WO2013129484A1 - Mixed crystal, method for manufacturing mixed crystal, solar cell, method for manufacturing solar cell, and electrocrystallization bath - Google Patents

Mixed crystal, method for manufacturing mixed crystal, solar cell, method for manufacturing solar cell, and electrocrystallization bath Download PDF

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WO2013129484A1
WO2013129484A1 PCT/JP2013/055169 JP2013055169W WO2013129484A1 WO 2013129484 A1 WO2013129484 A1 WO 2013129484A1 JP 2013055169 W JP2013055169 W JP 2013055169W WO 2013129484 A1 WO2013129484 A1 WO 2013129484A1
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mixed crystal
ions
mixed
copper
tin
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PCT/JP2013/055169
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French (fr)
Japanese (ja)
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池田　茂
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Ikeda Shigeru
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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
    • H01L31/0264—Inorganic materials
    • H01L31/032—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312
    • H01L31/0326—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312 comprising AIBIICIVDVI kesterite compounds, e.g. Cu2ZnSnSe4, Cu2ZnSnS4
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/56—Electroplating: Baths therefor from solutions of alloys
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D7/00—Electroplating characterised by the article coated
    • C25D7/12—Semiconductors
    • C25D7/123—Semiconductors first coated with a seed layer or a conductive layer
    • C25D7/126—Semiconductors first coated with a seed layer or a conductive layer for solar cells
    • 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
    • C30B7/00—Single-crystal growth from solutions using solvents which are liquid at normal temperature, e.g. aqueous solutions
    • C30B7/12—Single-crystal growth from solutions using solvents which are liquid at normal temperature, e.g. aqueous solutions by 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
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy

Definitions

  • the present invention relates to a mixed crystal, a mixed crystal manufacturing method, a solar cell, a solar cell manufacturing method, and an electrodeposition bath.
  • a solar cell (CZTS solar cell) containing Cu, Zn, Sn, and S (or Se) as a constituent component is a trivalent atom (In and Ga) contained in a CIGS solar cell, Zn (divalent) and Sn (tetravalent).
  • CZTS solar cell containing Cu, Zn, Sn, and S (or Se) as a constituent component
  • Non-Patent Document 1 and Non-Patent Document 2 demonstrate the possibility of application to solar cells. Recent intensive research has dramatically improved the conversion efficiency, which indicates the high potential of CZTS solar cells.
  • Non-Patent Document 3 discloses a CZTS manufacturing technique using an electrodeposition process.
  • the electrodeposition process is a non-vacuum chemical process capable of forming a film at room temperature. Since the constituent components can be deposited in a desired portion, there is a great advantage in the material utilization efficiency (effective utilization of elemental resources).
  • Non-Patent Document 1 is a vacuum process, it is difficult to greatly reduce the cost of the process.
  • the technique described in Non-Patent Document 2 uses hydrazine that is dangerous to handle, and cannot be handled easily. There is a problem in that.
  • each of a Cu thin film, a Zn thin film, and a Sn thin film is sequentially laminated to produce a laminated structure.
  • a CZTS solar cell is manufactured by sulfiding a laminated structure. Therefore, the manufacturing process of the CZTS solar cell is complicated, and the manufacturing time is long.
  • the present invention has been made in view of the above problems, and the present invention provides a mixed crystal manufactured by simultaneously depositing different components, a mixed crystal manufacturing method, a solar cell, a solar cell manufacturing method, and an electrodeposition bath.
  • the purpose is to provide.
  • the method for producing a mixed crystal according to the present invention comprises a mixed solution preparing step of preparing a mixed solution containing at least one of selenium ions and sulfur ions, copper ions, zinc ions and tin ions, and applying a voltage to the mixed solution. And an electrodeposition step of electrodepositing the mixed crystal, wherein the mixed crystal includes at least one of selenium-containing microcrystals and sulfur-containing microcrystals, copper-containing microcrystals, and zinc-containing microcrystals. Tin-containing microcrystals.
  • the at least one of the selenium-containing microcrystals and the sulfur-containing microcrystals, the copper-containing microcrystals, the zinc-containing microcrystals, and the tin-containing microcrystals. are deposited on the substrate.
  • the mixed solution includes a first mixed solution and a second mixed solution
  • the mixed crystal includes a first mixed crystal and a second mixed crystal
  • the electrodeposition step includes the first deposition step.
  • the first mixed liquid includes an electrolytic solution having a higher zinc ion content ratio than the second mixed liquid, and the second mixed liquid has a zinc ion content ratio higher than that of the first mixed liquid. Contains low electrolyte.
  • the first mixed solution includes at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions
  • the second mixed solution includes selenium ions and sulfur ions. At least one of them, including copper ions and tin ions
  • the first mixed crystal includes at least one of the selenium-containing microcrystals and the sulfur-containing microcrystals, the copper-containing microcrystals, and the zinc-containing
  • the second mixed crystal includes at least one of the selenium-containing microcrystal and the sulfur-containing microcrystal, the copper-containing microcrystal, and the tin-containing microcrystal. Including.
  • the electrodeposition step performs one of the first electrodeposition step and the second electrodeposition step, and after the one execution, the first electrodeposition step and the second electrodeposition step.
  • the electrodeposition step performs one of the first electrodeposition step and the second electrodeposition step, and after the one execution, the first electrodeposition step and the second electrodeposition step.
  • the electrodeposition step performs one of the other of the electrodeposition step, and performing the first electrodeposition step, the at least one of the selenium-containing microcrystals and the sulfur-containing microcrystals, the copper-containing microcrystals, and the zinc Containing microcrystals and tin-containing microcrystals are deposited on the substrate
  • the second electrodeposition step at least one of the selenium-containing microcrystals and the sulfur-containing microcrystals, and the copper-containing microcrystals Microcrystals and the tin-containing microcrystals are deposited on the substrate.
  • the content ratio of copper is smaller than the stoichiometric composition, and the content ratio of zinc is larger than the stoichiometric composition.
  • the copper content (Cu / (Zn + Sn)) is 0.8 to 0.9
  • the zinc content (Zn / Sn) is 1.0 to 2.0.
  • the mixed solution includes an additive
  • the mixed solution preparing step includes a complex forming step of forming a complex in which the additive is coordinated to the copper ion, the zinc ion, and the tin ion. To do.
  • the additive is lactic acid, sodium lactate, potassium lactate, ammonium lactate, tartaric acid, sodium tartrate, potassium sodium tartrate, ammonium tartrate, sodium hydrogen tartrate, potassium hydrogen tartrate, citric acid, sodium citrate, citric acid.
  • the mixed solution is acidic.
  • the method further includes an annealing step of annealing the mixed crystal.
  • a P-type photoresponsive crystal made of Cu 2 ZnSnSe 4 is obtained from the mixed crystal.
  • sulfur ions are used instead of selenium ions, or when selenium ions and sulfur ions are used, the crystals are Cu 2 ZnSnS 4 and Cu 2 ZnSn (S ⁇ Se) 4.
  • the crystals are collectively referred to as CZTS crystals for convenience.
  • a P-type photoresponsive crystal containing Cu 2 ZnSnSe 4 is manufactured by performing the annealing step.
  • a method for manufacturing a solar cell according to the present invention comprises preparing a mixed crystal containing at least one of selenium-containing microcrystals and sulfur-containing microcrystals, copper-containing microcrystals, zinc-containing microcrystals, and tin-containing microcrystals.
  • the mixed crystal preparing step includes a mixed solution preparing step of preparing a mixed solution including at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions, and the mixed solution.
  • the mixed solution includes an additive
  • the mixed solution preparing step includes a complex forming step of forming a complex in which the additive is coordinated to the copper ion, the zinc ion, and the tin ion. .
  • the mixed solution is acidic.
  • the method further includes an annealing step of annealing the mixed crystal.
  • the mixed solution preparing step includes the mixed crystal manufacturing method described above.
  • the mixed crystal according to the present invention includes at least one of selenium-containing microcrystals and sulfur-containing microcrystals, copper-containing microcrystals, zinc-containing microcrystals, and tin-containing microcrystals.
  • the solar cell according to the present invention includes at least one of selenium-containing microcrystals and sulfur-containing microcrystals, a mixed crystal layer containing copper-containing microcrystals, zinc-containing microcrystals and the tin-containing microcrystals, and the mixed A buffer layer stacked on the crystal layer; and a transparent electrode stacked on the buffer layer.
  • the mixed crystal layer includes a mixed crystal manufactured by the mixed crystal manufacturing method described above.
  • the electrodeposition bath according to the present invention contains at least one of selenium ions and sulfur ions, copper ions, zinc ions and tin ions.
  • an additive is further included, and a complex in which the additive is coordinated to the copper ion, the zinc ion, and the tin ion is included.
  • the additive is lactic acid, sodium lactate, potassium lactate, ammonium lactate, tartaric acid, sodium tartrate, potassium sodium tartrate, ammonium tartrate, sodium hydrogen tartrate, potassium hydrogen tartrate, citric acid, sodium citrate, citric acid.
  • FIG. 1 is a photograph showing a mixed crystal 100 according to Embodiment 1 of the present invention.
  • the X-ray-diffraction result of the mixed crystal 100 by Embodiment 1 of this invention is shown.
  • the Raman spectrum of the mixed crystal 100 by Embodiment 1 of this invention is shown.
  • 3 is a photograph showing a mixed crystal 200 according to Embodiment 1 of the present invention.
  • the X-ray-diffraction result of the mixed crystal 200 in Embodiment 1 of this invention is shown.
  • the Raman spectrum of the mixed crystal 200 in Embodiment 1 of this invention is shown.
  • the result of the photoelectrochemical measurement which aimed at the mixed crystal 200 in Embodiment 1 of this invention is shown.
  • It is a schematic diagram which shows the laminated structure E containing the mixed crystal 500 by Embodiment 2 of this invention.
  • 5 is a flowchart showing a method for manufacturing a mixed crystal 500 according to Embodiment 2 of the present invention.
  • the Raman spectrum of the mixed crystal 500 by Embodiment 2 of this invention is shown.
  • 6 is a photograph showing a mixed crystal 500 according to Embodiment 2 of the present invention.
  • the X-ray-diffraction result of the mixed crystal 600 in Embodiment 2 of this invention is shown.
  • the Raman spectrum of the mixed crystal 600 in Embodiment 2 of this invention is shown.
  • the composition analysis result of the mixed crystal 600 in Embodiment 2 of this invention is shown.
  • the SEM image of the mixed crystal 600 in Embodiment 2 of this invention is shown.
  • the schematic diagram of the solar cell 400 by Embodiment 3 of this invention is shown.
  • the measurement result of the characteristic of the solar cell (including the mixed crystal 600) by Embodiment 3 of this invention is shown.
  • FIG. 1 is a schematic diagram showing a laminated structure A including a mixed crystal 100 according to Embodiment 1 of the present invention.
  • the laminated structure A includes a substrate a, a substrate b, and a mixed crystal 100.
  • the substrate a is, for example, a glass substrate.
  • the substrate b is, for example, a Mo layer.
  • the substrate b functions as a back electrode (Mo electrode).
  • the mixed crystal 100 includes at least one of selenium (Se) -containing microcrystals and sulfur (S) -containing microcrystals, copper (Cu) -containing microcrystals, zinc (Zn) -containing microcrystals, and tin (Sn) -containing microcrystals.
  • the thickness of the mixed crystal 100 is, for example, 30 nm to 2.5 ⁇ m.
  • FIG. 2 is a flowchart showing a method for manufacturing the mixed crystal 100 according to Embodiment 1 of the present invention.
  • the mixed crystal 100 is manufactured by executing Steps S202 to S206.
  • an electrodeposition process is used. Formation of a compound thin film by an electrodeposition process is based on alloy plating which is deposited by electrochemically reducing constituent element ions of a compound dissolved in an electrodeposition bath on the electrode surface.
  • four components are reduced from an electrodeposition bath in which Cu, Zn, Sn, and S (or Se) ions as raw materials are dissolved.
  • steps S202 to S206 will be described with reference to FIG.
  • Step S202 A mixed liquid 302 containing at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions is prepared (mixed liquid preparing step).
  • the liquid mixture 302 is put in the electrolytic cell c.
  • selenite ion (SeO 3 2 ⁇ ) is dissociated and produced from Na 2 SeO 3 (molar concentration 5 mM), and copper ion (Cu 2 + ) is derived from CuSO 4 .5H 2 O (molar concentration 4 mM).
  • Zinc ions (Zn 2 + ) are dissociated and generated from ZnSO 4 (molar concentration 80 mM), and tin ions (Sn 4 + ) are dissociated and generated from SnCl 4 (molar concentration 20 mM).
  • Step S204 A voltage is applied to the mixed solution 302 to deposit the mixed crystal 100 (electrodeposition step).
  • a substrate a on which a Mo electrode b was laminated was used as the cathode electrode, and a platinum electrode was used as the anode electrode 304.
  • an electrode an industrially inexpensive and stable carbon electrode can be used, and a noble metal electrode such as platinum or gold which is not easily corroded in addition to carbon can be used for experiments.
  • the substrate a on which the Mo electrode a was laminated and the platinum electrode were immersed in an electrolytic cell c containing a mixed solution 302, and a voltage ( ⁇ 0.6 V) was applied between the electrodes by a power source 306.
  • the power source 306 is an external power source having a potentiostat (potential control) function and a galvanostat (current control) function.
  • the magnitude of the applied voltage is not particularly limited as long as the ions contained in the mixed liquid 302 are reduced.
  • the applied voltage can be -0.5 to -1.0 V.
  • the applied voltage is on the negative side of ⁇ 0.5 V, the number of ions that are not reduced can be reduced, and when it is on the positive side of ⁇ 1.0 V, the generation of hydrogen gas based on the reduction of water can be suppressed.
  • the applied voltage is on the negative side of ⁇ 1.0 V, the applied voltage is large, so that the reduction rate of ions can be increased, and the mixed crystal 100 can be manufactured efficiently.
  • step S202 and step S204 the laminated structure B including the mixed crystal 100 can be manufactured (step S206).
  • an additive is preferably mixed in the mixed solution 302.
  • the additive is, for example, tartaric acid.
  • Tartaric acid functions as a stabilizer that prevents Cu 2+ , Zn 2+ , and Sn 4+ in the mixed solution 302 from precipitating hydroxide.
  • a complex in which tartaric acid is coordinated to copper ion, zinc ion and tin ion is formed.
  • the liquid mixture 302 contains tartaric acid (500 mM).
  • Additives include, for example, lactic acid, compounds containing lactic acid (sodium lactate, potassium lactate, ammonium lactate, etc.), tartaric acid, compounds containing tartaric acid (sodium tartrate, potassium sodium tartrate, ammonium tartrate, sodium hydrogen tartrate, potassium hydrogen tartrate, etc.) , Citric acid, compounds containing citric acid (sodium citrate, potassium citrate, potassium dihydrogen citrate, sodium dihydrogen citrate, ammonium citrate, etc.), oxalic acid, compounds containing oxalic acid (sodium oxalate, Potassium malate, sodium hydrogen oxalate, potassium hydrogen oxalate, ammonium oxalate, etc.), malonic acid, and at least one of compounds containing malonic acid (sodium malonate, potassium malonate, ammoni
  • the pH of the mixed solution 302 is not particularly limited as long as the mixed solution 302 containing at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions is generated.
  • the hydroxide of ions contained in the mixed solution 302 can be suppressed.
  • the mixed solution 302 contains an NH 3 solution (28%) and the pH is 2.5.
  • the pH of the liquid mixture 302 can be kept acidic by the addition of the additive (buffering effect by the additive).
  • the laminated substrate a of the substrate b (Mo layer) is immersed in a weakly acidic mixed solution 302 containing Cu 2+ , Zn 2+ , Sn 4+ and Se 4+, and the laminated substrate a of the substrate b (Mo layer) is cathoded.
  • a microcrystalline black electrodeposited film (mixed crystal 100) was obtained.
  • the mixed crystal 100 contained CZTS crystals.
  • FIG. 3 is a photograph showing the mixed crystal 100 according to Embodiment 1 of the present invention.
  • FIG. 3A shows the mixed crystal 100 manufactured by performing electrodeposition for 1 minute in step S204.
  • the film thickness of the mixed crystal 100 was 30 nm.
  • FIG. 3B shows the mixed crystal 100 manufactured by performing electrodeposition in step S204 for 5 minutes.
  • the film thickness of the mixed crystal 100 was 114 nm.
  • FIG. 3C shows the mixed crystal 100 manufactured by performing electrodeposition for 10 minutes in step S204.
  • the film thickness of the mixed crystal 100 was 727 nm.
  • FIG. 3D shows the mixed crystal 100 manufactured by performing electrodeposition in step S204 for 20 minutes.
  • the film thickness of the mixed crystal 100 was 882 nm.
  • FIG. 3A shows the mixed crystal 100 manufactured by performing electrodeposition for 1 minute in step S204.
  • the film thickness of the mixed crystal 100 was 30 nm.
  • FIG. 3B shows the mixed crystal 100 manufactured by performing electrodeposition in step S204 for 5 minutes.
  • FIG. 3E shows the mixed crystal 100 manufactured by performing electrodeposition for 40 minutes in step S204.
  • the film thickness of the mixed crystal 100 was 1.11 ⁇ m.
  • FIG. 3F shows the mixed crystal 100 manufactured by performing electrodeposition in step S204 for 60 minutes.
  • the film thickness of the mixed crystal 100 was 2 ⁇ m.
  • FIG. 3G shows the mixed crystal 100 manufactured by performing electrodeposition in step S204 for 70 minutes.
  • the film thickness of the mixed crystal 100 was 2.5 ⁇ m.
  • FIG. 4 shows an X-ray diffraction (XRD) result of the mixed crystal 100.
  • the graph (a) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 1 minute.
  • the graph (b) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 5 minutes.
  • the graph (c) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 10 minutes.
  • the graph (d) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 20 minutes.
  • the graph (e) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 40 minutes.
  • the graph (f) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 60 minutes.
  • the graph (g) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 70 minutes.
  • FIG. 5 shows the Raman spectrum of the mixed crystal 100.
  • the graph (a) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 1 minute.
  • the graph (b) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 5 minutes.
  • the graph (c) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 10 minutes.
  • the graph (d) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 20 minutes.
  • the graph (e) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 40 minutes.
  • the graph (f) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 60 minutes.
  • the graph (g) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 70 minutes.
