US-12628458-B2 - Method for manufacturing stacked thin film, method for manufacturing solar cell, multi-junction solar cell, solar cell module, and photovoltaic power generation system

US12628458B2US 12628458 B2US12628458 B2US 12628458B2US-12628458-B2

Abstract

A method for manufacturing a stacked thin film of an embodiment includes forming a p-electrode on a substrate, forming a film that mainly contains a cuprous oxide and/or a complex oxide of cuprous oxides on the p-electrode, and performing an oxidation treatment on the film that mainly contains the cuprous oxide and/or the complex oxide of cuprous oxides. An ozone partial pressure in the oxidation treatment is 5 [Pa] or more and 200 [Pa] or less, a treatment temperature in the oxidation treatment is 273 [K] or more and 323 [K] or less, and a treatment time in the oxidation treatment is 1 second or more and 60 minutes or less.

Inventors

Yuya Honishi
Soichiro Shibasaki
Naoyuki Nakagawa
Yukitami Mizuno
Mutsuki Yamazaki
Yasutaka Nishida
Kazushige Yamamoto
Taro Asakura

Assignees

KABUSHIKI KAISHA TOSHIBA
Toshiba Energy Systems & Solutions Corporation

Dates

Publication Date: 20260512
Application Date: 20220824
Priority Date: 20210324

Claims (18)

