WO2017017886A1 - 光電極及びその製造方法、並びに光電気化学セル - Google Patents
光電極及びその製造方法、並びに光電気化学セル Download PDFInfo
- Publication number
- WO2017017886A1 WO2017017886A1 PCT/JP2016/002874 JP2016002874W WO2017017886A1 WO 2017017886 A1 WO2017017886 A1 WO 2017017886A1 JP 2016002874 W JP2016002874 W JP 2016002874W WO 2017017886 A1 WO2017017886 A1 WO 2017017886A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- film
- photoelectrode
- zno
- semiconductor film
- atoms
- Prior art date
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 239000004065 semiconductor Substances 0.000 claims abstract description 83
- 239000000758 substrate Substances 0.000 claims abstract description 48
- 229910052751 metal Inorganic materials 0.000 claims abstract description 41
- 150000004767 nitrides Chemical class 0.000 claims abstract description 33
- 239000002184 metal Substances 0.000 claims abstract description 31
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 40
- 229910020055 NbON Inorganic materials 0.000 claims description 38
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 31
- 229910021529 ammonia Inorganic materials 0.000 claims description 20
- 229910003071 TaON Inorganic materials 0.000 claims description 17
- 239000008151 electrolyte solution Substances 0.000 claims description 14
- 229910052733 gallium Inorganic materials 0.000 claims description 11
- 229910052782 aluminium Inorganic materials 0.000 claims description 10
- 239000010408 film Substances 0.000 description 295
- 239000010955 niobium Substances 0.000 description 39
- 230000015572 biosynthetic process Effects 0.000 description 27
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 17
- 239000001257 hydrogen Substances 0.000 description 17
- 229910052739 hydrogen Inorganic materials 0.000 description 17
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 16
- 239000001301 oxygen Substances 0.000 description 16
- 229910052760 oxygen Inorganic materials 0.000 description 16
- 238000002488 metal-organic chemical vapour deposition Methods 0.000 description 15
- 239000007789 gas Substances 0.000 description 13
- 229910052594 sapphire Inorganic materials 0.000 description 13
- 239000010980 sapphire Substances 0.000 description 13
- 238000001228 spectrum Methods 0.000 description 13
- 238000004544 sputter deposition Methods 0.000 description 12
- 238000000682 scanning probe acoustic microscopy Methods 0.000 description 10
- 238000000034 method Methods 0.000 description 9
- 239000007858 starting material Substances 0.000 description 8
- 238000000026 X-ray photoelectron spectrum Methods 0.000 description 7
- 238000000605 extraction Methods 0.000 description 7
- 230000001678 irradiating effect Effects 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 239000013078 crystal Substances 0.000 description 6
- 230000007547 defect Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000011261 inert gas Substances 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 239000004020 conductor Substances 0.000 description 5
- 238000000354 decomposition reaction Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 238000000926 separation method Methods 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 229910010413 TiO 2 Inorganic materials 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 238000002371 ultraviolet--visible spectrum Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- RDTGIHRWTHTOCP-UHFFFAOYSA-N ethyl(methyl)azanide;niobium(3+) Chemical compound [Nb+3].CC[N-]C.CC[N-]C.CC[N-]C RDTGIHRWTHTOCP-UHFFFAOYSA-N 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 150000002822 niobium compounds Chemical class 0.000 description 2
- 238000002233 thin-film X-ray diffraction Methods 0.000 description 2
- MHMBUJVKUFAYFM-UHFFFAOYSA-N C(C)N(C)[Ta] Chemical compound C(C)N(C)[Ta] MHMBUJVKUFAYFM-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000004847 absorption spectroscopy Methods 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 125000000484 butyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000006482 condensation reaction Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical group 0.000 description 1
- 125000001183 hydrocarbyl group Chemical group 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910052743 krypton Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052754 neon Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000005215 recombination Methods 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
- 238000005477 sputtering target Methods 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 1
- 229910001887 tin oxide Inorganic materials 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/16—Oxides
- C30B29/22—Complex oxides
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/01—Products
- C25B1/02—Hydrogen or oxygen
- C25B1/04—Hydrogen or oxygen by electrolysis of water
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/50—Processes
- C25B1/55—Photoelectrolysis
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
- C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
- C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
- C25B9/17—Cells comprising dimensionally-stable non-movable electrodes; Assemblies of constructional parts thereof
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B23/00—Single-crystal growth by condensing evaporated or sublimed materials
- C30B23/02—Epitaxial-layer growth
- C30B23/025—Epitaxial-layer growth characterised by the substrate
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
- C30B25/02—Epitaxial-layer growth
- C30B25/04—Pattern deposit, e.g. by using masks
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
- C30B25/02—Epitaxial-layer growth
- C30B25/18—Epitaxial-layer growth characterised by the substrate
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/16—Oxides
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/38—Nitrides
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/60—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape characterised by shape
- C30B29/68—Crystals with laminate structure, e.g. "superlattices"
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
- H01G9/20—Light-sensitive devices
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
- Y02P20/133—Renewable energy sources, e.g. sunlight
Definitions
- the present disclosure relates to a photoelectrode, a manufacturing method thereof, and a photoelectrochemical cell.
- Patent Document 1 a technique for decomposing water and collecting hydrogen and oxygen by irradiating a semiconductor material functioning as a photoelectrode with light is known (see, for example, Patent Document 1).
- an n-type semiconductor electrode (photoelectrode) and a counter electrode are arranged in an electrolyte solution, and hydrogen and oxygen are collected from the surfaces of both electrodes by irradiating light on the surfaces of the n-type semiconductor electrode.
- a TiO 2 electrode or the like is used as the n-type semiconductor electrode.
- the band gap of TiO 2 is 380 nm, only about 1% of sunlight can be used with the TiO 2 electrode.
- Patent Document 2 uses an ITO film as a conductive substrate and has a small band gap (between 700 nm and 1010 nm) obtained by the MOCVD method in which an organic Nb compound and ammonia are brought into contact therewith. It is disclosed that the use efficiency of sunlight is improved by using a Nb 3 N 5 film as a photoelectrode.
- the present disclosure discloses a conductive material used for a photoelectrode even though it includes a metal nitride or metal oxynitride semiconductor film that needs to be synthesized at a relatively high temperature using ammonia. It is an object of the present invention to provide a photoelectrode capable of realizing high quantum efficiency (photosemiconductor characteristics in which water is decomposed by irradiating light to collect hydrogen and oxygen) without lowering the conductivity of the film.
- a conductive material used for a photoelectrode despite including a semiconductor film of metal nitride or metal oxynitride that needs to be synthesized at a relatively high temperature using ammonia. It is possible to provide a photoelectrode capable of realizing high quantum efficiency (in this disclosure, a photo-semiconductor characteristic in which water is decomposed by irradiating light and hydrogen and oxygen are collected) without reducing the conductivity.