  • FIG. 6 is a flowchart showing a method for manufacturing the mixed crystal 200 in Embodiment 1 of the present invention.
  • the mixed crystal 200 is manufactured by executing Steps S206 to S208. In the manufacture of the mixed crystal 200, an annealing process is used.
  • Step S206 The laminated structure B manufactured by executing Step S202 and Step S204 is prepared (preparation process).
  • the laminated structure B includes the substrate a, the Mo electrode b, and the mixed crystal 100.
  • a Mo electrode b is stacked on the substrate a, and a mixed crystal 100 is stacked on the Mo electrode b.
  • Step S208 The mixed crystal 100 is annealed to produce a laminated structure C including the mixed crystal 200 (annealing step).
  • the laminated structure C includes a substrate a, a Mo electrode b, and a mixed crystal 200.
  • a Mo electrode b is stacked on the substrate a
  • a mixed crystal 200 is stacked on the Mo electrode b.
  • the CZTSSe thin film (mixed crystal 200) with high crystallinity was obtained by annealing the mixed crystal 100 manufactured by executing Step S202 and Step S204.
  • annealing was performed by raising the temperature to 500 ° C. or 550 ° C. (18 ° C./min) in an Ar gas atmosphere and holding the temperature for 10 min in an H 2 S (5%) atmosphere. Furthermore, the temperature was lowered in an N 2 gas atmosphere to produce a mixed crystal 200.
  • the mixed crystal 200 contained CZTSSe crystals. Since the CZTS crystal (mixed crystal 100) was annealed in an H 2 S atmosphere, sulfidation proceeded, and a CZTSSe crystal (mixed crystal 200) was obtained. Note that the annealing atmosphere is not limited to H 2 S (5%). In step S208, annealing can be performed in an S gas (5%) atmosphere instead of H 2 S (5%). Also in this case, the sulfidation progressed, and a CZTSSe crystal (mixed crystal 200) could be obtained.
  • FIG. 7 is a photograph showing the mixed crystal 200 according to Embodiment 1 of the present invention.
  • FIG. 7A shows the mixed crystal 100 manufactured by performing electrodeposition in step S204 for about 60 minutes.
  • the film thickness of the mixed crystal 100 was about 1.9 ⁇ m.
  • FIG. 7B shows a mixed crystal 200 manufactured by performing annealing for 10 minutes at 550 ° C. in step S208.
  • the film thickness of the mixed crystal 200 was about 1.5 ⁇ m.
  • FIG. 8 shows the X-ray diffraction result of the mixed crystal 200.
  • Graph (a) shows the XRD result of the mixed crystal 200 manufactured by performing annealing at 500 ° C.
  • Graph (b) shows the XRD result of the mixed crystal 200 manufactured by performing the annealing at 550 ° C. From the results of the graph (a) and the graph (b), it was confirmed that the CZTSSe crystal was grown on the mixed crystal 200.
  • FIG. 9 shows the Raman spectrum of the mixed crystal 200.
  • the graph (a) shows the Raman spectrum result of the mixed crystal 200 manufactured by performing annealing at 500 ° C.
  • the graph (b) shows the Raman spectrum result of the mixed crystal 200 manufactured by performing annealing at 550 ° C.
  • the graph (a) and the graph (b) show the main Raman peak due to the CZTSSe crystal. It was confirmed that the mixed crystal 100 contained CZTSSe crystals.
  • FIG. 10 shows the result of photoelectrochemical measurement for the mixed crystal 200.
  • the graph (a) shows the result of the photoelectrochemical measurement for the mixed crystal 200 manufactured by performing annealing at 500 ° C.
  • the graph (b) shows the result of the photoelectrochemical measurement for the mixed crystal 200 manufactured by performing annealing at 550 ° C. From the photoelectrochemical measurement results shown in graphs (a) and (b), it was confirmed that the obtained material exhibited a p-type photoresponse.
  • the embodiment of the mixed crystal, the mixed crystal manufacturing method, and the electrodeposition bath according to Embodiment 1 of the present invention has been described above with reference to FIGS.
  • the present invention discloses a technique for producing a CZTS (Se) thin film without using a vacuum process or a dangerous solvent.
  • Four components are reduced from an electrodeposition bath in which Cu, Zn, Sn, and Se ions as raw materials are dissolved to produce a CZTS crystal.
  • Embodiment 2 The mixed crystal, mixed crystal manufacturing method, and electrodeposition bath according to the second embodiment of the present invention will be described with reference to FIGS.
  • CZTS crystals were formed by one-step electrodeposition using one mixed solution.
  • a CZTS crystal is formed by a plurality of stages of electrodeposition using a plurality of electrolytic solutions.
  • FIG. 11 is a schematic diagram showing a laminated structure E including a mixed crystal 500 according to Embodiment 2 of the present invention.
  • the laminated structure E includes a substrate a, a substrate b, and a mixed crystal 500.
  • the substrate a is, for example, a glass substrate.
  • the substrate b is, for example, a Mo layer.
  • the substrate b functions as a back electrode (Mo electrode).
  • the mixed crystal 500 includes a first mixed crystal 510 stacked on the substrate b and a second mixed crystal 520 stacked on the first mixed crystal 510.
  • the first mixed crystal 510 includes at least one of selenium (Se) -containing microcrystals and sulfur (S) -containing microcrystals, copper (Cu) -containing microcrystals, zinc (Zn) -containing microcrystals, and tin (Sn). CZTS crystals containing contained microcrystals.
  • Second mixed crystal 520 is a CZTS crystal containing at least one of selenium (Se) -containing microcrystals and sulfur (S) -containing microcrystals, copper (Cu) -containing microcrystals, and tin (Sn) -containing microcrystals. It is.
  • the thickness of the first mixed crystal 510 and the thickness of the second mixed crystal 520 are, for example, 300 nm to 2 ⁇ m.
  • FIG. 12 is a flowchart showing a method for manufacturing the mixed crystal 500 according to the second embodiment of the present invention.
  • the mixed crystal 500 is manufactured by executing Steps S702 to S712.
  • an electrodeposition process is used. Formation of a compound thin film by an electrodeposition process is based on alloy plating which is deposited by electrochemically reducing constituent element ions of a compound dissolved in an electrodeposition bath on the electrode surface.
  • four components are reduced from an electrodeposition bath in which Cu, Zn, Sn, and S (or Se) ions as raw materials are dissolved, and Cu, Sn, and S as raw materials are further reduced. Three components are reduced from the electrodeposition bath in which each ion of (or Se) is dissolved.
  • steps S702 to S712 will be described with reference to FIG.
  • Step S702 A first mixed solution 802 containing at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions is prepared (first mixed solution preparing step).
  • first mixed solution preparing step the 1st liquid mixture 802 is put into the electrolytic vessel c.
  • selenite ions (SeO 3 2 ⁇ ) are dissociated and produced from Na 2 SeO 3 (molar concentration 5 mM), and copper ions (Cu 2+ ) are CuSO 4 .5H 2 O (molar concentration 2). .5 mM), zinc ions (Zn 2+ ) are dissociated from ZnSO 4 (molar concentration 80 mM), and tin ions (Sn 4+ ) are dissociated from SnCl 4 (molar concentration 20 mM).
  • Step S704 A voltage is applied to the first mixed solution 802 to deposit the first mixed crystal 510 (first electrodeposition step).
  • a substrate a on which a Mo electrode b was laminated was used as the cathode electrode, and a platinum electrode was used as the anode electrode 304.
  • an electrode an industrially inexpensive and stable carbon electrode can be used, and a noble metal electrode such as platinum or gold which is not easily corroded in addition to carbon can be used for experiments.
  • the substrate a on which the Mo electrode a was laminated and the platinum electrode were immersed in an electrolytic cell c containing the first mixed solution 802, and a voltage ( ⁇ 0.6 V) was applied between the electrodes by the power source 306 for 30 minutes.
  • the power source 306 is an external power source having a potentiostat (potential control) function and a galvanostat (current control) function.
  • 1st liquid mixture 802 contains the electrolyte solution whose zinc ion content rate is higher than the 2nd liquid mixture 804.
  • the first electrodeposition step at least one of selenium-containing microcrystals and sulfur-containing microcrystals, copper-containing microcrystals, zinc-containing microcrystals, and tin-containing microcrystals are deposited on the substrate a.
  • the magnitude of the applied voltage is not particularly limited as long as the ions contained in the first mixed liquid 802 are reduced.
  • the applied voltage can be ⁇ 0.5 to ⁇ 1.0 V. When it is on the negative side of ⁇ 0.5 V, the number of ions that are not reduced can be reduced, and when it is on the positive side of ⁇ 1.0 V, the generation of hydrogen gas based on the reduction of water can be suppressed.
  • the applied voltage is on the negative side of ⁇ 1.0 V, the applied voltage is large, so that the reduction rate of ions can be increased, and the first mixed crystal 510 can be manufactured efficiently.
  • the laminated structure D including the first mixed crystal 510 can be manufactured by executing Step S702 and Step S704 (Step S706).
  • Step S708 A second mixed liquid 804 containing at least one of selenium ions and sulfur ions and copper ions and tin ions is prepared (second mixed liquid preparing step).
  • the second mixed liquid 804 is placed in the electrolytic cell c ′.
  • selenite ion (SeO 3 2 ⁇ ) is dissociated and produced from Na 2 SeO 3 (molar concentration 7 mM), and copper ion (Cu 2+ ) is CuSO 4 .5H 2 O (molar concentration 1 mM).
  • tin ions (Sn 4+ ) are dissociated from SnCl 4 (molar concentration 20 mM).
  • Step S710 A voltage is applied to the second mixed solution 804 to deposit the second mixed crystal 520 (second electrodeposition step).
  • the substrate a on which the Mo electrode b and the first mixed crystal 510 were laminated was used as the cathode electrode, and the platinum electrode was used as the anode electrode 304.
  • an industrially inexpensive and stable carbon electrode can be used, and a noble metal electrode such as platinum or gold which is not easily corroded in addition to carbon can be used for experiments.
  • the substrate a on which the Mo electrode a was laminated and the platinum electrode were immersed in an electrolytic cell c ′ containing the second mixed solution 804, and a voltage ( ⁇ 0.6 V) was applied between the electrodes by the power source 306 for 20 minutes.
  • the power source 306 is an external power source having a potentiostat (potential control) function and a galvanostat (current control) function.
  • the second mixed liquid 804 includes an electrolytic solution having a lower zinc ion content than the first mixed liquid 802.
  • the applied voltage may be, for example, ⁇ 0.5 to ⁇ 1.0 V.
  • the applied voltage is more negative than ⁇ 1.0 V, so that the reduction rate of ions can be increased, and the second mixed crystal 520 can be manufactured efficiently.
  • the laminated structure E including the first mixed crystal 510 and the second mixed crystal 520 can be manufactured by executing Step S708 and Step S710 (Step S712).
  • an additive is preferably mixed in the first mixed liquid 802 and the second mixed liquid 804.
  • the additive is, for example, tartaric acid.
  • Tartaric acid functions as a stabilizing material that prevents Cu 2+ , Zn 2+ , and Sn 4+ in the first mixed solution 802 and the second mixed solution 804 from becoming hydroxide precipitates.
  • a complex in which tartaric acid is coordinated to copper ion, zinc ion and tin ion is formed.
  • the first mixed liquid 802 contains tartaric acid (500 mM)
  • the second mixed liquid 804 contains tartaric acid (500 mM).
  • Additives include, for example, lactic acid, compounds containing lactic acid (sodium lactate, potassium lactate, ammonium lactate, etc.), tartaric acid, compounds containing tartaric acid (sodium tartrate, potassium sodium tartrate, ammonium tartrate, sodium hydrogen tartrate, potassium hydrogen tartrate, etc.) , Citric acid, compounds containing citric acid (sodium citrate, potassium citrate, potassium dihydrogen citrate, sodium dihydrogen citrate, ammonium citrate, etc.), oxalic acid, compounds containing oxalic acid (sodium oxalate, Potassium malate, sodium hydrogen oxalate, potassium hydrogen oxalate, ammonium oxalate, etc.), malonic acid, and at least one of compounds containing malonic acid (sodium malonate, potassium malonate, ammoni
  • the pH is not particularly limited as long as a mixed liquid containing at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions is generated, but the pH is acidic. If present, the hydroxide of ions contained in the first mixed liquid 802 can be suppressed. Further, in step S702, the first mixed liquid 802 includes an NH 3 solution (28%) and has a pH of 2.5 to 2.6. In addition, the pH of the 1st liquid mixture 802 can be hold
  • the pH is not particularly limited as long as a mixed liquid containing at least one of selenium ions and sulfur ions and copper ions and tin ions is generated. , The ionization of ions contained in the second liquid mixture 804 can be suppressed.
  • the second mixed liquid 804 includes an NH 3 solution (28%), and the pH is 2.5 to 2.6.
  • the pH of the 2nd liquid mixture 804 can be hold
  • the mixed crystal 500 includes a first mixed crystal 510 stacked on the substrate b and a second mixed crystal 520 stacked on the first mixed crystal 510, and the first mixed crystal 510 and the second mixed crystal 520 are stacked.
  • the stacking relationship with the crystal 520 is not limited.
  • the mixed crystal 500 may include a second mixed crystal 520 stacked on the substrate b and a first mixed crystal 510 stacked on the second mixed crystal 520. About a manufacturing method, the following process is performed.
  • a voltage is applied to the second mixed solution 804 to deposit the second mixed crystal 520.
  • a substrate a on which a Mo electrode b was laminated was used as the cathode electrode, and a platinum electrode was used as the anode electrode 304.
  • the substrate a on which the Mo electrode a is laminated and the platinum electrode are immersed in an electrolytic cell c ′ containing the second mixed solution 804, and a voltage is applied between the electrodes by the power source 306.
  • a voltage is applied to the first mixed liquid 802 to deposit the first mixed crystal 510.
  • a substrate a on which a Mo electrode b and a second mixed crystal 520 were laminated was used as the cathode electrode, and a platinum electrode was used as the anode electrode 304.
  • the substrate a on which the Mo electrode a is laminated and the platinum electrode are immersed in an electrolytic cell c containing the first mixed liquid 802, and a voltage is applied between the electrodes by the power source 306.
  • FIG. 13 shows a Raman spectrum of the mixed crystal 500 according to Embodiment 2 of the present invention.
  • 13A shows a Raman spectrum of the first mixed crystal 510
  • FIG. 13B shows a Raman spectrum of the second mixed crystal 520.
  • the first mixed crystal 510 includes a Cu 2 ZnSnSe 4 (CZTS) crystal
  • the second mixed crystal 520 includes a mixed crystal Cu—Sn—Se
  • a Cu 3 SnSe 3 (CTSe) crystal It was confirmed that it contains.
  • FIG. 14 is a photograph showing a mixed crystal 500 according to Embodiment 2 of the present invention. Specifically, FIG. 14 shows a scanning electron microscope (SEM) image of the cross section (FIG. 14A) and the surface (FIG. 14B) of the mixed crystal 500. FIG. From the photograph shown in FIG. 14, it can be understood that the second mixed crystal 520 is uniformly deposited on the first mixed crystal 510. The film thicknesses of the first mixed crystal 510 and the second mixed crystal 520 were both about 1 ⁇ m.
  • SEM scanning electron microscope
  • FIG. 15 is a flowchart showing a method for manufacturing the mixed crystal 600 according to the second embodiment of the present invention.
  • the mixed crystal 600 is manufactured by executing Steps S714 to S716. In manufacturing the mixed crystal 600, an annealing process is used.
  • Step S714 The laminated structure E manufactured by executing Steps S702 to S712 is prepared (preparation process).
  • the laminated structure E includes a substrate a, a Mo electrode b, and a mixed crystal 500.
  • a Mo electrode b is stacked on the substrate a, and a mixed crystal 500 is stacked on the Mo electrode b.
  • Step S716 The mixed crystal 500 is annealed to produce a laminated structure F including the mixed crystal 600 (annealing process).
  • the laminated structure F includes a substrate a, a Mo electrode b, and a mixed crystal 600.
  • a Mo electrode b is stacked on the substrate a
  • a mixed crystal 600 is stacked on the Mo electrode b.
  • annealing the mixed crystal 500 manufactured by executing Steps S702 to S712 a CZTS crystal (mixed crystal 600) with high crystallinity was obtained.
  • annealing was performed by holding the temperature at 475 ° C. or 525 ° C. for 5 minutes in an Ar gas atmosphere, or by holding the temperature in Se vapor at 575 ° C. for 5 minutes.
  • FIG. 16 shows an X-ray diffraction result of the mixed crystal 600 according to the second embodiment of the present invention.
  • FIG. 17 shows the Raman spectrum of the mixed crystal 600 according to the second embodiment of the present invention.
  • graph (a) shows an analysis result of a mixed crystal 600 manufactured by performing annealing at 475 ° C. for 5 minutes in an Ar gas atmosphere.
  • the graph (b) shows the analysis result of the mixed crystal 600 manufactured by performing the temperature holding annealing at 525 ° C. for 5 minutes in the Ar gas atmosphere
  • the graph (c) shows the analysis result of 575 ° C. in Se vapor.
  • maintenance for 5 minutes is shown.
  • FIG. 18 shows a composition analysis result of the mixed crystal 600 according to the second embodiment of the present invention.
  • the copper content is less than the stoichiometric composition
  • the zinc content is More than quantity theory.
  • the composition of these samples is suitable as a CZTS crystal for solar cells.
  • the mixed crystal 600 (CZTS crystal) obtained by annealing in an Ar gas atmosphere the contents of Sn and Se are low. This is because Sn and Se volatilized during the annealing.
  • the mixed crystal 600 (CZTS crystal) obtained by annealing in Se vapor the contents of Sn and Se are relatively large.
  • the copper content (Cu / (Zn + Sn)) is 0.8 to 0.9
  • the zinc content (Zn / Sn) is 1.0 to 2.0. It is.
  • FIG. 19 shows an SEM image of the mixed crystal 600 according to the second embodiment of the present invention.
  • FIG. 19A shows an SEM image of a mixed crystal 600 manufactured by performing annealing at 525 ° C. for 5 minutes in an Ar gas atmosphere
  • FIG. 19B shows an SEM image at 575 ° C. in Se vapor.
  • 2 shows an SEM image of a mixed crystal 600 produced by performing a 5 minute temperature hold anneal. It can be understood that the mixed crystal 600 (CZTS crystal) obtained by annealing in Se vapor has a relatively dense shape.
