WO2023157884A1 - Light absorption layer, and light absorption layer forming method, and photoelectric conversion element - Google Patents

Light absorption layer, and light absorption layer forming method, and photoelectric conversion element Download PDF

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WO2023157884A1
WO2023157884A1 PCT/JP2023/005281 JP2023005281W WO2023157884A1 WO 2023157884 A1 WO2023157884 A1 WO 2023157884A1 JP 2023005281 W JP2023005281 W JP 2023005281W WO 2023157884 A1 WO2023157884 A1 WO 2023157884A1
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light absorption
absorption layer
peak
range
ray diffraction
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PCT/JP2023/005281
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French (fr)
Japanese (ja)
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嘉将 木下
義晴 高根
明佑子 山脇
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シチズン時計株式会社
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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
    • H01L31/0256—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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers
    • H01L31/075—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers the potential barriers being only of the PIN type, e.g. amorphous silicon PIN solar cells
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
    • H10K30/50—Photovoltaic [PV] devices

Definitions

  • the present invention relates to a light absorption layer, a method for forming the light absorption layer, and a photoelectric conversion element.
  • composition formula Ag a Bi b I c It is represented by the composition formula Ag a Bi b I c , and has a structure in which a plurality of octahedral units each consisting of six iodine (I) are connected while sharing two I ions on the edges, and a photoelectric conversion device Films used as light absorbing layers are known (see, for example, Patent Document 1).
  • the film described in Patent Document 1 can be used as a light absorption layer of a solar cell element, and when measured by X-ray diffraction, the maximum diffraction intensity peak appears in the range of 25° ⁇ 2 ⁇ 35°.
  • Patent Document 1 has a crystal structure in which the maximum peak appears in the range of 25° ⁇ 2 ⁇ ⁇ 35° when measured by X-ray diffraction, so that it does not contain lead or the like and has low toxicity. and is electrically and optically available.
  • Non-Patent Document 1 describes that a peak appears at 2 ⁇ 42° when a silver bismuth iodide-based thin film is measured by X-ray diffraction, and that the peak splits as the molar ratio of AgI to BiI 3 increases. It is
  • photoelectric conversion elements such as solar cell elements that convert energy into electrical energy.
  • the light-absorbing layer, the method for forming the light-absorbing layer, and the photoelectric conversion element according to the embodiment make it possible to improve the conversion efficiency of photoelectric conversion.
  • the light-absorbing layer according to the embodiment of the present invention is represented by the composition formula Ag a Bi b I c , in which a plurality of octahedral units each consisting of six I ions are connected, and each of the plurality of octahedral units A crystal having a structure in which either Ag ions or Bi ions are arranged in the center, and in the composition formula, the composition ratio a and b satisfies 1.5 ⁇ a / b ⁇ 4.0, and X-ray diffraction measurement Then, a first peak appears in the range of 42.0° ⁇ 2 ⁇ ⁇ 43.0°, and the intensity of the first peak is in the range of 41.0° ⁇ 2 ⁇ ⁇ 42.0° when measured by X-ray diffraction. It is characterized by being 1.7 times or more the intensity of the maximum measured value in .
  • a second peak appears in the range of 41.0 ° ⁇ 2 ⁇ ⁇ 42.0 °, and the intensity of the first peak is the intensity of the second peak is preferably 1.7 times or more and 7.0 times or less.
  • the maximum peak appears in the range of 11.5° ⁇ 2 ⁇ 14.0° when X-ray diffraction measurement is performed.
  • a third peak appears in the range of 28.0 ° ⁇ 2 ⁇ ⁇ 32.0 °, and the intensity of the maximum peak is the intensity of the third peak is preferably 1.2 times or more.
  • a photoelectric conversion element includes a film formed on a transport layer, a light absorption layer containing crystals represented by a composition formula Ag a Bi b I c , and a film formed on one surface of the light absorption layer. and a hole transport layer formed on the other side of the light absorption layer, and in the composition formula, the composition ratios a and b are 1.5 ⁇ a/b ⁇ 4.0 , the first peak appears in the range of 42.0° ⁇ 2 ⁇ ⁇ 43.0°, and the intensity of the first peak is 41.0° in the X-ray diffraction measurement. It is characterized by being 1.7 times or more the intensity of the maximum measured value in the range of 0° ⁇ 2 ⁇ 42.0°.
  • a substrate is placed in an atmosphere filled with an inert gas and a vaporized first organic substance, and a crystal represented by the composition formula Ag a Bi b I c is formed.
  • applying a precursor solution containing a formable precursor and a solvent containing a second organic substance different from the first organic substance to the surface of the substrate;
  • a light absorption layer is formed in which the composition ratio a and b in the composition formula satisfies 1.5 ⁇ a/b ⁇ 4.0, wherein the first organic substance is chlorobenzene.
  • the method for forming the light absorbing layer may further include dripping a third organic substance different from the second organic substance as a poor solvent onto the surface of the substrate while the precursor solution is being applied to the surface of the substrate. preferable.
  • FIG. 1 is a cross-sectional view of a photoelectric conversion element 1 according to an embodiment
  • FIG. 4 is a flow chart showing a method for manufacturing the photoelectric conversion element 1.
  • FIG. It is a flowchart which shows the more detailed process of a light absorption layer film-forming process.
  • (A) shows the (110) plane of the crystal structure contained in the light absorption layer 13
  • (B) shows the (018) plane of the crystal structure contained in the light absorption layer 13
  • (C) shows the light absorption layer 13.
  • 3D is a perspective view of octahedral units contained in the light absorption layer 13.
  • FIG. 3A and 3B are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 1;
  • FIG. 3A and 3B are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 1;
  • FIG. (A) and (B) are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 2.
  • FIG. (A) and (B) are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 3.
  • FIG. (A) and (B) are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 4.
  • FIG. (A) and (B) are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 5.
  • FIG. (A) and (B) are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 6.
  • FIG. (A) and (B) are diagrams showing X-ray diffraction patterns of light absorption layers according to comparative examples.
  • photoelectric conversion element refers to an element that converts light energy into electrical energy, and includes solar cell elements, photoelectric cell elements, and photovoltaic elements that convert light energy, including indoor light and sunlight, into electrical energy.
  • the photoelectric conversion element according to the embodiment may be used as a solar cell module, which is also called a solar panel, and a power supply device for mobile devices and the like.
  • FIG. 1 is a cross-sectional view of a photoelectric conversion element 1 according to an embodiment.
  • the photoelectric conversion element 1 has a substrate 10, a lower conductive layer 11, an electron transport layer 12, a light absorption layer 13, a hole transport layer 14, and an upper electrode 15.
  • a lower conductive layer is formed on the substrate 10.
  • a layer 11, an electron transport layer 12, a light absorption layer 13, a hole transport layer 14 and an upper electrode 15 are sequentially laminated. That is, in the photoelectric conversion element 1 , the electron transport layer 12 is formed on one surface of the light absorption layer 13 , and the hole transport layer 14 is formed on the other surface of the light absorption layer 13 .
  • the photoelectric conversion element 1 generates a voltage between the lower conductive layer 11 and the upper electrode 15 and current from the upper electrode 15 in response to light incident through the substrate 10 and the lower conductive layer 11 . This is a forward structure type solar cell element that outputs power.
  • the substrate 10 is made of a transparent material such as an insulating glass substrate that can support components included in the photoelectric conversion element 1 and that transmits incident light that enters the photoelectric conversion element 1 .
  • the transparent material is a material that transmits light in the wavelength region absorbed by the light absorption layer 13, and preferably has a transmittance of 80% or more for light in the wavelength region absorbed by the light absorption layer 13. It is more preferable that the transmittance of light in the wavelength region absorbed by the light absorption layer 13 is 95% or more.
  • Substrate 10 may be formed of a conductive material.
  • the lower conductive layer 11 is formed on the substrate 10 so as to cover the substrate 10 by using a material that is transparent like the substrate 10 and that is capable of transporting electrons with high efficiency and has a low resistance, for example, a sheet resistance of 10 ⁇ or less. be done.
  • the lower conductive layer 11 is, for example, a thin film formed of fluorine-added tin oxide (FTO), which has little change in resistivity due to high-temperature heat treatment, is transparent, and has high conductivity.
  • FTO fluorine-added tin oxide
  • the lower conductive layer 11 may be a thin film formed of, for example, tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), and niobium-doped titanium oxide (NTO).
  • the lower conductive layer 11 preferably has a thickness of 0.01 ⁇ m to 10.0 ⁇ m, more preferably 0.05 ⁇ m to 1.0 ⁇ m.
  • the electron transport layer 12 is an n-type semiconductor that blocks holes generated in the light absorption layer 13 and transports electrons generated in the light absorption layer 13 to the lower conductive layer 11 with high efficiency. A film is formed on the lower conductive layer 11 so as to cover it.
  • the electron transport layer 12 is preferably made of a material with high electron transport properties.
  • the electron transport layer 12 is made of metal oxide such as titanium oxide (TiO 2 etc.), tin oxide (SnO 2 etc.), tungsten oxide (WO 2 etc.), zinc oxide (ZnO) and aluminum oxide (Al 2 O 3 ).
  • the electron transport layer 12 preferably has a thickness of 5 nm or more and 200 nm or less, more preferably 20 nm or more and 60 nm or less.
  • the light absorption layer 13 is made of a material represented by the composition formula Ag a Bi b I c and deposited on the electron transport layer 12 .
  • the light absorption layer 13 preferably has a thickness of 10 nm or more and 10000 nm or less, more preferably 20 nm or more and 900 nm or less.
  • the light absorption layer 13 absorbs light incident through the lower conductive layer 11 and the electron transport layer 12 . Electrons are excited by the absorbed light, and electrons and holes are generated inside the light absorption layer 13 .
  • the hole transport layer 14 is made of selenium, iodides such as copper iodide (CuI), cobalt complexes such as layered cobalt oxide, CuSCN, molybdenum oxide (such as MoO 3 ), nickel oxide (such as NiO), 4CuBr ⁇ 3S ( C 4 H 9 ) and an organic hole transport material.
  • CuI copper iodide
  • cobalt complexes such as layered cobalt oxide
  • CuSCN molybdenum oxide (such as MoO 3 ), nickel oxide (such as NiO), 4CuBr ⁇ 3S ( C 4 H 9 ) and an organic hole transport material.
  • organic hole transport materials include poly-3-hexylthiophene (P3HT), polythiophene derivatives such as polyethylenedioxythiophene (PEDOT), 2,2′,7,7′-tetrakis-(N,N-di-p -methoxyphenylamine)-9,9'-spirobifluorene (spiro-MeO-TAD) and other fluorene derivatives, polyvinylcarbazole and other carbazole derivatives, poly[bis(4-phenyl)(2,4,6-triphenyl methyl)amine] (PTAA), diphenylamine derivatives, polysilane derivatives, polyaniline derivatives and the like.
  • the hole transport layer 14 preferably has a thickness of 0.01 ⁇ m or more and 10 ⁇ m or less, but is not limited thereto.
  • the upper electrode 15 is a metal layer such as a gold layer (Au) and is deposited on the hole transport layer 14 .
  • the upper electrode 15 may be a Ti/Au layer in which a gold layer (Au) is deposited on a titanium (Ti) layer.
  • the upper electrode 15 may be formed of a material that contacts the hole transport layer 14, and may be formed of a metal such as Au, Pt, or Ni having a relatively large work function, or a carbon-based electrode such as graphite.
  • the upper electrode 15 preferably has a thickness of 2 nm or more and 200 nm or less.
  • the thickness of the upper electrode 15 When the thickness of the upper electrode 15 is less than 2 nm, the resistance value in the direction in which the upper electrode 15 extends increases, so that the hole collection efficiency decreases and the conversion efficiency of the photoelectric conversion element 1 decreases. When the thickness of the upper electrode 15 is thicker than 200 nm, the resistance value of the upper electrode 15 in the film thickness direction increases, so that the conversion efficiency of the photoelectric conversion element 1 decreases and the amount of material forming the upper electrode 15 increases. This increases manufacturing costs.
  • FIG. 2 is a flow chart showing a method for manufacturing the photoelectric conversion element 1.
  • the substrate 10 on which the lower conductive layer 11 is formed is prepared (S101).
  • the substrate 10 on which the lower conductive layer 11 is formed is, for example, a flat glass substrate with FTO formed on one surface.
  • the substrate 10 on which the lower conductive layer 11 is formed is preferably subjected to cleaning treatment such as UV ozone cleaning treatment.
  • the electron transport layer 12 is deposited on the lower conductive layer 11 (S102).
  • An electron transport layer 12 is deposited on the FTO.
  • the electron transport layer 12 is formed by depositing the second layer after depositing the first layer.
  • the first layer is formed by spray pyrolysis.
  • the substrate 10 with the lower conductive layer 11 formed thereon is heated at a first temperature.
  • a solution containing a titanium chelate compound is then sprayed onto the lower conductive layer 11 .
  • the substrate 10 sprayed with the solution is baked at a second temperature for a predetermined heating time.
  • Titanium chelate compounds contained in the sprayed solution are, for example, tetrakis(2,4-pentanedionato)titanium(IV) or diisopropoxytitanium(IV) bis(acetylacetonate).
  • the first temperature is preferably 300° C. or higher and 600° C. or lower, more preferably 400° C. or higher and 500° C. or lower.
  • the second temperature is preferably 300° C. or higher and 900° C. or lower, and more preferably 450° C. or higher and 550° C. or lower.
  • the predetermined heating time is preferably 30 minutes or more and 600 minutes or less, more preferably 60 minutes or more and 180 minutes or less.
  • the second layer is formed by immersing the substrate 10 having the lower conductive layer 11 and the first layer formed thereon in an aqueous solution of titanium tetrachloride and then baking the substrate at a predetermined temperature for a predetermined heating time. be.
  • the predetermined temperature is preferably 300°C or higher and 900°C or lower, and more preferably 450°C or higher and 550°C or lower.
  • the predetermined heating time is preferably 20 minutes or more and 600 minutes or less, more preferably 60 minutes or more and 180 minutes or less.
  • interfacial treatment the surface of the electron transport layer 12 formed on the substrate 10 is subjected to interfacial treatment (S103).
  • the interfacial treatment is, for example, a treatment in which a silane coupling agent is applied to the surface of the electron transport layer 12 by spin coating, and the substrate 10 is baked at a predetermined temperature for a predetermined heating time.
  • the rotation speed is preferably 500 rpm or more and 3000 rpm or less, more preferably 1000 rpm or more and 2000 rpm or less.
  • the predetermined temperature is preferably 50° C. or higher and 150° C. or lower, more preferably 80° C. or higher and 120° C. or lower.
  • the predetermined heating time is preferably 1 minute or more and 30 minutes or less, more preferably 3 minutes or more and 10 minutes or less.
  • the light absorption layer 13 is formed on the substrate 10 on which the electron transport layer 12 is formed (S104).
  • the substrate 10 on which the electron transport layer 12 is deposited is an example of a substrate on which the light absorbing layer is deposited. The details of the light absorbing layer forming process will be described later.
  • the hole transport layer 14 is formed on the light absorption layer 13 (S105).
  • the hole transport layer 14 is formed by coating the surface of the light absorption layer 13 with a solution obtained by dissolving Spiro-OMeTAD in chlorobenzene, for example, by spin coating.
  • the rotation speed in the spin coating method is preferably 1000 rpm or more and 5000 rpm or less, more preferably 2000 rpm or more and 4000 rpm or less.
  • the predetermined temperature is preferably 20° C. or higher and 180° C. or lower, and more preferably 80° C. or higher and 120° C. or lower.
  • the predetermined heating time is preferably 1 minute or more and 180 minutes or less, more preferably 30 minutes or more and 90 minutes or less.
  • the upper electrode 15 is formed on the hole transport layer 14 (S106).
  • the upper electrode 15 is formed by evaporating a metal such as Au, Ti, Pt or Ni or graphite onto the hole transport layer 14 by a vacuum evaporation method.
  • a metal such as Au, Ti, Pt or Ni or graphite
  • FIG. 3 is a flow chart showing more detailed processing of the light absorbing layer forming step of S104.
  • the first organic substance is vaporized in the atmosphere inside the housing filled with inert gas, and the vapor concentration of the first organic substance inside the housing is adjusted (S201).
  • the housing is, for example, a glove box.
  • the inert gas with which the inside of the housing is filled is, for example, a rare gas such as argon, nitrogen gas, or the like.
  • the internal pressure of the housing is preferably 0.05 MPa or more and 0.15 MPa or less, more preferably 0.09 MPa or more and 0.11 MPa or less.