- FIG. 1 is a schematic diagram illustrating a configuration of a photoelectrochemical cell including an example of a photoelectrode according to an embodiment of the present disclosure.
- FIG. 2 is a schematic diagram illustrating a configuration of a photoelectrochemical cell including another example of a photoelectrode according to an embodiment of the present disclosure.
- FIG. 3 is a graph showing the sheet resistance of a ZnO conductive film (GZO film) used in Example 1 in which a part of Zn is replaced with Ga.
- FIG. 4 shows a thin film XRD (X-ray diffraction) spectrum of the GZO film used in Example 1.
- FIG. 5 shows the UV-Vis (Ultraviolet Visible Absorption Spectroscopy) spectrum of the photoelectrode of Example 1.
- FIG. 6 shows an XPS (X-ray-photoelectron-spectroscopic) spectrum at a depth of 10 nm from the surface of the NbON film in the photoelectrode of Example 1.
- FIG. 7 shows an AES (Auger Electron Spectroscopy) spectrum from the surface of the NbON film in the photoelectrode of Example 1.
- FIG. 8 is a graph showing the quantum efficiency of the photoelectrodes of Examples 1 and 2.
- FIG. 9 shows an AES spectrum from the surface of the NbON film in the photoelectrode of Comparative Example 1.
- FIG. 10 shows the UV-Vis spectrum of the photoelectrode of Example 3.
- FIG. 11 shows an XPS spectrum at a depth of 10 nm from the surface of the Nb 3 N 5 film in the photoelectrode of Example 3.
- FIG. 12 is a graph showing the sheet resistance of the GZO film used in Example 3.
- FIG. 13 is a graph showing the quantum efficiency of the photoelectrodes of Examples 3 and 4.
- FIG. 14 shows an XPS spectrum at a depth of 10 nm from the surface of the TaON film in the photoelectrode of Example 5.
- FIG. 15 is a graph showing the sheet resistance of the GZO film used in Example 5.
- FIG. 16 is a graph showing the quantum efficiency of the photoelectrode of Example 5.
- FIG. 17 shows an XPS spectrum at a depth of 10 nm from the surface of the Ta 3 N 5 film in the photoelectrode of Example 6.
- FIG. 18 is a graph showing the sheet resistance of the GZO film used in Example 6.
- FIG. 19 is a graph showing the quantum efficiency of the photoelectrode of Example 6.
- a photoelectrode includes a substrate, a ZnO conductive film provided on the substrate, wherein a part of Zn is substituted with at least one element of Ga and Al, A nitride or oxynitride of at least one metal element selected from the group 4A, 5A, 6A, and 3B metal elements provided on the opposite side of the ZnO conductive film from the substrate; A semiconductor film.
- the photoelectrode according to the first embodiment uses a ZnO conductive film in which a part of Zn is substituted with at least one element of Ga and Al. Therefore, it is necessary to carry out the synthesis using ammonia at a relatively high temperature. Nitride or oxynitridation of at least one metal element selected from the group 4A, 5A, 6A and 3B metal elements A semiconductor film made of a material can be manufactured without reducing the conductivity of the ZnO conductive film. As a result, the photoelectrode according to the first aspect can realize high quantum efficiency.
- the ratio of the total of Ga atoms and Al atoms to the total of Zn atoms, Ga atoms, and Al atoms in the ZnO conductive film is expressed as an atomic percentage.
- the ratio may be 2 atomic% or more and 6 atomic% or less.
- the quantum efficiency can be further improved.
- the ratio of the total of Ga atoms and Al atoms to the total of Zn atoms, Ga atoms, and Al atoms is expressed as an atomic percentage.
- the ratio may be 2 atomic% or more and 4 atomic% or less.
- the ZnO conductive film can be an epitaxial film.
- the crystal orientation of the ZnO conductive film is extremely good, and defects are rarely generated in the film and at the interface with other films, so that the quantum efficiency is further improved. be able to.
- the ZnO conductive film may be an epitaxial film.
- the ZnO conductive film is an epitaxial film
- the crystal orientation is very good, and defects are hardly generated in the film and at the interface with other films.
- the quantum efficiency can be further improved.
- the photoelectrode according to any one of the first to fourth aspects may further include a ZnO semiconductor film disposed between the ZnO conductive film and the semiconductor film.
- the ZnO semiconductor film acts as a charge separation layer, and since ZnO of the same crystal material as that of the ZnO conductive film is used, a defect occurs at the interface with the ZnO conductive film. The quantum efficiency can be further improved.
- the ZnO semiconductor film may be an epitaxial film.
- the ZnO semiconductor film is an epitaxial film
- the crystal orientation is very good, and defects are hardly generated in the film and at the interface with other films.
- the quantum efficiency can be further improved.
- a part of the ZnO conductive film may be exposed without being covered by the semiconductor film.
- the ZnO conductive film does not decrease in conductivity even when it is in contact with ammonia at a high temperature when forming a metal nitride or metal oxynitride semiconductor film. It is possible to use the exposed part of the electrode as it is as an electrode extraction part. Moreover, since the exposed part of such a ZnO electrically conductive film can be formed with a simple metal mask, without using a protective film etc., it can manufacture easily.
- the semiconductor film is made of Nb nitride, Ta nitride, Nb oxynitride, and Ta oxynitride. It may be at least one selected semiconductor film.
- the photoelectrode according to the eighth aspect it is possible to collect water and hydrogen by decomposing water using the visible light region of sunlight, and to improve the quantum efficiency.
- the semiconductor film may be at least one nitride semiconductor film selected from Nb 3 N 5 and Ta 3 N 5. Good.
- water and water can be collected by decomposing water using the visible light region of sunlight, and the quantum efficiency can be further improved.
- the semiconductor film may be at least one oxynitride semiconductor film selected from NbON and TaON.
- water and water can be collected by utilizing the visible light region of sunlight, and the quantum efficiency can be further improved.
- a photoelectrochemical cell includes a photoelectrode according to any one of the first to tenth aspects, a counter electrode electrically connected to the ZnO conductive film of the photoelectrode, And a container for accommodating the photoelectrode and the counter electrode.
- the photoelectrochemical cell according to the eleventh aspect includes the photoelectrode according to any one of the first to tenth aspects, hydrogen and oxygen are collected by decomposing water with high quantum efficiency. it can.
- the photoelectrochemical cell according to the eleventh aspect may further include an electrolyte containing water that is accommodated in the container and is in contact with the surface of the photoelectrode and the counter electrode.
- hydrogen and oxygen can be collected by decomposing water with high quantum efficiency.
- a thirteenth aspect of the present disclosure includes A ZnO conductive film in which a part of Zn is substituted with at least one element of Ga and Al on a substrate is produced, A nitride or oxynitride semiconductor film of at least one metal element selected from the group 4A, 5A, 6A, and 3B metal elements on the opposite side of the ZnO conductive film from the substrate Made with ammonia, A method for producing a photoelectrode is provided.