  • FIG. 20 shows a schematic diagram of a solar cell 400 according to Embodiment 3 of the present invention.
  • the solar cell 400 and the solar cell manufacturing method in Embodiment 3 of this invention are demonstrated.
  • Solar cell 400 includes substrate a, back electrode b, mixed crystal 100 (or mixed crystal 200), buffer layer 402, and transparent electrode layer 404.
  • the substrate a, the back electrode b, and the mixed crystal 100 (or the mixed crystal 200) are the same as the configurations and functions described with reference to FIGS. 1, 2, and 6, and thus detailed description thereof is omitted.
  • the buffer layer 402 is an n-type buffer layer laminated on a layer (mixed crystal layer) including the mixed crystal 100 (or mixed crystal 200).
  • the transparent electrode 404 is stacked on the buffer layer 402.
  • the transparent electrode 404 is, for example, a zinc oxide based transparent electrode (AZO electrode).
  • Solar cell 400 can be manufactured by sequentially laminating substrate b (Mo electrode), mixed crystal 100 (mixed crystal 200), buffer layer 402, and transparent electrode 404 on substrate a.
  • the solar cell 400 can include the substrate a, the back electrode b, the mixed crystal 500 (mixed crystal 600) according to the second embodiment, the buffer layer 402, and the transparent electrode layer 404.
  • the solar cell 400 can be manufactured by sequentially laminating the substrate b (Mo electrode), the mixed crystal 500 (mixed crystal 600), the buffer layer 402, and the transparent electrode 404 on the substrate a.
  • FIG. 21 shows the measurement results of the characteristics of the solar cell (including the mixed crystal 600) according to Embodiment 3 of the present invention.
  • the graph (a) shows the measurement results of the characteristics of the solar cell including the mixed crystal 600 manufactured by performing annealing at 475 ° C. for 5 minutes in an Ar gas atmosphere.
  • the graph (b) shows the measurement result of the characteristics of the solar cell including the mixed crystal 600 manufactured by performing the temperature holding annealing at 525 ° C. for 5 minutes in the Ar gas atmosphere
  • the graph (c) The measurement result of the characteristic of the solar cell containing the mixed crystal 600 manufactured by performing annealing of temperature holding for 5 minutes at 575 degreeC in Se vapor
  • CdS which is an n-type buffer layer is deposited on the thin film including the mixed crystal 600 (CZTS crystal) by about 70 nm by a chemical deposition method, and then a high resistance ZnO phase is further sputtered by about 50 nm. It was prepared by depositing and depositing an Al-doped ZnO transparent electrode thereon by sputtering to about 50 nm.
  • the mixed crystal manufactured by electrodepositing different components simultaneously a mixed crystal manufacturing method, a solar cell, a solar cell manufacturing method, and an electrodeposition bath can be provided, and it utilizes for various industrial fields. Is possible.

Abstract

The present invention is a method for manufacturing a mixed crystal. The mixed crystal includes either or both of a microcrystal containing selenium and a microcrystal containing sulfur, a microcrystal containing copper, a microcrystal containing zinc, and a microcrystal containing tin. The manufacturing method for the microcrystal includes a step for preparing a mixed liquid in which a mixed liquid that includes either or both of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions is prepared and an electrocrystallization step in which a voltage is applied to the mixed liquid, and the mixed crystal is electro-crystallized.

Description

混合結晶、混合結晶製造方法、太陽電池、太陽電池製造方法及び電析浴Mixed crystal, mixed crystal manufacturing method, solar cell, solar cell manufacturing method and electrodeposition bath
　本発明は、混合結晶、混合結晶製造方法、太陽電池、太陽電池製造方法及び電析浴に関する。 The present invention relates to a mixed crystal, a mixed crystal manufacturing method, a solar cell, a solar cell manufacturing method, and an electrodeposition bath.
　現在、シリコン太陽電池や、構成成分にＣｕ、Ｉｎ、Ｇａ及びＳeを含む太陽電池（ＣＩＧＳ太陽電池）が事業化されている。しかしながら、シリコン太陽電池やＣＩＧＳ太陽電池の発電コストは高く、更なる研究開発が求められている。一方、構成成分にＣｄ及びＴｅを含む太陽電池（ＣｄＴｅ太陽電池）の研究が進んでおり、ＣｄＴｅ太陽電池は低コスト太陽電池として急速に普及している。しかしながら、Ｃｄの使用が問題であり、わが国では受け入れられない。 Currently, silicon solar cells and solar cells (CIGS solar cells) containing Cu, In, Ga, and Se as constituent components have been commercialized. However, the power generation costs of silicon solar cells and CIGS solar cells are high, and further research and development are required. On the other hand, research on solar cells containing Cd and Te as constituent components (CdTe solar cells) is progressing, and CdTe solar cells are rapidly spreading as low-cost solar cells. However, the use of Cd is a problem and is not acceptable in Japan.
　構成成分にＣｕ、Ｚｎ、Ｓｎ及びＳ（又はＳｅ）を含む太陽電池（ＣＺＴＳ太陽電池）は、ＣＩＧＳ太陽電池に含まれる３価原子（ＩｎとＧａ）をＺｎ（２価）とＳｎ（４価）とで置き換えた太陽電池であり、ＣＩＧＳ太陽電池を代替する非Ｉｎのレアメタルフリー太陽電池として、現在もっとも有望な材料である。非特許文献１や非特許文献２において、太陽電池への適用の可能性が実証されている。最近の集中的な研究により変換効率は飛躍的に向上しており、ＣＺＴＳ太陽電池がもつ高いポテンシャルを示すものといえる。 A solar cell (CZTS solar cell) containing Cu, Zn, Sn, and S (or Se) as a constituent component is a trivalent atom (In and Ga) contained in a CIGS solar cell, Zn (divalent) and Sn (tetravalent). ) And is the most promising material at present as a non-In rare metal-free solar cell that replaces the CIGS solar cell. Non-Patent Document 1 and Non-Patent Document 2 demonstrate the possibility of application to solar cells. Recent intensive research has dramatically improved the conversion efficiency, which indicates the high potential of CZTS solar cells.
　非特許文献３は、電析プロセスを用いたＣＺＴＳ製造技術を開示する。電析プロセスは、常温での製膜が可能な非真空ケミカルプロセスである。構成成分を所望の部分に堆積することができるため、材料の利用効率（元素資源の有効利用）においても大きな利点がある。 Non-Patent Document 3 discloses a CZTS manufacturing technique using an electrodeposition process. The electrodeposition process is a non-vacuum chemical process capable of forming a film at room temperature. Since the constituent components can be deposited in a desired portion, there is a great advantage in the material utilization efficiency (effective utilization of elemental resources).
　しかしながら、非特許文献１に記載の技術は真空プロセスであるゆえ大幅なプロセスの低コスト化は難しく、非特許文献２に記載の技術は取扱いが危険なヒドラジンを用いており、簡便なハンドリングができないという点で問題がある。また、非特許文献３に記載の技術は、Ｃｕ薄膜、Ｚｎ薄膜およびＳｎ薄膜の各々を順次積層し積層構造物を作製する。そして積層構造物を硫化することによってＣＺＴＳ太陽電池を製造する。従って、ＣＺＴＳ太陽電池の製造工程は複雑となり、かつ製造時間は長時間に及ぶ。 However, since the technique described in Non-Patent Document 1 is a vacuum process, it is difficult to greatly reduce the cost of the process. The technique described in Non-Patent Document 2 uses hydrazine that is dangerous to handle, and cannot be handled easily. There is a problem in that. In the technique described in Non-Patent Document 3, each of a Cu thin film, a Zn thin film, and a Sn thin film is sequentially laminated to produce a laminated structure. And a CZTS solar cell is manufactured by sulfiding a laminated structure. Therefore, the manufacturing process of the CZTS solar cell is complicated, and the manufacturing time is long.
　本発明は上記課題を鑑みてなされたものであり、本発明は、異種成分を同時に電析することによって製造される混合結晶、混合結晶製造方法、太陽電池、太陽電池製造方法及び電析浴を提供することを目的とする。 The present invention has been made in view of the above problems, and the present invention provides a mixed crystal manufactured by simultaneously depositing different components, a mixed crystal manufacturing method, a solar cell, a solar cell manufacturing method, and an electrodeposition bath. The purpose is to provide.
　本発明による混合結晶の製造方法は、セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含む混合液を用意する混合液用意工程と、前記混合液に電圧を印加し、前記混合結晶を電析する電析工程とを包含し、前記混合結晶は、セレン含有微結晶と硫黄含有微結晶とのうちの少なくとも一方と、銅含有微結晶と亜鉛含有微結晶とスズ含有微結晶とを含む。 The method for producing a mixed crystal according to the present invention comprises a mixed solution preparing step of preparing a mixed solution containing at least one of selenium ions and sulfur ions, copper ions, zinc ions and tin ions, and applying a voltage to the mixed solution. And an electrodeposition step of electrodepositing the mixed crystal, wherein the mixed crystal includes at least one of selenium-containing microcrystals and sulfur-containing microcrystals, copper-containing microcrystals, and zinc-containing microcrystals. Tin-containing microcrystals.
　ある実施形態において、前記電析工程の実行によって、前記セレン含有微結晶と前記硫黄含有微結晶とのうちの前記少なくとも一方と、前記銅含有微結晶と前記亜鉛含有微結晶と前記スズ含有微結晶とが基板に堆積する。 In one embodiment, by performing the electrodeposition step, the at least one of the selenium-containing microcrystals and the sulfur-containing microcrystals, the copper-containing microcrystals, the zinc-containing microcrystals, and the tin-containing microcrystals. Are deposited on the substrate.
　ある実施形態において、前記混合液は、第１混合液と第２混合液とを含み、前記混合結晶は、第１混合結晶と第２混合結晶とを含み、前記電析工程は、前記第１混合液に電圧を印加し、前記第１混合結晶を電析する第１電析工程と、前記第２混合液に電圧を印加し、前記第２混合結晶を電析する第２電析工程とを包含する。 In one embodiment, the mixed solution includes a first mixed solution and a second mixed solution, the mixed crystal includes a first mixed crystal and a second mixed crystal, and the electrodeposition step includes the first deposition step. A first electrodeposition step of applying a voltage to the mixed solution to deposit the first mixed crystal; and a second electrodeposition step of applying a voltage to the second mixed solution to deposit the second mixed crystal. Is included.
　ある実施形態において、前記第１混合液は、前記第２混合液よりも亜鉛イオンの含有割合が高い電解液を含み、前記第２混合液は、前記第１混合液よりも亜鉛イオンの含有割合が低い電解液を含む。 In one embodiment, the first mixed liquid includes an electrolytic solution having a higher zinc ion content ratio than the second mixed liquid, and the second mixed liquid has a zinc ion content ratio higher than that of the first mixed liquid. Contains low electrolyte.
　ある実施形態において、前記第１混合液は、セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含み、前記第２混合液は、セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンとスズイオンとを含み、前記第１混合結晶は、前記セレン含有微結晶と前記硫黄含有微結晶とのうちの前記少なくとも一方と、前記銅含有微結晶と前記亜鉛含有微結晶と前記スズ含有微結晶とを含み、前記第２混合結晶は、前記セレン含有微結晶と前記硫黄含有微結晶とのうちの前記少なくとも一方と、前記銅含有微結晶と前記スズ含有微結晶とを含む。 In one embodiment, the first mixed solution includes at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions, and the second mixed solution includes selenium ions and sulfur ions. At least one of them, including copper ions and tin ions, and the first mixed crystal includes at least one of the selenium-containing microcrystals and the sulfur-containing microcrystals, the copper-containing microcrystals, and the zinc-containing The second mixed crystal includes at least one of the selenium-containing microcrystal and the sulfur-containing microcrystal, the copper-containing microcrystal, and the tin-containing microcrystal. Including.
　ある実施形態において、前記電析工程は、前記第１電析工程と前記第２電析工程とのうちの一方を実行し、前記一方の実行の後、前記第１電析工程と前記第２電析工程とのうちの他方を実行し、前記第１電析工程の実行によって、前記セレン含有微結晶と前記硫黄含有微結晶とのうちの前記少なくとも一方と、前記銅含有微結晶と前記亜鉛含有微結晶と前記スズ含有微結晶とが前記基板に堆積し、前記第２電析工程の実行によって、前記セレン含有微結晶と前記硫黄含有微結晶とのうちの前記少なくとも一方と、前記銅含有微結晶と前記スズ含有微結晶とが前記基板に堆積する。 In one embodiment, the electrodeposition step performs one of the first electrodeposition step and the second electrodeposition step, and after the one execution, the first electrodeposition step and the second electrodeposition step. Performing the other of the electrodeposition step, and performing the first electrodeposition step, the at least one of the selenium-containing microcrystals and the sulfur-containing microcrystals, the copper-containing microcrystals, and the zinc Containing microcrystals and tin-containing microcrystals are deposited on the substrate, and by performing the second electrodeposition step, at least one of the selenium-containing microcrystals and the sulfur-containing microcrystals, and the copper-containing microcrystals Microcrystals and the tin-containing microcrystals are deposited on the substrate.
　ある実施形態において、前記第１混合結晶の組成において、銅の含有割合は化学量論組成よりも少なく、亜鉛の含有割合は化学量論よりも多い。 In one embodiment, in the composition of the first mixed crystal, the content ratio of copper is smaller than the stoichiometric composition, and the content ratio of zinc is larger than the stoichiometric composition.
　ある実施形態において、銅の含有割合（Ｃｕ／（Ｚｎ＋Ｓｎ））は０．８～０．９であり、亜鉛の含有割合（Ｚｎ/Ｓｎ）は１．０～２．０である。 In an embodiment, the copper content (Cu / (Zn + Sn)) is 0.8 to 0.9, and the zinc content (Zn / Sn) is 1.0 to 2.0.
　ある実施形態において、前記混合液は、添加剤を含み、前記混合液用意工程は、前記銅イオンと前記亜鉛イオンと前記スズイオンとに前記添加剤が配位した錯体を形成する錯体形成工程を包含する。 In one embodiment, the mixed solution includes an additive, and the mixed solution preparing step includes a complex forming step of forming a complex in which the additive is coordinated to the copper ion, the zinc ion, and the tin ion. To do.
　ある実施形態において、前記添加剤は、乳酸、乳酸ナトリウム、乳酸カリウム、乳酸アンモニウム、酒石酸、酒石酸ナトリウム、酒石酸カリウムナトリウム、酒石酸アンモニウム、酒石酸水素ナトリウム、酒石酸水素カリウム、クエン酸、クエン酸ナトリウム、クエン酸カリウム、クエン酸二水素カリウム、クエン酸二水素ナトリウム、クエン酸アンモニウム、シュウ酸、シュウ酸ナトリウム、シュウ酸カリウム、シュウ酸水素ナトリウム、シュウ酸水素カリウム、シュウ酸アンモニウム、マロン酸、マロン酸ナトリウム、マロン酸カリウム、マロン酸アンモニウムのうちの少なくとも１種を含む。 In one embodiment, the additive is lactic acid, sodium lactate, potassium lactate, ammonium lactate, tartaric acid, sodium tartrate, potassium sodium tartrate, ammonium tartrate, sodium hydrogen tartrate, potassium hydrogen tartrate, citric acid, sodium citrate, citric acid. Potassium, potassium dihydrogen citrate, sodium dihydrogen citrate, ammonium citrate, oxalic acid, sodium oxalate, potassium oxalate, sodium hydrogen oxalate, potassium hydrogen oxalate, ammonium oxalate, malonic acid, sodium malonate, It contains at least one of potassium malonate and ammonium malonate.
　ある実施形態において、前記混合液は酸性である。 In one embodiment, the mixed solution is acidic.
　ある実施形態において、前記混合結晶をアニールするアニール工程を更に包含する。アニール工程によって、前記混合結晶からＣｕ2ＺｎＳｎＳｅ4からなるＰ型光応答性結晶が得られる。なお、セレンイオンに代えて硫黄イオンが利用された場合、又は、セレンイオン及び硫黄イオンが利用された場合には、当該結晶は、Ｃｕ2ＺｎＳｎＳ4、Ｃｕ2ＺｎＳｎ（Ｓ・Ｓｅ）4となるが、当該結晶を総称して便宜上ＣＺＴＳ結晶と表記する。 In one embodiment, the method further includes an annealing step of annealing the mixed crystal. By the annealing step, a P-type photoresponsive crystal made of Cu 2 ZnSnSe 4 is obtained from the mixed crystal. When sulfur ions are used instead of selenium ions, or when selenium ions and sulfur ions are used, the crystals are Cu 2 ZnSnS 4 and Cu 2 ZnSn (S · Se) 4. However, the crystals are collectively referred to as CZTS crystals for convenience.
　ある実施形態において、前記アニール工程の実行によって、Ｃｕ2ＺｎＳｎＳｅ4を含むＰ型光応答性結晶を製造する。 In one embodiment, a P-type photoresponsive crystal containing Cu 2 ZnSnSe 4 is manufactured by performing the annealing step.
　本発明による太陽電池製造方法は、セレン含有微結晶と硫黄含有微結晶とのうちの少なくとも一方と、銅含有微結晶と亜鉛含有微結晶とスズ含有微結晶とを含んだ混合結晶を用意する混合結晶用意工程と、前記混合結晶を含む混合結晶層の上にバッファ層を積層するバッファ層積層工程と、前記バッファ層の上に透明電極を積層する透明電極積層工程とを包含する。 A method for manufacturing a solar cell according to the present invention comprises preparing a mixed crystal containing at least one of selenium-containing microcrystals and sulfur-containing microcrystals, copper-containing microcrystals, zinc-containing microcrystals, and tin-containing microcrystals. A crystal preparation step, a buffer layer lamination step of laminating a buffer layer on the mixed crystal layer containing the mixed crystal, and a transparent electrode lamination step of laminating a transparent electrode on the buffer layer.
　ある実施形態において、前記混合結晶用意工程は、セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含む混合液を用意する混合液用意工程と、前記混合液に電圧を印加し、前記混合結晶を電析する電析工程とを包含する。 In one embodiment, the mixed crystal preparing step includes a mixed solution preparing step of preparing a mixed solution including at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions, and the mixed solution. An electrodeposition step of applying a voltage and electrodepositing the mixed crystal.