  • the first organic substance is, for example, chlorobenzene, chloromethane or isopropanol ethanol or a mixture thereof, preferably chlorobenzene.
  • the vapor concentration of the first organic substance is preferably adjusted to 0.01 g or more and 10 g or less with respect to 1 m 3 of inert gas when the internal pressure of the housing is 0.1 MPa, and is 0.1 g or more. And it is more preferable to adjust to 5 g or less.
  • the substrate 10 on which the electron transport layer 12 which has undergone the interface treatment is formed is placed in the inside of the housing filled with the inert gas and the vaporized first organic substance, the vapor concentration of the first organic substance being adjusted in S201. (S202).
  • a precursor solution containing a precursor capable of forming a crystal represented by the composition formula Ag a Bi b I c and a solvent containing a second organic substance different from the first organic substance is deposited on the substrate 10. is applied to the surface of the electron transport layer 12 (S203).
  • the precursors contained in the precursor solution are AgI and BiI3 .
  • the content ratio of AgI and BiI 3 (AgI:BiI 3 ) is 1.5 or more and 4.0 or less.
  • the composition ratios a and b satisfy 1.5 ⁇ a/b ⁇ 4.0.
  • the solvent contained in the precursor solution is, for example, dimethylsulfoxide (DMSO), dimethylformamide (DMF), or n-butylamine, preferably dimethylsulfoxide.
  • the precursor solution is applied onto the electron transport layer 12 by, for example, spin coating.
  • the rotation speed in the spin coating method is preferably 500 rpm or more and 3000 rpm or less, more preferably 1000 rpm or more and 2000 rpm or less.
  • a third organic material different from the second organic material is dropped onto the surface of the electron transport layer 12 as a poor solvent (S204).
  • the third organic substance is, for example, chlorobenzene or benzene, preferably chlorobenzene. Note that the process of S204 may be omitted.
  • the substrate 10 is baked at a predetermined temperature for a predetermined heating time while the precursor solution is applied to the surface of the electron transport layer 12 and the third organic substance is dropped onto the surface of the electron transport layer 12.
  • the predetermined temperature is preferably 50° C. or higher and 180° C. or lower, and more preferably 90° C. or higher and 120° C. or lower.
  • the predetermined heating time is preferably 1 minute or more and 180 minutes or less, more preferably 30 minutes or more and 90 minutes or less. Note that the substrate 10 may be fired while changing the temperature.
  • the light absorbing layer 13 is formed on the electron transporting layer 12, and the light absorbing layer forming process is completed.
  • the temperature of the precursor solution rises through the substrate 10, so that the film containing AgI and BiI 3 is redissolved by the solvent remaining in the film to form AgI and BiI.
  • the crystal quality of 3 may deteriorate.
  • Dropping the third organic substance as a poor solvent in S204 suppresses redissolution of the film containing AgI and BiI 3 , thereby preventing deterioration of crystal quality.
  • the atmosphere is filled with the first organic substance that functions as a poor solvent, so that the poor solvent is supplied from the atmosphere. is suppressed, and deterioration of crystal quality is prevented.
  • FIG. 4(A) is a diagram showing the (110) plane in the crystal structure 20 included in the light absorption layer 13 formed as described above.
  • FIG. 4B is a diagram showing the (018) plane in the crystal structure 20 included in the light absorption layer 13.
  • FIG. 4C is a diagram showing the (003) plane in the crystal structure 20 included in the light absorption layer 13.
  • FIG. 4D is a perspective view of octahedral units of the crystal structure included in the light absorption layer 13.
  • the crystal contained in the light absorption layer 13 is a trigonal crystal in which the structure of a plurality of octahedral units 21 is connected.
  • An I ion 22 is arranged at each of the six vertices of the octahedral unit 21 , and either one of Ag ion 23 and Bi ion 23 is arranged at the center of the octahedral unit 21 .
  • the unit cell included in the crystal structure 20 included in the light absorption layer 13 has a length of 4.35 ⁇ in the a-axis direction and the b-axis direction, and a length of 20.81 ⁇ in the c-axis direction.
  • the I ion 22 contained in one octahedral unit 21 is shared with other adjacent octahedral units 21 .
  • the crystal structure 20 included in the light-absorbing layer 13 has more orderly arrangement of atoms arranged on the (110) plane 25 shown in FIG. It is formed so that the arranged atoms are highly ordered.
  • the crystal structure 20 included in the light absorption layer 13 is arranged on the (003) plane 24 such that the orderliness of the arrangement of atoms arranged on the (003) plane 24 shown in FIG. formed in such a way that the arrangement of the atoms in the Since the crystals contained in the light absorption layer 13 have a highly ordered arrangement of atoms arranged on the (003) plane 24, they have a high degree of order in the c-axis direction.
  • the crystal structure of the light absorption layer 13 described above is measured by an X-ray diffraction method or the like.
  • the angle 2 ⁇ at which the first peak appears is the angle corresponding to the (018) plane of the crystal structure of the light absorption layer 13 .
  • the angle 2 ⁇ at which the second peak appears is the angle corresponding to the (110) plane of the crystal structure of the light absorption layer 13 .
  • the orderliness of the arrangement of atoms arranged on the (018) plane is higher than that of the arrangement of atoms arranged on the (110) plane. Therefore, the height of the first peak appearing at the angle corresponding to the (018) plane is higher than the height of the second peak appearing at the angle corresponding to the (110) plane.
  • the intensity of the first peak is preferably 1.7 times or more the intensity of the second peak, and more preferably 1.7 times or more and 7.0 times or less.
  • the second peak may not appear depending on the orderliness of the arrangement of atoms arranged on the (110) plane.
  • the height of the first peak is higher than the maximum measured value in the range of 41.0° ⁇ 2 ⁇ 42.0° when X-ray diffraction measurement is performed.
  • the intensity of the first peak is 1.7 times or more and 1.7 times or more and 7.0 times or less the intensity of the maximum measured value in the range of 41.0 ° ⁇ 2 ⁇ ⁇ 42.0 ° Preferably.
  • the angle 2 ⁇ at which the maximum peak appears is the angle corresponding to the (003) plane of the crystal structure of the light absorption layer 13 .
  • a third peak appears in the range of 28.0° ⁇ 2 ⁇ 32.0°.
  • the intensity of the maximum peak is preferably 1.2 times or more the intensity of the third peak.
  • the light-absorbing layer 13 is represented by the composition formula Ag a Bi b I c , in which a plurality of octahedral units each composed of six I ions are connected, and each of the plurality of octahedral units It includes a crystal having a structure in which either Ag ions or Bi ions are arranged in the center.
  • the composition ratios a and b satisfy 1.5 ⁇ a/b ⁇ 4.0.
  • the light absorption layer 13 makes it possible to improve the conversion efficiency of photoelectric conversion.
  • the photoelectric conversion element 1 includes a light absorption layer 13 formed on the transport layer, an electron transport layer 12 formed on one surface of the light absorption layer 13, and a light absorption layer 13 formed on the other surface of the light absorption layer 13. and a deposited hole transport layer 14 .
  • the light absorption layer 13 makes it possible to improve the conversion efficiency of photoelectric conversion.
  • the substrate 10 on which the electron transport layer 12 is formed is placed in an atmosphere filled with an inert gas and vaporized chlorobenzene, and the precursor solution is applied to the surface of the electron transport layer 12.
  • the substrate 10 coated with the precursor solution is baked to form the light absorption layer 13 .
  • the precursor solution contains a precursor capable of forming crystals represented by the composition formula Ag a Bi b I c , and the composition ratio a and b in the composition formula satisfies 1.5 ⁇ a/b ⁇ 4.0.
  • the light-absorbing layer forming process can prevent deterioration of the crystal quality of the light-absorbing layer 13 and further improve the photoelectric conversion efficiency of the light-absorbing layer 13 .
  • the photoelectric conversion element 1 is of the forward structure type, but the photoelectric conversion element may be of the reverse structure type.
  • the reverse structure type photoelectric conversion element includes a substrate, a lower conductive layer formed on the substrate, a hole transport layer formed on the lower conductive layer, and a light layer formed on the hole transport layer. It has an absorption layer, an electron transport layer deposited on the light absorption layer, and an upper electrode deposited on the electron transport layer.
  • the light absorption layer contains crystals represented by the composition formula Ag a Bi b I c similarly to the photoelectric conversion element 1, and is 42.0° ⁇ 2 ⁇ when measured by X-ray diffraction.
  • the first peak appears in the range of ⁇ 43.0 °, and the intensity ratio between the first peak and the maximum measured value in the range of 41.0 ° ⁇ 2 ⁇ ⁇ 42.0 ° when measured by X-ray diffraction is 1 .7 or more.
  • the electron-transporting layer is formed on one side of the light-absorbing layer, and the hole-transporting layer is formed on the other side of the light-absorbing layer.
  • Photoelectric conversion elements according to Examples 1 to 6 were manufactured by the manufacturing method described above.
  • a glass with FTO manufactured by Peccel Technologies, Inc. was prepared as the substrate 10 on which the lower conductive layer 11 was formed.
  • the FTO glass was UV ozone cleaned for 20 minutes.
  • the glass with FTO was heated to 450°C with a hot plate.
  • a solution containing tetrakis(2,4-pentanedionato) titanium(IV) was then sprayed onto the FTO.
  • the glass with FTO was baked at 500° C. for 1 hour to form the first layer of the electron transport layer.
  • the FTO-equipped glass was immersed in an aqueous solution of titanium tetrachloride, and then baked at 500° C. for 1 hour to form the second layer of the electron transport layer.
  • the surface of the electron transport layer was subjected to interfacial treatment.
  • a silane coupling agent (KBE-903) manufactured by Shin-Etsu Chemical Co., Ltd. was applied to the surface of the electron transport layer 12 by spin coating.
  • the rotation speed in the spin coating method was 1500 rpm.
  • the interface-treated glass with FTO was fired at 100° C. for 5 minutes.
  • a light absorbing layer was formed as described below.
  • chlorobenzene was vaporized in the atmosphere inside the nitrogen-filled glove box to adjust the vapor concentration of chlorobenzene.
  • a precursor solution was applied to the surface of the electron transport layer.
  • the content ratio of AgI and BiI 3 contained in the precursor solution was set to different values in Examples 1-6.
  • the solvent contained in the precursor solution was dimethylsulfoxide.
  • the precursor solution was applied by spin coating. The rotation speed in the spin coating method was 1500 rpm.
  • the glass with FTO was fired at 90°C for 5 minutes.
  • the light absorption layer was formed as described above.
  • a hole-transporting layer was deposited on the light-absorbing layer.
  • the hole transport layer was formed by applying a solution of Spiro-OMeTAD in chlorobenzene to the surface of the light absorption layer 13 by spin coating.
  • the rotation speed in the spin coating method was 3000 rpm.
  • an upper electrode was formed by depositing a metal on the hole transport layer by a vacuum deposition method. As described above, photoelectric conversion elements according to Examples 1 to 6 were manufactured.
  • X-ray diffraction measurements were performed on the light absorption layers according to Examples 1 to 6 and Comparative Example. Further, power generation efficiency was measured for the photoelectric conversion elements according to Examples 1 to 6 and Comparative Example.
  • the measurement conditions for X-ray diffraction measurement and power generation efficiency measurement are as follows.
  • Table 1 shows the composition ratio a/b of the light absorption layer according to Examples 1 to 6 and Comparative Example, the chlorobenzene vapor concentration adjusted in S201, and the power generation efficiency of the photoelectric conversion elements according to Examples 1 to 6.
  • "high concentration” indicates that 0.5 g or more of chlorobenzene vapor is contained per 1 m 3 of nitrogen, and "no" indicates that the nitrogen contains no chlorobenzene vapor.
  • Examples 1 and 2 have the same composition ratio and chlorobenzene vapor concentration, the atmosphere conditions adjusted in S201, the air flow at the time of production, the atmospheric pressure, the temperature of the atmosphere, the atmospheric temperature, the humidity, and the precursor solution Since different results were obtained due to factors such as the temperature of the solution, the lot of material used in the production, and variations in the adjacent transport layers, they are shown as different examples.
  • the power generation efficiencies of the photoelectric conversion elements according to Examples 1 to 6 were 8.3%, 4.6%, 5.4%, 5.7%, 4.6% and 5.2%, respectively, and all of them were 4. It was a good value exceeding 0.0%. On the other hand, the power generation efficiency of the photoelectric conversion element according to the comparative example was 0.6%.
  • FIGS. 5A and 5B are diagrams showing the waveform W1 of the X-ray diffraction pattern of the light absorption layer according to Example 1.
  • FIG. FIG. 5(B) is an enlarged view of the range of 40.0° ⁇ 2 ⁇ 45.0° in FIG. 5(A).
  • the maximum peak Pm in the range of 11.5° ⁇ 2 ⁇ 14.0°
  • a third peak P3 appeared in the range of 28.0° ⁇ 2 ⁇ 32.0°
  • a first peak P1 appeared in the range of 42.0° ⁇ 2 ⁇ 43.0°.
  • the second peak P2 did not appear.
  • FIGS. 6A and 6B are diagrams showing the waveform W2 of the X-ray diffraction pattern of the light absorption layer according to Example 2.
  • FIG. FIG. 6(B) is an enlarged view of the range of 40.0° ⁇ 2 ⁇ 45.0° in FIG. 6(A).
  • the maximum peak Pm appeared in the range of 11.5° ⁇ 2 ⁇ 14.0°.
  • the third peak P3 appears in the range of 28.0° ⁇ 2 ⁇ 32.0°
  • the second peak P2 appears in the range of 41.0° ⁇ 2 ⁇ 42.0°
  • FIGS. 7A and 7B are diagrams showing the waveform W3 of the X-ray diffraction pattern of the light absorption layer according to Example 3.
  • FIG. FIG. 7(B) is an enlarged view of the range of 40.0° ⁇ 2 ⁇ 45.0° in FIG. 7(A).
  • the maximum peak Pm appeared in the range of 11.5° ⁇ 2 ⁇ 14.0°.
  • the third peak P3 appears in the range of 28.0° ⁇ 2 ⁇ 32.0°
  • the second peak P2 appears in the range of 41.0° ⁇ 2 ⁇ 42.0°
  • a first peak P1 appeared in the range of 43.0°.
  • FIGS. 8A and 8B are diagrams showing the waveform W4 of the X-ray diffraction pattern of the light absorption layer according to Example 4.
  • FIG. FIG. 8(B) is an enlarged view of the range of 40.0° ⁇ 2 ⁇ 45.0° in FIG. 8(A).
  • the maximum peak Pm appeared in the range of 11.5° ⁇ 2 ⁇ 14.0°.
  • the third peak P3 appears in the range of 28.0° ⁇ 2 ⁇ 32.0°
  • the second peak P2 appears in the range of 41.0° ⁇ 2 ⁇ 42.0°
  • FIGS. 9A and 9B are diagrams showing the waveform W5 of the X-ray diffraction pattern of the light absorption layer according to Example 5.
  • FIG. FIG. 9(B) is an enlarged view of the range of 40.0° ⁇ 2 ⁇ 45.0° in FIG. 9(A).
  • the maximum peak Pm appeared in the range of 11.5° ⁇ 2 ⁇ 14.0°.
  • the third peak P3 appears in the range of 28.0° ⁇ 2 ⁇ 32.0°
  • the second peak P2 appears in the range of 41.0° ⁇ 2 ⁇ 42.0°
  • FIGS. 10A and 10B are diagrams showing the waveform W6 of the X-ray diffraction pattern of the light absorption layer according to Example 6.
  • FIG. FIG. 10(B) is an enlarged view of the range of 40.0° ⁇ 2 ⁇ 45.0° in FIG. 10(A).
  • the maximum peak Pm appeared in the range of 11.5° ⁇ 2 ⁇ 14.0°.
  • the third peak P3 appears in the range of 28.0° ⁇ 2 ⁇ 32.0°
  • the second peak P2 appears in the range of 41.0° ⁇ 2 ⁇ 42.0°
  • a first peak P1 appeared in the range of 43.0°.
  • FIGS. 11A and 11B are diagrams showing the waveform W7 of the X-ray diffraction pattern of the light absorption layer according to the comparative example.
  • FIG. 11(B) is an enlarged view of the range of 40.0° ⁇ 2 ⁇ 45.0° in FIG. 11(A).
  • a peak Pm appeared in the range of 11.5° ⁇ 2 ⁇ 14.0°, and 28.0°.
  • a third peak P3 appears in the range of 0° ⁇ 2 ⁇ 32.0°
  • a second peak P2 appears in the range of 41.0° ⁇ 2 ⁇ 42.0°, and 42.0° ⁇ 2 ⁇ 43.0°.
