the first groove P1, the surface region containing the group 11 element and the In element on the lower electrode layer 2 and at least opposite to the lower electrode layer 2 (hereinafter, opposite to the lower electrode layer 2 of the film) The surface region on the side is also simply referred to as the surface region of the film) to prepare a film containing Ga element. The film is heated and sulfurized in an atmosphere containing S element, and then heated in an atmosphere containing Se element to selenize the film. This makes it possible to easily control the content ratios of Ga element and S element in the surface portion 3a of the first semiconductor layer 3, and in the surface portion 3a on the side opposite to the lower electrode layer 2, the In element and Ga element. The first semiconductor layer 3 in which the relative atomic number ratio of Ga element and the relative atomic number ratio of S element with respect to the total number of atoms with the element increases as the distance from the lower electrode layer 2 increases easily and stably. can do.
　これは以下の理由によると考えられる。１１族元素、Ｉｎ元素およびＧａ元素を含む皮膜をセレン化する場合は、Ｇａ元素よりもＩｎ元素の方がセレン化物の結晶を生じやすい傾向がある。そのため、雰囲気中のＳｅ元素との反応が生じやすい皮膜の表面部において、Ｉｎ元素とＳｅ元素とが反応して結晶化するとともに、反応性の低いＧａ元素は下部電極層２側に移動する傾向がある。よって、第１の半導体層３の表面部３ａにおいて、Ｉｎ元素とＧａ元素との合計原子数に対するＧａ元素の相対原子数比は、低くなり易い。その結果、開放電圧が小さくなって光電変換効率を十分に高めることが困難である。一方、上記のように少なくとも表面部にＧａ元素を含む皮膜を形成し、この皮膜を硫化した後にセレン化すると、まず、硫化においては、Ｉｎ元素よりもＧａ元素の方が硫化物の結晶を生じやすい傾向がある。そのため、雰囲気中のＳ元素との反応が生じやすい皮膜の表面部において、Ｇａ元素とＳ元素とが反応して結晶化するとともに、反応性の低いＩｎ元素は下部電極層２側に移動する。そして、この皮膜をセレン化することにより、表面部３ａにおいてＧａ元素およびＳ元素の相対原子数比が下部電極層２から離れるに従って高くなる構成を有する第１の半導体層３を容易に作製することが可能となる。 This is thought to be due to the following reasons. When a film containing a group 11 element, an In element, and a Ga element is selenized, the In element tends to form a selenide crystal more easily than the Ga element. Therefore, the In element and the Se element react and crystallize on the surface portion of the film where the reaction with the Se element in the atmosphere is likely to occur, and the less reactive Ga element tends to move to the lower electrode layer 2 side. There is. Therefore, in the surface portion 3a of the first semiconductor layer 3, the relative atomic number ratio of the Ga element with respect to the total atomic number of the In element and the Ga element tends to be low. As a result, the open-circuit voltage becomes small and it is difficult to sufficiently increase the photoelectric conversion efficiency. On the other hand, when a film containing Ga element is formed at least on the surface as described above, and this film is sulfurized and then selenized, first, in sulfide, Ga element produces sulfide crystals rather than In element. It tends to be easy. For this reason, the Ga element and the S element react and crystallize at the surface portion of the film where the reaction with the S element in the atmosphere is likely to occur, and the less reactive In element moves to the lower electrode layer 2 side. Then, by selenizing the film, the first semiconductor layer 3 having a configuration in which the relative atomic number ratio of the Ga element and the S element becomes higher as the distance from the lower electrode layer 2 in the surface portion 3a is easily manufactured. Is possible.
　なお、皮膜中の１１族元素、Ｉｎ元素およびＧａ元素の各元素は、すべて均一に皮膜中に混在していてもよいが、複数の元素がそれぞれ別々の層に存在した状態（特定の元素が皮膜の厚み方向の一部分だけに存在する状態）であってもよい。これは、数μｍ～数１０μｍ程度の厚みの皮膜であれば、複数の元素がそれぞれ別々の層に存在していたとしても、皮膜を加熱処理する際に、各元素が拡散し合うことによって、各元素同士が反応し合うことができるためである。 In addition, each element of group 11 element, In element, and Ga element in the film may be uniformly mixed in the film, but a state in which a plurality of elements exist in separate layers (specific elements are It may be present only in a part of the thickness direction of the film. This is because, in the case of a film having a thickness of several μm to several tens of μm, even when a plurality of elements are present in separate layers, each element diffuses when the film is heat-treated, This is because each element can react with each other.