- the conductivity of the ZnO conductive film does not decrease, so that a photoelectrode capable of realizing high quantum efficiency can be manufactured.
- FIG. 1 shows an example of a configuration of a photoelectrochemical cell including an example of a photoelectrode according to an embodiment of the present disclosure.
- the photoelectrochemical cell 100 shown in FIG. 1 includes a photoelectrode 120, a counter electrode 130, an electrolytic solution 140 containing water, and a container 110 that houses the photoelectrode 120, the counter electrode 130, and the electrolytic solution 140.
- the photoelectrode 120 includes a substrate 121, a ZnO conductive film 122 provided on the substrate 121, in which a part of Zn is substituted with at least one element of Ga and Al, and the ZnO conductive film 122. And a nitride or oxynitride semiconductor film 123 of at least one metal element selected from the group 4A, 5A, 6A, and 3B metal elements.
- the semiconductor film 123 is an Nb oxynitride semiconductor film, more specifically, a case where it is an NbON film will be described as an example.
- the photoelectrode 120 and the counter electrode 130 are disposed so that the surfaces thereof are in contact with the electrolytic solution 140.
- a portion facing the semiconductor film 123 of the photoelectrode 120 disposed in the container 110 (hereinafter abbreviated as a light incident portion 111) is made of a material that transmits light such as sunlight. .
- the ZnO conductive film 122 and the counter electrode 130 in the photoelectrode 120 are electrically connected by a conducting wire 150.
- the counter electrode means an electrode that exchanges electrons with the photoelectrode without using an electrolytic solution. Therefore, the counter electrode 130 in this embodiment may be electrically connected to the ZnO conductive film 122 constituting the photoelectrode 120, and the positional relationship with the photoelectrode 120 is not particularly limited.
- NbON used for the semiconductor film 123 in this embodiment is an n-type semiconductor
- the counter electrode 130 serves as an electrode that receives electrons from the photoelectrode 120 without passing through the electrolytic solution 140.
- the counter electrode 130 it is preferable to use a material having a small overvoltage. For example, it is preferable to use a metal catalyst such as Pt, Au, Ag, Fe, or Ni because the activity of the counter electrode 130 is increased.
- the photoelectrochemical cell 100 further includes a separator 160.
- the interior of the container 110 is separated by the separator 160 into two regions, a region on the side where the photoelectrode 120 is disposed and a region where the counter electrode 130 is disposed.
- the electrolyte solution 140 is accommodated in both regions.
- the container 110 has an oxygen exhaust port 113 for exhausting oxygen generated in the region where the photoelectrode 120 is disposed, and a hydrogen exhaust for exhausting hydrogen generated in the region where the counter electrode 130 is disposed.
- a mouth 114 The container 110 further includes a water supply port 112 for supplying water into the container 110.
- the electrolytic solution 140 is not particularly limited as long as it contains water.
- the electrolytic solution 140 may be acidic or alkaline. Further, a solid electrolyte can be used instead of the electrolytic solution 140.
- a sapphire substrate can be used as the substrate 121.
- Sputtering is performed on a heated sapphire substrate using a ZnO target in which a part of Zn is substituted with at least one element of Ga and Al in an inert gas flow atmosphere.
- a ZnO conductive film 122 substituted with at least one element of Al can be formed.
- a metal mask is disposed in a portion corresponding to the electrode extraction portion of the ZnO conductive film 122 formed on the substrate 121, and then an inert gas flow atmosphere is formed on the ZnO conductive film 122 using an MOCVD apparatus.
- the NbON film can be formed (MOCVD film formation) by injecting a gas in which ammonia and water vapor are mixed into the starting material (for example, organic Nb compound) vaporized in step (b).
- a gas in which ammonia and water vapor are mixed into the starting material for example, organic Nb compound
- oxygen may be used instead of water vapor.
- the substrate material that can be used as the substrate 121 examples include metals, glass, ceramics, and the like in addition to sapphire. Note that in the case where the ZnO conductive film 122 is formed by epitaxial film formation, a substrate having orientation such as C-plane sapphire or R-plane sapphire is preferably used as the substrate 121. Further, it is more preferable to perform step processing on the substrate.
- the total ratio of Ga atoms and Al atoms is, for example, It is good also as 2 atomic% or more and 6 atomic% or less.
- the sheet resistance of the ZnO conductive film 122 can be, for example, 30 ⁇ / ⁇ or less. Thereby, the resistance loss of the ZnO electrically conductive film 121 etc. can reduce and the quantum efficiency of the photoelectrode 120 can be improved.
- the substrate 121 is an oriented substrate, for example, a sapphire substrate with an exposed C surface or R surface.
- the ZnO conductive film 122 can be an epitaxial film. Therefore, in this case, the quantum efficiency of the photoelectrode 120 can be further improved.
- the above ratio is the ratio of Ga atoms to the total of Zn atoms and Ga atoms.
- the above ratio is the ratio of Al atoms to the total of Zn atoms and Al atoms.
- the temperature of the substrate 121 when the ZnO conductive film 122 is formed by sputtering may be, for example, from room temperature to 300 ° C. When the temperature of the substrate 121 is 350 ° C. or higher, for example, there may be a composition shift between the sputtering target and the film.
- the inert gas used when the ZnO conductive film 122 is formed by sputtering is, for example, nitrogen gas in addition to gases such as He, Ne, Ar, Kr, and Xe, which are called rare gases. Good. However, it is desirable to use an inert gas having a low oxygen and water content.
- Examples of the organic niobium compound used when forming the semiconductor film 123 include R 1 N ⁇ Nb (NR 2 R 3 ) 3 (where R 1 , R 2, and R 3 are each an independent hydrocarbon group) ) Can be used. By using such an organic niobium compound as a starting material, the self-condensation reaction of the starting material can be prevented.
- R 1 is a liquid, so that it is easy to handle, vaporize, easily undergo a uniform reaction, and can be further increased in decomposition temperature.
- C (CH 3 ) 3 ) is preferred.
- R 2 and R 3 are excellent in a linear hydrocarbon group from the viewpoint of increasing the decomposition temperature, and for example, CH 3 — and C 2 H 5 — are desirable.
- the temperature at which the semiconductor film 123 is formed by MOCVD (the temperature of the substrate 121) is equal to or higher than the decomposition temperature of the starting material.
- the decomposition temperature of the starting material can be determined by TG-DTA measurement using an inert gas flow, DSC measurement in a closed container, or the like.
- R 1 is a tertiary butyl group (—C (CH 3 ) 3 )
- R 2 and R 3 are CH 3 — and C 2 H 5 —, respectively.
- the temperature during film formation is, for example, 250 ° C. or higher, and may be 500 ° C. or higher from the viewpoint of a uniform film.