　ある実施形態において、前記混合液は、添加剤を含み、前記混合液用意工程は、前記銅イオンと前記亜鉛イオンとスズイオンとに前記添加剤が配位した錯体を形成する錯体形成工程を包含する。 In one embodiment, the mixed solution includes an additive, and the mixed solution preparing step includes a complex forming step of forming a complex in which the additive is coordinated to the copper ion, the zinc ion, and the tin ion. .
　ある実施形態において、前記混合液は酸性である。 In one embodiment, the mixed solution is acidic.
　ある実施形態において、前記混合結晶をアニールするアニール工程を更に包含する。 In one embodiment, the method further includes an annealing step of annealing the mixed crystal.
　ある実施形態において、前記混合液用意工程は、上記記載の混合結晶製造方法を包含する。 In one embodiment, the mixed solution preparing step includes the mixed crystal manufacturing method described above.
　本発明による混合結晶は、セレン含有微結晶と硫黄含有微結晶とのうちの少なくとも一方と、銅含有微結晶と亜鉛含有微結晶とスズ含有微結晶とを含む。 The mixed crystal according to the present invention includes at least one of selenium-containing microcrystals and sulfur-containing microcrystals, copper-containing microcrystals, zinc-containing microcrystals, and tin-containing microcrystals.
　本発明による太陽電池は、セレン含有微結晶と硫黄含有微結晶とのうちの少なくとも一方と、銅含有微結晶と亜鉛含有微結晶と前記スズ含有微結晶とを含んだ混合結晶層と、前記混合結晶層の上に積層されたバッファ層と、前記バッファ層の上に積層された透明電極とを備える。 The solar cell according to the present invention includes at least one of selenium-containing microcrystals and sulfur-containing microcrystals, a mixed crystal layer containing copper-containing microcrystals, zinc-containing microcrystals and the tin-containing microcrystals, and the mixed A buffer layer stacked on the crystal layer; and a transparent electrode stacked on the buffer layer.
　ある実施形態において、前記混合結晶層は、上記記載の混合結晶製造方法によって製造された混合結晶を含む。 In one embodiment, the mixed crystal layer includes a mixed crystal manufactured by the mixed crystal manufacturing method described above.
　本発明による電析浴は、セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含む。 The electrodeposition bath according to the present invention contains at least one of selenium ions and sulfur ions, copper ions, zinc ions and tin ions.
　ある実施形態において、添加剤を更に含み、前記銅イオンと前記亜鉛イオンと前記スズイオンとに前記添加剤が配位した錯体を含む。 In one embodiment, an additive is further included, and a complex in which the additive is coordinated to the copper ion, the zinc ion, and the tin ion is included.
　ある実施形態において、前記添加剤は、乳酸、乳酸ナトリウム、乳酸カリウム、乳酸アンモニウム、酒石酸、酒石酸ナトリウム、酒石酸カリウムナトリウム、酒石酸アンモニウム、酒石酸水素ナトリウム、酒石酸水素カリウム、クエン酸、クエン酸ナトリウム、クエン酸カリウム、クエン酸二水素カリウム、クエン酸二水素ナトリウム、クエン酸アンモニウム、シュウ酸、シュウ酸ナトリウム、シュウ酸カリウム、シュウ酸水素ナトリウム、シュウ酸水素カリウム、シュウ酸アンモニウム、マロン酸、マロン酸ナトリウム、マロン酸カリウム、マロン酸アンモニウムのうちの少なくとも１種を含む。 In one embodiment, the additive is lactic acid, sodium lactate, potassium lactate, ammonium lactate, tartaric acid, sodium tartrate, potassium sodium tartrate, ammonium tartrate, sodium hydrogen tartrate, potassium hydrogen tartrate, citric acid, sodium citrate, citric acid. Potassium, potassium dihydrogen citrate, sodium dihydrogen citrate, ammonium citrate, oxalic acid, sodium oxalate, potassium oxalate, sodium hydrogen oxalate, potassium hydrogen oxalate, ammonium oxalate, malonic acid, sodium malonate, It contains at least one of potassium malonate and ammonium malonate.
本発明の実施形態１による混合結晶１００を含む積層構造物Ａを示す模式図である。It is a schematic diagram which shows the laminated structure A containing the mixed crystal 100 by Embodiment 1 of this invention. 本発明の実施形態１による混合結晶１００の製造方法を示すフローチャートである。3 is a flowchart showing a method for manufacturing the mixed crystal 100 according to Embodiment 1 of the present invention. 本発明の実施形態１による混合結晶１００を示す写真である。1 is a photograph showing a mixed crystal 100 according to Embodiment 1 of the present invention. 本発明の実施形態１による混合結晶１００のＸ線回折結果を示す。The X-ray-diffraction result of the mixed crystal 100 by Embodiment 1 of this invention is shown. 本発明の実施形態１による混合結晶１００のラマンスペクトルを示す。The Raman spectrum of the mixed crystal 100 by Embodiment 1 of this invention is shown. 本発明の実施形態１における混合結晶２００の製造方法を示すフローチャートである。It is a flowchart which shows the manufacturing method of the mixed crystal 200 in Embodiment 1 of this invention. 本発明の実施形態１による混合結晶２００を示す写真である。3 is a photograph showing a mixed crystal 200 according to Embodiment 1 of the present invention. 本発明の実施形態１における混合結晶２００のＸ線回折結果を示す。The X-ray-diffraction result of the mixed crystal 200 in Embodiment 1 of this invention is shown. 本発明の実施形態１における混合結晶２００のラマンスペクトルを示す。The Raman spectrum of the mixed crystal 200 in Embodiment 1 of this invention is shown. 本発明の実施形態１における混合結晶２００を対象とした光電気化学測定の結果を示す。The result of the photoelectrochemical measurement which aimed at the mixed crystal 200 in Embodiment 1 of this invention is shown. 本発明の実施形態２による混合結晶５００を含む積層構造物Ｅを示す模式図である。It is a schematic diagram which shows the laminated structure E containing the mixed crystal 500 by Embodiment 2 of this invention. 本発明の実施形態２による混合結晶５００の製造方法を示すフローチャートである。5 is a flowchart showing a method for manufacturing a mixed crystal 500 according to Embodiment 2 of the present invention. 本発明の実施形態２による混合結晶５００のラマンスペクトルを示す。The Raman spectrum of the mixed crystal 500 by Embodiment 2 of this invention is shown. 本発明の実施形態２による混合結晶５００を示す写真である。6 is a photograph showing a mixed crystal 500 according to Embodiment 2 of the present invention. 本発明の実施形態２における混合結晶６００の製造方法を示すフローチャートである。It is a flowchart which shows the manufacturing method of the mixed crystal 600 in Embodiment 2 of this invention. 本発明の実施形態２における混合結晶６００のＸ線回折結果を示す。The X-ray-diffraction result of the mixed crystal 600 in Embodiment 2 of this invention is shown. 本発明の実施形態２における混合結晶６００のラマンスペクトルを示す。The Raman spectrum of the mixed crystal 600 in Embodiment 2 of this invention is shown. 本発明の実施形態２における混合結晶６００の組成分析結果を示す。The composition analysis result of the mixed crystal 600 in Embodiment 2 of this invention is shown. 本発明の実施形態２における混合結晶６００のＳＥＭ像を示す。The SEM image of the mixed crystal 600 in Embodiment 2 of this invention is shown. 本発明の実施形態３による太陽電池４００の模式図を示す。The schematic diagram of the solar cell 400 by Embodiment 3 of this invention is shown. 本発明の実施形態３による太陽電池（混合結晶６００を含む）の特性の測定結果を示す。The measurement result of the characteristic of the solar cell (including the mixed crystal 600) by Embodiment 3 of this invention is shown.
　以下、図面を参照して本発明による混合結晶、混合結晶製造方法、太陽電池、太陽電池製造方法及び電析浴の実施形態を説明する。ただし、本発明は以下の実施形態に限定されない。 Hereinafter, embodiments of a mixed crystal, a mixed crystal manufacturing method, a solar cell, a solar cell manufacturing method, and an electrodeposition bath according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments.
　［実施形態１］
［混合結晶］
図１は、本発明の実施形態１による混合結晶１００を含む積層構造物Ａを示す模式図である。積層構造物Ａは、基板ａと基板ｂと混合結晶１００とを含む。基板ａは、例えば、ガラス基板である。基板ｂは例えばＭｏ層である。積層構造物Ａが太陽電池に適用される場合には、基板ｂは裏面電極（Ｍｏ電極）として機能する。 [Embodiment 1]
[Mixed crystal]
FIG. 1 is a schematic diagram showing a laminated structure A including a mixed crystal 100 according to Embodiment 1 of the present invention. The laminated structure A includes a substrate a, a substrate b, and a mixed crystal 100. The substrate a is, for example, a glass substrate. The substrate b is, for example, a Mo layer. When the laminated structure A is applied to a solar cell, the substrate b functions as a back electrode (Mo electrode).
　混合結晶１００は、セレン（Ｓｅ）含有微結晶と硫黄（Ｓ）含有微結晶とのうちの少なくとも一方と、銅（Ｃｕ）含有微結晶と亜鉛（Ｚｎ）含有微結晶とスズ（Ｓｎ）含有微結晶とを含むＣＺＴＳ結晶である。図１において、混合結晶１００の厚さは、例えば、３０ｎｍ～２．５μｍである。 The mixed crystal 100 includes at least one of selenium (Se) -containing microcrystals and sulfur (S) -containing microcrystals, copper (Cu) -containing microcrystals, zinc (Zn) -containing microcrystals, and tin (Sn) -containing microcrystals. A CZTS crystal including the crystal. In FIG. 1, the thickness of the mixed crystal 100 is, for example, 30 nm to 2.5 μm.
   [混合結晶製造方法]
図２は、本発明の実施形態１による混合結晶１００の製造方法を示すフローチャートである。混合結晶１００は、ステップＳ２０２～ステップＳ２０６を実行することで製造される。混合結晶１００の製造では、電析プロセスが用いられる。電析プロセスによる化合物薄膜の形成は、電析浴に溶解させた化合物の構成元素イオンが電極表面において電気化学的に還元されることにより堆積する合金めっきを基本原理としている。混合結晶１００を製造するには、原料となるＣｕ、Ｚｎ、Ｓｎ、Ｓ（又はＳｅ）の各イオンを溶解させた電析浴から、４つの成分を還元させる。以下、図２を参照してステップＳ２０２～ステップＳ２０６を説明する。 [Mixed crystal manufacturing method]
FIG. 2 is a flowchart showing a method for manufacturing the mixed crystal 100 according to Embodiment 1 of the present invention. The mixed crystal 100 is manufactured by executing Steps S202 to S206. In the manufacture of the mixed crystal 100, an electrodeposition process is used. Formation of a compound thin film by an electrodeposition process is based on alloy plating which is deposited by electrochemically reducing constituent element ions of a compound dissolved in an electrodeposition bath on the electrode surface. In order to manufacture the mixed crystal 100, four components are reduced from an electrodeposition bath in which Cu, Zn, Sn, and S (or Se) ions as raw materials are dissolved. Hereinafter, steps S202 to S206 will be described with reference to FIG.
　ステップＳ２０２：セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含む混合液３０２を用意する（混合液用意工程）。図２において、混合液３０２は電解槽ｃに入れられている。 Step S202: A mixed liquid 302 containing at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions is prepared (mixed liquid preparing step). In FIG. 2, the liquid mixture 302 is put in the electrolytic cell c.
　本実施形態において、亜セレン酸イオン（ＳｅＯ3 2-）はＮａ2ＳｅＯ3（モル濃度５ｍＭ）から解離生成され、銅イオン（Ｃｕ2 +）はＣｕＳＯ4・５Ｈ2Ｏ（モル濃度４ｍＭ）から解離生成され、亜鉛イオン（Ｚｎ2 +）はＺｎＳＯ4（モル濃度８０ｍＭ）から解離生成され、スズイオン（Ｓｎ4 +）はＳｎＣｌ4（モル濃度２０ｍＭ）から解離生成される。 In this embodiment, selenite ion (SeO 3 2− ) is dissociated and produced from Na 2 SeO 3 (molar concentration 5 mM), and copper ion (Cu 2 + ) is derived from CuSO 4 .5H 2 O (molar concentration 4 mM). Zinc ions (Zn 2 + ) are dissociated and generated from ZnSO 4 (molar concentration 80 mM), and tin ions (Sn 4 + ) are dissociated and generated from SnCl 4 (molar concentration 20 mM).
　ステップＳ２０４：混合液３０２に電圧を印加し、混合結晶１００を電析する（電析工程）。カソード電極としてＭｏ電極ｂが積層した基板ａを用い、アノード電極３０４として白金電極を用いた。電極としては、工業的には安価で安定な炭素電極を、実験用には炭素の他に腐食されにくい白金や金などの貴金属電極を用い得る。Ｍｏ電極ａが積層した基板ａと白金電極とを混合液３０２が入った電解槽ｃに浸け、電源３０６によって電極間に電圧（－０．６Ｖ）を印加した。電源３０６は、ポテンショスタット（電位制御）機能及びガルバノスタット（電流制御）機能を有する外部電源である。 Step S204: A voltage is applied to the mixed solution 302 to deposit the mixed crystal 100 (electrodeposition step). A substrate a on which a Mo electrode b was laminated was used as the cathode electrode, and a platinum electrode was used as the anode electrode 304. As an electrode, an industrially inexpensive and stable carbon electrode can be used, and a noble metal electrode such as platinum or gold which is not easily corroded in addition to carbon can be used for experiments. The substrate a on which the Mo electrode a was laminated and the platinum electrode were immersed in an electrolytic cell c containing a mixed solution 302, and a voltage (−0.6 V) was applied between the electrodes by a power source 306. The power source 306 is an external power source having a potentiostat (potential control) function and a galvanostat (current control) function.
　なお、印加電圧の大きさは、混合液３０２に含まれるイオンが還元される限りは特に限定されないが、例えば印加電圧は－０．５～－１．０Ｖであり得る。－０．５Ｖよりも負側である場合は還元しないイオンを少なくすることができ、－１．０Ｖよりも正側である場合は、水の還元に基づく水素ガス発生を抑制し得る。なお、印加電圧が－１．０Ｖよりも負側である場合は、印加電圧が大きいためイオンの還元速度を増すことが可能になり、効率よく混合結晶１００を製造することができる。 The magnitude of the applied voltage is not particularly limited as long as the ions contained in the mixed liquid 302 are reduced. For example, the applied voltage can be -0.5 to -1.0 V. When it is on the negative side of −0.5 V, the number of ions that are not reduced can be reduced, and when it is on the positive side of −1.0 V, the generation of hydrogen gas based on the reduction of water can be suppressed. When the applied voltage is on the negative side of −1.0 V, the applied voltage is large, so that the reduction rate of ions can be increased, and the mixed crystal 100 can be manufactured efficiently.
　ステップＳ２０２とステップＳ２０４とを実行することで、混合結晶１００を含んだ積層構造物Ｂを製造することができる（ステップＳ２０６）。 By executing step S202 and step S204, the laminated structure B including the mixed crystal 100 can be manufactured (step S206).
　以上、図２を参照してステップＳ２０２～ステップＳ２０６を説明した。なお、混合液３０２において、添加剤を混ぜるのが好ましい。添加剤は、例えば酒石酸である。酒石酸は混合液３０２中のＣｕ2+、Ｚｎ2+、Ｓｎ4+が水酸化物の沈殿となるのを防ぐ安定化材として機能する。銅イオンと亜鉛イオンとスズイオンとに酒石酸が配位した錯体を形成する。ステップＳ２０２において、混合液３０２は酒石酸（５００ｍＭ）を含む。 The steps S202 to S206 have been described above with reference to FIG. Note that an additive is preferably mixed in the mixed solution 302. The additive is, for example, tartaric acid. Tartaric acid functions as a stabilizer that prevents Cu 2+ , Zn 2+ , and Sn 4+ in the mixed solution 302 from precipitating hydroxide. A complex in which tartaric acid is coordinated to copper ion, zinc ion and tin ion is formed. In step S202, the liquid mixture 302 contains tartaric acid (500 mM).
　なお、添加剤は、銅イオンと亜鉛イオンとスズイオンとが配位した錯体を形成し得る限りは、酒石酸に限定されない。添加剤は、例えば、乳酸、乳酸を含む化合物（乳酸ナトリウム、乳酸カリウム、乳酸アンモニウムなど）、酒石酸、酒石酸を含む化合物（酒石酸ナトリウム、酒石酸カリウムナトリウム、酒石酸アンモニウム、酒石酸水素ナトリウム、酒石酸水素カリウムなど）、クエン酸、クエン酸を含む化合物（クエン酸ナトリウム、クエン酸カリウム、クエン酸二水素カリウム、クエン酸二水素ナトリウム、クエン酸アンモニウムなど）、シュウ酸、シュウ酸を含む化合物（シュウ酸ナトリウム、シュウ酸カリウム、シュウ酸水素ナトリウム、シュウ酸水素カリウム、シュウ酸アンモニウムなど）、マロン酸、マロン酸を含む化合物（マロン酸ナトリウム、マロン酸カリウム、マロン酸アンモニウムなど）のうちの少なくとも１種であり得る。 The additive is not limited to tartaric acid as long as it can form a complex in which copper ions, zinc ions, and tin ions are coordinated. Additives include, for example, lactic acid, compounds containing lactic acid (sodium lactate, potassium lactate, ammonium lactate, etc.), tartaric acid, compounds containing tartaric acid (sodium tartrate, potassium sodium tartrate, ammonium tartrate, sodium hydrogen tartrate, potassium hydrogen tartrate, etc.) , Citric acid, compounds containing citric acid (sodium citrate, potassium citrate, potassium dihydrogen citrate, sodium dihydrogen citrate, ammonium citrate, etc.), oxalic acid, compounds containing oxalic acid (sodium oxalate, Potassium malate, sodium hydrogen oxalate, potassium hydrogen oxalate, ammonium oxalate, etc.), malonic acid, and at least one of compounds containing malonic acid (sodium malonate, potassium malonate, ammonium malonate, etc.) .
　さらに、混合液３０２において、セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含む混合液３０２が生成される限りｐＨは特に問わないが、ｐＨが酸性であれば、混合液３０２に含まれるイオンの水酸化物化を抑制し得る。さらに、ステップＳ２０２において、混合液３０２はＮＨ3溶液（２８％）を含み、ｐＨは２．５である。なお、添加剤の添加によって、混合液３０２のｐＨを酸性に保持し得る（添加剤による緩衝効果）。 Furthermore, the pH of the mixed solution 302 is not particularly limited as long as the mixed solution 302 containing at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions is generated. For example, the hydroxide of ions contained in the mixed solution 302 can be suppressed. Further, in step S202, the mixed solution 302 contains an NH 3 solution (28%) and the pH is 2.5. In addition, the pH of the liquid mixture 302 can be kept acidic by the addition of the additive (buffering effect by the additive).