1 . A method for manufacturing a stacked thin film, comprising: forming a p-electrode on a substrate; forming a film that mainly contains a cuprous oxide and/or a complex oxide of cuprous oxides on the p-electrode; and performing an oxidation treatment on the film that mainly contains the cuprous oxide and/or the complex oxide of cuprous oxides, wherein an ozone partial pressure in the oxidation treatment is from 5 [Pa] to 200 [Pa] where both the lower and upper endpoints of the ozone partial pressure range are inclusive, a treatment temperature in the oxidation treatment is from 273 [K] to 323 [K] where both the lower and upper endpoint of the treatment temperature range are inclusive, and a treatment time in the oxidation treatment is from 1 second to 60 minutes where both the lower and upper endpoints of the treatment time range are inclusive.
2 . The method for manufacturing the stacked thin film according to claim 1 , wherein the ozone partial pressure in the oxidation treatment is from 7 [Pa] to 100 [Pa] where both the lower and upper endpoints of the ozone partial pressure range are inclusive, the treatment temperature in the oxidation treatment is from 283 [K] to 308 [K] where both the lower and upper endpoint of the treatment temperature range are inclusive, and the treatment time in the oxidation treatment is from 1 minute to 30 minutes where both the lower and upper endpoints of the treatment time range are inclusive.
3 . The method for manufacturing the stacked thin film according to claim 1 , wherein the ozone partial pressure in the oxidation treatment is from 10 [Pa] to 50 [Pa] where both the lower and upper endpoints of the ozone partial pressure range are inclusive, the treatment temperature in the oxidation treatment is from 283 [K] to 308 [K] where both the lower and upper endpoint of the treatment temperature range are inclusive, and the treatment time in the oxidation treatment is from 1 minute to 10 minutes where both the lower and upper endpoints of the treatment time range are inclusive.
4 . The method for manufacturing the stacked thin film according to claim 1 , wherein, when the ozone partial pressure in the oxidation treatment is P [Pa], the treatment temperature in the oxidation treatment is Temp [K], and the treatment time in the oxidation treatment is Time [minutes], a relationship of 1.0≤240*(1−exp(−0.01*P))*exp(−4175/8.31/Temp)*(1−exp(−2*Time))≤50.0 is satisfied.
5 . The method for manufacturing the stacked thin film according to claim 1 , wherein a total pressure in the oxidation treatment is from 5 [Pa] to 10000 [Pa] where both the lower and upper endpoints of the total pressure range are inclusive.
6 . The method for manufacturing the stacked thin film according to claim 1 , wherein, when the ozone partial pressure in the oxidation treatment is P [Pa], the treatment temperature in the oxidation treatment is Temp [K], and the treatment time in the oxidation treatment is Time [minutes], a relationship of 3.0≤240*(1−exp(−0.01*P))*exp(−4175/8.31/Temp)*(1−exp(−2*Time))≤35.0 is satisfied.
7 . The method for manufacturing the stacked thin film according to claim 1 , wherein, in the oxidation treatment, a surface of the cuprous oxide and/or the complex oxide of cuprous oxides is irradiated with ultraviolet rays with a wavelength from 100 nm to 400 nm where both the lower and upper endpoints of the wavelength range are inclusive, and irradiation intensity of the ultraviolet rays is from 0.5 μW/cm 2 to 800 μW/cm 2 where both the lower and upper endpoints of the range of the irradiation intensity of the ultraviolet rays are inclusive.
8 . The method for manufacturing the stacked thin film according to claim 1 , wherein, in the oxidation treatment, a surface of the cuprous oxide and/or the complex oxide of cuprous oxides is irradiated with ultraviolet rays with a wavelength from 100 nm to 400 nm where both the lower and upper endpoints of the wavelength range are inclusive, irradiation intensity of the ultraviolet rays is from 0.5 μW/cm 2 to 800 μW/cm 2 where both the lower and upper endpoints of the range of the irradiation intensity of the ultraviolet rays are inclusive, and when the oxygen partial pressure in the oxidation treatment is P [Pa], the treatment temperature in the oxidation treatment is Temp [K], and the treatment time in the oxidation treatment is Time [minutes], a relationship of 1.0≤240*(1−exp(−0.01*P))*exp(−4175/8.31/Temp)*(1−exp(−2*Time))≤50.0 is satisfied.
9 . The method for manufacturing the stacked thin film according to claim 1 , wherein, in the oxidation treatment, a surface of the cuprous oxide and/or the complex oxide of cuprous oxides is irradiated with ultraviolet rays with a wavelength from 100 nm to 400 nm where both the lower and upper endpoints of the wavelength range are inclusive, irradiation intensity of the ultraviolet rays is from 0.5 μW/cm 2 to 800 μW/cm 2 where both the lower and upper endpoints of the range of the irradiation intensity of the ultraviolet rays are inclusive, and when the oxygen partial pressure in the oxidation treatment is P [Pa], the treatment temperature in the oxidation treatment is Temp [K], and the treatment time in the oxidation treatment is Time [minutes], a relationship of 3.0≤240*(1−exp(−0.01*P))*exp(−4175/8.31/Temp)*(1−exp(−2*Time))≤35.0 is satisfied.
10 . The method for manufacturing the stacked thin film according to claim 1 , wherein, in the oxidation treatment, a surface of the cuprous oxide and/or the complex oxide of cuprous oxides is irradiated with ultraviolet rays with a wavelength from 100 nm to 400 nm where both the lower and upper endpoints of the wavelength range are inclusive, irradiation intensity of the ultraviolet rays is from 0.5 μW/cm 2 to 800 μW/cm 2 where both the lower and upper endpoints of the range of the irradiation intensity of the ultraviolet rays are inclusive, and when the oxygen partial pressure in the oxidation treatment is P [Pa], the treatment temperature in the oxidation treatment is Temp [K], and the treatment time in the oxidation treatment is Time [minutes], a relationship of 5.0≤240*(1−exp(−0.01*P))*exp(−4175/8.31/Temp)*(1−exp(−2*Time))≤20.0 is satisfied.