　皮膜は、１１族元素、Ｉｎ元素およびＧａ元素のうち、いずれか１種または複数種を含む原料を用いて作製することができる。具体的には、上記原料を含む原料溶液を塗布することによって、あるいはスパッタリング法や蒸着法等によって、皮膜を形成することができる。皮膜は複数層から成る積層体であってもよい。 The coating can be produced using a raw material containing any one or more of group 11 elements, In elements and Ga elements. Specifically, the film can be formed by applying a raw material solution containing the above raw materials, or by sputtering, vapor deposition, or the like. The film may be a laminate composed of a plurality of layers.
　１１族元素、Ｉｎ元素およびＧａ元素の各元素は、それぞれ皮膜中に化合物の状態、合金の状態、および単体の状態のいずれの状態で存在していてもよい。雰囲気中のＳ元素との反応性を高め、生成する第１の半導体層３の表面部におけるＧａ元素の相対原子数比をより容易に高くできるという観点からは、上記各元素は、有機配位子が配位した有機錯体の状態で皮膜中に存在していてもよい。特に、反応性を高くして、結晶性を高めるという観点からは、上記有機錯体として、１１族元素、Ｉｎ元素およびＧａ元素の少なくとも１種に、有機配位子として有機カルコゲン化合物が配位したものを用いてもよい。 Each element of group 11 element, In element, and Ga element may be present in the film in any state of a compound, an alloy, and a simple substance. From the viewpoint that the reactivity with the S element in the atmosphere is increased and the relative atomic number ratio of the Ga element in the surface portion of the first semiconductor layer 3 to be generated can be more easily increased, each of the above elements has an organic coordination. It may be present in the film in the state of an organic complex coordinated by a child. In particular, from the viewpoint of increasing the reactivity and improving the crystallinity, as the organic complex, an organic chalcogen compound is coordinated as an organic ligand to at least one of group 11 element, In element and Ga element. A thing may be used.
　有機カルコゲン化合物とは、カルコゲン元素を含む有機化合物であり、炭素元素とカルコゲン元素との共有結合を有する有機化合物である。なお、カルコゲン元素としては、Ｓｅ元素またはＳ元素を使用することができる。有機カルコゲン化合物としては、例えば、チオールや、スルフィド、ジスルフィド、セレノール、セレニド、ジセレニド等を用いることができる。有機カルコゲン化合物が配位した有機錯体の具体例としては、Ｃｕ元素やＡｇ元素等の１１族元素に有機カルコゲン化合物が配位した有機錯体、Ｉｎ元素に有機カルコゲン化合物が配位した有機錯体、Ｇａ元素に有機カルコゲン化合物が配位した有機錯体、または、有機カルコゲン化合物が１１族元素および１３族元素の両方に配位して１つの分子中に１１族元素と１３族元素とカルコゲン元素とを有する単一源有機錯体（特許文献２参照）等を用いることができる。 An organic chalcogen compound is an organic compound containing a chalcogen element, and is an organic compound having a covalent bond between a carbon element and a chalcogen element. As the chalcogen element, Se element or S element can be used. As the organic chalcogen compound, for example, thiol, sulfide, disulfide, selenol, selenide, diselenide and the like can be used. Specific examples of an organic complex in which an organic chalcogen compound is coordinated include an organic complex in which an organic chalcogen compound is coordinated with a group 11 element such as a Cu element or an Ag element, an organic complex in which an organic chalcogen compound is coordinated with an In element, Ga An organic complex in which an organic chalcogen compound is coordinated to an element, or an organic chalcogen compound is coordinated to both a group 11 element and a group 13 element and has a group 11 element, a group 13 element, and a chalcogen element in one molecule A single source organic complex (see Patent Document 2) or the like can be used.
　以上のような、１１族元素、Ｉｎ元素およびＧａ元素のいずれかを含む有機錯体を、ピリジンやアニリン等の有機溶媒に溶解して原料溶液とする。そして、この原料溶液を、例えば、スピンコータ、スクリーン印刷、ディッピング、スプレー、ダイコータ等によって第１の電極層２上に膜状に被着し、溶媒を乾燥によって除去することにより、皮膜を形成することができる。なお、皮膜は、上記皮膜形成工程を繰り返すことによって、複数層の積層体としてもよい。 The organic complex containing any of the group 11 element, In element and Ga element as described above is dissolved in an organic solvent such as pyridine or aniline to obtain a raw material solution. Then, this raw material solution is deposited in the form of a film on the first electrode layer 2 by, for example, a spin coater, screen printing, dipping, spraying, a die coater, etc., and the solvent is removed by drying to form a film. Can do. In addition, a film | membrane is good also as a laminated body of two or more layers by repeating the said film formation process.