　基板ｂ（Ｍｏ層）の積層基板ａをＣｕ2+、Ｚｎ2+、Ｓｎ4+、Ｓｅ4+を含む弱酸性の混合液３０２に浸し、基板ｂ（Ｍｏ層）の積層基板ａをカソードして電解還元反応させることで、微結晶黒色の電析膜（混合結晶１００）を得た。ラマンスペクトルと組成分析の結果、混合結晶１００はＣＺＴＳ結晶を含むことを確認した。 The laminated substrate a of the substrate b (Mo layer) is immersed in a weakly acidic mixed solution 302 containing Cu 2+ , Zn 2+ , Sn 4+ and Se 4+, and the laminated substrate a of the substrate b (Mo layer) is cathoded. By carrying out an electrolytic reduction reaction, a microcrystalline black electrodeposited film (mixed crystal 100) was obtained. As a result of Raman spectrum and composition analysis, it was confirmed that the mixed crystal 100 contained CZTS crystals.
　図３は、本発明の実施形態１による混合結晶１００を示す写真である。図３（ａ）は、ステップＳ２０４において電析を１分間実行したことによって製造された混合結晶１００を示す。混合結晶１００の膜厚は３０ｎｍであった。図３（ｂ）は、ステップＳ２０４において電析を５分間実行したことによって製造された混合結晶１００を示す。混合結晶１００の膜厚は１１４ｎｍであった。図３（ｃ）は、ステップＳ２０４において電析を１０分間実行したことによって製造された混合結晶１００を示す。混合結晶１００の膜厚は７２７ｎｍであった。図３（ｄ）は、ステップＳ２０４において電析を２０分間実行したことによって製造された混合結晶１００を示す。混合結晶１００の膜厚は８８２ｎｍであった。図３（ｅ）は、ステップＳ２０４において電析を４０分間実行したことによって製造された混合結晶１００を示す。混合結晶１００の膜厚は１．１１μｍであった。図３（ｆ）は、ステップＳ２０４において電析を６０分間実行したことによって製造された混合結晶１００を示す。混合結晶１００の膜厚は２μｍであった。図３（ｇ）は、ステップＳ２０４において電析を７０分間実行したことによって製造された混合結晶１００を示す。混合結晶１００の膜厚は２．５μｍであった。 FIG. 3 is a photograph showing the mixed crystal 100 according to Embodiment 1 of the present invention. FIG. 3A shows the mixed crystal 100 manufactured by performing electrodeposition for 1 minute in step S204. The film thickness of the mixed crystal 100 was 30 nm. FIG. 3B shows the mixed crystal 100 manufactured by performing electrodeposition in step S204 for 5 minutes. The film thickness of the mixed crystal 100 was 114 nm. FIG. 3C shows the mixed crystal 100 manufactured by performing electrodeposition for 10 minutes in step S204. The film thickness of the mixed crystal 100 was 727 nm. FIG. 3D shows the mixed crystal 100 manufactured by performing electrodeposition in step S204 for 20 minutes. The film thickness of the mixed crystal 100 was 882 nm. FIG. 3E shows the mixed crystal 100 manufactured by performing electrodeposition for 40 minutes in step S204. The film thickness of the mixed crystal 100 was 1.11 μm. FIG. 3F shows the mixed crystal 100 manufactured by performing electrodeposition in step S204 for 60 minutes. The film thickness of the mixed crystal 100 was 2 μm. FIG. 3G shows the mixed crystal 100 manufactured by performing electrodeposition in step S204 for 70 minutes. The film thickness of the mixed crystal 100 was 2.5 μm.
　図３（ａ）～図３（ｇ）の結果から、電析時間を長くする従って、混合結晶１００の膜厚が厚くなることが確認できた。 From the results shown in FIGS. 3A to 3G, it was confirmed that the film thickness of the mixed crystal 100 was increased as the electrodeposition time was increased.
　図４は、混合結晶１００のＸ線回折（ＸＲＤ：Ｘ－ｒａｙ　ｄｉｆｆｒａｃｔｉｏｎ）結果を示す。グラフ（ａ）は、１分間の電析を実行することによって製造された混合結晶１００のＸＲＤ結果を示す。グラフ（ｂ）は、５分間の電析を実行することによって製造された混合結晶１００のＸＲＤ結果を示す。グラフ（ｃ）は、１０分間の電析を実行することによって製造された混合結晶１００のＸＲＤ結果を示す。グラフ（ｄ）は、２０分間の電析を実行することによって製造された混合結晶１００のＸＲＤ結果を示す。グラフ（ｅ）は、４０分間の電析を実行することによって製造された混合結晶１００のＸＲＤ結果を示す。グラフ（ｆ）は、６０分間の電析を実行することによって製造された混合結晶１００のＸＲＤ結果を示す。グラフ（ｇ）は、７０分間の電析を実行することによって製造された混合結晶１００のＸＲＤ結果を示す。 FIG. 4 shows an X-ray diffraction (XRD) result of the mixed crystal 100. The graph (a) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 1 minute. The graph (b) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 5 minutes. The graph (c) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 10 minutes. The graph (d) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 20 minutes. The graph (e) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 40 minutes. The graph (f) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 60 minutes. The graph (g) shows the XRD result of the mixed crystal 100 manufactured by performing the electrodeposition for 70 minutes.
　グラフ（ａ）～グラフ（ｇ）の結果から、混合結晶１００には、結晶子サイズの小さいＣＺＴＳが含まれていることが確認できた。 From the results of graph (a) to graph (g), it was confirmed that the mixed crystal 100 contained CZTS having a small crystallite size.
　図５は、混合結晶１００のラマンスペクトルを示す。グラフ（ａ）は、１分間の電析を実行することによって製造された混合結晶１００のラマンスペクトル結果を示す。グラフ（ｂ）は、５分間の電析を実行することによって製造された混合結晶１００のラマンスペクトル結果を示す。グラフ（ｃ）は、１０分間の電析を実行することによって製造された混合結晶１００のラマンスペクトル結果を示す。グラフ（ｄ）は、２０分間の電析を実行することによって製造された混合結晶１００のラマンスペクトル結果を示す。グラフ（ｅ）は、４０分間の電析を実行することによって製造された混合結晶１００のラマンスペクトル結果を示す。グラフ（ｆ）は、６０分間の電析を実行することによって製造された混合結晶１００のラマンスペクトル結果を示す。グラフ（ｇ）は、７０分間の電析を実行することによって製造された混合結晶１００のラマンスペクトル結果を示す。 FIG. 5 shows the Raman spectrum of the mixed crystal 100. The graph (a) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 1 minute. The graph (b) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 5 minutes. The graph (c) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 10 minutes. The graph (d) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 20 minutes. The graph (e) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 40 minutes. The graph (f) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 60 minutes. The graph (g) shows the Raman spectrum result of the mixed crystal 100 manufactured by performing the electrodeposition for 70 minutes.
　グラフ（ａ）～グラフ（ｇ）の全てに、ＣＺＴＳ結晶によるメインラマンピークが表れている。混合結晶１００にはＣＺＴＳ結晶が含まれることが確認できた。 In all graphs (a) to (g), the main Raman peak due to the CZTS crystal appears. It was confirmed that the mixed crystal 100 contained CZTS crystals.
　図６は、本発明の実施形態１における混合結晶２００の製造方法を示すフローチャートである。混合結晶２００は、ステップＳ２０６～ステップＳ２０８を実行することで製造される。混合結晶２００の製造では、アニールプロセスが用いられる。 FIG. 6 is a flowchart showing a method for manufacturing the mixed crystal 200 in Embodiment 1 of the present invention. The mixed crystal 200 is manufactured by executing Steps S206 to S208. In the manufacture of the mixed crystal 200, an annealing process is used.
　ステップＳ２０６：ステップＳ２０２とステップＳ２０４とを実行することによって製造した積層構造物Ｂを準備する（準備工程）。積層構造物Ｂは、基板ａとＭｏ電極ｂと混合結晶１００とを含む。基板ａの上にはＭｏ電極ｂが積層し、Ｍｏ電極ｂの上には混合結晶１００が積層している。 Step S206: The laminated structure B manufactured by executing Step S202 and Step S204 is prepared (preparation process). The laminated structure B includes the substrate a, the Mo electrode b, and the mixed crystal 100. A Mo electrode b is stacked on the substrate a, and a mixed crystal 100 is stacked on the Mo electrode b.
　ステップＳ２０８：混合結晶１００をアニールし、混合結晶２００を含んだ積層構造Ｃを製造する（アニール工程）。積層構造物Ｃは、基板ａとＭｏ電極ｂと混合結晶２００とを含む。基板ａの上にはＭｏ電極ｂが積層し、Ｍｏ電極ｂの上には混合結晶２００が積層している。ステップＳ２０２とステップＳ２０４とを実行することによって製造した混合結晶１００をアニールすることで、結晶性の高いＣＺＴＳＳｅ薄膜（混合結晶２００）が得られた。ステップＳ２０８において、アニールは、Ａｒガス雰囲気中で５００℃または５５０℃まで昇温（１８℃／ｍｉｎ）し、Ｈ2Ｓ（５％）雰囲気中で１０ｍｉｎ温度保持することによって行った。更に、Ｎ２ガス雰囲気中で降温し、混合結晶２００を製造した。 Step S208: The mixed crystal 100 is annealed to produce a laminated structure C including the mixed crystal 200 (annealing step). The laminated structure C includes a substrate a, a Mo electrode b, and a mixed crystal 200. A Mo electrode b is stacked on the substrate a, and a mixed crystal 200 is stacked on the Mo electrode b. The CZTSSe thin film (mixed crystal 200) with high crystallinity was obtained by annealing the mixed crystal 100 manufactured by executing Step S202 and Step S204. In step S208, annealing was performed by raising the temperature to 500 ° C. or 550 ° C. (18 ° C./min) in an Ar gas atmosphere and holding the temperature for 10 min in an H 2 S (5%) atmosphere. Furthermore, the temperature was lowered in an N 2 gas atmosphere to produce a mixed crystal 200.
　ラマンスペクトルと組成分析の結果、混合結晶２００はＣＺＴＳＳｅ結晶を含むことを確認した。ＣＺＴＳ結晶（混合結晶１００）をＨ2Ｓ雰囲気中でアニールしたため硫化が進み、ＣＺＴＳＳｅ結晶（混合結晶２００）を得た。なお、アニール実施の雰囲気はＨ2Ｓ（５％）に限定されない。ステップＳ２０８において、Ｈ2Ｓ（５％）に代わり、Ｓガス（５％）雰囲気中でアニールし得る。この場合も硫化が進み、ＣＺＴＳＳｅ結晶（混合結晶２００）を得ることができた。 As a result of Raman spectrum and composition analysis, it was confirmed that the mixed crystal 200 contained CZTSSe crystals. Since the CZTS crystal (mixed crystal 100) was annealed in an H 2 S atmosphere, sulfidation proceeded, and a CZTSSe crystal (mixed crystal 200) was obtained. Note that the annealing atmosphere is not limited to H 2 S (5%). In step S208, annealing can be performed in an S gas (5%) atmosphere instead of H 2 S (5%). Also in this case, the sulfidation progressed, and a CZTSSe crystal (mixed crystal 200) could be obtained.
　図７は、本発明の実施形態１による混合結晶２００を示す写真である。図７（ａ）は、ステップＳ２０４において電析を約６０分間実行したことによって製造された混合結晶１００を示す。混合結晶１００の膜厚は約１．９μｍであった。図７（ｂ）は、ステップＳ２０８において１０分間アニールを５５０℃で実行したことによって製造された混合結晶２００を示す。混合結晶２００の膜厚は約１．５μｍであった。図７（ａ）および図７（ｂ）に示された写真を比較することで、混合結晶２００では結晶塊（グレイン）のサイズが大きくなり、混合結晶１００に含まれた微結晶が成長していることが確認できた。 FIG. 7 is a photograph showing the mixed crystal 200 according to Embodiment 1 of the present invention. FIG. 7A shows the mixed crystal 100 manufactured by performing electrodeposition in step S204 for about 60 minutes. The film thickness of the mixed crystal 100 was about 1.9 μm. FIG. 7B shows a mixed crystal 200 manufactured by performing annealing for 10 minutes at 550 ° C. in step S208. The film thickness of the mixed crystal 200 was about 1.5 μm. By comparing the photographs shown in FIG. 7A and FIG. 7B, the size of the crystal lump (grain) increases in the mixed crystal 200, and the microcrystal contained in the mixed crystal 100 grows. It was confirmed that
　図８は、混合結晶２００のＸ線回折結果を示す。グラフ（ａ）は、５００℃のアニールを実行することによって製造された混合結晶２００のＸＲＤ結果を示す。グラフ（ｂ）は、５５０℃のアニールを実行することによって製造された混合結晶２００のＸＲＤ結果を示す。グラフ（ａ）とグラフ（ｂ）との結果から、混合結晶２００にはＣＺＴＳＳｅ結晶が成長していることが確認できた。 FIG. 8 shows the X-ray diffraction result of the mixed crystal 200. Graph (a) shows the XRD result of the mixed crystal 200 manufactured by performing annealing at 500 ° C. Graph (b) shows the XRD result of the mixed crystal 200 manufactured by performing the annealing at 550 ° C. From the results of the graph (a) and the graph (b), it was confirmed that the CZTSSe crystal was grown on the mixed crystal 200.
　図９は、混合結晶２００のラマンスペクトルを示す。グラフ（ａ）は、５００℃のアニールを実行することによって製造された混合結晶２００のラマンスペクトル結果を示す。グラフ（ｂ）は、５５０℃のアニールを実行することによって製造された混合結晶２００のラマンスペクトル結果を示す。グラフ（ａ）とグラフ（ｂ）とには、ＣＺＴＳＳｅ結晶によるメインラマンピークが表れている。混合結晶１００にはＣＺＴＳＳｅ結晶が含まれることが確認できた。 FIG. 9 shows the Raman spectrum of the mixed crystal 200. The graph (a) shows the Raman spectrum result of the mixed crystal 200 manufactured by performing annealing at 500 ° C. The graph (b) shows the Raman spectrum result of the mixed crystal 200 manufactured by performing annealing at 550 ° C. The graph (a) and the graph (b) show the main Raman peak due to the CZTSSe crystal. It was confirmed that the mixed crystal 100 contained CZTSSe crystals.
　図１０は、混合結晶２００を対象とした光電気化学測定の結果を示す。グラフ（ａ）は、５００℃のアニールを実行することによって製造された混合結晶２００を対象とした光電気化学測定の結果を示す。グラフ（ｂ）は、５５０℃のアニールを実行することによって製造された混合結晶２００を対象とした光電気化学測定の結果を示す。グラフ（ａ）とグラフ（ｂ）とに示した光電気化学測定結果から、得られた材料がｐ型の光応答を示すことが確認された。 FIG. 10 shows the result of photoelectrochemical measurement for the mixed crystal 200. The graph (a) shows the result of the photoelectrochemical measurement for the mixed crystal 200 manufactured by performing annealing at 500 ° C. The graph (b) shows the result of the photoelectrochemical measurement for the mixed crystal 200 manufactured by performing annealing at 550 ° C. From the photoelectrochemical measurement results shown in graphs (a) and (b), it was confirmed that the obtained material exhibited a p-type photoresponse.
　以上、図１～図１０を参照して本発明の実施形態１による混合結晶、混合結晶製造方法及び電析浴の実施形態を説明した。本発明は、ＣＺＴＳ（Ｓｅ）薄膜を真空プロセスや危険な溶剤を用いないで製造する技術を開示する。原料となるＣｕ、Ｚｎ、Ｓｎ、Ｓｅの各イオンを溶解させた電析浴から４つの成分を還元させＣＺＴＳ結晶を製造する。 The embodiment of the mixed crystal, the mixed crystal manufacturing method, and the electrodeposition bath according to Embodiment 1 of the present invention has been described above with reference to FIGS. The present invention discloses a technique for producing a CZTS (Se) thin film without using a vacuum process or a dangerous solvent. Four components are reduced from an electrodeposition bath in which Cu, Zn, Sn, and Se ions as raw materials are dissolved to produce a CZTS crystal.
　［実施形態２］
図１１～図１９を参照して本発明の実施形態２による混合結晶、混合結晶製造方法及び電析浴の実施形態を説明する。実施形態１においては、ＣＺＴＳ結晶を一つの混合液を用いて一段の電析によって形成した。一方、実施形態２においては、ＣＺＴＳ結晶を複数の電解液を用いて複数の段階の電析によって形成する。 [Embodiment 2]
The mixed crystal, mixed crystal manufacturing method, and electrodeposition bath according to the second embodiment of the present invention will be described with reference to FIGS. In Embodiment 1, CZTS crystals were formed by one-step electrodeposition using one mixed solution. On the other hand, in Embodiment 2, a CZTS crystal is formed by a plurality of stages of electrodeposition using a plurality of electrolytic solutions.
　［混合結晶］
図１１は、本発明の実施形態２による混合結晶５００を含む積層構造物Ｅを示す模式図である。積層構造物Ｅは、基板ａと基板ｂと混合結晶５００とを含む。基板ａは、例えば、ガラス基板である。基板ｂは例えばＭｏ層である。積層構造物Ｅが太陽電池に適用される場合には、基板ｂは裏面電極（Ｍｏ電極）として機能する。 [Mixed crystal]
FIG. 11 is a schematic diagram showing a laminated structure E including a mixed crystal 500 according to Embodiment 2 of the present invention. The laminated structure E includes a substrate a, a substrate b, and a mixed crystal 500. The substrate a is, for example, a glass substrate. The substrate b is, for example, a Mo layer. When the laminated structure E is applied to a solar cell, the substrate b functions as a back electrode (Mo electrode).