- the semiconductor film 123 When sunlight is irradiated from the light incident portion 111 of the container 110 in the photoelectrochemical cell 100 to the semiconductor film 123 accommodated in the container 110 and in contact with the electrolytic solution 140, the semiconductor film 123 has a conduction band. Electrons generate holes in the valence band. The holes generated at this time move to the surface of the semiconductor film 123 by band bending due to a depletion layer generated by contact with the electrolytic solution 140. On the surface of the semiconductor film 123, water is decomposed by the following reaction formula (1) to generate oxygen. On the other hand, electrons move to the ZnO conductive film 122 by the band bending and further reach the counter electrode 130. At the counter electrode 130, hydrogen is generated according to the following reaction formula (2).
- the generated hydrogen and oxygen are separated by the separator 160 in the container, and oxygen is discharged from the oxygen exhaust port 113 and hydrogen is discharged from the hydrogen exhaust port 114.
- the water to be decomposed is supplied into the container 110 from the supply port 112.
- NbON used for the semiconductor film 123 has excellent semiconductor characteristics and has a low probability of recombination of holes and electrons. Therefore, the photoelectrode 120 has a high quantum efficiency of a hydrogen generation reaction by light irradiation. Furthermore, since NbON has a small band gap, it also responds to visible light from sunlight. As a result, the photoelectrode 120 can generate a lot of hydrogen.
- the photoelectrode 220 is different from the photoelectrode 120 in that it further includes a ZnO semiconductor film 221 disposed between the ZnO conductive film 122 and the semiconductor film 123.
- the ZnO semiconductor film 221 functions as a semiconductor rather than functioning as a conductive film by replacing part of Zn with at least one element of Ga and Al. Therefore, the ZnO semiconductor film 221 does not contain, for example, at least one element of Ga and Al.
- the ZnO semiconductor film 221 functions as a charge separation layer. Accordingly, since the photoelectrode 220 can efficiently separate holes and electrons generated by irradiating light, the quantum efficiency can be further improved as compared with the photoelectrode 120. In addition, since ZnO, which is the same crystal material as the ZnO conductive film 122, is used for the ZnO semiconductor film 221, defects at the interface with the ZnO conductive film 122 are extremely rare, and quantum efficiency is further improved. be able to.
- the ZnO semiconductor film 221 may be an epitaxial film.
- the crystal orientation of the ZnO semiconductor film 221 is extremely good, and defects may occur in the film and at the interfaces with the other films of the ZnO conductive film 122 and the semiconductor film 123. Since the amount is extremely small, the quantum efficiency can be further improved.
- a ZnO conductive film 122 is first formed on the substrate 121 in the same manner as the method for manufacturing the photoelectrode 120.
- the ZnO semiconductor film 221 may be formed on the ZnO conductive film 122 by sputtering in an inert gas flow atmosphere using, for example, a ZnO target that does not contain Ga and Al prepared in advance.
- an NbON film may be formed on the ZnO semiconductor film 221 similarly to the semiconductor film 123 of the photoelectrode 120.
- the NbON film is described as an example of the semiconductor film 123.
- the semiconductor film 123 is not limited to the NbON film, but the 4A group, the 5A group, and the 6A group.
- the semiconductor film 123 is not limited to the NbON film, but the 4A group, the 5A group, and the 6A group.
- it is a semiconductor film of a nitride or oxynitride of at least one metal element selected from Group 3B metal elements, any of them can be used.
- high quantum efficiency can be realized as in the case of using an NbON film.
- the configuration of the photoelectrode of the present disclosure includes Nb nitride (Nb nitride) among nitrides or oxynitrides of at least one metal element selected from Group 4A, Group 5A, Group 6A, and Group 3B metal elements.
- Nb nitride for example, Ta 3 N 5
- Nb oxynitride for example, NbON
- Ta oxynitride for example, TaON
- the ZnO conductive film can be synthesized without reducing the conductivity.
- water and water can be collected by utilizing the visible light region of sunlight, and the quantum efficiency of the photoelectrode can be improved.
- Nb nitride for example, Nb 3 N 5
- MOCVD film formation of the NbON film exemplified above water vapor is generated from a gas in which ammonia and water vapor are mixed.
- a gas other than the above an Nb nitride semiconductor film can be formed.
- a Ta oxynitride (for example, TaON) or Ta nitride (for example, Ta 3 N 5 ) semiconductor film is formed by MOCVD film formation
- a Ta compound as a starting material is appropriately selected
- the starting material may be used to form a film using the same gas as the MOCVD film formation of the NbON film and Nb 3 N 5 film exemplified above.
- Nb nitride and Nb oxynitride semiconductors are similarly formed using appropriate starting materials.
- the film can be formed by the same method as the film.
- the conductive members of the photoelectrodes 120 and 220 a portion exposed without being covered with another film (for example, when the substrate 121 is a metal substrate, the ZnO conductive film 122 of the substrate 121 is not disposed).
- the side surface or the like may be covered with an insulator such as a resin. If it does in this way, it can prevent that the part of the conductor of a photoelectrode melt
- photoelectrodes 120 and 220 in the photoelectrochemical cells 100 and 200 such as the container 110, the counter electrode 130, the conducting wire 150, the separator 160, and the like are not particularly limited.
- Known containers, conducting wires, separation membranes, and the like used in photoelectrochemical cells that generate gas can be used as appropriate.
- Example 1 ZnO targets in which 1 atomic%, 2 atomic%, 3 atomic%, 4 atomic%, 5 atomic%, 6 atomic%, 7 atomic%, and 8 atomic% of Zn were substituted with Ga were prepared.
- “atomic%” is simply expressed as “%”.
- GZO films in which 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 8% of Zn are substituted with Ga are formed by sputtering using each prepared ZnO target. Filmed.
- the sheet resistance of the obtained GZO film is shown in FIG.
- the sheet resistance of the GZO film in which 2 to 6% of Zn was replaced with Ga was 30 ⁇ / ⁇ or less.
- a thin film XRD spectrum of the GZO film is shown in FIG.
- FIG. 4 it can be seen that an epitaxial film having only an A-plane orientation is formed in a GZO film in which 4% or less of Zn is replaced with Ga.
- FIG. 5 shows the UV-vis spectrum of the produced photoelectrode of Example 1.
- FIG. 6 shows an XPS spectrum at a depth of 10 nm from the surface of the NbON film in the photoelectrode of Example 1.
- the sheet resistance value of the portion where the GZO film is exposed is shown in FIG. 3 (result of “after NbON film formation” in FIG. 3). It can be seen that the sheet resistance value hardly changes before and after the formation of the NbON film, and the GZO film does not change due to the formation of the NbON film.
- a photoelectrochemical cell 100 shown in FIG. 1 was produced.
- a 1 mol / L NaOH aqueous solution was used as the electrolyte, and a Pt electrode was used as the counter electrode 130.