　そして、作製した皮膜を、Ｓ元素が硫黄蒸気または硫化水素等として含まれている雰囲気において、３００～６５０℃で１０～１２０分加熱して硫化を行なう。その後、この皮膜を、Ｓｅ元素がセレン蒸気またはセレン化水素として含まれている雰囲気において４００～６５０℃で１０～１２０分加熱してセレン化を行なう。このような加熱工程における硫化の段階では、雰囲気中のＳ元素によって特に皮膜中のＧａ元素の硫化が進行しやすくなり、表面部のＧａ元素およびＳ元素の比率が増加する。そして、続くセレン化工程における段階では、皮膜の硫化が完了していない内部や下部において、セレン化が進行し、Ｇａ元素が下部電極層２側へ移動しやすくなる。一方、表面部の硫化時に反応したＧａ元素は、セレン化時における移動はほとんどない。その結果、表面部３ａにおいて、Ｉｎ元素とＧａ元素との合計原子数に対するＧａ元素の相対原子数比およびＳ元素の相対原子数比が、下部電極層２から離れるに従って増加した第１の半導体層３を得ることができる。なお、皮膜の硫化の際には第１の半導体層３の結晶化温度である４００℃以上の温度にして加熱すると、皮膜の硫化が良好に行なわれ、その後のセレン化においてもＧａ元素およびＳ元素の濃度分布をより良好に維持できる。 The produced film is then sulfided by heating at 300 to 650 ° C. for 10 to 120 minutes in an atmosphere containing S element as sulfur vapor or hydrogen sulfide. Thereafter, this film is selenized by heating at 400 to 650 ° C. for 10 to 120 minutes in an atmosphere containing Se element as selenium vapor or hydrogen selenide. In the sulfidation stage in such a heating process, sulfidation of Ga element in the film is particularly facilitated by S element in the atmosphere, and the ratio of Ga element and S element in the surface portion increases. Then, in the subsequent selenization step, selenization proceeds inside and below the film where the sulfidation of the film is not completed, and the Ga element easily moves to the lower electrode layer 2 side. On the other hand, the Ga element reacted at the time of sulfidation of the surface portion hardly moves during selenization. As a result, the first semiconductor layer in which the relative atomic number ratio of the Ga element and the relative atomic number ratio of the S element with respect to the total number of atoms of the In element and the Ga element increase as the distance from the lower electrode layer 2 increases. 3 can be obtained. When the film is sulfidized, if the film is heated to a temperature of 400 ° C. or higher, which is the crystallization temperature of the first semiconductor layer 3, the film is sulfidized satisfactorily. The concentration distribution of elements can be maintained better.
　以上のように硫化およびセレン化の条件を調整することによって、第１の半導体層３中のＳ元素の濃度分布、Ｇａ元素の濃度分布を容易に変えることができる。例えば、硫化の際の加熱温度を高くするほど、あるいは加熱時間を長くするほど、第１の半導体層３中の表面部３ａの厚みが厚くなったり、第１の半導体層３の表面部３ａにおけるＧａ元素またはＳ元素の相対原子数比の変化率が大きくなったりする（すなわち、図３のグラフの表面部におけるＧａ元素の分布の傾きまたはＳ元素の分布の傾きが大きくなる）傾向がある。また、セレン化の際の加熱温度を高くするほど、あるいは加熱時間を長くするほど、第１の半導体層の残部３ｂにおけるＧａ元素の相対原子数比の変化率が大きくなる（すなわち、図３のグラフの残部におけるＧａ元素の分布の傾きが大きくなる）傾向がある。 By adjusting the conditions for sulfidation and selenization as described above, the concentration distribution of S element and the concentration distribution of Ga element in the first semiconductor layer 3 can be easily changed. For example, as the heating temperature at the time of sulfiding is increased or the heating time is increased, the thickness of the surface portion 3a in the first semiconductor layer 3 increases or the surface portion 3a of the first semiconductor layer 3 increases. There is a tendency that the change rate of the relative atomic number ratio of the Ga element or the S element increases (that is, the slope of the distribution of the Ga element or the slope of the distribution of the S element increases in the surface portion of the graph of FIG. 3). Further, as the heating temperature at the time of selenization is increased or the heating time is increased, the rate of change of the relative atomic number ratio of Ga element in the remaining portion 3b of the first semiconductor layer increases (that is, in FIG. There is a tendency for the slope of the Ga element distribution in the remainder of the graph to increase.