　混合結晶５００は、基板ｂの上に積層された第１混合結晶５１０と、第１混合結晶５１０の上に積層された第２混合結晶５２０とを含む。第１混合結晶５１０は、セレン（Ｓｅ）含有微結晶と硫黄（Ｓ）含有微結晶とのうちの少なくとも一方と、銅（Ｃｕ）含有微結晶と亜鉛（Ｚｎ）含有微結晶とスズ（Ｓｎ）含有微結晶とを含むＣＺＴＳ結晶である。第２混合結晶５２０は、セレン（Ｓｅ）含有微結晶と硫黄（Ｓ）含有微結晶とのうちの少なくとも一方と、銅（Ｃｕ）含有微結晶とスズ（Ｓｎ）含有微結晶とを含むＣＺＴＳ結晶である。図１１において、第１混合結晶５１０の厚さ及び第２混合結晶５２０の厚さは、例えば、３００ｎｍ～２μｍである。 The mixed crystal 500 includes a first mixed crystal 510 stacked on the substrate b and a second mixed crystal 520 stacked on the first mixed crystal 510. The first mixed crystal 510 includes at least one of selenium (Se) -containing microcrystals and sulfur (S) -containing microcrystals, copper (Cu) -containing microcrystals, zinc (Zn) -containing microcrystals, and tin (Sn). CZTS crystals containing contained microcrystals. Second mixed crystal 520 is a CZTS crystal containing at least one of selenium (Se) -containing microcrystals and sulfur (S) -containing microcrystals, copper (Cu) -containing microcrystals, and tin (Sn) -containing microcrystals. It is. In FIG. 11, the thickness of the first mixed crystal 510 and the thickness of the second mixed crystal 520 are, for example, 300 nm to 2 μm.
　[混合結晶製造方法]
図１２は、本発明の実施形態２による混合結晶５００の製造方法を示すフローチャートである。混合結晶５００は、ステップＳ７０２～ステップＳ７１２を実行することで製造される。混合結晶５００の製造では、電析プロセスが用いられる。電析プロセスによる化合物薄膜の形成は、電析浴に溶解させた化合物の構成元素イオンが電極表面において電気化学的に還元されることにより堆積する合金めっきを基本原理としている。混合結晶５００を製造するには、原料となるＣｕ、Ｚｎ、Ｓｎ、Ｓ（又はＳｅ）の各イオンを溶解させた電析浴から４つの成分を還元させ、更に原料となるＣｕ、Ｓｎ、Ｓ（又はＳｅ）の各イオンを溶解させた電析浴から３つの成分を還元させる。以下、図１２を参照してステップＳ７０２～ステップＳ７１２を説明する。 [Mixed crystal manufacturing method]
FIG. 12 is a flowchart showing a method for manufacturing the mixed crystal 500 according to the second embodiment of the present invention. The mixed crystal 500 is manufactured by executing Steps S702 to S712. In manufacturing the mixed crystal 500, an electrodeposition process is used. Formation of a compound thin film by an electrodeposition process is based on alloy plating which is deposited by electrochemically reducing constituent element ions of a compound dissolved in an electrodeposition bath on the electrode surface. In order to manufacture the mixed crystal 500, four components are reduced from an electrodeposition bath in which Cu, Zn, Sn, and S (or Se) ions as raw materials are dissolved, and Cu, Sn, and S as raw materials are further reduced. Three components are reduced from the electrodeposition bath in which each ion of (or Se) is dissolved. Hereinafter, steps S702 to S712 will be described with reference to FIG.
　ステップＳ７０２：セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含む第１混合液８０２を用意する（第１混合液用意工程）。図１２において、第１混合液８０２は電解槽ｃに入れられている。 Step S702: A first mixed solution 802 containing at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions is prepared (first mixed solution preparing step). In FIG. 12, the 1st liquid mixture 802 is put into the electrolytic vessel c.
　第１混合液８０２において、亜セレン酸イオン（ＳｅＯ3 2-）はＮａ2ＳｅＯ3（モル濃度５ｍＭ）から解離生成され、銅イオン（Ｃｕ2+）はＣｕＳＯ4・５Ｈ2Ｏ（モル濃度２．５ｍＭ）から解離生成され、亜鉛イオン（Ｚｎ2+）はＺｎＳＯ4（モル濃度８０ｍＭ）から解離生成され、スズイオン（Ｓｎ4+）はＳｎＣｌ4（モル濃度２０ｍＭ）から解離生成される。 In the first liquid mixture 802, selenite ions (SeO 3 2− ) are dissociated and produced from Na 2 SeO 3 (molar concentration 5 mM), and copper ions (Cu 2+ ) are CuSO 4 .5H 2 O (molar concentration 2). .5 mM), zinc ions (Zn 2+ ) are dissociated from ZnSO 4 (molar concentration 80 mM), and tin ions (Sn 4+ ) are dissociated from SnCl 4 (molar concentration 20 mM).
　ステップＳ７０４：第１混合液８０２に電圧を印加し、第１混合結晶５１０を電析する（第１電析工程）。カソード電極としてＭｏ電極ｂが積層した基板ａを用い、アノード電極３０４として白金電極を用いた。電極としては、工業的には安価で安定な炭素電極を、実験用には炭素の他に腐食されにくい白金や金などの貴金属電極を用い得る。Ｍｏ電極ａが積層した基板ａと白金電極とを第１混合液８０２が入った電解槽ｃに浸け、電源３０６によって電極間に電圧（－０．６Ｖ）を３０分間印加した。電源３０６は、ポテンショスタット（電位制御）機能及びガルバノスタット（電流制御）機能を有する外部電源である。 Step S704: A voltage is applied to the first mixed solution 802 to deposit the first mixed crystal 510 (first electrodeposition step). A substrate a on which a Mo electrode b was laminated was used as the cathode electrode, and a platinum electrode was used as the anode electrode 304. As an electrode, an industrially inexpensive and stable carbon electrode can be used, and a noble metal electrode such as platinum or gold which is not easily corroded in addition to carbon can be used for experiments. The substrate a on which the Mo electrode a was laminated and the platinum electrode were immersed in an electrolytic cell c containing the first mixed solution 802, and a voltage (−0.6 V) was applied between the electrodes by the power source 306 for 30 minutes. The power source 306 is an external power source having a potentiostat (potential control) function and a galvanostat (current control) function.
　第１混合液８０２は、第２混合液８０４よりも亜鉛イオンの含有割合が高い電解液を含む。第１電析工程の実行によって、セレン含有微結晶と硫黄含有微結晶とのうちの少なくとも一方と、銅含有微結晶と亜鉛含有微結晶とスズ含有微結晶とが基板ａに堆積される。 1st liquid mixture 802 contains the electrolyte solution whose zinc ion content rate is higher than the 2nd liquid mixture 804. By performing the first electrodeposition step, at least one of selenium-containing microcrystals and sulfur-containing microcrystals, copper-containing microcrystals, zinc-containing microcrystals, and tin-containing microcrystals are deposited on the substrate a.
　なお、印加電圧の大きさは、第１混合液８０２に含まれるイオンが還元される限りは特に限定されないが、例えば印加電圧は－０．５～－１．０Ｖであり得る。－０．５Ｖよりも負側である場合は還元しないイオンを少なくすることができ、－１．０Ｖよりも正側である場合は、水の還元に基づく水素ガス発生を抑制し得る。なお、印加電圧が－１．０Ｖよりも負側である場合は、印加電圧が大きいためイオンの還元速度を増すことが可能になり、効率よく第１混合結晶５１０を製造することができる。 The magnitude of the applied voltage is not particularly limited as long as the ions contained in the first mixed liquid 802 are reduced. For example, the applied voltage can be −0.5 to −1.0 V. When it is on the negative side of −0.5 V, the number of ions that are not reduced can be reduced, and when it is on the positive side of −1.0 V, the generation of hydrogen gas based on the reduction of water can be suppressed. When the applied voltage is on the negative side of −1.0 V, the applied voltage is large, so that the reduction rate of ions can be increased, and the first mixed crystal 510 can be manufactured efficiently.
　ステップＳ７０２とステップＳ７０４とを実行することで、第１混合結晶５１０を含んだ積層構造物Ｄを製造することができる（ステップＳ７０６）。 The laminated structure D including the first mixed crystal 510 can be manufactured by executing Step S702 and Step S704 (Step S706).
　ステップＳ７０８：セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンとスズイオンとを含む第２混合液８０４を用意する（第２混合液用意工程）。図１２において、第２混合液８０４は電解槽ｃ’に入れられている。 Step S708: A second mixed liquid 804 containing at least one of selenium ions and sulfur ions and copper ions and tin ions is prepared (second mixed liquid preparing step). In FIG. 12, the second mixed liquid 804 is placed in the electrolytic cell c ′.
　第２混合液８０４において、亜セレン酸イオン（ＳｅＯ3 2-）はＮａ2ＳｅＯ3（モル濃度７ｍＭ）から解離生成され、銅イオン（Ｃｕ2+）はＣｕＳＯ4・５Ｈ2Ｏ（モル濃度１ｍＭ）から解離生成され、スズイオン（Ｓｎ4+）はＳｎＣｌ4（モル濃度２０ｍＭ）から解離生成される。 In the second liquid mixture 804, selenite ion (SeO 3 2− ) is dissociated and produced from Na 2 SeO 3 (molar concentration 7 mM), and copper ion (Cu 2+ ) is CuSO 4 .5H 2 O (molar concentration 1 mM). ), And tin ions (Sn 4+ ) are dissociated from SnCl 4 (molar concentration 20 mM).
　ステップＳ７１０：第２混合液８０４に電圧を印加し、第２混合結晶５２０を電析する（第２電析工程）。カソード電極としてＭｏ電極ｂ及び第１混合結晶５１０が積層した基板ａを用い、アノード電極３０４として白金電極を用いた。電極としては、工業的には安価で安定な炭素電極を、実験用には炭素の他に腐食されにくい白金や金などの貴金属電極を用い得る。Ｍｏ電極ａが積層した基板ａと白金電極とを第２混合液８０４が入った電解槽ｃ’に浸け、電源３０６によって電極間に電圧（－０．６Ｖ）を２０分間印加した。電源３０６は、ポテンショスタット（電位制御）機能及びガルバノスタット（電流制御）機能を有する外部電源である。 Step S710: A voltage is applied to the second mixed solution 804 to deposit the second mixed crystal 520 (second electrodeposition step). The substrate a on which the Mo electrode b and the first mixed crystal 510 were laminated was used as the cathode electrode, and the platinum electrode was used as the anode electrode 304. As an electrode, an industrially inexpensive and stable carbon electrode can be used, and a noble metal electrode such as platinum or gold which is not easily corroded in addition to carbon can be used for experiments. The substrate a on which the Mo electrode a was laminated and the platinum electrode were immersed in an electrolytic cell c ′ containing the second mixed solution 804, and a voltage (−0.6 V) was applied between the electrodes by the power source 306 for 20 minutes. The power source 306 is an external power source having a potentiostat (potential control) function and a galvanostat (current control) function.
　第２混合液８０４は、第１混合液８０２よりも亜鉛イオンの含有割合が低い電解液を含む。第２電析工程の実行によって、セレン含有微結晶と硫黄含有微結晶とのうちの少なくとも一方と、銅含有微結晶とスズ含有微結晶とが基板ａに堆積する
　なお、印加電圧の大きさは、第２混合液８０４に含まれるイオンが還元される限りは特に限定されないが、例えば印加電圧は－０．５～－１．０Ｖであり得る。－０．５Ｖよりも負側である場合は還元しないイオンを少なくすることができ、－１．０Ｖよりも正側である場合は、水の還元に基づく水素ガス発生を抑制し得る。なお、印加電圧が－１．０Ｖよりも負側である場合は、印加電圧が大きいためイオンの還元速度を増すことが可能になり、効率よく第２混合結晶５２０を製造することができる。 The second mixed liquid 804 includes an electrolytic solution having a lower zinc ion content than the first mixed liquid 802. By execution of the second electrodeposition step, at least one of selenium-containing microcrystals and sulfur-containing microcrystals, copper-containing microcrystals, and tin-containing microcrystals are deposited on the substrate a. As long as ions contained in the second mixed liquid 804 are reduced, the applied voltage may be, for example, −0.5 to −1.0 V. When it is on the negative side of −0.5 V, it is possible to reduce the number of ions that are not reduced. When the applied voltage is more negative than −1.0 V, the applied voltage is large, so that the reduction rate of ions can be increased, and the second mixed crystal 520 can be manufactured efficiently.
　ステップＳ７０８とステップＳ７１０とを実行することで、第１混合結晶５１０及び第２混合結晶５２０を含んだ積層構造物Ｅを製造することができる（ステップＳ７１２）。 The laminated structure E including the first mixed crystal 510 and the second mixed crystal 520 can be manufactured by executing Step S708 and Step S710 (Step S712).
　以上、図１２を参照してステップＳ７０２～ステップＳ７１２を説明した。なお、第１混合液８０２及び第２混合液８０４に添加剤を混ぜることが好ましい。添加剤は、例えば酒石酸である。酒石酸は第１混合液８０２中及び第２混合液８０４中のＣｕ2+、Ｚｎ2+、Ｓｎ4+が水酸化物の沈殿となるのを防ぐ安定化材として機能する。銅イオンと亜鉛イオンとスズイオンとに酒石酸が配位した錯体を形成する。ステップＳ７０２において、第１混合液８０２は酒石酸（５００ｍＭ）を含み、ステップＳ７０８において、第２混合液８０４は酒石酸（５００ｍＭ）を含む。 The steps S702 to S712 have been described above with reference to FIG. Note that an additive is preferably mixed in the first mixed liquid 802 and the second mixed liquid 804. The additive is, for example, tartaric acid. Tartaric acid functions as a stabilizing material that prevents Cu 2+ , Zn 2+ , and Sn 4+ in the first mixed solution 802 and the second mixed solution 804 from becoming hydroxide precipitates. A complex in which tartaric acid is coordinated to copper ion, zinc ion and tin ion is formed. In step S702, the first mixed liquid 802 contains tartaric acid (500 mM), and in step S708, the second mixed liquid 804 contains tartaric acid (500 mM).
　なお、添加剤は、銅イオンと亜鉛イオンとスズイオンとが配位した錯体を形成し得る限りは、酒石酸に限定されない。添加剤は、例えば、乳酸、乳酸を含む化合物（乳酸ナトリウム、乳酸カリウム、乳酸アンモニウムなど）、酒石酸、酒石酸を含む化合物（酒石酸ナトリウム、酒石酸カリウムナトリウム、酒石酸アンモニウム、酒石酸水素ナトリウム、酒石酸水素カリウムなど）、クエン酸、クエン酸を含む化合物（クエン酸ナトリウム、クエン酸カリウム、クエン酸二水素カリウム、クエン酸二水素ナトリウム、クエン酸アンモニウムなど）、シュウ酸、シュウ酸を含む化合物（シュウ酸ナトリウム、シュウ酸カリウム、シュウ酸水素ナトリウム、シュウ酸水素カリウム、シュウ酸アンモニウムなど）、マロン酸、マロン酸を含む化合物（マロン酸ナトリウム、マロン酸カリウム、マロン酸アンモニウムなど）のうちの少なくとも１種であり得る。 The additive is not limited to tartaric acid as long as it can form a complex in which copper ions, zinc ions, and tin ions are coordinated. Additives include, for example, lactic acid, compounds containing lactic acid (sodium lactate, potassium lactate, ammonium lactate, etc.), tartaric acid, compounds containing tartaric acid (sodium tartrate, potassium sodium tartrate, ammonium tartrate, sodium hydrogen tartrate, potassium hydrogen tartrate, etc.) , Citric acid, compounds containing citric acid (sodium citrate, potassium citrate, potassium dihydrogen citrate, sodium dihydrogen citrate, ammonium citrate, etc.), oxalic acid, compounds containing oxalic acid (sodium oxalate, Potassium malate, sodium hydrogen oxalate, potassium hydrogen oxalate, ammonium oxalate, etc.), malonic acid, and at least one of compounds containing malonic acid (sodium malonate, potassium malonate, ammonium malonate, etc.) .
　さらに、第１混合液８０２において、セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含む混合液が生成される限りｐＨは特に問わないが、ｐＨが酸性であれば、第１混合液８０２に含まれるイオンの水酸化物化を抑制し得る。さらに、ステップＳ７０２において、第１混合液８０２はＮＨ3溶液（２８％）を含み、ｐＨは２．５～２．６である。なお、添加剤の添加によって、第１混合液８０２のｐＨを酸性に保持し得る（添加剤による緩衝効果）。 Further, in the first mixed liquid 802, the pH is not particularly limited as long as a mixed liquid containing at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions is generated, but the pH is acidic. If present, the hydroxide of ions contained in the first mixed liquid 802 can be suppressed. Further, in step S702, the first mixed liquid 802 includes an NH 3 solution (28%) and has a pH of 2.5 to 2.6. In addition, the pH of the 1st liquid mixture 802 can be hold | maintained acidic by addition of an additive (buffer effect by an additive).
　同様に、第２混合液８０４において、セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンとスズイオンとを含む混合液が生成される限りｐＨは特に問わないが、ｐＨが酸性であれば、第２混合液８０４に含まれるイオンの水酸化物化を抑制し得る。さらに、ステップＳ７０８において、第２混合液８０４はＮＨ3溶液（２８％）を含み、ｐＨは２．５～２．６である。なお、添加剤の添加によって、第２混合液８０４のｐＨを酸性に保持し得る（添加剤による緩衝効果）。 Similarly, in the second mixed liquid 804, the pH is not particularly limited as long as a mixed liquid containing at least one of selenium ions and sulfur ions and copper ions and tin ions is generated. , The ionization of ions contained in the second liquid mixture 804 can be suppressed. Further, in step S708, the second mixed liquid 804 includes an NH 3 solution (28%), and the pH is 2.5 to 2.6. In addition, the pH of the 2nd liquid mixture 804 can be hold | maintained acidic by addition of an additive (buffer effect by an additive).
　以上、図１１及び図１２を参照して、本発明の実施形態２による混合結晶及び混合結晶製造方法を説明した。混合結晶５００は、基板ｂの上に積層された第１混合結晶５１０と、第１混合結晶５１０の上に積層された第２混合結晶５２０とを含むが、第１混合結晶５１０と第２混合結晶５２０との積層関係は限定されない。 The mixed crystal and the mixed crystal manufacturing method according to the second embodiment of the present invention have been described above with reference to FIGS. 11 and 12. The mixed crystal 500 includes a first mixed crystal 510 stacked on the substrate b and a second mixed crystal 520 stacked on the first mixed crystal 510, and the first mixed crystal 510 and the second mixed crystal 520 are stacked. The stacking relationship with the crystal 520 is not limited.