- the photoelectrochemical cell 100 was irradiated with sunlight from the photoelectrode 120 side, and the quantum efficiency was measured from the generated photocurrent. The results are shown in FIG. 8 (results of “NbON / GZO” in FIG. 8).
- the photoelectrochemical cell using the photoelectrode of Example 1 can achieve high quantum efficiency, and further uses a photoelectrode including a GZO film having a low sheet resistance with a Ga doping amount of 2 to 6%. It was confirmed that the quantum efficiency was particularly high in the cell, and that the quantum efficiency was further increased in the cell using the photoelectrode in which the GZO film with Ga doping amount of 2 to 4% is the epitaxial film. .
- Comparative Example 1 A photoelectrode of Comparative Example 1 was produced in the same manner as in Example 1 except that an ATO film (antimony-doped tin oxide film) was formed instead of the GZO film as the conductive film. The conditions for forming the ATO film were the same as those for the GZO film of Example 1.
- ATO film antimony-doped tin oxide film
- FIG. 9 shows an AES spectrum from the surface of the NbON film in the photoelectrode of Comparative Example 1. According to the AES spectrum, it can be seen that tin (Sn) and antimony (Sb), which are components of the ATO film, diffuse into the NbON film and the NbON film is destroyed. In fact, using the photoelectrode of Comparative Example 1, a photoelectrochemical cell was prepared in the same manner as in Example 1, and the quantum efficiency was measured from the generated photocurrent by irradiating sunlight from the photoelectrode side. No photocurrent was observed.
- Sn tin
- Sb antimony
- Example 2 A photoelectrode of Example 2 was produced in the same manner as in Example 1 except that a ZnO film was provided between the GZO film and the NbON film of the photoelectrode of Example 1. That is, first, as in Example 1, using a sputtering apparatus, a flow rate of 3.38 ⁇ 10 ⁇ 3 Pa ⁇ m was applied on a sapphire substrate (2 inch square) exposed to 300 ° C. exposed R-plane. 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 8% of Zn by sputtering using each prepared ZnO target in an Ar gas flow atmosphere of 3 / s (20 sccm) GZO films in which is replaced with Ga were formed.
- Example 2 a ZnO semiconductor film having a thickness of 50 nm was formed on each GZO film by sputtering using a ZnO target in which Zn was not substituted with Ga.
- an NbON film was formed on the ZnO semiconductor film by the same method as in Example 1, and a photoelectrode of Example 2 was obtained.
- Example 2 Using the photoelectrode of Example 2, a photoelectrochemical cell was prepared in the same manner as in Example 1, irradiated with sunlight from the photoelectrode side, and the quantum efficiency was measured from the generated photocurrent. The results are shown in FIG. (Result of “NbON / ZnO / GZO” in FIG. 8). From this result, the photoelectrochemical cell using the photoelectrode of Example 2 can realize high quantum efficiency, and further uses a photoelectrode including a GZO film having a low sheet resistance with a Ga doping amount of 2 to 6%.
- the quantum efficiency was particularly high in the cell, and that the quantum efficiency was further improved in the cell using the photoelectrode in which the GZO film with Ga doping amount of 2 to 4% is the epitaxial film. . Furthermore, it was confirmed that the quantum efficiency of the photoelectrode of Example 2 was higher due to the charge separation effect of the ZnO film as compared with the photoelectrode of Example 1 in which no ZnO film was provided.
- Example 3 In the MOCVD film formation of Example 1, ammonia (1.69 ⁇ 10 ⁇ 3 Pa ⁇ m 3 / s (10 sccm)) and water vapor (1.69 ⁇ 10 ⁇ 5 Pa ⁇ m 3 / s (0.1 sccm)) Instead of injecting a gas mixed with A and B onto the substrate, by injecting only ammonia (1.69 ⁇ 10 ⁇ 3 Pa ⁇ m 3 / s (10 sccm)), an Nb 3 N 5 film is substituted for the NbON film. A film was formed. As a result, the photoelectrode of Example 3 in which the GZO film was provided on the sapphire substrate and the Nb 3 N 5 film was provided on the GZO film was produced.
- FIG. 10 shows the UV-vis spectrum of the produced photoelectrode of Example 3.
- FIG. 11 shows an XPS spectrum at a depth of 10 nm from the surface of the Nb 3 N 5 film in the photoelectrode of Example 3.
- the sheet resistance value of the portion where the GZO film is exposed is shown in FIG. 12 (result of “after Nb 3 N 5 film formation” in FIG. 12) ).
- Nb 3 N 5 film not sheet resistance hardly changes before and after the deposition film formation, Nb 3 N 5 by formation of the film it can be seen that the GZO film is not changed.
- Example 3 Using the photoelectrode of Example 3, a photoelectrochemical cell was prepared in the same manner as in Example 1, and sunlight was irradiated from the photoelectrode side, and the quantum efficiency was measured from the generated photocurrent. The results are shown in FIG. (Result of “Nb 3 N 5 / GZO” in FIG. 13). From this result, the photoelectrochemical cell using the photoelectrode of Example 3 can realize high quantum efficiency, and further uses a photoelectrode including a GZO film having a low sheet resistance with a Ga doping amount of 2 to 6%. It was confirmed that the quantum efficiency was particularly high in the cell, and that the quantum efficiency was further increased in the cell using the photoelectrode in which the GZO film with Ga doping amount of 2 to 4% is the epitaxial film. .
- Example 4 A photoelectrode of Example 4 was produced in the same manner as in Example 3 except that a ZnO film was provided between the GZO film and the Nb 3 N 5 film of the photoelectrode of Example 3. That is, first, as in Example 3, using a sputtering apparatus, a flow rate of 3.38 ⁇ 10 ⁇ 3 Pa ⁇ m was applied on a sapphire substrate (2 inch square) exposed to 300 ° C. and exposed on the R surface.
- Example 4 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 8% of Zn by sputtering using each prepared ZnO target in an Ar gas flow atmosphere of 3 / s (20 sccm) GZO films in which is replaced with Ga were formed.
- a ZnO semiconductor film having a thickness of 50 nm was formed on each GZO film by sputtering using a ZnO target in which Zn was not substituted with Ga.
- an Nb 3 N 5 film was produced on the ZnO semiconductor film by the same method as in Example 3, and a photoelectrode of Example 4 was obtained.
- Example 4 Using the photoelectrode of Example 4, a photoelectrochemical cell was produced in the same manner as in Example 1, and sunlight was irradiated from the photoelectrode side, and the quantum efficiency was measured from the generated photocurrent. The results are shown in FIG. (Result of “Nb 3 N 5 / ZnO / GZO” in FIG. 13). From this result, the photoelectrochemical cell using the photoelectrode of Example 4 can realize high quantum efficiency, and further uses a photoelectrode including a GZO film having a low sheet resistance with a Ga doping amount of 2 to 6%.