  • a first peak P1 appeared in the range of °. Unlike the photoelectric conversion elements according to Examples 1 to 6, in the waveform W7, the intensity of the third peak P3 is greater than that of the peak Pm. That is, the peak Pm appearing in the range of 11.5° ⁇ 2 ⁇ 14.0° when the photoelectric conversion element according to the comparative example was subjected to X-ray diffraction measurement was not the maximum peak.
  • the intensity ratios P1/P2 of the first peak P1 to the second peak P2 in the photoelectric conversion elements according to Examples 2 to 6 are 7.0 and 1.7, respectively. , 2.7, 4.6 and 5.6, all of which were greater than or equal to 1.7. Further, as shown in Table 1 and FIG. 5, in the photoelectric conversion device according to Example 1, the second peak P2 does not appear, so it can be said that the intensity ratio P1/P2 is infinite. Therefore, in the photoelectric conversion elements according to Examples 1 to 6, the intensity of the first peak P1 is 1.7 times or more the intensity of the maximum measured value in the range of 41.0° ⁇ 2 ⁇ 42.0°. Met. On the other hand, as shown in Table 1 and FIG.
  • the intensity ratio P1/P2 of the first peak P1 to the second peak P2 in the photoelectric conversion element according to the comparative example was 0.3.
  • the intensities of the first peak P1 and the second peak P2 and the maximum measured value in the range of 41.0° ⁇ 2 ⁇ ⁇ 42.0° are all from the measured values shown in FIGS. 5 to 10 to the baseline. It is the value obtained by subtracting the measured value of
  • the crystal structure included in the light absorption layer changed, and the diffraction at the (110) plane of the unit lattice decreased and the diffraction at the (018) plane increased. It is presumed that the height of the peak P1 is higher than the height of the second peak P2.
  • the disturbance of the atomic arrangement on the (110) plane of the unit cell is increased, and the disturbance of the atomic arrangement on the (018) plane of the unit cell is decreased. It is presumed that the height of the first peak P1 is higher than the height of the second peak P2. Diffraction on the (018) plane largely reflects the orderliness in the c-axis direction represented by the (003) plane.
  • the c-axis direction is the direction in which the layers of the center of Ag atoms surrounded by iodine atoms and the center of Bi atoms surrounded by iodine atoms are laminated, and the atomic arrangement is easily disturbed.
  • the fact that the first peak was high in Examples 1 to 6 means that the order of the interatomic distance in the c-axis direction of the atomic arrangement was increased and the number of defects in the atomic arrangement was reduced. is reduced, and the carrier lifetime is assumed to be longer. As a result, carriers are more likely to move in the light absorption layer and more carriers can move in the transport layer, so it is presumed that the power generation efficiency of the photoelectric conversion elements according to Examples 1 to 6 was improved. .
  • the crystal structure of the light absorption layer according to the embodiment is considered to be specified mainly by the first peak P1 appearing when X-ray diffraction is measured. This is because the second peak P2 is very small in the light absorption layer with good power generation efficiency.
  • the intensity of the first peak may change depending on the conditions of the X-ray diffraction measurement, in order to specify the intensity of the first peak, the maximum The intensity ratio to the measured value (intensity of the second peak when the second peak appears) was used.
  • the The intensity ratio Pm/P3 of the maximum peak Pm appearing to the third peak P3 appearing at 28.0° ⁇ 2 ⁇ 32.0°, specifically at 29.28°, is 1.7, 2.1, 1 .2, 1.2, 2.2 and 1.2. That is, the intensity of the maximum peak Pm was 1.2 times or more the intensity of the third peak P3.
  • the maximum peak Pm was a peak appearing at an angle of 12.76° corresponding to the (003) plane. presumed to have been high.
  • the light-absorbing layers of the photoelectric conversion elements according to Examples 1 to 6 had a high degree of order in the c-axis direction and few crystal defects contained in the light-absorbing layers. It is presumed that the loss due to the recombination of the fuel was reduced, and the power generation efficiency was improved due to the improvement of the transportation performance.
  • the peak appearing at 12.76° in the photoelectric conversion element according to the comparative example was not the maximum peak of the X-ray diffraction pattern. It is presumed that the light absorption layer did not have high orderliness in the c-axis direction.
  • the light-absorbing layer of the photoelectric conversion element according to the comparative example has a low degree of order in the c-axis direction, and many defects are formed in the crystals included in the light-absorbing layer. It is presumed that the loss due to the recombination of the fuel increased and the power generation efficiency decreased due to the deterioration of the transport performance.
  • the intensity ratio of the peak Pm appearing at 12.76° to the third peak P3 was 0.9.

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Abstract

Provided are a light absorption layer and the like that enable improvement in conversion efficiency of a photoelectric conversion element. This light absorption layer includes a crystal having a structure which is indicated by a composition formula AgaBibIc, in which a plurality of octahedral units, each formed of six I ions, are connected, and in which an either one of Ag ion and Bi ion is positioned at each of the centers of the plurality of octahedral units. In the composition formula, a composition ratio between a and b satisfies 1.5≤a/b≤4.0. When an X-ray diffraction measurement is performed, a first peak appears in a range of 42.0°≤2θ≤43.0°. The intensity of the first peak is 1.7 times or more the intensity of the maximum measured value in a range of 41.0°≤2θ≤42.0° as measured by the X-ray diffraction.

Description

光吸収層及び光吸収層の形成方法、並びに光電変換素子Light absorption layer, method for forming light absorption layer, and photoelectric conversion element
　本発明は、光吸収層及び光吸収層の形成方法、並びに光電変換素子に関する。 The present invention relates to a light absorption layer, a method for forming the light absorption layer, and a photoelectric conversion element.
　組成式ＡｇaＢｉbＩcで示され、それぞれ六つのヨウ素（Ｉ）からなる複数の八面体単位が稜上の二つのＩイオンを互いに共有して連なった構造を有し、光電変換素子の光吸収層として使用される膜が知られている（例えば、特許文献１を参照）。特許文献１に記載される膜は、太陽電池素子の光吸収層として使用可能であり、Ｘ線回折測定したとき、回折強度の最大のピークが２５°≦２θ≦３５°の範囲に現れる。特許文献１に記載される膜は、Ｘ線回折測定したとき、最大のピークが２５°≦２θ≦３５°の範囲に現れるような結晶構造を有することで、鉛等を含有せず毒性が低く且つ電気的及び光学的に利用可能である。 It is represented by the composition formula Ag a Bi b I c , and has a structure in which a plurality of octahedral units each consisting of six iodine (I) are connected while sharing two I ions on the edges, and a photoelectric conversion device Films used as light absorbing layers are known (see, for example, Patent Document 1). The film described in Patent Document 1 can be used as a light absorption layer of a solar cell element, and when measured by X-ray diffraction, the maximum diffraction intensity peak appears in the range of 25°≦2θ≦35°. The film described in Patent Document 1 has a crystal structure in which the maximum peak appears in the range of 25° ≤ 2θ ≤ 35° when measured by X-ray diffraction, so that it does not contain lead or the like and has low toxicity. and is electrically and optically available.
　非特許文献１には、ヨウ化銀ビスマス系の薄膜をＸ線回折測定したときに２θ≒４２°にピークが現れること、およびＡｇＩのＢｉＩ３に対するモル比が大きくなるとピークが分裂することが記載されている。 Non-Patent Document 1 describes that a peak appears at 2θ≈42° when a silver bismuth iodide-based thin film is measured by X-ray diffraction, and that the peak splits as the molar ratio of AgI to BiI 3 increases. It is
特開２０１８－３０７３０号公報JP 2018-30730 A
　太陽電池素子等のエネルギーを電気エネルギーに変換する光電変換素子において、変換効率の更なる向上が望まれている。 Further improvement in conversion efficiency is desired in photoelectric conversion elements such as solar cell elements that convert energy into electrical energy.
　実施形態に係る光吸収層及び光吸収層の形成方法並びに光電変換素子は、光電変換の変換効率を向上させることを可能とする。 The light-absorbing layer, the method for forming the light-absorbing layer, and the photoelectric conversion element according to the embodiment make it possible to improve the conversion efficiency of photoelectric conversion.
　本発明の実施形態に係る光吸収層は、組成式ＡｇaＢｉbＩcで示され、それぞれ六つのＩイオンからなる複数の八面体単位が連接され、且つ、複数の八面体単位のそれぞれの中心にＡｇイオン及びＢｉイオンの何れかが配置される構造を有する結晶を含み、組成式において、組成比ａ及びｂは、１．５≦ａ／ｂ≦４．０を満たし、Ｘ線回折測定したとき、４２．０°≦２θ≦４３．０°の範囲に第１ピークが現れ、第１ピークの強度は、Ｘ線回折測定したときの４１．０°≦２θ＜４２．０°の範囲における最大の測定値の強度に対して１．７倍以上である、ことを特徴とする。 The light-absorbing layer according to the embodiment of the present invention is represented by the composition formula Ag a Bi b I c , in which a plurality of octahedral units each consisting of six I ions are connected, and each of the plurality of octahedral units A crystal having a structure in which either Ag ions or Bi ions are arranged in the center, and in the composition formula, the composition ratio a and b satisfies 1.5 ≤ a / b ≤ 4.0, and X-ray diffraction measurement Then, a first peak appears in the range of 42.0° ≤ 2θ ≤ 43.0°, and the intensity of the first peak is in the range of 41.0° ≤ 2θ < 42.0° when measured by X-ray diffraction. It is characterized by being 1.7 times or more the intensity of the maximum measured value in .
　また、実施形態に係る光吸収層において、Ｘ線回折測定したとき、４１．０°≦２θ＜４２．０°の範囲に第２ピークが現れ、第１ピークの強度は、第２ピークの強度に対して１．７倍以上且つ７．０倍以下であることが好ましい。 In addition, in the light absorption layer according to the embodiment, when X-ray diffraction measurement is performed, a second peak appears in the range of 41.0 ° ≤ 2θ < 42.0 °, and the intensity of the first peak is the intensity of the second peak is preferably 1.7 times or more and 7.0 times or less.
　また、実施形態に係る光吸収層において、Ｘ線回折測定したとき、最大のピークが１１．５°≦２θ≦１４．０°の範囲に現れることが好ましい。 In addition, in the light absorption layer according to the embodiment, it is preferable that the maximum peak appears in the range of 11.5°≦2θ≦14.0° when X-ray diffraction measurement is performed.
　また、実施形態に係る光吸収層において、Ｘ線回折測定したとき、２８．０°≦２θ＜３２．０°の範囲に第３ピークが現れ、最大のピークの強度は、第３ピークの強度に対して１．２倍以上であることが好ましい。 In addition, in the light absorption layer according to the embodiment, when X-ray diffraction measurement is performed, a third peak appears in the range of 28.0 ° ≤ 2θ < 32.0 °, and the intensity of the maximum peak is the intensity of the third peak is preferably 1.2 times or more.
　本発明の実施形態に係る光電変換素子は、輸送層上に成膜され、組成式ＡｇaＢｉbＩcで示される結晶を含む光吸収層と、光吸収層の一方の面に成膜された電子輸送層と、光吸収層の他方の面に成膜された正孔輸送層と、を有し、組成式において、組成比ａ及びｂは、１．５≦ａ／ｂ≦４．０を満たし、光吸収層をＸ線回折測定したとき、４２．０°≦２θ≦４３．０°の範囲に第１ピークが現れ、第１ピークの強度は、Ｘ線回折測定したときの４１．０°≦２θ＜４２．０°の範囲における最大の測定値の強度に対して１．７倍以上である、ことを特徴とする。 A photoelectric conversion element according to an embodiment of the present invention includes a film formed on a transport layer, a light absorption layer containing crystals represented by a composition formula Ag a Bi b I c , and a film formed on one surface of the light absorption layer. and a hole transport layer formed on the other side of the light absorption layer, and in the composition formula, the composition ratios a and b are 1.5 ≤ a/b ≤ 4.0 , the first peak appears in the range of 42.0° ≤ 2θ ≤ 43.0°, and the intensity of the first peak is 41.0° in the X-ray diffraction measurement. It is characterized by being 1.7 times or more the intensity of the maximum measured value in the range of 0°≦2θ<42.0°.
　本発明の実施形態に係る光吸収層の形成方法は、不活性ガス及び気化した第１有機物が充填された雰囲気中に基材を配置し、組成式ＡｇaＢｉbＩcで示される結晶を形成可能な前駆体と、第１有機物と異なる第２有機物を含有する溶媒とを含有する前駆体溶液を基材の表面に塗布し、前駆体溶液が基材の表面に塗布された基材を焼成することによって、組成式における組成比ａ及びｂが１．５≦ａ／ｂ≦４．０を満たす光吸収層を形成する、ことを含み、第１有機物は、クロロベンゼンである、ことを特徴とする。 In the method for forming a light absorption layer according to an embodiment of the present invention, a substrate is placed in an atmosphere filled with an inert gas and a vaporized first organic substance, and a crystal represented by the composition formula Ag a Bi b I c is formed. applying a precursor solution containing a formable precursor and a solvent containing a second organic substance different from the first organic substance to the surface of the substrate; By firing, a light absorption layer is formed in which the composition ratio a and b in the composition formula satisfies 1.5≦a/b≦4.0, wherein the first organic substance is chlorobenzene. and
　また、光吸収層の形成方法は、前駆体溶液を基材の表面に塗布する間に、第２有機物と異なる第３有機物を貧溶媒として基材の表面に滴下する、ことを更に含むことが好ましい。 In addition, the method for forming the light absorbing layer may further include dripping a third organic substance different from the second organic substance as a poor solvent onto the surface of the substrate while the precursor solution is being applied to the surface of the substrate. preferable.
　本発明の目的及び効果は、特に請求項に記載された構成及びその組み合わせを用いることにより認識され、及び得られるものである。前述の簡単な説明及び後述の詳細な説明は、例示的及び説明的なものであり、本発明の技術的範囲を限定するものではない。 The objects and effects of the present invention are recognized and obtained by using the configurations and combinations thereof particularly described in the claims. The foregoing brief description and the following detailed description are exemplary and explanatory and are not intended to limit the scope of the invention.
実施形態に係る光電変換素子１の断面図である。1 is a cross-sectional view of a photoelectric conversion element 1 according to an embodiment; FIG. 光電変換素子１の製造方法を示すフローチャートである。4 is a flow chart showing a method for manufacturing the photoelectric conversion element 1. FIG. 光吸収層成膜工程のより詳細な処理を示すフローチャートである。It is a flowchart which shows the more detailed process of a light absorption layer film-forming process. （Ａ）は光吸収層１３に含まれる結晶構造の（１１０）面を示し、（Ｂ）は光吸収層１３に含まれる結晶構造の（０１８）面を示し、（Ｃ）は光吸収層１３に含まれる結晶構造の（００３）面を示し、（Ｄ）は光吸収層１３に含まれる八面体単位の斜視図である。(A) shows the (110) plane of the crystal structure contained in the light absorption layer 13, (B) shows the (018) plane of the crystal structure contained in the light absorption layer 13, and (C) shows the light absorption layer 13. 3D is a perspective view of octahedral units contained in the light absorption layer 13. FIG. （Ａ）及び（Ｂ）は、実施例１に係る光吸収層のＸ線回折パターンを示す図である。3A and 3B are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 1; FIG. （Ａ）及び（Ｂ）は、実施例２に係る光吸収層のＸ線回折パターンを示す図である。(A) and (B) are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 2. FIG. （Ａ）及び（Ｂ）は、実施例３に係る光吸収層のＸ線回折パターンを示す図である。(A) and (B) are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 3. FIG. （Ａ）及び（Ｂ）は、実施例４に係る光吸収層のＸ線回折パターンを示す図である。(A) and (B) are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 4. FIG. （Ａ）及び（Ｂ）は、実施例５に係る光吸収層のＸ線回折パターンを示す図である。(A) and (B) are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 5. FIG. （Ａ）及び（Ｂ）は、実施例６に係る光吸収層のＸ線回折パターンを示す図である。(A) and (B) are diagrams showing X-ray diffraction patterns of a light absorption layer according to Example 6. FIG. （Ａ）及び（Ｂ）は、比較例に係る光吸収層のＸ線回折パターンを示す図である。(A) and (B) are diagrams showing X-ray diffraction patterns of light absorption layers according to comparative examples.
　以下、本発明の好適な実施形態に係る光吸収層及び光電変換素子を、図面を参照して説明する。ただし、本発明の技術的範囲はそれらの実施形態に限定されず、特許請求の範囲に記載された発明とその均等物に及ぶ点に留意されたい。 A light absorption layer and a photoelectric conversion element according to preferred embodiments of the present invention will be described below with reference to the drawings. However, it should be noted that the technical scope of the present invention is not limited to those embodiments, but extends to the invention described in the claims and equivalents thereof.