　なお、上記の硫化工程およびセレン化工程においては、それぞれ多段階の加熱工程を行なってもよい。例えば、硫化工程において、３００～４５０℃で硫化を行なった後、５００～６００℃で硫化を行なってよい。同様に、セレン化工程において、３５０～４５０℃でセレン化を行なった後、５００～６００℃でセレン化を行なってよい。このように多段階で加熱を行なうことによって、Ｇａ元素の相対原子数比およびＳ元素の相対原子数比の制御をより容易に行なうことが可能になる。さらに、セレン化工程において、５００～６００℃でセレン化を行なった後、４５０℃～５５０℃でセレン化を行なってもよい。 In the above sulfidation step and selenization step, multiple heating steps may be performed. For example, in the sulfiding step, sulfiding may be performed at 500 to 600 ° C. after sulfiding at 300 to 450 ° C. Similarly, in the selenization step, selenization may be performed at 500 to 600 ° C. after performing selenization at 350 to 450 ° C. By performing heating in multiple stages as described above, it becomes possible to more easily control the relative atomic number ratio of Ga element and the relative atomic number ratio of S element. Further, in the selenization step, selenization may be performed at 450 to 550 ° C. after performing selenization at 500 to 600 ° C.
　また、上記の硫化工程において、雰囲気中に酸素を、例えば分圧比で１～１００ｐｐｍｖ含めてもよい。これにより、表面部に酸素元素を、Ｇａ元素やＳ元素と同様に、下部電極層２から離れるに従って増加するように含めることができる。その結果、Ｇａ元素やＳ元素の含有率が高まるにつれて生じやすい欠陥に対し、Ｇａ元素やＳ元素の含有率に応じた最適な酸素量を供給することで、キャリア再結合に起因した効率低下を抑制できる。 Further, in the above sulfiding step, oxygen may be included in the atmosphere, for example, 1 to 100 ppmv at a partial pressure ratio. Thereby, the oxygen element can be included in the surface portion so as to increase as the distance from the lower electrode layer 2 is increased, similarly to the Ga element and the S element. As a result, by supplying an optimal amount of oxygen corresponding to the content of Ga element or S element to defects that are likely to occur as the content ratio of Ga element or S element increases, efficiency reduction due to carrier recombination can be reduced. Can be suppressed.
　また、上記の皮膜を作製した後、この皮膜を硫化する前に、皮膜を、カルコゲン元素を含まない雰囲気中で、例えば５０～３５０℃で加熱して、皮膜中の有機成分を熱分解しておいてもよい。これにより、第１の半導体層３中に有機成分が残存するのを低減でき、第１の半導体層３の光電変換効率をより高めることができる。特に、この皮膜中の有機成分を熱分解する際に、雰囲気中に水蒸気や酸素等の酸化性ガスを、分圧比で５０～３００ｐｐｍｖ程度含有させておいてもよい。これにより、第１の半導体層３中に酸素元素を含有させることができる。その結果、酸素元素が第１の半導体層３の格子欠陥に入ることによって、電荷の再結合を低減することができる。 In addition, after the above-described film is formed and before the film is sulfided, the film is heated in an atmosphere containing no chalcogen element, for example, at 50 to 350 ° C. to thermally decompose organic components in the film. It may be left. Thereby, it can reduce that an organic component remains in the 1st semiconductor layer 3, and can improve the photoelectric conversion efficiency of the 1st semiconductor layer 3 more. In particular, when the organic component in the film is thermally decomposed, an oxidizing gas such as water vapor or oxygen may be contained in the atmosphere at a partial pressure ratio of about 50 to 300 ppmv. Thereby, an oxygen element can be contained in the first semiconductor layer 3. As a result, the recombination of charges can be reduced by the oxygen element entering the lattice defects of the first semiconductor layer 3.