　混合結晶５００は、基板ｂの上に積層された第２混合結晶５２０と、第２混合結晶５２０の上に積層された第１混合結晶５１０とを含み得る。製造方法については、次の工程を実行する。 The mixed crystal 500 may include a second mixed crystal 520 stacked on the substrate b and a first mixed crystal 510 stacked on the second mixed crystal 520. About a manufacturing method, the following process is performed.
　まず、第２混合液８０４に電圧を印加し、第２混合結晶５２０を電析する。カソード電極としてＭｏ電極ｂが積層した基板ａを用い、アノード電極３０４として白金電極を用いた。Ｍｏ電極ａが積層した基板ａと白金電極とを第２混合液８０４が入った電解槽ｃ’に浸け、電源３０６によって電極間に電圧を印加する。 First, a voltage is applied to the second mixed solution 804 to deposit the second mixed crystal 520. A substrate a on which a Mo electrode b was laminated was used as the cathode electrode, and a platinum electrode was used as the anode electrode 304. The substrate a on which the Mo electrode a is laminated and the platinum electrode are immersed in an electrolytic cell c ′ containing the second mixed solution 804, and a voltage is applied between the electrodes by the power source 306.
　次に第１混合液８０２に電圧を印加し、第１混合結晶５１０を電析する。カソード電極としてＭｏ電極ｂ及び第２混合結晶５２０が積層した基板ａを用い、アノード電極３０４として白金電極を用いた。Ｍｏ電極ａが積層した基板ａと白金電極とを第１混合液８０２が入った電解槽ｃに浸け、電源３０６によって電極間に電圧を印加する。 Next, a voltage is applied to the first mixed liquid 802 to deposit the first mixed crystal 510. A substrate a on which a Mo electrode b and a second mixed crystal 520 were laminated was used as the cathode electrode, and a platinum electrode was used as the anode electrode 304. The substrate a on which the Mo electrode a is laminated and the platinum electrode are immersed in an electrolytic cell c containing the first mixed liquid 802, and a voltage is applied between the electrodes by the power source 306.
　図１３は、本発明の実施形態２による混合結晶５００のラマンスペクトルを示す。図１３（ａ）は、第１混合結晶５１０のラマンスペクトルを示し、図１３（ｂ）は、第２混合結晶５２０のラマンスペクトルを示す。 FIG. 13 shows a Raman spectrum of the mixed crystal 500 according to Embodiment 2 of the present invention. 13A shows a Raman spectrum of the first mixed crystal 510, and FIG. 13B shows a Raman spectrum of the second mixed crystal 520.
　図１３に示されたメインラマンピークから、第１混合結晶５１０がＣｕ2ＺｎＳｎＳｅ4（ＣＺＴＳ）結晶を含み、第２混合結晶５２０が混合結晶Ｃｕ－Ｓｎ－ＳｅがＣｕ3ＳｎＳｅ3（ＣＴＳｅ）結晶を含むことを確認できた。 From the main Raman peak shown in FIG. 13, the first mixed crystal 510 includes a Cu 2 ZnSnSe 4 (CZTS) crystal, the second mixed crystal 520 includes a mixed crystal Cu—Sn—Se, and a Cu 3 SnSe 3 (CTSe) crystal. It was confirmed that it contains.
　図１４は、本発明の実施形態２による混合結晶５００を示す写真である。具体的には、図１４は、混合結晶５００の断面（図１４（ａ））と表面（図１４（ｂ））との走査型電子顕微鏡（ＳＥＭ）像を示す。図１４に示された写真から、第１混合結晶５１０上に第２混合結晶５２０が均一に堆積していることが理解できる。なお第１混合結晶５１０及び第２混合結晶５２０の膜厚はいずれも約１μｍであった。 FIG. 14 is a photograph showing a mixed crystal 500 according to Embodiment 2 of the present invention. Specifically, FIG. 14 shows a scanning electron microscope (SEM) image of the cross section (FIG. 14A) and the surface (FIG. 14B) of the mixed crystal 500. FIG. From the photograph shown in FIG. 14, it can be understood that the second mixed crystal 520 is uniformly deposited on the first mixed crystal 510. The film thicknesses of the first mixed crystal 510 and the second mixed crystal 520 were both about 1 μm.
　図１５は、本発明の実施形態２における混合結晶６００の製造方法を示すフローチャートである。混合結晶６００は、ステップＳ７１４～ステップＳ７１６を実行することで製造される。混合結晶６００の製造では、アニールプロセスが用いられる。 FIG. 15 is a flowchart showing a method for manufacturing the mixed crystal 600 according to the second embodiment of the present invention. The mixed crystal 600 is manufactured by executing Steps S714 to S716. In manufacturing the mixed crystal 600, an annealing process is used.
　ステップＳ７１４：ステップＳ７０２～ステップＳ７１２を実行することによって製造した積層構造物Ｅを準備する（準備工程）。積層構造物Ｅは、基板ａとＭｏ電極ｂと混合結晶５００とを含む。基板ａの上にはＭｏ電極ｂが積層し、Ｍｏ電極ｂの上には混合結晶５００が積層している。 Step S714: The laminated structure E manufactured by executing Steps S702 to S712 is prepared (preparation process). The laminated structure E includes a substrate a, a Mo electrode b, and a mixed crystal 500. A Mo electrode b is stacked on the substrate a, and a mixed crystal 500 is stacked on the Mo electrode b.
　ステップＳ７１６：混合結晶５００をアニールし、混合結晶６００を含んだ積層構造Ｆを製造する（アニール工程）。積層構造物Ｆは、基板ａとＭｏ電極ｂと混合結晶６００とを含む。基板ａの上にはＭｏ電極ｂが積層し、Ｍｏ電極ｂの上には混合結晶６００が積層している。ステップＳ７０２～ステップＳ７１２を実行することによって製造した混合結晶５００をアニールすることで、結晶性の高いＣＺＴＳ結晶（混合結晶６００）が得られた。ステップＳ７１６において、アニールは、Ａｒガス雰囲気中で４７５℃または５２５℃で５分間温度保持することによって、或いはＳｅ蒸気中で５７５℃、５分間温度保持することによって行った。 Step S716: The mixed crystal 500 is annealed to produce a laminated structure F including the mixed crystal 600 (annealing process). The laminated structure F includes a substrate a, a Mo electrode b, and a mixed crystal 600. A Mo electrode b is stacked on the substrate a, and a mixed crystal 600 is stacked on the Mo electrode b. By annealing the mixed crystal 500 manufactured by executing Steps S702 to S712, a CZTS crystal (mixed crystal 600) with high crystallinity was obtained. In step S716, annealing was performed by holding the temperature at 475 ° C. or 525 ° C. for 5 minutes in an Ar gas atmosphere, or by holding the temperature in Se vapor at 575 ° C. for 5 minutes.
　図１６は、本発明の実施形態２における混合結晶６００のＸ線回折結果を示す。図１７は、本発明の実施形態２における混合結晶６００のラマンスペクトルを示す。図１６及び図１７において、グラフ（ａ）は、Ａｒガス雰囲気中４７５℃で５分間温度保持のアニールを実行することによって製造された混合結晶６００の分析結果を示す。同様に、グラフ（ｂ）は、Ａｒガス雰囲気中５２５℃で５分間温度保持のアニールを実行することによって製造された混合結晶６００の分析結果を示し、グラフ（ｃ）は、Ｓｅ蒸気中５７５℃で５分間温度保持のアニールを実行することによって製造された混合結晶６００の分析結果を示す。 FIG. 16 shows an X-ray diffraction result of the mixed crystal 600 according to the second embodiment of the present invention. FIG. 17 shows the Raman spectrum of the mixed crystal 600 according to the second embodiment of the present invention. 16 and 17, graph (a) shows an analysis result of a mixed crystal 600 manufactured by performing annealing at 475 ° C. for 5 minutes in an Ar gas atmosphere. Similarly, the graph (b) shows the analysis result of the mixed crystal 600 manufactured by performing the temperature holding annealing at 525 ° C. for 5 minutes in the Ar gas atmosphere, and the graph (c) shows the analysis result of 575 ° C. in Se vapor. The analysis result of the mixed crystal 600 manufactured by performing annealing of temperature holding | maintenance for 5 minutes is shown.
　図１６と図１７とを参照して、グラフ（ａ）～グラフ（ｃ）の結果から、混合結晶６００にはＣＺＴＳ結晶を含むことを確認できた。 Referring to FIG. 16 and FIG. 17, it was confirmed from the results of graphs (a) to (c) that the mixed crystal 600 contains CZTS crystals.
　図１８は、本発明の実施形態２における混合結晶６００の組成分析結果を示す。図１６と図１７とを参照して説明したグラフ（ａ）～グラフ（ｃ）の各々に対応する試料の全てにおいて、銅の含有割合は化学量論組成よりも少なく、亜鉛の含有割合は化学量論よりも多い。これらの試料の組成は、太陽電池用のＣＺＴＳ結晶としては好適である。また、Ａｒガス雰囲気中でアニールすることで得られた混合結晶６００（ＣＺＴＳ結晶）では、ＳｎとＳｅの含量が少なくなっている。アニール中にＳｎとＳｅが揮発したためである。なお、Ｓｅ蒸気中でアニールすることで得られた混合結晶６００（ＣＺＴＳ結晶）では、ＳｎとＳｅの含量が比較的多くなっている。アニール中のＳｎやＳｅの揮発が抑制されたためと考えられる。図１８を参照して理解できるように、銅の含有割合（Ｃｕ／（Ｚｎ＋Ｓｎ））は０．８～０．９であり、亜鉛の含有割合（Ｚｎ/Ｓｎ）は１．０～２．０である。 FIG. 18 shows a composition analysis result of the mixed crystal 600 according to the second embodiment of the present invention. In all the samples corresponding to each of the graphs (a) to (c) described with reference to FIG. 16 and FIG. 17, the copper content is less than the stoichiometric composition, and the zinc content is More than quantity theory. The composition of these samples is suitable as a CZTS crystal for solar cells. Further, in the mixed crystal 600 (CZTS crystal) obtained by annealing in an Ar gas atmosphere, the contents of Sn and Se are low. This is because Sn and Se volatilized during the annealing. In the mixed crystal 600 (CZTS crystal) obtained by annealing in Se vapor, the contents of Sn and Se are relatively large. This is probably because the volatilization of Sn and Se during annealing was suppressed. As can be understood with reference to FIG. 18, the copper content (Cu / (Zn + Sn)) is 0.8 to 0.9, and the zinc content (Zn / Sn) is 1.0 to 2.0. It is.
　図１９は、本発明の実施形態２における混合結晶６００のＳＥＭ像を示す。図１９（ａ）は、Ａｒガス雰囲気中５２５℃で５分間温度保持のアニールを実行することによって製造された混合結晶６００のＳＥＭ像を示し、図１９（ｂ）は、Ｓｅ蒸気中５７５℃で５分間温度保持のアニールを実行することによって製造された混合結晶６００のＳＥＭ像を示す。Ｓｅ蒸気中でのアニールで得られた混合結晶６００（ＣＺＴＳ結晶）が比較的緻密な形状をしていることが理解できる。 FIG. 19 shows an SEM image of the mixed crystal 600 according to the second embodiment of the present invention. FIG. 19A shows an SEM image of a mixed crystal 600 manufactured by performing annealing at 525 ° C. for 5 minutes in an Ar gas atmosphere, and FIG. 19B shows an SEM image at 575 ° C. in Se vapor. 2 shows an SEM image of a mixed crystal 600 produced by performing a 5 minute temperature hold anneal. It can be understood that the mixed crystal 600 (CZTS crystal) obtained by annealing in Se vapor has a relatively dense shape.
　［実施形態３］
 [適用例：太陽電池及び太陽電池製造方法]
本発明は、様々な工業分野に適用可能である。以下、図２０を参照して、本発明の適用例（太陽電池及び太陽電池製造方法）を説明する。 [Embodiment 3]
[Application example: Solar cell and solar cell manufacturing method]
The present invention is applicable to various industrial fields. Hereinafter, with reference to FIG. 20, the application example (solar cell and solar cell manufacturing method) of the present invention will be described.
　混合結晶１００（または混合結晶２００）、ｎ型バッファ層及び透明電極を積層させた積層構造体から光起電力が得られることを確認した。図２０は、本発明の実施形態３による太陽電池４００の模式図を示す。以下、図２０を参照して本発明の実施形態３における太陽電池４００および太陽電池製造方法を説明する。 It was confirmed that photovoltaic power was obtained from a laminated structure in which the mixed crystal 100 (or the mixed crystal 200), the n-type buffer layer, and the transparent electrode were laminated. FIG. 20 shows a schematic diagram of a solar cell 400 according to Embodiment 3 of the present invention. Hereinafter, with reference to FIG. 20, the solar cell 400 and the solar cell manufacturing method in Embodiment 3 of this invention are demonstrated.
　太陽電池４００は、基板ａと裏面電極ｂと混合結晶１００（または混合結晶２００）とバッファ層４０２と透明電極層４０４とを含む。基板ａと裏面電極ｂと混合結晶１００（または混合結晶２００）とは、図１、図２、図６を参照して説明した構成や機能と同様のため、詳細な説明を省略する。 Solar cell 400 includes substrate a, back electrode b, mixed crystal 100 (or mixed crystal 200), buffer layer 402, and transparent electrode layer 404. The substrate a, the back electrode b, and the mixed crystal 100 (or the mixed crystal 200) are the same as the configurations and functions described with reference to FIGS. 1, 2, and 6, and thus detailed description thereof is omitted.
　バッファ層４０２は、混合結晶１００（又は混合結晶２００）を含んだ層（混合結晶層）の上に積層されたｎ型バッファ層である。透明電極４０４は、バッファ層４０２の上に積層されている。透明電極４０４は、例えば、酸化亜鉛系透明電極（ＡＺＯ電極）である。 The buffer layer 402 is an n-type buffer layer laminated on a layer (mixed crystal layer) including the mixed crystal 100 (or mixed crystal 200). The transparent electrode 404 is stacked on the buffer layer 402. The transparent electrode 404 is, for example, a zinc oxide based transparent electrode (AZO electrode).
　太陽電池４００は、基板ａの上に基板ｂ（Ｍｏ電極）、混合結晶１００（混合結晶２００）、バッファ層４０２及び透明電極４０４を順次積層することにより、製造することができる。 Solar cell 400 can be manufactured by sequentially laminating substrate b (Mo electrode), mixed crystal 100 (mixed crystal 200), buffer layer 402, and transparent electrode 404 on substrate a.
　なお、太陽電池４００は、基板ａと裏面電極ｂと実施形態２による混合結晶５００（混合結晶６００）とバッファ層４０２と透明電極層４０４とを含み得る。この場合、太陽電池４００は、基板ａの上に基板ｂ（Ｍｏ電極）、混合結晶５００（混合結晶６００）、バッファ層４０２及び透明電極４０４を順次積層することにより、製造し得る。 The solar cell 400 can include the substrate a, the back electrode b, the mixed crystal 500 (mixed crystal 600) according to the second embodiment, the buffer layer 402, and the transparent electrode layer 404. In this case, the solar cell 400 can be manufactured by sequentially laminating the substrate b (Mo electrode), the mixed crystal 500 (mixed crystal 600), the buffer layer 402, and the transparent electrode 404 on the substrate a.
　図２１は、本発明の実施形態３による太陽電池（混合結晶６００を含む）の特性の測定結果を示す。図２１において、グラフ（ａ）は、Ａｒガス雰囲気中４７５℃で５分間温度保持のアニールを実行することによって製造された混合結晶６００を含む太陽電池の特性の測定結果を示す。同様に、グラフ（ｂ）は、Ａｒガス雰囲気中５２５℃で５分間温度保持のアニールを実行することによって製造された混合結晶６００を含む太陽電池の特性の測定結果を示し、グラフ（ｃ）は、Ｓｅ蒸気中５７５℃で５分間温度保持のアニールを実行することによって製造された混合結晶６００を含む太陽電池の特性の測定結果を示す。 FIG. 21 shows the measurement results of the characteristics of the solar cell (including the mixed crystal 600) according to Embodiment 3 of the present invention. In FIG. 21, the graph (a) shows the measurement results of the characteristics of the solar cell including the mixed crystal 600 manufactured by performing annealing at 475 ° C. for 5 minutes in an Ar gas atmosphere. Similarly, the graph (b) shows the measurement result of the characteristics of the solar cell including the mixed crystal 600 manufactured by performing the temperature holding annealing at 525 ° C. for 5 minutes in the Ar gas atmosphere, and the graph (c) The measurement result of the characteristic of the solar cell containing the mixed crystal 600 manufactured by performing annealing of temperature holding for 5 minutes at 575 degreeC in Se vapor | steam is shown.
　混合結晶６００を含む太陽電池は、混合結晶６００（ＣＺＴＳ結晶）を含む薄膜上にｎ型バッファ層であるＣｄＳを化学析出法によって約７０ｎｍ堆積させたあと、さらに高抵抗ＺｎＯ相をスパッタリングによって約５０ｎｍ堆積させて、その上にＡｌドープＺｎＯ透明電極をスパッタリングによって約５０ｎｍ堆積させることによって製造した。 In the solar cell including the mixed crystal 600, CdS which is an n-type buffer layer is deposited on the thin film including the mixed crystal 600 (CZTS crystal) by about 70 nm by a chemical deposition method, and then a high resistance ZnO phase is further sputtered by about 50 nm. It was prepared by depositing and depositing an Al-doped ZnO transparent electrode thereon by sputtering to about 50 nm.
　グラフ（ａ）～グラフ（ｃ）を参照して理解できるように、いずれの素子においても光起電力が得られることが確認された。グラフ（ｃ）によって示された混合結晶６００（ＣＺＴＳ結晶）を含む太陽電池が比較的良好な太陽電池特性を示した。上述のとおり、Ｓｅ蒸気中でアニールした混合結晶６００（ＣＺＴＳ結晶）のほうが緻密な構造をしているためと思われる。アニール条件によるこのような大きな特性の違いは、アニール条件を最適化することで、さらに特性が改善されることを示唆している。 As can be understood with reference to graphs (a) to (c), it was confirmed that photovoltaic power was obtained in any of the elements. The solar cell including the mixed crystal 600 (CZTS crystal) shown by the graph (c) showed relatively good solar cell characteristics. As described above, it seems that the mixed crystal 600 (CZTS crystal) annealed in Se vapor has a dense structure. Such a large difference in characteristics depending on the annealing conditions suggests that the characteristics can be further improved by optimizing the annealing conditions.