　用語「光電変換素子」は、光エネルギーを電気エネルギーに変換する素子を示し、屋内光及び太陽光を含む光エネルギーを電気エネルギーに変換する太陽電池素子、光電池素子、及び光起電素子を含む。実施形態に係る光電変換素子は、ソーラーパネルとも称される太陽電池モジュール及び携帯機器等の電源装置として使用されてもよい。 The term "photoelectric conversion element" refers to an element that converts light energy into electrical energy, and includes solar cell elements, photoelectric cell elements, and photovoltaic elements that convert light energy, including indoor light and sunlight, into electrical energy. The photoelectric conversion element according to the embodiment may be used as a solar cell module, which is also called a solar panel, and a power supply device for mobile devices and the like.
　図１は、実施形態に係る光電変換素子１の断面図である。 FIG. 1 is a cross-sectional view of a photoelectric conversion element 1 according to an embodiment.
　光電変換素子１は、基板１０と、下部導電層１１と、電子輸送層１２と、光吸収層１３と、正孔輸送層１４と、上部電極１５とを有し、基板１０上に、下部導電層１１、電子輸送層１２、光吸収層１３、正孔輸送層１４及び上部電極１５が順次積層される。すなわち、光電変換素子１において、電子輸送層１２は光吸収層１３の一方の面に成膜され、正孔輸送層１４は光吸収層１３の他方の面に成膜される。光電変換素子１は、基板１０及び下部導電層１１を介して光が入射されることに応じて、下部導電層１１と上部電極１５との間に電圧を発生すると共に、上部電極１５から電流を出力する順構造型の太陽電池素子である。 The photoelectric conversion element 1 has a substrate 10, a lower conductive layer 11, an electron transport layer 12, a light absorption layer 13, a hole transport layer 14, and an upper electrode 15. A lower conductive layer is formed on the substrate 10. A layer 11, an electron transport layer 12, a light absorption layer 13, a hole transport layer 14 and an upper electrode 15 are sequentially laminated. That is, in the photoelectric conversion element 1 , the electron transport layer 12 is formed on one surface of the light absorption layer 13 , and the hole transport layer 14 is formed on the other surface of the light absorption layer 13 . The photoelectric conversion element 1 generates a voltage between the lower conductive layer 11 and the upper electrode 15 and current from the upper electrode 15 in response to light incident through the substrate 10 and the lower conductive layer 11 . This is a forward structure type solar cell element that outputs power.
　基板１０は、絶縁性のガラス基板等の、光電変換素子１に含まれる構成要素を支持可能であり、且つ光電変換素子１に入射する入射光を透過する透明な材料により形成される。透明な材料は、光吸収層１３で吸収される波長領域の光を透過する材料であり、光吸収層１３で吸収される波長領域の光の透過率が８０％以上の材料であることが好ましく、光吸収層１３で吸収される波長領域の光の透過率が９５％以上であることが更に好ましい。基板１０は、導電性材料によって形成されてもよい。 The substrate 10 is made of a transparent material such as an insulating glass substrate that can support components included in the photoelectric conversion element 1 and that transmits incident light that enters the photoelectric conversion element 1 . The transparent material is a material that transmits light in the wavelength region absorbed by the light absorption layer 13, and preferably has a transmittance of 80% or more for light in the wavelength region absorbed by the light absorption layer 13. It is more preferable that the transmittance of light in the wavelength region absorbed by the light absorption layer 13 is 95% or more. Substrate 10 may be formed of a conductive material.
　下部導電層１１は、基板１０と同様に透明であり、且つ電子を高効率で輸送可能な、例えばシート抵抗が１０Ω以下の低抵抗な材料により、基板１０を覆うように基板１０上に成膜される。下部導電層１１は、例えば、高温の熱処理による抵抗率の変化が少なく、透明であり且つ導電性が高いフッ素添加酸化スズ（ＦＴＯ）により形成される薄膜である。下部導電層１１は、例えばスズ添加酸化インジウム（ＩＴＯ）、アルミ添加酸化亜鉛（ＡＺＯ）、ガリウム添加酸化亜鉛（ＧＺＯ）及びニオブ添加酸化チタン（ＮＴＯ）より形成される薄膜であってもよい。下部導電層１１は、０．０１μｍ以上１０．０μｍ以下の厚さを有することが好ましく、０．０５μｍ以上１．０μｍ以下の厚さを有することが更に好ましい。 The lower conductive layer 11 is formed on the substrate 10 so as to cover the substrate 10 by using a material that is transparent like the substrate 10 and that is capable of transporting electrons with high efficiency and has a low resistance, for example, a sheet resistance of 10Ω or less. be done. The lower conductive layer 11 is, for example, a thin film formed of fluorine-added tin oxide (FTO), which has little change in resistivity due to high-temperature heat treatment, is transparent, and has high conductivity. The lower conductive layer 11 may be a thin film formed of, for example, tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), and niobium-doped titanium oxide (NTO). The lower conductive layer 11 preferably has a thickness of 0.01 μm to 10.0 μm, more preferably 0.05 μm to 1.0 μm.
　電子輸送層１２は、光吸収層１３で発生した正孔をブロックすると共に、光吸収層１３で発生した電子を下部導電層１１に高効率で輸送するｎ形半導体であり、下部導電層１１を覆うように下部導電層１１上に成膜される。電子輸送層１２は、電子輸送特性が高い材料で形成されることが好ましい。電子輸送層１２は、例えば酸化チタン（ＴｉＯ2等）、酸化スズ（ＳｎＯ2等）、酸化タングステン（ＷＯ2等）、酸化亜鉛（ＺｎＯ）及び酸化アルミニウム（Ａｌ2Ｏ3）等の金属酸化物により形成される。電子輸送層１２は、５ｎｍ以上２００ｎｍ以下の厚さを有することが好ましく、２０ｎｍ以上６０ｎｍ以下の厚さを有することが更に好ましい。 The electron transport layer 12 is an n-type semiconductor that blocks holes generated in the light absorption layer 13 and transports electrons generated in the light absorption layer 13 to the lower conductive layer 11 with high efficiency. A film is formed on the lower conductive layer 11 so as to cover it. The electron transport layer 12 is preferably made of a material with high electron transport properties. The electron transport layer 12 is made of metal oxide such as titanium oxide (TiO 2 etc.), tin oxide (SnO 2 etc.), tungsten oxide (WO 2 etc.), zinc oxide (ZnO) and aluminum oxide (Al 2 O 3 ). Formed by The electron transport layer 12 preferably has a thickness of 5 nm or more and 200 nm or less, more preferably 20 nm or more and 60 nm or less.
　光吸収層１３は、組成式ＡｇaＢｉbＩcで示される材料によって形成され、電子輸送層１２上に成膜される。組成式ＡｇaＢｉbＩcにおいて、ａ、ｂ及びｃは組成比を示し、ｃ＝ａ＋３ｂを満たし、１．５≦ａ／ｂ≦４．０であることが好ましい。光吸収層１３は、１０ｎｍ以上１００００ｎｍ以下の厚さを有することが好ましく、２０ｎｍ以上９００ｎｍ以下の厚さを有することが更に好ましい。光吸収層１３は、下部導電層１１及び電子輸送層１２を介して入射された光を吸収する。吸収した光により電子が励起され、電子及び正孔が光吸収層１３の内部に発生する。光吸収層１３の内部に発生した正孔は正孔輸送層１４を介して上部電極１５に輸送され、光吸収層１３の内部に発生した電子は電子輸送層１２を介して下部導電層１１に輸送される。このようにして、光電変換素子１に起電力が発生する。 The light absorption layer 13 is made of a material represented by the composition formula Ag a Bi b I c and deposited on the electron transport layer 12 . In the compositional formula Ag a Bi b I c , a, b, and c represent the composition ratio, c=a+3b, and preferably 1.5≦a/b≦4.0. The light absorption layer 13 preferably has a thickness of 10 nm or more and 10000 nm or less, more preferably 20 nm or more and 900 nm or less. The light absorption layer 13 absorbs light incident through the lower conductive layer 11 and the electron transport layer 12 . Electrons are excited by the absorbed light, and electrons and holes are generated inside the light absorption layer 13 . Holes generated inside the light absorption layer 13 are transported to the upper electrode 15 through the hole transport layer 14, and electrons generated inside the light absorption layer 13 are transported to the lower conductive layer 11 through the electron transport layer 12. be transported. Thus, an electromotive force is generated in the photoelectric conversion element 1 .
　正孔輸送層１４は、セレン、ヨウ化銅（ＣｕＩ）等のヨウ化物、層状コバルト酸化物等のコバルト錯体、ＣｕＳＣＮ、酸化モリブデン（ＭｏＯ3等）、酸化ニッケル（ＮｉＯ等）、４ＣｕＢｒ・３Ｓ（Ｃ4Ｈ9）及び有機ホール輸送材等によって形成される。有機ホール輸送材は、例えば、ポリ－３－ヘキシルチオフェン（Ｐ３ＨＴ）、ポリエチレンジオキシチオフェン（ＰＥＤＯＴ）等のポリチオフェン誘導体、２，２'，７，７'－テトラキス－（Ｎ，Ｎ－ジ－ｐ－メトキシフェニルアミン）－９，９'－スピロビフルオレン（spiro-MeO-TAD）等のフルオレン誘導体、ポリビニルカルバゾール等のカルバゾール誘導体、ポリ［ビス（４－フェニル）（２，４，６－トリフェニルメチル）アミン］（ＰＴＡＡ）等のトリフェニルアミン誘導体、ジフェニルアミン誘導体、ポリシラン誘導体、ポリアニリン誘導体等である。正孔輸送層１４は、０．０１μｍ以上１０μｍ以下の厚さを有することが好ましいが、これに限定されない。 The hole transport layer 14 is made of selenium, iodides such as copper iodide (CuI), cobalt complexes such as layered cobalt oxide, CuSCN, molybdenum oxide (such as MoO 3 ), nickel oxide (such as NiO), 4CuBr·3S ( C 4 H 9 ) and an organic hole transport material. Examples of organic hole transport materials include poly-3-hexylthiophene (P3HT), polythiophene derivatives such as polyethylenedioxythiophene (PEDOT), 2,2′,7,7′-tetrakis-(N,N-di-p -methoxyphenylamine)-9,9'-spirobifluorene (spiro-MeO-TAD) and other fluorene derivatives, polyvinylcarbazole and other carbazole derivatives, poly[bis(4-phenyl)(2,4,6-triphenyl methyl)amine] (PTAA), diphenylamine derivatives, polysilane derivatives, polyaniline derivatives and the like. The hole transport layer 14 preferably has a thickness of 0.01 μm or more and 10 μm or less, but is not limited thereto.
　上部電極１５は、金層（Ａｕ）等の金属層であり、正孔輸送層１４上に成膜される。上部電極１５は、チタン（Ｔｉ）層上に金層（Ａｕ）が成膜されたＴｉ／Ａｕ層であってもよい。上部電極１５は、正孔輸送層１４と接触する材料により形成されればよく、仕事関数が比較的大きいＡｕ、Ｐｔ若しくはＮｉ等の金属又はグラファイト等の炭素系電極によって形成されてもよい。上部電極１５は、２ｎｍ以上２００ｎｍ以下の厚さを有することが好ましい。上部電極１５の厚さが２ｎｍよりも薄いとき、上部電極１５が延伸する延伸方向の抵抗値が高くなるため、正孔の収集効率が低下して光電変換素子１の変換効率が低下する。上部電極１５の厚さが２００ｎｍよりも厚いとき、上部電極１５の膜厚方向の抵抗値が高くなるため、光電変換素子１の変換効率が低下すると共に、上部電極１５を形成する材料の量が増加するため、製造コストが高くなる。 The upper electrode 15 is a metal layer such as a gold layer (Au) and is deposited on the hole transport layer 14 . The upper electrode 15 may be a Ti/Au layer in which a gold layer (Au) is deposited on a titanium (Ti) layer. The upper electrode 15 may be formed of a material that contacts the hole transport layer 14, and may be formed of a metal such as Au, Pt, or Ni having a relatively large work function, or a carbon-based electrode such as graphite. The upper electrode 15 preferably has a thickness of 2 nm or more and 200 nm or less. When the thickness of the upper electrode 15 is less than 2 nm, the resistance value in the direction in which the upper electrode 15 extends increases, so that the hole collection efficiency decreases and the conversion efficiency of the photoelectric conversion element 1 decreases. When the thickness of the upper electrode 15 is thicker than 200 nm, the resistance value of the upper electrode 15 in the film thickness direction increases, so that the conversion efficiency of the photoelectric conversion element 1 decreases and the amount of material forming the upper electrode 15 increases. This increases manufacturing costs.
　図２は、光電変換素子１の製造方法を示すフローチャートである。 FIG. 2 is a flow chart showing a method for manufacturing the photoelectric conversion element 1. FIG.
　まず、基板準備工程において、下部導電層１１が成膜された基板１０が準備される（Ｓ１０１）。下部導電層１１が成膜された基板１０は、例えば一方の面にＦＴＯが形成された平板状のガラス基板である。下部導電層１１が成膜された基板１０には、ＵＶオゾン洗浄処理等の洗浄処理が施されることが好ましい。 First, in the substrate preparation process, the substrate 10 on which the lower conductive layer 11 is formed is prepared (S101). The substrate 10 on which the lower conductive layer 11 is formed is, for example, a flat glass substrate with FTO formed on one surface. The substrate 10 on which the lower conductive layer 11 is formed is preferably subjected to cleaning treatment such as UV ozone cleaning treatment.
　次いで、電子輸送層成膜工程において、電子輸送層１２が下部導電層１１上に成膜される（Ｓ１０２）。電子輸送層１２は、ＦＴＯ上に成膜される。電子輸送層１２は、第１層を成膜した後に、第２層を成膜することにより形成される。 Next, in the electron transport layer deposition step, the electron transport layer 12 is deposited on the lower conductive layer 11 (S102). An electron transport layer 12 is deposited on the FTO. The electron transport layer 12 is formed by depositing the second layer after depositing the first layer.
　第１層は、スプレー熱分解法により成膜される。スプレー熱分解法では、下部導電層１１が成膜された基板１０が第１の温度で加熱され。その後、下部導電層１１上にチタンキレート化合物を含む溶液が噴霧される。その後、溶液が噴霧された基板１０が第２の温度で所定の加熱時間に亘って焼成する。噴霧される溶液に含まれるチタンキレート化合物は、例えば、テトラキス（２，４－ペンタンジオナート）チタニウム（IV）又はジイソプロポキシチタニウム（IV）ビス（アセチルアセトナート）である。 The first layer is formed by spray pyrolysis. In the spray pyrolysis method, the substrate 10 with the lower conductive layer 11 formed thereon is heated at a first temperature. A solution containing a titanium chelate compound is then sprayed onto the lower conductive layer 11 . After that, the substrate 10 sprayed with the solution is baked at a second temperature for a predetermined heating time. Titanium chelate compounds contained in the sprayed solution are, for example, tetrakis(2,4-pentanedionato)titanium(IV) or diisopropoxytitanium(IV) bis(acetylacetonate).
　第１層を成膜するためのスプレー熱分解法において、第１の温度は３００℃以上であり且つ６００℃以下であることが好ましく、４００℃以上であり且つ５００℃以下であることが更に好ましい。第２の温度は３００℃以上であり且つ９００℃以下であることが好ましく、４５０℃以上であり且つ５５０℃以下であることが更に好ましい。所定の加熱時間は３０分以上であり且つ６００分以下であることが好ましく、６０分以上であり且つ１８０分以下であることが更に好ましい。 In the spray pyrolysis method for forming the first layer, the first temperature is preferably 300° C. or higher and 600° C. or lower, more preferably 400° C. or higher and 500° C. or lower. . The second temperature is preferably 300° C. or higher and 900° C. or lower, and more preferably 450° C. or higher and 550° C. or lower. The predetermined heating time is preferably 30 minutes or more and 600 minutes or less, more preferably 60 minutes or more and 180 minutes or less.
　第２層は、下部導電層１１及び第１層が成膜された基板１０が四塩化チタン水溶液に浸漬された後に、所定の温度で所定の加熱時間に亘って焼成されることで成膜される。 The second layer is formed by immersing the substrate 10 having the lower conductive layer 11 and the first layer formed thereon in an aqueous solution of titanium tetrachloride and then baking the substrate at a predetermined temperature for a predetermined heating time. be.