- the quantum efficiency was particularly high in the cell, and that the quantum efficiency was further increased in the cell using the photoelectrode in which the GZO film with Ga doping amount of 2 to 4% is the epitaxial film. . Further, it was confirmed that the quantum efficiency of the photoelectrode of Example 4 was higher due to the charge separation effect of the ZnO film as compared with the photoelectrode of Example 3 in which no ZnO film was provided.
- the photoelectrode of Example 5 was a photoelectrode in which a TaON film was provided instead of the NbON film in the photoelectrode of Example 1.
- a photoelectrochemical cell was prepared in the same manner as in Example 1, irradiated with sunlight from the photoelectrode side, and the quantum efficiency was measured from the generated photocurrent.
- the results are shown in FIG. (Result of “TaON / GZO” in FIG. 16). From this result, the photoelectrochemical cell using the photoelectrode of Example 5 can realize high quantum efficiency, and further uses a photoelectrode including a GZO film having a low sheet resistance with a Ga doping amount of 2 to 6%. It was confirmed that the quantum efficiency was particularly high in the cell, and that the quantum efficiency was further increased in the cell using the photoelectrode in which the GZO film with Ga doping amount of 2 to 4% is the epitaxial film. .
- Example 6 In the MOCVD film formation of Example 5, ammonia (1.69 ⁇ 10 ⁇ 3 Pa ⁇ m 3 / s (10 sccm)) and water vapor (1.69 ⁇ 10 ⁇ 5 Pa ⁇ m 3 / s (0.1 sccm)) Instead of injecting a mixed gas to the substrate, by injecting only ammonia (1.69 ⁇ 10 ⁇ 3 Pa ⁇ m 3 / s (10 sccm)), a Ta 3 N 5 film can be used instead of the TaON film. A film was formed. As a result, a photoelectrode of Example 6 in which a GZO film was provided on the sapphire substrate and a Ta 3 N 5 film was provided on the GZO film was produced.
- FIG. 17 shows an XPS spectrum at a depth of 10 nm from the surface of the Ta 3 N 5 film in the photoelectrode of Example 6.
- the sheet resistance value of the portion where the GZO film is exposed is shown in FIG. 18 (result of “after Ta 3 N 5 film formation” in FIG. 18).
- Ta 3 N 5 film not sheet resistance hardly changes before and after the deposition film formation, Ta 3 N 5 by formation of the film it can be seen that the GZO film is not changed.
- Example 6 Using the photoelectrode of Example 6, a photoelectrochemical cell was prepared in the same manner as in Example 1, and sunlight was irradiated from the photoelectrode side, and the quantum efficiency was measured from the generated photocurrent. The results are shown in FIG. (Result of “Ta 3 N 5 / GZO” in FIG. 19). From this result, the photoelectrochemical cell using the photoelectrode of Example 6 can realize high quantum efficiency, and further uses a photoelectrode including a GZO film having a low sheet resistance with a Ga doping amount of 2 to 6%. It was confirmed that the quantum efficiency was particularly high in the cell, and that the quantum efficiency was further increased in the cell using the photoelectrode in which the GZO film with Ga doping amount of 2 to 4% is the epitaxial film. .
- a metal nitride or metal oxynitride semiconductor film can be formed using high-temperature ammonia, and the orientation of the metal nitride or metal oxynitride semiconductor film is improved.
- Photo-semiconductor properties quantum efficiency
- visible light can also be used by using Ta 3 N 5 or Nb 3 N 5 as the metal nitride and NbON or TaON as the metal oxynitride. Therefore, it can be said that the present disclosure has extremely high industrial applicability.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Power Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
- Photovoltaic Devices (AREA)
- Catalysts (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Led Devices (AREA)
Abstract
Description
基板と、
前記基板上に設けられた、Znの一部がGa及びAlの少なくともいずれか1種の元素で置換されているZnO導電膜と、
前記ZnO導電膜に対して前記基板と反対側に設けられた、4A族、5A族、6A族及び3B族の金属元素から選ばれる少なくともいずれか1種の金属元素の窒化物又は酸窒化物の半導体膜と、
を含む、光電極を提供する。
基板上に、Znの一部がGa及びAlの少なくともいずれか1種の元素で置換されているZnO導電膜を作製し、
前記ZnO導電膜に対して前記基板とは反対側に、4A族、5A族、6A族及び3B族の金属元素から選ばれる少なくともいずれか1種の金属元素の窒化物又は酸窒化物の半導体膜を、アンモニアを用いて作製する、
光電極の製造方法を提供する。
4e-+4H+→2H2↑ …(2)
Znの1原子%、2原子%、3原子%、4原子%、5原子%、6原子%、7原子%及び8原子%がGaに置換されたZnOターゲットをそれぞれ準備した。なお、以下、特に言及しない限り、「原子%」を単に「%」と表記する。スパッタ装置を用いて、300℃に加熱したR面が露出しているサファイア基板(2インチ角)上に、流量3.38×10-3Pa・m3/s(20sccm)のArガスフロー雰囲気下で、準備した各ZnOターゲットを用いたスパッタリングにより、Znの1%、2%、3%、4%、5%、6%、7%及び8%がGaに置換されたGZO膜をそれぞれ成膜した。得られたGZO膜のシート抵抗を図3に示す。図3に示されたNbON成膜前のシート抵抗からわかるように、Znの2~6%がGaに置換されたGZO膜は、シート抵抗が30Ω/□以下であった。また、GZO膜の薄膜XRDスペクトルを図4に示す。図4に示すように、Znの4%以下がGaに置換されたGZO膜において、A面配向のみのエピタキシャル膜が成膜されていることがわかる。