　以上、図１～図２１を参照して、本発明の実施形態による混合結晶、混合結晶製造方法、太陽電池、太陽電池製造方法及び電析浴を説明した。 The mixed crystal, mixed crystal manufacturing method, solar cell, solar cell manufacturing method, and electrodeposition bath according to the embodiment of the present invention have been described above with reference to FIGS.
　本発明によれば、異種成分を同時に電析することによって製造される混合結晶、混合結晶製造方法、太陽電池、太陽電池製造方法及び電析浴を提供することができ、様々な工業分野に利用可能である。 ADVANTAGE OF THE INVENTION According to this invention, the mixed crystal manufactured by electrodepositing different components simultaneously, a mixed crystal manufacturing method, a solar cell, a solar cell manufacturing method, and an electrodeposition bath can be provided, and it utilizes for various industrial fields. Is possible.
１００　　混合結晶
２００　　混合結晶
５００　　混合結晶
６００　　混合結晶
Ａ　　　　積層構造物
Ｂ　　　　積層構造物
Ｃ　　　　積層構造物
Ｄ　　　　積層構造物
Ｅ　　　　積層構造物
Ｆ　　　　積層構造物
ａ　　　　基板
ｂ　　　　基板
５１０　　第１混合結晶
５２０　　第２混合結晶
８０２　　第１混合液
８０４　　第２混合液 100 Mixed Crystal 200 Mixed Crystal 500 Mixed Crystal 600 Mixed Crystal A Laminated Structure B Laminated Structure C Laminated Structure D Laminated Structure E Laminated Structure F Laminated Structure a Substrate b Substrate 510 First Mixed Crystal 520 Second Mixed Crystal 802 First mixed liquid 804 Second mixed liquid

Claims (25)

  1. 　混合結晶の製造方法であって、
    　前記混合結晶は、セレン含有微結晶と硫黄含有微結晶とのうちの少なくとも一方と、銅含有微結晶と亜鉛含有微結晶とスズ含有微結晶とを含み、
    　混合結晶製造方法は、
    　セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含む混合液を用意する混合液用意工程と、
    　前記混合液に電圧を印加し、前記混合結晶を電析する電析工程と
    　を包含する、混合結晶製造方法。     A method for producing a mixed crystal comprising:
    The mixed crystal includes at least one of a selenium-containing microcrystal and a sulfur-containing microcrystal, a copper-containing microcrystal, a zinc-containing microcrystal, and a tin-containing microcrystal,
    The mixed crystal manufacturing method is:
    A mixed solution preparing step of preparing a mixed solution containing at least one of selenium ions and sulfur ions, and copper ions, zinc ions and tin ions;
    A mixed crystal manufacturing method comprising: an electrodeposition step of applying a voltage to the mixed solution to deposit the mixed crystal.
  2. 　前記電析工程の実行によって、前記セレン含有微結晶と前記硫黄含有微結晶とのうちの前記少なくとも一方と、前記銅含有微結晶と前記亜鉛含有微結晶と前記スズ含有微結晶とが基板に堆積する、請求項１に記載の混合結晶製造方法。 By performing the electrodeposition step, at least one of the selenium-containing microcrystals and the sulfur-containing microcrystals, the copper-containing microcrystals, the zinc-containing microcrystals, and the tin-containing microcrystals are deposited on the substrate. The mixed crystal manufacturing method according to claim 1.
  3. 　前記混合液は、第１混合液と第２混合液とを含み、
    　前記混合結晶は、第１混合結晶と第２混合結晶とを含み、
    　前記電析工程は、
    　前記第１混合液に電圧を印加し、前記第１混合結晶を電析する第１電析工程と、
    　前記第２混合液に電圧を印加し、前記第２混合結晶を電析する第２電析工程とを包含する、請求項１又は請求項２に記載の混合結晶製造方法。     The liquid mixture includes a first liquid mixture and a second liquid mixture,
    The mixed crystal includes a first mixed crystal and a second mixed crystal,
    The electrodeposition process includes:
    Applying a voltage to the first mixed solution to deposit the first mixed crystal;
    The mixed crystal manufacturing method according to claim 1, further comprising: a second electrodeposition step of applying a voltage to the second mixed solution to deposit the second mixed crystal.
  4. 　前記第１混合液は、前記第２混合液よりも亜鉛イオンの含有割合が高い電解液を含み、
    　前記第２混合液は、前記第１混合液よりも亜鉛イオンの含有割合が低い電解液を含む、請求項３に記載の混合結晶製造方法。     The first mixed solution includes an electrolytic solution having a higher zinc ion content than the second mixed solution,
    The mixed crystal manufacturing method according to claim 3, wherein the second mixed solution includes an electrolytic solution having a zinc ion content lower than that of the first mixed solution.
  5. 　前記第１混合液は、セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含み、
    　前記第２混合液は、セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンとスズイオンとを含み、
    　前記第１混合結晶は、前記セレン含有微結晶と前記硫黄含有微結晶とのうちの前記少なくとも一方と、前記銅含有微結晶と前記亜鉛含有微結晶と前記スズ含有微結晶とを含み、
    　前記第２混合結晶は、前記セレン含有微結晶と前記硫黄含有微結晶とのうちの前記少なくとも一方と、前記銅含有微結晶と前記スズ含有微結晶とを含む、請求項４に記載の混合結晶製造方法。     The first mixed solution includes at least one of selenium ions and sulfur ions, copper ions, zinc ions, and tin ions,
    The second mixed liquid contains at least one of selenium ions and sulfur ions, copper ions and tin ions,
    The first mixed crystal includes the at least one of the selenium-containing microcrystal and the sulfur-containing microcrystal, the copper-containing microcrystal, the zinc-containing microcrystal, and the tin-containing microcrystal,
    5. The mixed crystal according to claim 4, wherein the second mixed crystal includes the at least one of the selenium-containing microcrystal and the sulfur-containing microcrystal, the copper-containing microcrystal, and the tin-containing microcrystal. Production method.
  6. 　前記電析工程は、
    　前記第１電析工程と前記第２電析工程とのうちの一方を実行し、
    　前記一方の実行の後、前記第１電析工程と前記第２電析工程とのうちの他方を実行し、
    　前記第１電析工程の実行によって、前記セレン含有微結晶と前記硫黄含有微結晶とのうちの前記少なくとも一方と、前記銅含有微結晶と前記亜鉛含有微結晶と前記スズ含有微結晶とが前記基板に堆積し、
    　前記第２電析工程の実行によって、前記セレン含有微結晶と前記硫黄含有微結晶とのうちの前記少なくとも一方と、前記銅含有微結晶と前記スズ含有微結晶とが前記基板に堆積する、請求項３から請求項５のうちの１項に記載の混合結晶製造方法。     The electrodeposition process includes:
    Performing one of the first electrodeposition step and the second electrodeposition step;
    After the one execution, execute the other of the first electrodeposition step and the second electrodeposition step,
    By performing the first electrodeposition step, the at least one of the selenium-containing microcrystals and the sulfur-containing microcrystals, the copper-containing microcrystals, the zinc-containing microcrystals, and the tin-containing microcrystals are Deposited on the substrate,
    The execution of the second electrodeposition step deposits the at least one of the selenium-containing microcrystals and the sulfur-containing microcrystals, the copper-containing microcrystals, and the tin-containing microcrystals on the substrate. The mixed crystal production method according to claim 3, wherein the mixed crystal is produced.
  7. 　前記第１混合結晶の組成において、銅の含有割合は化学量論組成よりも少なく、亜鉛の含有割合は化学量論よりも多い、請求項５又は請求項６に記載の混合結晶製造方法。 The mixed crystal manufacturing method according to claim 5 or 6, wherein in the composition of the first mixed crystal, the content ratio of copper is smaller than the stoichiometric composition, and the content ratio of zinc is larger than the stoichiometric amount.
  8. 　銅の含有割合（Ｃｕ／（Ｚｎ＋Ｓｎ））は０．８～０．９であり、亜鉛の含有割合（Ｚｎ/Ｓｎ）は１．０～２．０である、請求項７に記載の混合結晶製造方法。 The mixed crystal according to claim 7, wherein the copper content (Cu / (Zn + Sn)) is 0.8 to 0.9, and the zinc content (Zn / Sn) is 1.0 to 2.0. Production method.
  9. 　前記混合液は、添加剤を含み、
    　前記混合液用意工程は、
    　前記銅イオンと前記亜鉛イオンと前記スズイオンとに前記添加剤が配位した錯体を形成する錯体形成工程を包含する、請求項１から請求項８のうちの１項に記載の混合結晶製造方法。     The mixed solution includes an additive,
    The mixed liquid preparation step includes
    The mixed crystal manufacturing method according to claim 1, comprising a complex forming step of forming a complex in which the additive is coordinated to the copper ion, the zinc ion, and the tin ion.
  10. 　前記添加剤は、乳酸、乳酸ナトリウム、乳酸カリウム、乳酸アンモニウム、酒石酸、酒石酸ナトリウム、酒石酸カリウムナトリウム、酒石酸アンモニウム、酒石酸水素ナトリウム、酒石酸水素カリウム、クエン酸、クエン酸ナトリウム、クエン酸カリウム、クエン酸二水素カリウム、クエン酸二水素ナトリウム、クエン酸アンモニウム、シュウ酸、シュウ酸ナトリウム、シュウ酸カリウム、シュウ酸水素ナトリウム、シュウ酸水素カリウム、シュウ酸アンモニウム、マロン酸、マロン酸ナトリウム、マロン酸カリウム、マロン酸アンモニウムのうちの少なくとも１種を含む、請求項９に記載の混合結晶製造方法。 The additives include lactic acid, sodium lactate, potassium lactate, ammonium lactate, tartaric acid, sodium tartrate, potassium sodium tartrate, ammonium tartrate, sodium hydrogen tartrate, potassium hydrogen tartrate, citric acid, sodium citrate, potassium citrate, dicitrate Potassium hydrogen, sodium dihydrogen citrate, ammonium citrate, oxalic acid, sodium oxalate, potassium oxalate, sodium hydrogen oxalate, potassium hydrogen oxalate, ammonium oxalate, malonic acid, sodium malonate, potassium malonate, malon The mixed crystal manufacturing method according to claim 9, comprising at least one of ammonium acid.
  11. 　前記混合液は酸性である、請求項１から請求項１０のうちの１項に記載の混合結晶製造方法。 The mixed crystal manufacturing method according to claim 1, wherein the mixed solution is acidic.
  12. 　前記混合結晶をアニールするアニール工程を更に包含する、請求項１から請求項１１のうちの１項に記載の混合結晶製造方法。 The mixed crystal manufacturing method according to claim 1, further comprising an annealing step of annealing the mixed crystal.
  13. 　前記アニール工程の実行によって、Ｃｕ2ＺｎＳｎＳｅ4を含むＰ型光応答性結晶を製造する、請求項１２に記載の混合結晶製造方法。 The mixed crystal manufacturing method according to claim 12, wherein a P-type photoresponsive crystal containing Cu 2 ZnSnSe 4 is manufactured by performing the annealing step.
  14. 　セレン含有微結晶と硫黄含有微結晶とのうちの少なくとも一方と、銅含有微結晶と亜鉛含有微結晶とスズ含有微結晶とを含んだ混合結晶を用意する混合結晶用意工程と、
    　前記混合結晶を含む混合結晶層の上にバッファ層を積層するバッファ層積層工程と、
    　前記バッファ層の上に透明電極を積層する透明電極積層工程と
    　を包含した、太陽電池製造方法。     A mixed crystal preparation step of preparing a mixed crystal containing at least one of a selenium-containing microcrystal and a sulfur-containing microcrystal, a copper-containing microcrystal, a zinc-containing microcrystal, and a tin-containing microcrystal;
    A buffer layer laminating step of laminating a buffer layer on the mixed crystal layer containing the mixed crystal;
    And a transparent electrode stacking step of stacking a transparent electrode on the buffer layer.
  15. 　前記混合結晶用意工程は、
    　セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含む混合液を用意する混合液用意工程と、
    　前記混合液に電圧を印加し、前記混合結晶を電析する電析工程と
    　を包含した、請求項１４に記載の太陽電池製造方法。     The mixed crystal preparation step includes
    A mixed solution preparing step of preparing a mixed solution containing at least one of selenium ions and sulfur ions, and copper ions, zinc ions and tin ions;
    The method for manufacturing a solar cell according to claim 14, further comprising: an electrodeposition step of applying a voltage to the mixed solution to deposit the mixed crystal.
  16. 　前記混合液は、添加剤を含み、
    　前記混合液用意工程は、
    　前記銅イオンと前記亜鉛イオンと前記スズイオンとに前記添加剤が配位した錯体を形成する錯体形成工程を包含する、請求項１５に記載の太陽電池製造方法。     The mixed solution includes an additive,
    The mixed liquid preparation step includes
    The solar cell manufacturing method according to claim 15, comprising a complex forming step of forming a complex in which the additive is coordinated to the copper ion, the zinc ion, and the tin ion.
  17. 　前記混合液は酸性である、請求項１４から請求項１６のうちの１項に記載の太陽電池製造方法。 The method for manufacturing a solar cell according to claim 14, wherein the mixed solution is acidic.
  18. 　前記混合結晶をアニールするアニール工程を更に包含する、請求項１４から請求項１７のうちの１項に記載の太陽電池製造方法。 The solar cell manufacturing method according to any one of claims 14 to 17, further comprising an annealing step of annealing the mixed crystal.
  19. 　前記混合液用意工程は、請求項１から請求項１２のうちの１項に記載の混合結晶製造方法を包含する、請求項１４から請求項１８のうちの１項に記載の太陽電池製造方法。 The solar cell manufacturing method according to claim 14, wherein the mixed solution preparing step includes the mixed crystal manufacturing method according to claim 1.
  20. 　セレン含有微結晶と硫黄含有微結晶とのうちの少なくとも一方と、銅含有微結晶と亜鉛含有微結晶とスズ含有微結晶とを含む、混合結晶。 A mixed crystal comprising at least one of selenium-containing microcrystals and sulfur-containing microcrystals, copper-containing microcrystals, zinc-containing microcrystals, and tin-containing microcrystals.
  21. 　セレン含有微結晶と硫黄含有微結晶とのうちの少なくとも一方と、銅含有微結晶と亜鉛含有微結晶とスズ含有微結晶とを含んだ混合結晶層と、
    　前記混合結晶層の上に積層されたバッファ層と、
    　前記バッファ層の上に積層された透明電極と
    　を備えた、太陽電池。     A mixed crystal layer containing at least one of selenium-containing microcrystals and sulfur-containing microcrystals, copper-containing microcrystals, zinc-containing microcrystals, and tin-containing microcrystals,
    A buffer layer stacked on the mixed crystal layer;
    A solar cell comprising: a transparent electrode laminated on the buffer layer.
  22. 　前記混合結晶層は、請求項１から請求項１３のうちの１項に記載の混合結晶製造方法によって製造された混合結晶を含む、請求項２１に記載の太陽電池。 The solar cell according to claim 21, wherein the mixed crystal layer includes a mixed crystal manufactured by the mixed crystal manufacturing method according to one of claims 1 to 13.
  23. 　セレンイオンと硫黄イオンとのうちの少なくとも一方と、銅イオンと亜鉛イオンとスズイオンとを含む、電析浴。 An electrodeposition bath containing at least one of selenium ions and sulfur ions, and copper ions, zinc ions and tin ions.
  24. 　添加剤を更に含み、
    　前記銅イオンと前記亜鉛イオンと前記スズイオンとに前記添加剤が配位した錯体を含む、請求項２３に記載の電析浴。     Further comprising an additive,
    The electrodeposition bath according to claim 23, comprising a complex in which the additive is coordinated to the copper ion, the zinc ion, and the tin ion.
  25. 　前記添加剤は、乳酸、乳酸ナトリウム、乳酸カリウム、乳酸アンモニウム、酒石酸、酒石酸ナトリウム、酒石酸カリウムナトリウム、酒石酸アンモニウム、酒石酸水素ナトリウム、酒石酸水素カリウム、クエン酸、クエン酸ナトリウム、クエン酸カリウム、クエン酸二水素カリウム、クエン酸二水素ナトリウム、クエン酸アンモニウム、シュウ酸、シュウ酸ナトリウム、シュウ酸カリウム、シュウ酸水素ナトリウム、シュウ酸水素カリウム、シュウ酸アンモニウム、マロン酸、マロン酸ナトリウム、マロン酸カリウム、マロン酸アンモニウムのうちの少なくとも１種を含む、請求項２３又は請求項２４に記載の電析浴。 The additives include lactic acid, sodium lactate, potassium lactate, ammonium lactate, tartaric acid, sodium tartrate, potassium sodium tartrate, ammonium tartrate, sodium hydrogen tartrate, potassium hydrogen tartrate, citric acid, sodium citrate, potassium citrate, dicitrate Potassium hydrogen, sodium dihydrogen citrate, ammonium citrate, oxalic acid, sodium oxalate, potassium oxalate, sodium hydrogen oxalate, potassium hydrogen oxalate, ammonium oxalate, malonic acid, sodium malonate, potassium malonate, malon The electrodeposition bath according to claim 23 or 24, comprising at least one of ammonium acid salts.
PCT/JP2013/055169 2012-02-29 2013-02-27 Mixed crystal, method for manufacturing mixed crystal, solar cell, method for manufacturing solar cell, and electrocrystallization bath WO2013129484A1 (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63206494A (en) * 1987-02-20 1988-08-25 Yutaka Fujiwara Bright copper-zinc-tin alloy electroplating bath containing no cyanide compound
JP2009537997A (en) * 2006-05-24 2009-10-29 アトーテヒ ドイッチュラント ゲゼルシャフト ミット ベシュレンクテル ハフツング Metal plating composition and method for copper-zinc-tin deposition suitable for manufacturing thin film solar cells

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63206494A (en) * 1987-02-20 1988-08-25 Yutaka Fujiwara Bright copper-zinc-tin alloy electroplating bath containing no cyanide compound
JP2009537997A (en) * 2006-05-24 2009-10-29 アトーテヒ ドイッチュラント ゲゼルシャフト ミット ベシュレンクテル ハフツング Metal plating composition and method for copper-zinc-tin deposition suitable for manufacturing thin film solar cells

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