　また、上記の皮膜中にＳｅ元素を含めておいてもよい。これにより、生成する第１の半導体層３においてＳｅ元素不足が生じるのを有効に低減できる。また、皮膜を、Ｓ元素を含む雰囲気で加熱して硫化する際に、硫化の程度を制御しやすくなり、表面部におけるＳ元素の濃度分布を所望のものとしやすくなる。 In addition, Se element may be included in the above film. Thereby, it is possible to effectively reduce the occurrence of Se element deficiency in the first semiconductor layer 3 to be generated. In addition, when the film is heated and sulfided in an atmosphere containing S element, the degree of sulfidation can be easily controlled, and the concentration distribution of S element on the surface portion can be easily made desired.
　皮膜中にＳｅ元素を含める方法としては、上述したように有機カルコゲン化合物として有機セレン化合物を用いればよい。あるいは、上記皮膜をＳ元素雰囲気で加熱する前にＳｅ雰囲気で加熱して、皮膜が完全にはセレン化されない程度にセレン化を行なってもよい。 As a method for including Se element in the film, an organic selenium compound may be used as the organic chalcogen compound as described above. Alternatively, the film may be selenized to such an extent that the film is not completely selenized by heating in the Se atmosphere before heating the film in the S element atmosphere.
　第２の半導体層４は、溶液成長法（ＣＢＤ法ともいう）によって形成することができる。例えば、酢酸カドミウムとチオ尿素とをアンモニア水に溶解し、これに第１の半導体層３の形成まで行なった基板１を浸漬することで、第１の半導体層３の上にＣｄＳを含む第２の半導体層４を形成することができる。 The second semiconductor layer 4 can be formed by a solution growth method (also referred to as a CBD method). For example, cadmium acetate and thiourea are dissolved in ammonia water, and the substrate 1 that has been formed up to the formation of the first semiconductor layer 3 is immersed in the second semiconductor layer 3 so as to contain the second CdS on the first semiconductor layer 3. The semiconductor layer 4 can be formed.
　上部電極層５は、例えば、Ｓｎが含まれた酸化インジウム（ＩＴＯ）等を主成分とする透明導電膜であり、スパッタリング法、蒸着法またはＣＶＤ法等で形成することができる。図７は、第２の半導体層４および上部電極層５を形成した後の状態を示す図である。 The upper electrode layer 5 is a transparent conductive film containing, for example, indium oxide (ITO) containing Sn as a main component, and can be formed by a sputtering method, a vapor deposition method, a CVD method, or the like. FIG. 7 is a view showing a state after the second semiconductor layer 4 and the upper electrode layer 5 are formed.
　上部電極層５を形成した後、上部電極層５の上面のうちのＹ方向に沿った直線状の形成対象位置からその直下の下部電極層２の上面にかけて、第２溝部Ｐ２を形成する。第２溝部Ｐ２は、例えば、スクライブ針を用いたメカニカルスクライビング加工によって形成することができる。図８は、第２溝部Ｐ２を形成した後の状態を示す図である。第２溝部Ｐ２は、第１溝部Ｐ１よりも若干Ｘ方向（図中では＋Ｘ方向）にずれた位置に形成する。 After forming the upper electrode layer 5, the second groove portion P <b> 2 is formed from the linear formation target position along the Y direction on the upper surface of the upper electrode layer 5 to the upper surface of the lower electrode layer 2 immediately below it. The second groove portion P2 can be formed by, for example, mechanical scribing using a scribe needle. FIG. 8 is a diagram illustrating a state after the second groove portion P2 is formed. The second groove portion P2 is formed at a position slightly deviated in the X direction (+ X direction in the drawing) from the first groove portion P1.
　第２溝部Ｐ２を形成した後、集電電極７および接続導体６を形成する。集電電極７および接続導体６については、例えば、Ａｇ等の金属粉を樹脂バインダー等に分散した導電性を有するペースト（導電ペーストともいう）を所望のパターンを描くように印刷し、これを加熱することで形成できる。図９は、集電電極７および接続導体６を形成した後の状態を示す図である。 After forming the second groove P2, the collecting electrode 7 and the connecting conductor 6 are formed. For the collector electrode 7 and the connection conductor 6, for example, a conductive paste (also referred to as a conductive paste) in which a metal powder such as Ag is dispersed in a resin binder is printed in a desired pattern and heated. Can be formed. FIG. 9 is a view showing a state after the current collecting electrode 7 and the connection conductor 6 are formed.