導電膜として、GZO膜に代えて、ATO膜(アンチモンドープ酸化錫膜)を成膜した点を除いて、実施例1と同じ方法で比較例1の光電極を作製した。なお、ATO膜の成膜条件は、実施例1のGZO膜の場合と同じであった。
実施例1の光電極のGZO膜とNbON膜との間にZnO膜を設けたこと以外、実施例1と同じ方法で実施例2の光電極を作製した。すなわち、まず、実施例1と同様に、スパッタ装置を用いて、300℃に加熱したR面が露出しているサファイア基板(2インチ角)上に、流量3.38×10-3Pa・m3/s(20sccm)のArガスフロー雰囲気下で、準備した各ZnOターゲットを用いたスパッタリングにより、Znの1%、2%、3%、4%、5%、6%、7%及び8%がGaに置換されたGZO膜をそれぞれ成膜した。次に、各GZO膜上に、ZnがGaに置換していないZnOターゲットを用いたスパッタリングにより、ZnO半導体膜を厚さ50nmで設けた。次に、ZnO半導体膜上に実施例1と同様の方法でNbON膜を作製して、実施例2の光電極を得た。
実施例1のMOCVD成膜において、アンモニア(1.69×10-3Pa・m3/s(10sccm))と水蒸気(1.69×10-5Pa・m3/s(0.1sccm))とを混合したガスを基板に噴射することに代わり、アンモニア(1.69×10-3Pa・m3/s(10sccm))のみを噴射することで、NbON膜に代わりNb3N5膜を成膜した。これにより、サファイア基板上にGZO膜が設けられ、そのGZO膜上にNb3N5膜が設けられた実施例3の光電極が作製された。
実施例3の光電極のGZO膜とNb3N5膜との間にZnO膜を設けたこと以外、実施例3と同じ方法で実施例4の光電極を作製した。すなわち、まず、実施例3と同様に、スパッタ装置を用いて、300℃に加熱したR面が露出しているサファイア基板(2インチ角)上に、流量3.38×10-3Pa・m3/s(20sccm)のArガスフロー雰囲気下で、準備した各ZnOターゲットを用いたスパッタリングにより、Znの1%、2%、3%、4%、5%、6%、7%及び8%がGaに置換されたGZO膜をそれぞれ成膜した。次に、各GZO膜上に、ZnがGaに置換していないZnOターゲットを用いたスパッタリングにより、ZnO半導体膜を厚さ50nmで設けた。次に、ZnO半導体膜上に実施例3と同様の方法でNb3N5膜を作製して、実施例4の光電極を得た。
実施例1のMOCVD成膜で使用したTertiary-butylimino tris-(ethylmethylamino)niobium((CH3)3CN=Nb(N(C2H5)CH3)3)に代えて、Tertiary-butylimino tris-(ethylmethylamino)tantalum((CH3)3CN=Ta(N(C2H5)CH3)3))を使用した以外は、実施例1と同様の方法で光電極を作製した。すなわち、実施例5の光電極は、実施例1の光電極においてNbON膜の代わりにTaON膜が設けられた光電極であった。図14は、実施例5の光電極におけるTaON膜の表面から10nm深さのXPSスペクトルを示す。また、実施例5の光電極におけるTaON膜の表面からのAESスペクトルにより、TaON膜の膜組成はほぼTa/O/N=1/1/1になっており、TaONの生成が確認できた。また、実施例5の光電極について、GZO膜が露出した部分(電極取り出し部)のシート抵抗値が図15に示されている(図15中の、「TaON成膜後」の結果)。TaON膜の成膜前と成膜後とでシート抵抗値がほとんど変化しておらず、TaON膜の成膜によってGZO膜が変化していないことがわかる。
実施例5のMOCVD成膜において、アンモニア(1.69×10-3Pa・m3/s(10sccm))と水蒸気(1.69×10-5Pa・m3/s(0.1sccm))とを混合したガスを基板に噴射することに代わり、アンモニア(1.69×10-3Pa・m3/s(10sccm))のみを噴射することで、TaON膜に代わりTa3N5膜を成膜した。これにより、サファイア基板上にGZO膜が設けられ、そのGZO膜上にTa3N5膜が設けられた実施例6の光電極が作製された。
Claims (13)
- 基板と、
前記基板上に設けられた、Znの一部がGa及びAlの少なくともいずれか1種の元素で置換されているZnO導電膜と、
前記ZnO導電膜に対して前記基板と反対側に設けられた、4A族、5A族、6A族及び3B族の金属元素から選ばれる少なくともいずれか1種の金属元素の窒化物又は酸窒化物の半導体膜と、
を含む、光電極。 - 前記ZnO導電膜において、Zn原子とGa原子とAl原子との合計に対する、Ga原子とAl原子との合計の割合を原子百分率で表した場合、前記割合が2原子%以上6原子%以下である、
請求項1に記載の光電極。 - 前記ZnO導電膜において、Zn原子とGa原子とAl原子との合計に対する、Ga原子とAl原子との合計の割合を原子百分率で表した場合、前記割合が2原子%以上4原子%以下である、
請求項2に記載の光電極。 - 前記ZnO導電膜がエピタキシャル膜である、
請求項1~3のいずれか1項に記載の光電極。 - 前記ZnO導電膜と前記半導体膜との間に配置されたZnO半導体膜をさらに含む、
請求項1~4のいずれか1項に記載の光電極。 - 前記ZnO半導体膜がエピタキシャル膜である、
請求項5に記載の光電極。 - 前記ZnO導電膜の一部が、前記半導体膜に覆われることなく露出している、
請求項1~6のいずれか1項に記載の光電極。 - 前記半導体膜が、Nb窒化物、Ta窒化物、Nb酸窒化物及びTa酸窒化物から選ばれる少なくともいずれか1種の半導体膜である、
請求項1~7のいずれか1項に記載の光電極。 - 前記半導体膜が、Nb3N5及びTa3N5から選ばれる少なくともいずれか1種の窒化物の半導体膜である、
請求項8に記載の光電極。 - 前記半導体膜が、NbON及びTaONから選ばれる少なくともいずれか1種の酸窒化物の半導体膜である、
請求項8に記載の光電極。 - 請求項1~10のいずれか1項に記載の光電極と、
前記光電極のZnO導電膜と電気的に接続された対極と、
前記光電極および前記対極を収容する容器と、
を備えた光電気化学セル。 - 前記容器内に収容され、かつ前記光電極および前記対極の表面と接触する、水を含む電解液をさらに備えた、請求項11に記載の光電気化学セル。
- 基板上に、Znの一部がGa及びAlの少なくともいずれか1種の元素で置換されているZnO導電膜を作製し、
前記ZnO導電膜に対して前記基板とは反対側に、4A族、5A族、6A族及び3B族の金属元素から選ばれる少なくともいずれか1種の金属元素の窒化物又は酸窒化物の半導体膜を、アンモニアを用いて作製する、
光電極の製造方法。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201680041939.XA CN107849711B (zh) | 2015-07-24 | 2016-06-14 | 光电极及其制造方法、以及光电化学元件 |
JP2017530992A JP6213802B2 (ja) | 2015-07-24 | 2016-06-14 | 光電極及びその製造方法、並びに光電気化学セル |
US15/746,581 US20180216244A1 (en) | 2015-07-24 | 2016-06-14 | Photoelectrode, method for producing same and photoelectrochemical cell |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2015-146998 | 2015-07-24 | ||
JP2015146998 | 2015-07-24 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2017017886A1 true WO2017017886A1 (ja) | 2017-02-02 |
Family
ID=57884158
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2016/002874 WO2017017886A1 (ja) | 2015-07-24 | 2016-06-14 | 光電極及びその製造方法、並びに光電気化学セル |
Country Status (4)
Country | Link |
---|---|
US (1) | US20180216244A1 (ja) |
JP (1) | JP6213802B2 (ja) |
CN (1) | CN107849711B (ja) |
WO (1) | WO2017017886A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2019039048A (ja) * | 2017-08-25 | 2019-03-14 | 富士通株式会社 | 光化学電極、及びその製造方法、並びに光電気化学反応装置 |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112309723B (zh) * | 2020-10-29 | 2021-09-21 | 齐鲁工业大学 | 一种基于碳布/镓氧氮化物的工作电极和超级电容器 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002167300A (ja) * | 2000-09-21 | 2002-06-11 | Canon Inc | 酸化物針状結晶の製造方法、酸化物針状結晶および光電変換装置 |
JP2006310252A (ja) * | 2005-03-28 | 2006-11-09 | Toyota Central Res & Dev Lab Inc | 透明電極、並びにこれを備えた色素増感型太陽電池及び色素増感型太陽電池モジュール |