　第２層の成膜において、所定の温度は３００℃以上であり且つ９００℃以下であることが好ましく、４５０℃以上であり且つ５５０℃以下であることが更に好ましい。所定の加熱時間は、２０分以上であり且つ６００分以下であることが好ましく、６０分以上であり且つ１８０分以下であることが更に好ましい。 In the deposition of the second layer, the predetermined temperature is preferably 300°C or higher and 900°C or lower, and more preferably 450°C or higher and 550°C or lower. The predetermined heating time is preferably 20 minutes or more and 600 minutes or less, more preferably 60 minutes or more and 180 minutes or less.
　次いで、界面処理工程において、基板１０上に成膜された電子輸送層１２の表面に界面処理が施される（Ｓ１０３）。界面処理は、例えばシランカップリング剤をスピンコート法により電子輸送層１２の表面に塗布し、基板１０を所定の温度で所定の加熱時間に亘って焼成する処理である。 Next, in the interfacial treatment step, the surface of the electron transport layer 12 formed on the substrate 10 is subjected to interfacial treatment (S103). The interfacial treatment is, for example, a treatment in which a silane coupling agent is applied to the surface of the electron transport layer 12 by spin coating, and the substrate 10 is baked at a predetermined temperature for a predetermined heating time.
　界面処理のスピンコート法において、回転速度は５００ｒｐｍ以上であり且つ３０００ｒｐｍ以下であることが好ましく、１０００ｒｐｍ以上であり且つ２０００ｒｐｍ以下であることが更に好ましい。界面処理の焼成において、所定の温度は５０℃以上であり且つ１５０℃以下であることが好ましく、８０℃以上であり且つ１２０℃以下であることが更に好ましい。界面処理の焼成において、所定の加熱時間は１分以上であり且つ３０分以下であることが好ましく、３分以上であり且つ１０分以下であることが更に好ましい。 In the spin coating method for interface treatment, the rotation speed is preferably 500 rpm or more and 3000 rpm or less, more preferably 1000 rpm or more and 2000 rpm or less. In the firing of the interfacial treatment, the predetermined temperature is preferably 50° C. or higher and 150° C. or lower, more preferably 80° C. or higher and 120° C. or lower. In the firing of the interface treatment, the predetermined heating time is preferably 1 minute or more and 30 minutes or less, more preferably 3 minutes or more and 10 minutes or less.
　次いで、光吸収層成膜工程において、電子輸送層１２が成膜された基板１０上に光吸収層１３が成膜される（Ｓ１０４）。電子輸送層１２が成膜された基板１０は、光吸収層が成膜される基材の一例である。光吸収層成膜工程の詳細は後述する。 Next, in the light absorption layer forming process, the light absorption layer 13 is formed on the substrate 10 on which the electron transport layer 12 is formed (S104). The substrate 10 on which the electron transport layer 12 is deposited is an example of a substrate on which the light absorbing layer is deposited. The details of the light absorbing layer forming process will be described later.
　次いで、正孔輸送層成膜工程において、正孔輸送層１４が光吸収層１３上に成膜される（Ｓ１０５）。正孔輸送層１４は、例えばSpiro-OMeTADをクロロベンゼンに溶解させた溶液がスピンコート法により光吸収層１３の表面に塗布されることにより成膜される。 Next, in the hole transport layer forming process, the hole transport layer 14 is formed on the light absorption layer 13 (S105). The hole transport layer 14 is formed by coating the surface of the light absorption layer 13 with a solution obtained by dissolving Spiro-OMeTAD in chlorobenzene, for example, by spin coating.
　スピンコート法における回転速度は、１０００ｒｐｍ以上であり且つ５０００ｒｐｍ以下であることが好ましく、２０００ｒｐｍ以上であり且つ４０００ｒｐｍ以下であることが更に好ましい。所定の温度は、２０℃以上であり且つ１８０℃以下であることが好ましく、８０℃以上であり且つ１２０℃以下であることが更に好ましい。所定の加熱時間は、１分以上であり且つ１８０分以下であることが好ましく、３０分以上であり且つ９０分以下であることが更に好ましい。 The rotation speed in the spin coating method is preferably 1000 rpm or more and 5000 rpm or less, more preferably 2000 rpm or more and 4000 rpm or less. The predetermined temperature is preferably 20° C. or higher and 180° C. or lower, and more preferably 80° C. or higher and 120° C. or lower. The predetermined heating time is preferably 1 minute or more and 180 minutes or less, more preferably 30 minutes or more and 90 minutes or less.
　次いで、上部電極成膜工程において、上部電極１５が正孔輸送層１４上に成膜される（Ｓ１０６）。上部電極１５は、Ａｕ、Ｔｉ、Ｐｔ若しくはＮｉ等の金属又はグラファイトが真空蒸着法によって正孔輸送層１４上に蒸着されることによって成膜される。以上で、光電変換素子１の製造工程が終了する。 Then, in the upper electrode film formation process, the upper electrode 15 is formed on the hole transport layer 14 (S106). The upper electrode 15 is formed by evaporating a metal such as Au, Ti, Pt or Ni or graphite onto the hole transport layer 14 by a vacuum evaporation method. Thus, the manufacturing process of the photoelectric conversion element 1 is completed.
　図３は、Ｓ１０４の光吸収層成膜工程のより詳細な処理を示すフローチャートである。 FIG. 3 is a flow chart showing more detailed processing of the light absorbing layer forming step of S104.
　まず、不活性ガスが充填された筐体の内部の雰囲気中で第１有機物が気化されて、筐体の内部における第１有機物の蒸気濃度が調整される（Ｓ２０１）。筐体は、例えばグローブボックスである。筐体の内部に充填される不活性ガスは、例えばアルゴン等の希ガス、及び窒素ガス等である。筐体の内部圧力は、０．０５ＭＰａ以上であり且つ０．１５ＭＰａ以下であることが好ましく、０．０９ＭＰａ以上であり且つ０．１１ＭＰａ以下であることが更に好ましい。第１有機物は、例えばクロロベンゼン、クロロメタン若しくはイソプロパノールエタノール又はこれらの混合物であり、クロロベンゼンであることが好ましい。第１有機物の蒸気濃度は、筐体の内部圧力が０．１ＭＰａであるときに、１ｍ3の不活性ガスに対して０．０１ｇ以上且つ１０ｇ以下に調整されることが好ましく、０．１ｇ以上且つ５ｇ以下に調整されることが更に好ましい。 First, the first organic substance is vaporized in the atmosphere inside the housing filled with inert gas, and the vapor concentration of the first organic substance inside the housing is adjusted (S201). The housing is, for example, a glove box. The inert gas with which the inside of the housing is filled is, for example, a rare gas such as argon, nitrogen gas, or the like. The internal pressure of the housing is preferably 0.05 MPa or more and 0.15 MPa or less, more preferably 0.09 MPa or more and 0.11 MPa or less. The first organic substance is, for example, chlorobenzene, chloromethane or isopropanol ethanol or a mixture thereof, preferably chlorobenzene. The vapor concentration of the first organic substance is preferably adjusted to 0.01 g or more and 10 g or less with respect to 1 m 3 of inert gas when the internal pressure of the housing is 0.1 MPa, and is 0.1 g or more. And it is more preferable to adjust to 5 g or less.
　次いで、界面処理が施された電子輸送層１２が成膜された基板１０が、Ｓ２０１において第１有機物の蒸気濃度が調整され、不活性ガス及び気化した第１有機物が充填された筐体の内部の雰囲気中に配置される（Ｓ２０２）。 Next, the substrate 10 on which the electron transport layer 12 which has undergone the interface treatment is formed is placed in the inside of the housing filled with the inert gas and the vaporized first organic substance, the vapor concentration of the first organic substance being adjusted in S201. (S202).
　次いで、組成式ＡｇaＢｉbＩcで示される結晶を形成可能な前駆体と、第１有機物と異なる第２有機物を含有する溶媒とを含有する前駆体溶液が、基板１０上に成膜された電子輸送層１２の表面に塗布される（Ｓ２０３）。前駆体溶液に含有される前駆体は、ＡｇＩ及びＢｉＩ3である。ＡｇＩ及びＢｉＩ3の含有比率（ＡｇＩ：ＢｉＩ3）は１．５以上且つ４．０以下である。これにより、光吸収層１３に含まれる結晶の組成式ＡｇaＢｉbＩcにおいて、組成比ａ及びｂが１．５≦ａ／ｂ≦４．０を満たす。前駆体溶液に含有される溶媒は、例えばジメチルスルホキシド（ＤＭＳＯ）、ジメチルホルムアミド（ＤＭＦ）、又はｎ―ブチルアミンであるが、ジメチルスルホキシドであることが好ましい。 Next, a precursor solution containing a precursor capable of forming a crystal represented by the composition formula Ag a Bi b I c and a solvent containing a second organic substance different from the first organic substance is deposited on the substrate 10. is applied to the surface of the electron transport layer 12 (S203). The precursors contained in the precursor solution are AgI and BiI3 . The content ratio of AgI and BiI 3 (AgI:BiI 3 ) is 1.5 or more and 4.0 or less. As a result, in the composition formula Ag a Bi b I c of the crystals contained in the light absorption layer 13, the composition ratios a and b satisfy 1.5≦a/b≦4.0. The solvent contained in the precursor solution is, for example, dimethylsulfoxide (DMSO), dimethylformamide (DMF), or n-butylamine, preferably dimethylsulfoxide.
　前駆体溶液は、例えばスピンコート法により電子輸送層１２上に塗布される。スピンコート法における回転速度は、５００ｒｐｍ以上であり且つ３０００ｒｐｍ以下であることが好ましく、１０００ｒｐｍ以上であり且つ２０００ｒｐｍ以下であることが更に好ましい。 The precursor solution is applied onto the electron transport layer 12 by, for example, spin coating. The rotation speed in the spin coating method is preferably 500 rpm or more and 3000 rpm or less, more preferably 1000 rpm or more and 2000 rpm or less.
　次いで、前駆体溶液が電子輸送層１２の表面に塗布されている間に、第２有機物と異なる第３有機物が貧溶媒として電子輸送層１２の表面に滴下される（Ｓ２０４）。第３有機物は、例えばクロロベンゼン又はベンゼンであり、クロロベンゼンであることが好ましい。なお、Ｓ２０４の処理は、省略されてもよい。 Next, while the precursor solution is being applied to the surface of the electron transport layer 12, a third organic material different from the second organic material is dropped onto the surface of the electron transport layer 12 as a poor solvent (S204). The third organic substance is, for example, chlorobenzene or benzene, preferably chlorobenzene. Note that the process of S204 may be omitted.
　次いで、前駆体溶液が電子輸送層１２の表面に塗布されると共に第３有機物が電子輸送層１２の表面に滴下された状態で、基板１０が所定の温度で所定の加熱時間に亘って焼成される（Ｓ２０５）。所定の温度は、５０℃以上であり且つ１８０℃以下であることが好ましく、９０℃以上であり且つ１２０℃以下であることが更に好ましい。所定の加熱時間は、１分以上であり且つ１８０分以下であることが好ましく、３０分以上であり且つ９０分以下であることが更に好ましい。なお、基板１０は、温度を変化させながら焼成されてもよい。以上のようにして、電子輸送層１２上に光吸収層１３が成膜され、光吸収層成膜工程が終了する。 Next, the substrate 10 is baked at a predetermined temperature for a predetermined heating time while the precursor solution is applied to the surface of the electron transport layer 12 and the third organic substance is dropped onto the surface of the electron transport layer 12. (S205). The predetermined temperature is preferably 50° C. or higher and 180° C. or lower, and more preferably 90° C. or higher and 120° C. or lower. The predetermined heating time is preferably 1 minute or more and 180 minutes or less, more preferably 30 minutes or more and 90 minutes or less. Note that the substrate 10 may be fired while changing the temperature. As described above, the light absorbing layer 13 is formed on the electron transporting layer 12, and the light absorbing layer forming process is completed.
　Ｓ２０５において基板１０が焼成されるときに、基板１０を介して前駆体溶液の温度が上昇するため、ＡｇＩ及びＢｉＩ3を含有する膜が、膜中に残存する溶媒によって再溶解され、ＡｇＩ及びＢｉＩ3の結晶の質が低下する場合がある。Ｓ２０４において第３有機物が貧溶媒として滴下されることにより、ＡｇＩ及びＢｉＩ3を含有する膜が再溶解することが抑制されるため、結晶の質の低下が防止される。また、Ｓ２０１において、貧溶媒として機能する第１有機物が雰囲気中に充填されることにより、雰囲気から貧溶媒が供給されるようになるため、同様にＡｇＩ及びＢｉＩ3を含有する膜が再溶解することが抑制され、結晶の質の低下が防止される。 When the substrate 10 is baked in S205, the temperature of the precursor solution rises through the substrate 10, so that the film containing AgI and BiI 3 is redissolved by the solvent remaining in the film to form AgI and BiI. The crystal quality of 3 may deteriorate. Dropping the third organic substance as a poor solvent in S204 suppresses redissolution of the film containing AgI and BiI 3 , thereby preventing deterioration of crystal quality. In addition, in S201, the atmosphere is filled with the first organic substance that functions as a poor solvent, so that the poor solvent is supplied from the atmosphere. is suppressed, and deterioration of crystal quality is prevented.
　図４（Ａ）は、上述のようにして形成された光吸収層１３に含まれる結晶構造２０において（１１０）面を示す図である。図４（Ｂ）は、光吸収層１３に含まれる結晶構造２０において（０１８）面を示す図である。図４（Ｃ）は、光吸収層１３に含まれる結晶構造２０において（００３）面を示す図である。図４（Ｄ）は、光吸収層１３に含まれる結晶構造の八面体単位の斜視図である。 FIG. 4(A) is a diagram showing the (110) plane in the crystal structure 20 included in the light absorption layer 13 formed as described above. FIG. 4B is a diagram showing the (018) plane in the crystal structure 20 included in the light absorption layer 13. As shown in FIG. FIG. 4C is a diagram showing the (003) plane in the crystal structure 20 included in the light absorption layer 13. As shown in FIG. FIG. 4D is a perspective view of octahedral units of the crystal structure included in the light absorption layer 13. FIG.
　光吸収層１３に含まれる結晶は、複数の八面体単位２１の構造が連接された３方晶系の結晶である。八面体単位２１の六つの頂点のそれぞれには、Ｉイオン２２が配置され、八面体単位２１の中心には、Ａｇイオン２３及びＢｉイオン２３の何れか一方が配置される。光吸収層１３に含まれる結晶構造２０に内包される単位格子は、ａ軸方向及びｂ軸方向の長さが４．３５Åであり、ｃ軸方向の長さが２０．８１Åである。一つの八面体単位２１に含まれるＩイオン２２は、隣接する他の八面体単位２１と共有される。 The crystal contained in the light absorption layer 13 is a trigonal crystal in which the structure of a plurality of octahedral units 21 is connected. An I ion 22 is arranged at each of the six vertices of the octahedral unit 21 , and either one of Ag ion 23 and Bi ion 23 is arranged at the center of the octahedral unit 21 . The unit cell included in the crystal structure 20 included in the light absorption layer 13 has a length of 4.35 Å in the a-axis direction and the b-axis direction, and a length of 20.81 Å in the c-axis direction. The I ion 22 contained in one octahedral unit 21 is shared with other adjacent octahedral units 21 .
　光吸収層１３に含まれる結晶構造２０は、図４（Ａ）に示す（１１０）面２５に配置される原子の配列の秩序性よりも、図４（Ｂ）に示す（０１８）面２６に配置される原子の配列の秩序性が高くなるように形成される。 The crystal structure 20 included in the light-absorbing layer 13 has more orderly arrangement of atoms arranged on the (110) plane 25 shown in FIG. It is formed so that the arranged atoms are highly ordered.
　光吸収層１３に含まれる結晶構造２０は、図４（Ｃ）に示す（００３）面２４に配置される原子の配列の秩序性が最も高くなるように、すなわち（００３）面２４に配置される原子の配列が最も揃っているように形成される。光吸収層１３に含まれる結晶は、（００３）面２４に配置される原子の配列の秩序性が高いので、ｃ軸方向に高い秩序性を有する。 The crystal structure 20 included in the light absorption layer 13 is arranged on the (003) plane 24 such that the orderliness of the arrangement of atoms arranged on the (003) plane 24 shown in FIG. formed in such a way that the arrangement of the atoms in the Since the crystals contained in the light absorption layer 13 have a highly ordered arrangement of atoms arranged on the (003) plane 24, they have a high degree of order in the c-axis direction.