　集電電極７および接続導体６を形成した後、上部電極層５の上面のうちの直線状の形成対象位置からその直下の下部電極層２の上面にかけて、第３溝部Ｐ３を形成する。第３溝部Ｐ３の幅は、例えば４０～１０００μｍ程度とすることができる。また、第３溝部Ｐ３は、第２溝部Ｐ２と同様に、メカニカルスクライビング加工によって形成することができる。このようにして、第３溝部Ｐ３の形成によって、図１および図２に示した光電変換装置１１を製作したことになる。 After forming the current collecting electrode 7 and the connection conductor 6, the third groove portion P <b> 3 is formed from the linear formation target position on the upper surface of the upper electrode layer 5 to the upper surface of the lower electrode layer 2 immediately below it. The width of the third groove portion P3 can be set to about 40 to 1000 μm, for example. Moreover, the 3rd groove part P3 can be formed by a mechanical scribing process similarly to the 2nd groove part P2. In this way, the photoelectric conversion device 11 shown in FIGS. 1 and 2 is manufactured by forming the third groove portion P3.
　なお、本発明は上述の実施の形態に限定されるものではなく、本発明の要旨を逸脱しない範囲において種々の変更、改良などが可能である。 It should be noted that the present invention is not limited to the above-described embodiment, and various changes and improvements can be made without departing from the gist of the present invention.
　１：基板
　２：下部電極層
　３：第１の半導体層
　　３ａ：表面部
　　３ｂ：残部
　４：第２の半導体層
　５：上部電極層
　６：接続導体
　７：集電電極
　１０：光電変換セル
　１１：光電変換装置 1: Substrate 2: Lower electrode layer 3: First semiconductor layer 3a: Surface portion 3b: Remaining portion 4: Second semiconductor layer 5: Upper electrode layer 6: Connection conductor 7: Current collecting electrode 10: Photoelectric conversion cell 11: Photoelectric conversion device

Claims (9)

  1. 　電極層上に、１１族元素、インジウム元素、ガリウム元素、硫黄元素およびセレン元素を含む半導体層を具備しており、該半導体層は、前記電極層とは反対側の表面部において、インジウム元素とガリウム元素との合計原子数に対するガリウム元素の相対原子数比および硫黄元素の相対原子数比が、前記電極層から離れるに従って増加している光電変換装置。 A semiconductor layer containing a group 11 element, an indium element, a gallium element, a sulfur element, and a selenium element is provided on the electrode layer, and the semiconductor layer has an indium element on the surface portion opposite to the electrode layer. A photoelectric conversion device in which a relative atomic number ratio of a gallium element and a relative atomic number ratio of a sulfur element with respect to a total number of atoms with a gallium element increase as the distance from the electrode layer increases.
  2. 　前記半導体層は、前記表面部よりも前記電極層側の残部において、インジウム元素とガリウム元素との合計原子数に対するガリウム元素の相対原子数比が、前記電極層に近づくに従って増加している、請求項１に記載の光電変換装置。 In the remaining portion of the semiconductor layer closer to the electrode layer than the surface portion, the relative atomic number ratio of the gallium element to the total atomic number of indium element and gallium element increases as the electrode layer approaches. Item 2. The photoelectric conversion device according to Item 1.
  3. 　前記表面部は酸素元素をさらに含んでいる、請求項１または２に記載の光電変換装置。 The photoelectric conversion device according to claim 1 or 2, wherein the surface portion further contains an oxygen element.
  4. 　前記酸素元素は前記表面部において、前記電極層から離れるに従って増加している、請求項３に記載の光電変換装置。 The photoelectric conversion device according to claim 3, wherein the oxygen element increases in the surface portion as the distance from the electrode layer increases.
  5. 　電極層上に、１１族元素およびインジウム元素を含むとともに少なくとも前記電極層とは反対側の表面領域にガリウム元素を含む皮膜を作製する工程と、
    該皮膜を硫黄元素を含む雰囲気で加熱した後、セレン元素を含む雰囲気で加熱することによって、前記皮膜を、前記電極層とは反対側の表面部において、インジウム元素とガリウム元素との合計原子数に対するガリウム元素の相対原子数比および硫黄元素の相対原子数比が、前記電極層から離れるに従って増加している半導体層にする工程と
    を具備する光電変換装置の製造方法。     Forming a film containing a group 11 element and an indium element on the electrode layer and containing a gallium element in a surface region opposite to the electrode layer;
    The film is heated in an atmosphere containing sulfur element, and then heated in an atmosphere containing selenium element, whereby the film is heated at the surface portion opposite to the electrode layer, so that the total number of atoms of indium element and gallium element is increased. And a step of forming a semiconductor layer in which a relative atomic number ratio of gallium element and a relative atomic number ratio of sulfur element increase with distance from the electrode layer.