CN101853973A (zh) * | 2010-05-07 | 2010-10-06 | 北京理工大学 | 一种用于太阳能制氢的纳米结构光电化学电池及制备方法 |
WO2011108271A1 (ja) * | 2010-03-04 | 2011-09-09 | パナソニック株式会社 | 光半導体、それを用いた光半導体電極及び光電気化学セル、並びに、エネルギーシステム |
WO2013133338A1 (ja) * | 2012-03-08 | 2013-09-12 | 国立大学法人東京大学 | 光水分解反応用電極およびその製造方法 |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8822263B2 (en) * | 2008-06-30 | 2014-09-02 | National University Corporation Tokyo University Of Agriculture And Technology | Epitaxial growth method of a zinc oxide based semiconductor layer, epitaxial crystal structure, epitaxial crystal growth apparatus, and semiconductor device |
CN102651281B (zh) * | 2012-02-13 | 2015-03-04 | 湖北大学 | Ga掺杂ZnO纳米线阵列染料敏化太阳能电池及其制备方法 |
KR20140041117A (ko) * | 2012-09-27 | 2014-04-04 | 엘지이노텍 주식회사 | 전기변색미러 및 그 제조 방법 |
-
2016
- 2016-06-14 JP JP2017530992A patent/JP6213802B2/ja active Active
- 2016-06-14 US US15/746,581 patent/US20180216244A1/en not_active Abandoned
- 2016-06-14 CN CN201680041939.XA patent/CN107849711B/zh active Active
- 2016-06-14 WO PCT/JP2016/002874 patent/WO2017017886A1/ja active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002167300A (ja) * | 2000-09-21 | 2002-06-11 | Canon Inc | 酸化物針状結晶の製造方法、酸化物針状結晶および光電変換装置 |
JP2006310252A (ja) * | 2005-03-28 | 2006-11-09 | Toyota Central Res & Dev Lab Inc | 透明電極、並びにこれを備えた色素増感型太陽電池及び色素増感型太陽電池モジュール |
WO2011108271A1 (ja) * | 2010-03-04 | 2011-09-09 | パナソニック株式会社 | 光半導体、それを用いた光半導体電極及び光電気化学セル、並びに、エネルギーシステム |
CN101853973A (zh) * | 2010-05-07 | 2010-10-06 | 北京理工大学 | 一种用于太阳能制氢的纳米结构光电化学电池及制备方法 |
WO2013133338A1 (ja) * | 2012-03-08 | 2013-09-12 | 国立大学法人東京大学 | 光水分解反応用電極およびその製造方法 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2019039048A (ja) * | 2017-08-25 | 2019-03-14 | 富士通株式会社 | 光化学電極、及びその製造方法、並びに光電気化学反応装置 |
JP6989762B2 (ja) | 2017-08-25 | 2022-02-03 | 富士通株式会社 | 光化学電極、及びその製造方法、並びに光電気化学反応装置 |
Also Published As
Publication number | Publication date |
---|---|
US20180216244A1 (en) | 2018-08-02 |
JP6213802B2 (ja) | 2017-10-18 |
JPWO2017017886A1 (ja) | 2017-11-02 |
CN107849711A (zh) | 2018-03-27 |
CN107849711B (zh) | 2019-10-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Wang et al. | Amorphous inorganic semiconductors for the development of solar cell, photoelectrocatalytic and photocatalytic applications | |
Vikraman et al. | Improved hydrogen evolution reaction performance using MoS2–WS2 heterostructures by physicochemical process | |
Seo et al. | Visible‐light‐responsive photoanodes for highly active, stable water oxidation | |
Wen et al. | Nanoengineering energy conversion and storage devices via atomic layer deposition | |
Wang et al. | Synthesis of nanostructured BaTaO2N thin films as photoanodes for solar water splitting | |
KR102014990B1 (ko) | 광전극 구조체용 복합 보호층, 이를 포함하는 광전극 구조체 및 이를 포함하는 광전기화학 전지 | |
WO2013084447A1 (ja) | ニオブ窒化物およびその製造方法、ニオブ窒化物含有膜およびその製造方法、並びに、半導体、半導体デバイス、光触媒、水素生成デバイスおよびエネルギーシステム | |
Kulmas et al. | Composite nanostructures of TiO2 and ZnO for water splitting application: atomic layer deposition growth and density functional theory investigation | |
JP5274663B2 (ja) | 光電気化学セル及びそれを用いたエネルギーシステム | |
JP5807218B2 (ja) | 光電極およびその製造方法、光電気化学セルおよびそれを用いたエネルギーシステム、並びに水素生成方法 | |
Yoshida et al. | Photocatalytic CO2 reduction using a pristine Cu2ZnSnS4 film electrode under visible light irradiation | |
KR20080024988A (ko) | 전해용 전극 및 그것을 이용한 전해 방법 및 그것을 이용한전해 장치 | |
JP4980497B2 (ja) | 光半導体、それを用いた光半導体電極及び光電気化学セル、並びに、エネルギーシステム | |
WO2013018366A1 (ja) | NbON膜およびNbON膜の製造方法、並びに、水素生成デバイスおよびそれを備えたエネルギーシステム | |
Pastukhova et al. | Atomic layer deposition for the photoelectrochemical applications | |
JP6213802B2 (ja) | 光電極及びその製造方法、並びに光電気化学セル | |
CN115152042A (zh) | 太阳电池 | |
Suzuki et al. | Ta3N5 Photoanodes Fabricated by Providing NaCl–Na2CO3 Evaporants to Tantalum Substrate Surface under NH3 Atmosphere | |
JP2018024939A (ja) | 小さいキャリア密度を有するストロンチウムニオブ酸窒化物膜の製法およびその用途 | |
Kong et al. | Recent progress in the development of tin tungstate (α-SnWO 4) photoanodes for solar water oxidation | |
JP5515613B2 (ja) | 半導体光応答体 | |
JP6920656B2 (ja) | 半導体電極及びそれを備えたデバイス、並びに、半導体電極の製造方法 | |
TW200805683A (en) | Methods of reducing the bandgap energy of a metal oxide | |
KR101712240B1 (ko) | 광 전기화학 장치 및 그 제조 방법 | |
US11322310B2 (en) | Method for producing photochemical electrode |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 16829995 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2017530992 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 15746581 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 16829995 Country of ref document: EP Kind code of ref document: A1 |