　上述した光吸収層１３の結晶構造は、Ｘ線回折法等により測定される。光吸収層１３をＸ線回折測定したとき、４２．０°≦２θ≦４３．０°の範囲、より具体的には２θ＝４２．２０°付近に第１ピークが現れる。第１ピークが現れる角度２θは、光吸収層１３の結晶構造の（０１８）面に対応する角度である。また、光吸収層１３をＸ線回折測定したとき、４１．０°≦２θ＜４２．０°の範囲、より具体的には２θ＝４１．５０°付近に第２ピークが現れることがある。第２ピークが現れる角度２θは、光吸収層１３の結晶構造の（１１０）面に対応する角度である。 The crystal structure of the light absorption layer 13 described above is measured by an X-ray diffraction method or the like. When the light absorption layer 13 is subjected to X-ray diffraction measurement, the first peak appears in the range of 42.0°≦2θ≦43.0°, more specifically near 2θ=42.20°. The angle 2θ at which the first peak appears is the angle corresponding to the (018) plane of the crystal structure of the light absorption layer 13 . Further, when the light absorption layer 13 is subjected to X-ray diffraction measurement, a second peak may appear in the range of 41.0°≦2θ<42.0°, more specifically in the vicinity of 2θ=41.50°. The angle 2θ at which the second peak appears is the angle corresponding to the (110) plane of the crystal structure of the light absorption layer 13 .
　上述したように、光吸収層１３の結晶構造において、（０１８）面に配置される原子の配列の秩序性は、（１１０）面に配置される原子の配列の秩序性よりも高い。したがって、（０１８）面に対応する角度に現れる第１ピークの高さは、（１１０）面に対応する角度に現れる第２ピークの高さよりも高い。第１ピークの強度は、第２ピークの強度に対して１．７倍以上であることが好ましく、１．７倍以上且つ７．０倍以下であることが更に好ましい。 As described above, in the crystal structure of the light absorption layer 13, the orderliness of the arrangement of atoms arranged on the (018) plane is higher than that of the arrangement of atoms arranged on the (110) plane. Therefore, the height of the first peak appearing at the angle corresponding to the (018) plane is higher than the height of the second peak appearing at the angle corresponding to the (110) plane. The intensity of the first peak is preferably 1.7 times or more the intensity of the second peak, and more preferably 1.7 times or more and 7.0 times or less.
　また、（１１０）面に配置される原子の配列の秩序性によっては、第２ピークが現れないことがある。この場合、第１ピークの高さは、Ｘ線回折測定したときの４１．０°≦２θ＜４２．０°の範囲における最大の測定値よりも高い。第１ピークの強度は、４１．０°≦２θ＜４２．０°の範囲における最大の測定値の強度に対して１．７倍以上であり、１．７倍以上且つ７．０倍以下であることが好ましい。 In addition, the second peak may not appear depending on the orderliness of the arrangement of atoms arranged on the (110) plane. In this case, the height of the first peak is higher than the maximum measured value in the range of 41.0°≦2θ<42.0° when X-ray diffraction measurement is performed. The intensity of the first peak is 1.7 times or more and 1.7 times or more and 7.0 times or less the intensity of the maximum measured value in the range of 41.0 ° ≤ 2θ < 42.0 ° Preferably.
　また、光吸収層１３をＸ線回折測定したとき、１１．５°≦２θ≦１４．０°の範囲、より具体的には２θ＝１２．７６°付近に最大のピークが現れることがある。最大のピークが現れる角度２θは、光吸収層１３の結晶構造の（００３）面に対応する角度である。また、光吸収層１３をＸ線回折測定したとき、２８．０°≦２θ≦３２．０°の範囲に第３ピークが現れる。最大のピークの強度は、第３ピークの強度に対して１．２倍以上であることが好ましい。 Also, when the light absorption layer 13 is subjected to X-ray diffraction measurement, the maximum peak may appear in the range of 11.5°≦2θ≦14.0°, more specifically in the vicinity of 2θ=12.76°. The angle 2θ at which the maximum peak appears is the angle corresponding to the (003) plane of the crystal structure of the light absorption layer 13 . Further, when the light absorption layer 13 is subjected to X-ray diffraction measurement, a third peak appears in the range of 28.0°≦2θ≦32.0°. The intensity of the maximum peak is preferably 1.2 times or more the intensity of the third peak.
　以上説明したように、光吸収層１３は、組成式ＡｇaＢｉbＩcで示され、それぞれ六つのＩイオンからなる複数の八面体単位が連接され、且つ、複数の八面体単位のそれぞれの中心にＡｇイオン及びＢｉイオンの何れかが配置される構造を有する結晶を含む。また、組成式において、組成比ａ及びｂは、１．５≦ａ／ｂ≦４．０を満たす。また、Ｘ線回折測定したとき、４２．０°≦２θ≦４３．０°の範囲に第１ピークが現れ、第１ピークの強度は、Ｘ線回折測定したときの４１．０°≦２θ＜４２．０°の範囲における最大の測定値の強度に対して１．７倍以上である。これにより、光吸収層１３は、光電変換の変換効率を向上させることを可能とする。 As described above, the light-absorbing layer 13 is represented by the composition formula Ag a Bi b I c , in which a plurality of octahedral units each composed of six I ions are connected, and each of the plurality of octahedral units It includes a crystal having a structure in which either Ag ions or Bi ions are arranged in the center. In the composition formula, the composition ratios a and b satisfy 1.5≦a/b≦4.0. Further, when X-ray diffraction measurement was performed, a first peak appeared in the range of 42.0° ≤ 2θ ≤ 43.0°, and the intensity of the first peak was 41.0° ≤ 2θ < It is 1.7 times or more the intensity of the maximum measured value in the range of 42.0°. Thereby, the light absorption layer 13 makes it possible to improve the conversion efficiency of photoelectric conversion.
　また、光電変換素子１は、輸送層上に成膜された光吸収層１３と、光吸収層１３の一方の面に成膜された電子輸送層１２と、光吸収層１３の他方の面に成膜された正孔輸送層１４とを有する。これにより、光吸収層１３は、光電変換の変換効率を向上させることを可能とする。 Further, the photoelectric conversion element 1 includes a light absorption layer 13 formed on the transport layer, an electron transport layer 12 formed on one surface of the light absorption layer 13, and a light absorption layer 13 formed on the other surface of the light absorption layer 13. and a deposited hole transport layer 14 . Thereby, the light absorption layer 13 makes it possible to improve the conversion efficiency of photoelectric conversion.
　また、光吸収層成膜工程は、不活性ガス及び気化したクロロベンゼンが充填された雰囲気中に電子輸送層１２が成膜された基板１０を配置し、前駆体溶液を電子輸送層１２の表面に塗布し、前駆体溶液が塗布された基板１０を焼成することにより光吸収層１３を形成する。前駆体溶液は、組成式ＡｇaＢｉbＩcで示される結晶を形成可能な前駆体を含有し、組成式における組成比ａ及びｂは１．５≦ａ／ｂ≦４．０を満たす。これにより、光吸収層成膜工程は、光吸収層１３の光電変換の変換効率を向上させることを可能とする。 In addition, in the light absorbing layer forming step, the substrate 10 on which the electron transport layer 12 is formed is placed in an atmosphere filled with an inert gas and vaporized chlorobenzene, and the precursor solution is applied to the surface of the electron transport layer 12. The substrate 10 coated with the precursor solution is baked to form the light absorption layer 13 . The precursor solution contains a precursor capable of forming crystals represented by the composition formula Ag a Bi b I c , and the composition ratio a and b in the composition formula satisfies 1.5≦a/b≦4.0. Thereby, the light absorption layer film-forming process makes it possible to improve the photoelectric conversion efficiency of the light absorption layer 13 .
　また、光吸収層成膜工程は、前駆体溶液を基材の表面に塗布する間に、第２有機物と異なる第３有機物を貧溶媒として基材の表面に滴下する。これにより、光吸収層成膜工程は、光吸収層１３の結晶の質の低下を防止し、光吸収層１３の光電変換の変換効率を更に向上させることを可能とする。 In addition, in the light absorbing layer forming step, while the precursor solution is being applied to the surface of the base material, a third organic material different from the second organic material is dropped onto the surface of the base material as a poor solvent. As a result, the light-absorbing layer forming process can prevent deterioration of the crystal quality of the light-absorbing layer 13 and further improve the photoelectric conversion efficiency of the light-absorbing layer 13 .
　光電変換素子１には、次に述べるような変形例が適用されてもよい。 The following modifications may be applied to the photoelectric conversion element 1.
　上述した説明では、光電変換素子１は順構造型であったが、光電変換素子は逆構造型であってもよい。逆構造型の光電変換素子は、基板と、基板上に成膜された下部導電層と、下部導電層上に成膜された正孔輸送層と、正孔輸送層上に成膜された光吸収層と、光吸収層上に成膜された電子輸送層と、電子輸送層上に成膜された上部電極とを有する。逆構造型の光電変換素子において、光吸収層は、光電変換素子１と同様に、組成式ＡｇaＢｉbＩcで示される結晶を含み、Ｘ線回折測定したとき、４２．０°≦２θ≦４３．０°の範囲に第１ピークが現れ、第１ピークと、Ｘ線回折測定したときに４１．０°≦２θ＜４２．０°の範囲における最大の測定値との強度比は１．７以上である。この場合、光電変換素子では、電子輸送層は光吸収層の一方の面に成膜され、正孔輸送層は光吸収層の他方の面に成膜される。 In the above description, the photoelectric conversion element 1 is of the forward structure type, but the photoelectric conversion element may be of the reverse structure type. The reverse structure type photoelectric conversion element includes a substrate, a lower conductive layer formed on the substrate, a hole transport layer formed on the lower conductive layer, and a light layer formed on the hole transport layer. It has an absorption layer, an electron transport layer deposited on the light absorption layer, and an upper electrode deposited on the electron transport layer. In the photoelectric conversion element of the reverse structure type, the light absorption layer contains crystals represented by the composition formula Ag a Bi b I c similarly to the photoelectric conversion element 1, and is 42.0°≦2θ when measured by X-ray diffraction. The first peak appears in the range of ≤ 43.0 °, and the intensity ratio between the first peak and the maximum measured value in the range of 41.0 ° ≤ 2θ < 42.0 ° when measured by X-ray diffraction is 1 .7 or more. In this case, in the photoelectric conversion element, the electron-transporting layer is formed on one side of the light-absorbing layer, and the hole-transporting layer is formed on the other side of the light-absorbing layer.
　上述の製造方法により、実施例１～６に係る光電変換素子を製造した。 Photoelectric conversion elements according to Examples 1 to 6 were manufactured by the manufacturing method described above.
　Ｓ１０１において、下部導電層１１が成膜された基板１０として、ペクセル・テクノロジーズ株式会社製のＦＴＯ付ガラスが準備された。ＦＴＯ付ガラスは、２０分に亘ってＵＶオゾン洗浄された。 In S101, as the substrate 10 on which the lower conductive layer 11 was formed, a glass with FTO manufactured by Peccel Technologies, Inc. was prepared. The FTO glass was UV ozone cleaned for 20 minutes.
　Ｓ１０２において、ＦＴＯ付ガラスはホットプレートで４５０℃に加熱された。その後、ＦＴＯ上にテトラキス（２，４－ペンタンジオナート）チタニウム（IV）を含む溶液が噴霧された。その後、ＦＴＯ付ガラスが５００℃で１時間に亘って焼成され、電子輸送層の第１層が成膜された。その後、ＦＴＯ付ガラスが四塩化チタン水溶液に浸漬された後に、５００℃で１時間に亘って焼成されることで電子輸送層の第２層が成膜された。 At S102, the glass with FTO was heated to 450°C with a hot plate. A solution containing tetrakis(2,4-pentanedionato) titanium(IV) was then sprayed onto the FTO. After that, the glass with FTO was baked at 500° C. for 1 hour to form the first layer of the electron transport layer. After that, the FTO-equipped glass was immersed in an aqueous solution of titanium tetrachloride, and then baked at 500° C. for 1 hour to form the second layer of the electron transport layer.
　Ｓ１０３において、電子輸送層の表面に界面処理が施された。界面処理では、信越化学工業株式会社製のシランカップリング剤（ＫＢＥ－９０３）がスピンコート法により電子輸送層１２の表面に塗布された。スピンコート法における回転速度は１５００ｒｐｍであった。その後、界面処理が施されたＦＴＯ付ガラスは１００℃で５分に渡って焼成された。 In S103, the surface of the electron transport layer was subjected to interfacial treatment. In the interface treatment, a silane coupling agent (KBE-903) manufactured by Shin-Etsu Chemical Co., Ltd. was applied to the surface of the electron transport layer 12 by spin coating. The rotation speed in the spin coating method was 1500 rpm. After that, the interface-treated glass with FTO was fired at 100° C. for 5 minutes.
　Ｓ１０４において、次に述べるように光吸収層が形成された。 In S104, a light absorbing layer was formed as described below.
　Ｓ２０１において、窒素が充填されたグローブボックスの内部の雰囲気中でクロロベンゼンが気化されて、クロロベンゼンの蒸気濃度が調整された。 In S201, chlorobenzene was vaporized in the atmosphere inside the nitrogen-filled glove box to adjust the vapor concentration of chlorobenzene.
　Ｓ２０２において、界面処理されたＦＴＯ付ガラスがグローブボックスの内部の雰囲気中に配置された。 In S202, the interface-treated glass with FTO was placed in the atmosphere inside the glove box.
　Ｓ２０３において、前駆体溶液が電子輸送層の表面に塗布された。前駆体溶液に含有されるＡｇＩ及びＢｉＩ3の含有比率は、実施例１～６において異なる値に設定された。前駆体溶液に含有される溶媒は、ジメチルスルホキシドであった。前駆体溶液は、スピンコート法により塗布された。スピンコート法における回転速度は１５００ｒｐｍであった。 At S203, a precursor solution was applied to the surface of the electron transport layer. The content ratio of AgI and BiI 3 contained in the precursor solution was set to different values in Examples 1-6. The solvent contained in the precursor solution was dimethylsulfoxide. The precursor solution was applied by spin coating. The rotation speed in the spin coating method was 1500 rpm.
　Ｓ２０４において、前駆体溶液が電子輸送層の表面に塗布されている間に、クロロベンゼンが貧溶媒として電子輸送層の表面に滴下された。 In S204, while the precursor solution was being applied to the surface of the electron transport layer, chlorobenzene was dropped as a poor solvent onto the surface of the electron transport layer.
　Ｓ２０５において、ＦＴＯ付ガラスが９０℃で５分に渡って焼成された。以上のようにして、光吸収層が成膜された。 In S205, the glass with FTO was fired at 90°C for 5 minutes. The light absorption layer was formed as described above.
　Ｓ１０５において、正孔輸送層が光吸収層上に成膜された。正孔輸送層は、Spiro-OMeTADをクロロベンゼンに溶解させた溶液がスピンコート法により光吸収層１３の表面に塗布されて成膜された。スピンコート法における回転速度は３０００ｒｐｍであった。 At S105, a hole-transporting layer was deposited on the light-absorbing layer. The hole transport layer was formed by applying a solution of Spiro-OMeTAD in chlorobenzene to the surface of the light absorption layer 13 by spin coating. The rotation speed in the spin coating method was 3000 rpm.
　Ｓ１０６において、金属が真空蒸着法によって正孔輸送層上に蒸着されることによって上部電極が成膜された。以上のようにして、実施例１～６に係る光電変換素子が製造された。 In S106, an upper electrode was formed by depositing a metal on the hole transport layer by a vacuum deposition method. As described above, photoelectric conversion elements according to Examples 1 to 6 were manufactured.
　上述の方法において、Ｓ２０１及びＳ２０４を省略するとともに、Ｓ２０３において前駆体溶液に含有されるＡｇＩ及びＢｉＩ3の含有比率を異ならせて、比較例に係る光電変換素子を製造した。すなわち、比較例においては、グローブボックスの内部の雰囲気にクロロベンゼンが充填されていない。また、貧溶媒としてクロロベンゼンが滴下されていない。 In the above method, S201 and S204 were omitted, and the content ratios of AgI and BiI 3 contained in the precursor solution in S203 were varied to produce photoelectric conversion devices according to comparative examples. That is, in the comparative example, the atmosphere inside the glove box was not filled with chlorobenzene. Also, chlorobenzene was not dropped as a poor solvent.
　実施例１～６及び比較例に係る光吸収層に対して、Ｘ線回折測定が行われた。また、実施例１～６及び比較例に係る光電変換素子に対して、発電効率測定が行われた。Ｘ線回折測定及び発電効率測定の測定条件は、次に示すとおりである。 X-ray diffraction measurements were performed on the light absorption layers according to Examples 1 to 6 and Comparative Example. Further, power generation efficiency was measured for the photoelectric conversion elements according to Examples 1 to 6 and Comparative Example. The measurement conditions for X-ray diffraction measurement and power generation efficiency measurement are as follows.