  6. 　前記皮膜を作製する工程において、前記皮膜にカルコゲン元素をさらに含ませる、請求項５に記載の光電変換装置の製造方法。 The method for manufacturing a photoelectric conversion device according to claim 5, wherein in the step of forming the film, the film further includes a chalcogen element.
  7. 　前記カルコゲン元素を、前記１１族元素、前記インジウム元素および前記ガリウム元素の少なくとも１種に配位した有機カルコゲン化合物として前記皮膜に含ませる、請求項６に記載の光電変換装置の製造方法。 The method for producing a photoelectric conversion device according to claim 6, wherein the chalcogen element is included in the film as an organic chalcogen compound coordinated to at least one of the group 11 element, the indium element, and the gallium element.
  8. 　前記皮膜を硫黄元素を含む雰囲気で加熱する前に、前記皮膜に含まれる有機成分を熱分解により除去する、請求項７に記載の光電変換装置の製造方法。 The method for manufacturing a photoelectric conversion device according to claim 7, wherein an organic component contained in the coating is removed by thermal decomposition before the coating is heated in an atmosphere containing elemental sulfur.
  9. 　前記皮膜を硫黄元素を含む雰囲気で加熱する前に前記皮膜の一部を酸化する、請求項５乃至８のいずれかに記載の光電変換装置の製造方法。 The method for manufacturing a photoelectric conversion device according to any one of claims 5 to 8, wherein a part of the film is oxidized before the film is heated in an atmosphere containing sulfur element.
PCT/JP2013/066473 2012-06-25 2013-06-14 Photoelectric conversion apparatus and method for manufacturing photoelectric conversion apparatus WO2014002796A1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10341029A (en) * 1997-06-05 1998-12-22 Matsushita Electric Ind Co Ltd Deposition of semiconductor thin film and production of thin film solar cell
JP2000174306A (en) * 1998-12-01 2000-06-23 Asahi Chem Ind Co Ltd Manufacture of compound semiconductor thin film
JP2009135299A (en) * 2007-11-30 2009-06-18 Showa Shell Sekiyu Kk Method of manufacturing a light absorbing layer of cis-based thin film solar cell
WO2011152334A1 (en) * 2010-05-31 2011-12-08 京セラ株式会社 Photoelectric conversion device
JP2012074671A (en) * 2010-08-31 2012-04-12 Kyocera Corp Photoelectric conversion device, manufacturing method therefor, and photoelectric conversion module
JP2013098191A (en) * 2011-10-28 2013-05-20 Kyocera Corp Photoelectric conversion device

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007059484A (en) * 2005-08-22 2007-03-08 Matsushita Electric Ind Co Ltd Solar cell and method of manufacturing the same
JP2013504215A (en) * 2009-09-02 2013-02-04 ボルマン、ブレント Methods and devices for processing precursor layers in a Group VIA environment

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10341029A (en) * 1997-06-05 1998-12-22 Matsushita Electric Ind Co Ltd Deposition of semiconductor thin film and production of thin film solar cell
JP2000174306A (en) * 1998-12-01 2000-06-23 Asahi Chem Ind Co Ltd Manufacture of compound semiconductor thin film
JP2009135299A (en) * 2007-11-30 2009-06-18 Showa Shell Sekiyu Kk Method of manufacturing a light absorbing layer of cis-based thin film solar cell
WO2011152334A1 (en) * 2010-05-31 2011-12-08 京セラ株式会社 Photoelectric conversion device
JP2012074671A (en) * 2010-08-31 2012-04-12 Kyocera Corp Photoelectric conversion device, manufacturing method therefor, and photoelectric conversion module
JP2013098191A (en) * 2011-10-28 2013-05-20 Kyocera Corp Photoelectric conversion device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
TOKIO NAKATA: "CIGS Taiyo Denchi no Kiso Gijutsu", THE NIKKAN KOGYO SHINBUN, LTD., 2010, pages 63 - 70, 101 TO 112 *

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