　（Ｘ線回折測定条件）
　測定装置：株式会社リガク製ＳｍａｒｔＬａｂ
　Ｘ線源：ＣｕＫα
　Ｘ線波長：１．５４０５Å、１．５４４３Å
　測定範囲：２θ＝１０～７０°
　測定ステップ幅：０．０２°
　スキャン速度：１．０ｄｅｇ／ｍｉｎ
　測定温度：常温
　（発電効率測定条件）
　光源：分光計器株式会社製ＢＬＤ－１００
　評価照度：２００Ｌｕｘ
　発電面積：６．２５ｍｍ2 (X-ray diffraction measurement conditions)
Measuring device: SmartLab manufactured by Rigaku Corporation
X-ray source: CuKα
X-ray wavelength: 1.5405 Å, 1.5443 Å
Measurement range: 2θ = 10 to 70°
Measurement step width: 0.02°
Scanning speed: 1.0deg/min
Measurement temperature: normal temperature (power generation efficiency measurement conditions)
Light source: BLD-100 manufactured by Spectrometer Co., Ltd.
Evaluation illuminance: 200Lux
Power generation area: 6.25 mm 2
　表１は、実施例１～６及び比較例に係る光吸収層の組成比ａ／ｂ、Ｓ２０１において調整されたクロロベンゼン蒸気濃度および実施例１～６に係る光電変換素子の発電効率を示す。表１のクロロベンゼン蒸気濃度において、「高濃度」は１ｍ3の窒素当たり０．５ｇ以上のクロロベンゼンの蒸気が含まれることを示し、「無」は窒素にクロロベンゼンの蒸気が含まれないことを示す。なお、実施例１及び２は、組成比及びクロロベンゼン蒸気濃度において同条件であるが、Ｓ２０１において調整された雰囲気の条件、製造時の気流、気圧、雰囲気の温度、大気温度、湿度、前駆体溶液の溶液温度、製造に用いた材料のロット、隣接輸送層のばらつき等の要因で異なる結果が得られたため、異なる実施例として示している。 Table 1 shows the composition ratio a/b of the light absorption layer according to Examples 1 to 6 and Comparative Example, the chlorobenzene vapor concentration adjusted in S201, and the power generation efficiency of the photoelectric conversion elements according to Examples 1 to 6. In the chlorobenzene vapor concentrations in Table 1, "high concentration" indicates that 0.5 g or more of chlorobenzene vapor is contained per 1 m 3 of nitrogen, and "no" indicates that the nitrogen contains no chlorobenzene vapor. In addition, although Examples 1 and 2 have the same composition ratio and chlorobenzene vapor concentration, the atmosphere conditions adjusted in S201, the air flow at the time of production, the atmospheric pressure, the temperature of the atmosphere, the atmospheric temperature, the humidity, and the precursor solution Since different results were obtained due to factors such as the temperature of the solution, the lot of material used in the production, and variations in the adjacent transport layers, they are shown as different examples.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　実施例１～６に係る光電変換素子の発電効率はそれぞれ８．３％、４．６％、５．４％、５．７％、４．６％及び５．２％であり、いずれも４．０％を超える良好な値であった。これに対し、比較例に係る光電変換素子の発電効率は０．６％であった。 The power generation efficiencies of the photoelectric conversion elements according to Examples 1 to 6 were 8.3%, 4.6%, 5.4%, 5.7%, 4.6% and 5.2%, respectively, and all of them were 4. It was a good value exceeding 0.0%. On the other hand, the power generation efficiency of the photoelectric conversion element according to the comparative example was 0.6%.
　図５（Ａ）及び（Ｂ）は、実施例１に係る光吸収層のＸ線回折パターンの波形Ｗ１を示す図である。図５（Ｂ）は、図５（Ａ）の４０．０°≦２θ≦４５．０°の範囲の拡大図である。図５（Ａ）及び（Ｂ）に示すように、実施例１に係る光吸収層をＸ線回折測定したとき、１１．５°≦２θ≦１４．０°の範囲に最大のピークＰｍが、２８．０°≦２θ≦３２．０°の範囲に第３ピークＰ３が、４２．０°≦２θ≦４３．０°に第１ピークＰ１が現れた。実施例１に係る光吸収層をＸ線回折測定したとき、第２ピークＰ２は現れなかった。 5(A) and (B) are diagrams showing the waveform W1 of the X-ray diffraction pattern of the light absorption layer according to Example 1. FIG. FIG. 5(B) is an enlarged view of the range of 40.0°≦2θ≦45.0° in FIG. 5(A). As shown in FIGS. 5A and 5B, when the light absorption layer according to Example 1 was subjected to X-ray diffraction measurement, the maximum peak Pm in the range of 11.5°≦2θ≦14.0° A third peak P3 appeared in the range of 28.0°≦2θ≦32.0°, and a first peak P1 appeared in the range of 42.0°≦2θ≦43.0°. When the light absorption layer according to Example 1 was subjected to X-ray diffraction measurement, the second peak P2 did not appear.
　図６（Ａ）及び（Ｂ）は、実施例２に係る光吸収層のＸ線回折パターンの波形Ｗ２を示す図である。図６（Ｂ）は、図６（Ａ）の４０．０°≦２θ≦４５．０°の範囲の拡大図である。図６（Ａ）及び（Ｂ）に示すように、実施例２に係る光吸収層をＸ線回折測定したとき、１１．５°≦２θ≦１４．０°の範囲に最大のピークＰｍが現れ、２８．０°≦２θ≦３２．０°の範囲に第３ピークＰ３が現れ、４１．０°≦２θ≦４２．０°の範囲に第２ピークＰ２が現れ、４２．０°≦２θ≦４３．０°の範囲に第１ピークＰ１が現れた。 6(A) and (B) are diagrams showing the waveform W2 of the X-ray diffraction pattern of the light absorption layer according to Example 2. FIG. FIG. 6(B) is an enlarged view of the range of 40.0°≦2θ≦45.0° in FIG. 6(A). As shown in FIGS. 6A and 6B, when the light absorption layer according to Example 2 was subjected to X-ray diffraction measurement, the maximum peak Pm appeared in the range of 11.5°≦2θ≦14.0°. , the third peak P3 appears in the range of 28.0°≦2θ≦32.0°, the second peak P2 appears in the range of 41.0°≦2θ≦42.0°, and 42.0°≦2θ≦ A first peak P1 appeared in the range of 43.0°.
　図７（Ａ）及び（Ｂ）は、実施例３に係る光吸収層のＸ線回折パターンの波形Ｗ３を示す図である。図７（Ｂ）は、図７（Ａ）の４０．０°≦２θ≦４５．０°の範囲の拡大図である。図７（Ａ）及び（Ｂ）に示すように、実施例３に係る光吸収層をＸ線回折測定したとき、１１．５°≦２θ≦１４．０°の範囲に最大のピークＰｍが現れ、２８．０°≦２θ≦３２．０°の範囲に第３ピークＰ３が現れ、４１．０°≦２θ≦４２．０°の範囲に第２ピークＰ２が現れ、４２．０°≦２θ≦４３．０°の範囲に第１ピークＰ１が現れた。 7(A) and (B) are diagrams showing the waveform W3 of the X-ray diffraction pattern of the light absorption layer according to Example 3. FIG. FIG. 7(B) is an enlarged view of the range of 40.0°≦2θ≦45.0° in FIG. 7(A). As shown in FIGS. 7A and 7B, when the light absorption layer according to Example 3 was subjected to X-ray diffraction measurement, the maximum peak Pm appeared in the range of 11.5°≦2θ≦14.0°. , the third peak P3 appears in the range of 28.0°≦2θ≦32.0°, the second peak P2 appears in the range of 41.0°≦2θ≦42.0°, and 42.0°≦2θ≦ A first peak P1 appeared in the range of 43.0°.
　図８（Ａ）及び（Ｂ）は、実施例４に係る光吸収層のＸ線回折パターンの波形Ｗ４を示す図である。図８（Ｂ）は、図８（Ａ）の４０．０°≦２θ≦４５．０°の範囲の拡大図である。図８（Ａ）及び（Ｂ）に示すように、実施例４に係る光吸収層をＸ線回折測定したとき、１１．５°≦２θ≦１４．０°の範囲に最大のピークＰｍが現れ、２８．０°≦２θ≦３２．０°の範囲に第３ピークＰ３が現れ、４１．０°≦２θ≦４２．０°の範囲に第２ピークＰ２が現れ、４２．０°≦２θ≦４３．０°の範囲に第１ピークＰ１が現れた。 8(A) and (B) are diagrams showing the waveform W4 of the X-ray diffraction pattern of the light absorption layer according to Example 4. FIG. FIG. 8(B) is an enlarged view of the range of 40.0°≦2θ≦45.0° in FIG. 8(A). As shown in FIGS. 8A and 8B, when the light absorption layer according to Example 4 was subjected to X-ray diffraction measurement, the maximum peak Pm appeared in the range of 11.5°≦2θ≦14.0°. , the third peak P3 appears in the range of 28.0°≦2θ≦32.0°, the second peak P2 appears in the range of 41.0°≦2θ≦42.0°, and 42.0°≦2θ≦ A first peak P1 appeared in the range of 43.0°.
　図９（Ａ）及び（Ｂ）は、実施例５に係る光吸収層のＸ線回折パターンの波形Ｗ５を示す図である。図９（Ｂ）は、図９（Ａ）の４０．０°≦２θ≦４５．０°の範囲の拡大図である。図９（Ａ）及び（Ｂ）に示すように、実施例５に係る光吸収層をＸ線回折測定したとき、１１．５°≦２θ≦１４．０°の範囲に最大のピークＰｍが現れ、２８．０°≦２θ≦３２．０°の範囲に第３ピークＰ３が現れ、４１．０°≦２θ≦４２．０°の範囲に第２ピークＰ２が現れ、４２．０°≦２θ≦４３．０°の範囲に第１ピークＰ１が現れた。 9(A) and (B) are diagrams showing the waveform W5 of the X-ray diffraction pattern of the light absorption layer according to Example 5. FIG. FIG. 9(B) is an enlarged view of the range of 40.0°≦2θ≦45.0° in FIG. 9(A). As shown in FIGS. 9A and 9B, when the light absorption layer according to Example 5 was subjected to X-ray diffraction measurement, the maximum peak Pm appeared in the range of 11.5°≦2θ≦14.0°. , the third peak P3 appears in the range of 28.0°≦2θ≦32.0°, the second peak P2 appears in the range of 41.0°≦2θ≦42.0°, and 42.0°≦2θ≦ A first peak P1 appeared in the range of 43.0°.
　図１０（Ａ）及び（Ｂ）は、実施例６に係る光吸収層のＸ線回折パターンの波形Ｗ６を示す図である。図１０（Ｂ）は、図１０（Ａ）の４０．０°≦２θ≦４５．０°の範囲の拡大図である。図１０（Ａ）及び（Ｂ）に示すように、実施例６に係る光吸収層をＸ線回折測定したとき、１１．５°≦２θ≦１４．０°の範囲に最大のピークＰｍが現れ、２８．０°≦２θ≦３２．０°の範囲に第３ピークＰ３が現れ、４１．０°≦２θ≦４２．０°の範囲に第２ピークＰ２が現れ、４２．０°≦２θ≦４３．０°の範囲に第１ピークＰ１が現れた。 10(A) and (B) are diagrams showing the waveform W6 of the X-ray diffraction pattern of the light absorption layer according to Example 6. FIG. FIG. 10(B) is an enlarged view of the range of 40.0°≦2θ≦45.0° in FIG. 10(A). As shown in FIGS. 10A and 10B, when the light absorption layer according to Example 6 was subjected to X-ray diffraction measurement, the maximum peak Pm appeared in the range of 11.5°≦2θ≦14.0°. , the third peak P3 appears in the range of 28.0°≦2θ≦32.0°, the second peak P2 appears in the range of 41.0°≦2θ≦42.0°, and 42.0°≦2θ≦ A first peak P1 appeared in the range of 43.0°.
　図１１（Ａ）及び（Ｂ）は、比較例に係る光吸収層のＸ線回折パターンの波形Ｗ７を示す図である。図１１（Ｂ）は、図１１（Ａ）の４０．０°≦２θ≦４５．０°の範囲の拡大図である。図１１（Ａ）及び（Ｂ）に示すように、比較例に係る光吸収層をＸ線回折測定したとき、１１．５°≦２θ≦１４．０°の範囲にピークＰｍが現れ、２８．０°≦２θ≦３２．０°の範囲に第３ピークＰ３が現れ、４１．０°≦２θ≦４２．０°の範囲に第２ピークＰ２が現れ、４２．０°≦２θ≦４３．０°の範囲に第１ピークＰ１が現れた。実施例１～６に係る光電変換素子の場合とは異なり、波形Ｗ７において、ピークＰｍよりも第３ピークＰ３の強度が大きい。すなわち、比較例に係る光電変換素子をＸ線回折測定したときに１１．５°≦２θ≦１４．０°の範囲に現れるピークＰｍは、最大のピークではなかった。 FIGS. 11A and 11B are diagrams showing the waveform W7 of the X-ray diffraction pattern of the light absorption layer according to the comparative example. FIG. 11(B) is an enlarged view of the range of 40.0°≦2θ≦45.0° in FIG. 11(A). As shown in FIGS. 11A and 11B, when the light absorption layer according to the comparative example was subjected to X-ray diffraction measurement, a peak Pm appeared in the range of 11.5°≦2θ≦14.0°, and 28.0°. A third peak P3 appears in the range of 0°≦2θ≦32.0°, a second peak P2 appears in the range of 41.0°≦2θ≦42.0°, and 42.0°≦2θ≦43.0°. A first peak P1 appeared in the range of °. Unlike the photoelectric conversion elements according to Examples 1 to 6, in the waveform W7, the intensity of the third peak P3 is greater than that of the peak Pm. That is, the peak Pm appearing in the range of 11.5°≦2θ≦14.0° when the photoelectric conversion element according to the comparative example was subjected to X-ray diffraction measurement was not the maximum peak.
　表１及び図６～図１０に示したように、実施例２～６に係る光電変換素子における第１ピークＰ１の第２ピークＰ２に対する強度比Ｐ１／Ｐ２は、それぞれ７．０、１．７、２．７、４．６及び５．６であり、いずれも１．７以上であった。また、表１及び図５に示したように、実施例１に係る光電変換素子においては、第２ピークＰ２が現れていないため、強度比Ｐ１／Ｐ２は無限大であるということができる。したがって、実施例１～６に係る光電変換素子において、第１ピークＰ１の強度は、４１．０°≦２θ＜４２．０°の範囲における最大の測定値の強度に対して１．７倍以上であった。これに対し、表１及び図１１に示したように、比較例に係る光電変換素子における第１ピークＰ１の第２ピークＰ２に対する強度比Ｐ１／Ｐ２は、０．３であった。ここで、第１ピークＰ１及び第２ピークＰ２の強度並びに４１．０°≦２θ＜４２．０°の範囲における最大の測定値は、いずれも図５～図１０に示した測定値からベースラインとなる測定値を減じた値である。 As shown in Table 1 and FIGS. 6 to 10, the intensity ratios P1/P2 of the first peak P1 to the second peak P2 in the photoelectric conversion elements according to Examples 2 to 6 are 7.0 and 1.7, respectively. , 2.7, 4.6 and 5.6, all of which were greater than or equal to 1.7. Further, as shown in Table 1 and FIG. 5, in the photoelectric conversion device according to Example 1, the second peak P2 does not appear, so it can be said that the intensity ratio P1/P2 is infinite. Therefore, in the photoelectric conversion elements according to Examples 1 to 6, the intensity of the first peak P1 is 1.7 times or more the intensity of the maximum measured value in the range of 41.0°≦2θ<42.0°. Met. On the other hand, as shown in Table 1 and FIG. 11, the intensity ratio P1/P2 of the first peak P1 to the second peak P2 in the photoelectric conversion element according to the comparative example was 0.3. Here, the intensities of the first peak P1 and the second peak P2 and the maximum measured value in the range of 41.0° ≤ 2θ < 42.0° are all from the measured values shown in FIGS. 5 to 10 to the baseline. It is the value obtained by subtracting the measured value of
　実施例１～６に係る光電変換素子では、光吸収層に含まれる結晶構造が変化して単位格子の（１１０）面における回折が減少すると共に（０１８）面における回折が増加したために、第１ピークＰ１の高さが第２ピークＰ２の高さよりも高くなったと推察される。また、実施例１～６に係る光電変換素子では、単位格子の（１１０）面の原子配列の乱れが大きくなると共に、単位格子の（０１８）面の原子配列の乱れが小さくなることで、第１ピークＰ１の高さが第２ピークＰ２の高さよりも高くなったと推察される。（０１８）面における回折は、（００３）面に代表されるｃ軸方向の秩序性を多分に反映したものである。ｃ軸方向はヨウ素原子に囲まれたＡｇ原子中心とヨウ素原子に囲まれたＢｉ原子中心の層が積層される方向であり、原子配列が乱れやすい。実施例１～６において第１ピークが高くなったということは、原子配列のｃ軸方向の原子間距離の秩序性が高くなり原子配列の欠陥が少なくなったことで、欠陥にトラップされるキャリアが減少し、キャリア寿命が長くなったと推察される。その結果、光吸収層内でのキャリアの移動がしやすくなり輸送層により多くのキャリアが移動できるようになったため、実施例１～６に係る光電変換素子の発電効率が向上したと推察される。 In the photoelectric conversion elements according to Examples 1 to 6, the crystal structure included in the light absorption layer changed, and the diffraction at the (110) plane of the unit lattice decreased and the diffraction at the (018) plane increased. It is presumed that the height of the peak P1 is higher than the height of the second peak P2. In addition, in the photoelectric conversion elements according to Examples 1 to 6, the disturbance of the atomic arrangement on the (110) plane of the unit cell is increased, and the disturbance of the atomic arrangement on the (018) plane of the unit cell is decreased. It is presumed that the height of the first peak P1 is higher than the height of the second peak P2. Diffraction on the (018) plane largely reflects the orderliness in the c-axis direction represented by the (003) plane. The c-axis direction is the direction in which the layers of the center of Ag atoms surrounded by iodine atoms and the center of Bi atoms surrounded by iodine atoms are laminated, and the atomic arrangement is easily disturbed. The fact that the first peak was high in Examples 1 to 6 means that the order of the interatomic distance in the c-axis direction of the atomic arrangement was increased and the number of defects in the atomic arrangement was reduced. is reduced, and the carrier lifetime is assumed to be longer. As a result, carriers are more likely to move in the light absorption layer and more carriers can move in the transport layer, so it is presumed that the power generation efficiency of the photoelectric conversion elements according to Examples 1 to 6 was improved. .
　なお、実施形態に係る光吸収層の結晶構造は、主としてＸ線回折測定したときに現れる第１ピークＰ１によって特定されると考えられる。第２ピークＰ２が発電効率の良好な光吸収層では非常に微小であるからである。しかしながら、第１ピークの強度はＸ線回折測定の条件によって変化する可能性があるので、第１ピークの強度を特定するために、４１．０°≦２θ＜４２．０°の範囲の最大の測定値（第２ピークが現れた場合には、第２ピークの強度）との強度比を用いた。 The crystal structure of the light absorption layer according to the embodiment is considered to be specified mainly by the first peak P1 appearing when X-ray diffraction is measured. This is because the second peak P2 is very small in the light absorption layer with good power generation efficiency. However, since the intensity of the first peak may change depending on the conditions of the X-ray diffraction measurement, in order to specify the intensity of the first peak, the maximum The intensity ratio to the measured value (intensity of the second peak when the second peak appears) was used.
　また、表１及び図６～図１０に示したように、実施例１～６に係る光電変換素子において１１．５°≦２θ≦１４．０°の範囲、具体的には１２．７６°に現れる最大のピークＰｍの、２８．０°≦２θ≦３２．０°、具体的には２９．２８°に現れる第３ピークＰ３に対する強度比Ｐｍ／Ｐ３は、１．７、２．１、１．２、１．２、２．２及び１．２であった。すなわち、最大のピークＰｍの強度は、第３ピークＰ３の強度に対して１．２倍以上であった。最大のピークＰｍは、（００３）面に対応する角度である１２．７６°に現れるピークであったから、実施例１～６に係る光電変換素子の光吸収層は、ｃ軸方向の秩序性が高かったと推察される。実施例１～６に係る光電変換素子の光吸収層は、ｃ軸方向の秩序性が高く、光吸収層に含まれる結晶の欠陥が少なかったため、光吸収により生成した電子と正孔との間の再結合による損失が低減したと共に、輸送性能の向上により発電効率が向上したと推察される。 Further, as shown in Table 1 and FIGS. 6 to 10, in the photoelectric conversion elements according to Examples 1 to 6, the The intensity ratio Pm/P3 of the maximum peak Pm appearing to the third peak P3 appearing at 28.0°≦2θ≦32.0°, specifically at 29.28°, is 1.7, 2.1, 1 .2, 1.2, 2.2 and 1.2. That is, the intensity of the maximum peak Pm was 1.2 times or more the intensity of the third peak P3. The maximum peak Pm was a peak appearing at an angle of 12.76° corresponding to the (003) plane. presumed to have been high. The light-absorbing layers of the photoelectric conversion elements according to Examples 1 to 6 had a high degree of order in the c-axis direction and few crystal defects contained in the light-absorbing layers. It is presumed that the loss due to the recombination of the fuel was reduced, and the power generation efficiency was improved due to the improvement of the transportation performance.
　一方、表１及び図１１に示したように、比較例に係る光電変換素子において１２．７６°に現れたピークはＸ線回折パターンの最大のピークではなかったため、比較例に係る光電変換素子の光吸収層は、ｃ軸方向の秩序性が高くなかったと推察される。比較例に係る光電変換素子の光吸収層は、ｃ軸方向の秩序性が低く、光吸収層に含まれる結晶に多くの欠陥が形成されたため、光吸収により生成した電子と正孔との間の再結合による損失が増加したと共に、輸送性能の低下により発電効率が低下したと推察される。比較例において、１２．７６°に現れたピークＰｍの第３ピークＰ３に対する強度比は０．９であった。 On the other hand, as shown in Table 1 and FIG. 11, the peak appearing at 12.76° in the photoelectric conversion element according to the comparative example was not the maximum peak of the X-ray diffraction pattern. It is presumed that the light absorption layer did not have high orderliness in the c-axis direction. The light-absorbing layer of the photoelectric conversion element according to the comparative example has a low degree of order in the c-axis direction, and many defects are formed in the crystals included in the light-absorbing layer. It is presumed that the loss due to the recombination of the fuel increased and the power generation efficiency decreased due to the deterioration of the transport performance. In the comparative example, the intensity ratio of the peak Pm appearing at 12.76° to the third peak P3 was 0.9.
　　１　光電変換素子
　　１０　基板
　　１１　下部導電層
　　１２　電子輸送層
　　１３　光吸収層
　　１４　正孔輸送層
　　１５　　上部電極 REFERENCE SIGNS LIST 1 photoelectric conversion element 10 substrate 11 lower conductive layer 12 electron transport layer 13 light absorption layer 14 hole transport layer 15 upper electrode

Claims (7)

  1. 　組成式ＡｇaＢｉbＩcで示され、それぞれ六つのＩイオンからなる複数の八面体単位が連接され、且つ、前記複数の八面体単位のそれぞれの中心にＡｇイオン及びＢｉイオンの何れかが配置される構造を有する結晶を含み、
    　前記組成式において、組成比ａ及びｂは、１．５≦ａ／ｂ≦４．０を満たし、
    　Ｘ線回折測定したとき、４２．０°≦２θ≦４３．０°の範囲に第１ピークが現れ、
    　前記第１ピークの強度は、Ｘ線回折測定したときの４１．０°≦２θ＜４２．０°の範囲における最大の測定値の強度に対して１．７倍以上である、
    　ことを特徴とする光吸収層。     A plurality of octahedral units represented by the compositional formula Ag a Bi b I c each consisting of six I ions are connected, and either Ag ion or Bi ion is at the center of each of the plurality of octahedral units comprising a crystal having a structure arranged therein;
    In the composition formula, the composition ratios a and b satisfy 1.5 ≤ a/b ≤ 4.0,
    When measured by X-ray diffraction, a first peak appears in the range of 42.0° ≤ 2θ ≤ 43.0°,
    The intensity of the first peak is 1.7 times or more the intensity of the maximum measured value in the range of 41.0 ° ≤ 2θ < 42.0 ° when X-ray diffraction measurement is performed.
    A light absorption layer characterized by:
  2. 　Ｘ線回折測定したとき、４１．０°≦２θ＜４２．０°の範囲に第２ピークが現れ、
    　前記第１ピークの強度は、前記第２ピークの強度に対して１．７倍以上且つ７．０倍以下である、請求項１に記載の光吸収層。     When measured by X-ray diffraction, a second peak appears in the range of 41.0° ≤ 2θ < 42.0°,
    2. The light absorption layer according to claim 1, wherein the intensity of the first peak is 1.7 times or more and 7.0 times or less the intensity of the second peak.
  3. 　Ｘ線回折測定したとき、１１．５°≦２θ≦１４．０°の範囲に最大のピークが現れる、請求項１又は２に記載の光吸収層。 3. The light absorbing layer according to claim 1 or 2, wherein the maximum peak appears in the range of 11.5°≤2θ≤14.0° when measured by X-ray diffraction.
  4. 　Ｘ線回折測定したとき、２８．０°≦２θ＜３２．０°の範囲に第３ピークが現れ、
    　前記最大のピークの強度は、前記第３ピークの強度に対して１．２倍以上である、請求項３に記載の光吸収層。     When measured by X-ray diffraction, a third peak appears in the range of 28.0° ≤ 2θ < 32.0°,
    4. The light absorption layer according to claim 3, wherein the intensity of said maximum peak is 1.2 times or more the intensity of said third peak.
  5. 　輸送層上に成膜され、組成式ＡｇaＢｉbＩcで示される結晶を含む光吸収層と、
    　前記光吸収層の一方の面に成膜された電子輸送層と、
    　前記光吸収層の他方の面に成膜された正孔輸送層と、を有し、
    　前記組成式において、組成比ａ及びｂは、１．５≦ａ／ｂ≦４．０を満たし、
    　前記光吸収層をＸ線回折測定したとき、４２．０°≦２θ≦４３．０°の範囲に第１ピークが現れ、
    　前記第１ピークの強度は、Ｘ線回折測定したときの４１．０°≦２θ＜４２．０°の範囲における最大の測定値の強度に対して１．７倍以上である、
    　ことを特徴とする光電変換素子。     a light absorption layer formed on the transport layer and containing crystals represented by the composition formula Ag a Bi b I c ;
    an electron transport layer deposited on one surface of the light absorption layer;
    a hole transport layer formed on the other surface of the light absorption layer;
    In the composition formula, the composition ratios a and b satisfy 1.5 ≤ a/b ≤ 4.0,
    When the light absorption layer is subjected to X-ray diffraction measurement, a first peak appears in the range of 42.0° ≤ 2θ ≤ 43.0°,
    The intensity of the first peak is 1.7 times or more the intensity of the maximum measured value in the range of 41.0 ° ≤ 2θ < 42.0 ° when X-ray diffraction measurement is performed.
    A photoelectric conversion device characterized by:
  6. 　不活性ガス及び気化した第１有機物が充填された雰囲気中に基材を配置し、
    　組成式ＡｇaＢｉbＩcで示される結晶を形成可能な前駆体と、前記第１有機物と異なる第２有機物を含有する溶媒とを含有する前駆体溶液を基材の表面に塗布し、
    　前記前駆体溶液が基材の表面に塗布された基材を焼成することによって、前記組成式における組成比ａ及びｂが１．５≦ａ／ｂ≦４．０を満たす光吸収層を形成する、
    　ことを含み、
    　前記第１有機物は、クロロベンゼンである、
    　ことを特徴とする光吸収層の形成方法。     placing the substrate in an atmosphere filled with an inert gas and the vaporized first organic substance;
    applying a precursor solution containing a precursor capable of forming crystals represented by the composition formula Ag a Bi b I c and a solvent containing a second organic substance different from the first organic substance to the surface of the substrate;
    By baking the substrate coated with the precursor solution on the surface of the substrate, the composition ratio a and b in the composition formula satisfies 1.5≦a/b≦4.0 to form a light absorbing layer. ,
    including
    The first organic substance is chlorobenzene,
    A method for forming a light absorption layer, characterized by:
  7. 　前記前駆体溶液を基材の表面に塗布する間に、前記第２有機物と異なる第３有機物を貧溶媒として基材の表面に滴下する、ことを更に含む請求項６に記載の光吸収層の形成方法。 7. The light absorbing layer according to claim 6, further comprising dripping a third organic substance different from the second organic substance as a poor solvent onto the surface of the substrate while the precursor solution is applied to the surface of the substrate. Forming method.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018030730A (en) * 2016-08-22 2018-03-01 次世代化学材料評価技術研究組合 Film, optical device, electronic device, photoelectric conversion apparatus, and film production method
JP2018512364A (en) * 2015-03-24 2018-05-17 キング アブドラ ユニバーシティ オブ サイエンス アンド テクノロジー Method for forming organometallic halide structure
KR101941783B1 (en) * 2017-09-12 2019-01-23 인하대학교 산학협력단 organic inorganic hybrid perovskite compound containing silver bismuth iodide, preparation method thereof and an organic inorganic hybrid solar cell containing the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018512364A (en) * 2015-03-24 2018-05-17 キング アブドラ ユニバーシティ オブ サイエンス アンド テクノロジー Method for forming organometallic halide structure
JP2018030730A (en) * 2016-08-22 2018-03-01 次世代化学材料評価技術研究組合 Film, optical device, electronic device, photoelectric conversion apparatus, and film production method
KR101941783B1 (en) * 2017-09-12 2019-01-23 인하대학교 산학협력단 organic inorganic hybrid perovskite compound containing silver bismuth iodide, preparation method thereof and an organic inorganic hybrid solar cell containing the same

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
GHOSH BIPLAB, WU BO, GUO XINTONG, HARIKESH PADINHARE CHOLAKKAL, JOHN ROHIT ABRAHAM, BAIKIE TOM, ARRAMEL, WEE ANDREW T. S., GUET CL: "Superior Performance of Silver Bismuth Iodide Photovoltaics Fabricated via Dynamic Hot‐Casting Method under Ambient Conditions", ADVANCED ENERGY MATERIALS, WILEY - V C H VERLAG GMBH & CO. KGAA, DE, vol. 8, no. 33, 1 November 2018 (2018-11-01), DE , pages 1802051, XP093086766, ISSN: 1614-6832, DOI: 10.1002/aenm.201802051 *
KHAZAEE MARYAM, SARDASHTI KASRA, CHUNG CHING-CHANG, SUN JON-PAUL, ZHOU HANHAN, BERGMANN ERIC, DUNLAP-SHOHL WILEY A., HAN QIWEI, HI: "Dual-source evaporation of silver bismuth iodide films for planar junction solar cells", JOURNAL OF MATERIALS CHEMISTRY A, ROYAL SOCIETY OF CHEMISTRY, GB, vol. 7, no. 5, 29 January 2019 (2019-01-29), GB , pages 2095 - 2105, XP093086758, ISSN: 2050-7488, DOI: 10.1039/C8TA08679F *
MASHADIEVA LEYLA F.; ALIEV ZIYA S.; SHEVELKOV ANDREI V.; BABANLY MAHAMMAD B.: "Experimental investigation of the Ag–Bi–I ternary system and thermodynamic properties of the ternary phases", JOURNAL OF ALLOYS AND COMPOUNDS, ELSEVIER SEQUOIA, LAUSANNE., CH, vol. 551, 16 November 2012 (2012-11-16), CH , pages 512 - 520, XP028963100, ISSN: 0925-8388, DOI: 10.1016/j.jallcom.2012.11.033 *
PECUNIA VINCENZO, YUAN YUE, ZHAO JING, XIA KAI, WANG YAN, DUHM STEFFEN, PORTILLA LUIS, LI FENGZHU: "Perovskite-Inspired Lead-Free Ag2BiI5 for Self-Powered NIR-Blind Visible Light Photodetection", NANO-MICRO LETTERS, vol. 12, no. 1, 20 January 2020 (2020-01-20), pages 27, XP093086764, ISSN: 2311-6706, DOI: 10.1007/s40820-020-0371-0 *
PRASAD MUVVA D., KRISHNA M. GHANASHYAM, BATABYAL SUDIP K.: "Silver Bismuth Iodide Nanomaterials as Lead-Free Perovskite for Visible Light Photodetection", ACS APPLIED NANO MATERIALS, vol. 4, no. 2, 26 February 2021 (2021-02-26), pages 1252 - 1259, XP093086760, ISSN: 2574-0970, DOI: 10.1021/acsanm.0c02857 *

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