11 . The method for manufacturing the stacked thin film according to claim 1 , wherein irradiation intensity of the ultraviolet rays is from 10 μW/cm 2 to 800 μW/cm 2 where both the lower and upper endpoints of the range of the irradiation intensity of the ultraviolet rays are inclusive.
12 . The method for manufacturing the stacked thin film according to claim 1 , further comprising: forming an n-type layer on the film which the oxidation treatment is performed and which mainly contains the cuprous oxide and/or the complex oxide of cuprous oxides.
13 . The method for manufacturing the stacked thin film according to claim 1 , wherein a total pressure in the oxidation treatment is from 5 [Pa] to 5000 [Pa] where both the lower and upper endpoints of the total pressure range are inclusive.
14 . The method for manufacturing the stacked thin film according to claim 1 , wherein a total pressure in the oxidation treatment is from 5 [Pa] to 1000 [Pa] where both the lower and upper endpoints of the total pressure range are inclusive.
15 . A method for manufacturing a solar cell, comprising: forming the p-electrode on the substrate according to the method for manufacturing the stacked thin film according to claim 1 ; forming the film that mainly contains the cuprous oxide and/or the complex oxide of cuprous oxides on the p-electrode according to the method for manufacturing a stacked thin film according to claim 1 ; performing an oxidation treatment on the film that mainly contains the cuprous oxide and/or the complex oxide of cuprous oxides on the p-electrode according to the method for manufacturing a stacked thin film according to claim 1 ; forming an n-type layer on the film on which an oxidation treatment is performed and which mainly contains the cuprous oxide and/or the complex oxide of cuprous oxides; and forming the n-electrode on the n-type layer.
16 . The method for manufacturing a solar cell according to claim 15 , further comprising: incorporating the solar cell into a multi-junction solar cell.
17 . The method for manufacturing a solar cell according to claim 15 , further comprising: incorporating the solar cell into a solar cell module.
18 . The method for manufacturing a solar cell according to claim 15 , further comprising: incorporating the solar cell into a photovoltaic power generation system.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a Continuation application of PCT International Patent Application No. PCT/JP2021/33995, the International Filing Date of which is Sep. 15, 2021, which is based upon and claims the benefit of priority from Japanese Application 2021-049685, the filling Date of which is Mar. 24, 2021, the entire contents of both of which are incorporated herein by reference. FIELD Embodiments described herein relate generally to a method for manufacturing a stacked thin film, a method for manufacturing a solar cell, a multi-junction solar cell, a solar cell module, and a photovoltaic power generation system. BACKGROUND One of new solar cells is a solar cell using a cuprous oxide (Cu2O) for a light-absorbing layer. Cu2O is a wide-gap semiconductor. Since Cu2O is a safe and inexpensive material including copper and oxygen abundantly present on the earth, it is expected that a high-efficiency and low-cost solar cell can be realized. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a solar cell according to an embodiment; FIG. 2 is a diagram illustrating analysis spots of a solar cell according to an embodiment; FIG. 3 is a flowchart of a method for manufacturing a stacked thin film and a solar cell according to an embodiment; FIG. 4 is a cross-sectional view of a multi-junction solar cell according to an embodiment; FIG. 5 is a perspective view of a solar cell module according to an embodiment; FIG. 6 is a cross-sectional view of a solar cell module according to an embodiment; FIG. 7 is a structural view of a photovoltaic power generation system according to an embodiment; FIG. 8 is a conceptual diagram of a vehicle according to an embodiment; FIG. 9 is conceptual diagram of a flying object. FIG. 10 is a table related to Examples; and FIG. 11 is a table related to Examples. DETAILED DESCRIPTION A method for manufacturing a stacked thin film of an embodiment includes forming a p-electrode on a substrate, forming a film that mainly contains a cuprous oxide and/or a complex oxide of cuprous oxides on the p-electrode, and performing an oxidation treatment on the film that mainly contains the cuprous oxide and/or the complex oxide of cuprous oxides. An ozone partial pressure in the oxidation treatment is 5 [Pa] or more and 200 [Pa] or less, a treatment temperature in the oxidation treatment is 273 [K] or more and 323 [K] or less, and a treatment time in the oxidation treatment is 1 second or more and 60 minutes or less. Hereinafter, an embodiment will be described in detail with reference to the drawings. Unless otherwise specified, values at 25° C. and 1 atm (atmosphere) are illustrated. An average represents an arithmetic mean value. First Embodiment A first embodiment relates to a method for manufacturing a stacked thin film, a solar cell, and a method for manufacturing a solar cell. The stacked thin film is a member in a procedure of manufacturing the solar cell, has a substrate, a p-electrode on the substrate, and a film that mainly contains a cuprous oxide and/or a complex oxide of cuprous oxides on the p-electrode. A surface of the film that mainly contains the cuprous oxide and/or the complex oxide of cuprous oxides is oxidized. FIG. 1 illustrates a cross-sectional view of a solar cell 100 of the first embodiment. As illustrated in FIG. 1, the solar cell 100 according to the present embodiment includes a substrate 1, a p-electrode 2 as a first electrode, a p-type light-absorbing layer 3, an n-type layer 4, and an n-electrode 5 as a second electrode. An intermediate layer (not illustrated) may be included between the n-type layer 4 and the n-electrode 5. Sunlight may be incident from either the n-electrode 5 side or the p-electrode 2 side, but is more preferably incident from the n-electrode 5 side. Since the solar cell 100 of the embodiment is a transmissive solar cell, it is preferable that the solar cell is used as a top cell (light incident side) of a multi-junction solar cell. In FIG. 1, the substrate 1 is provided on a side of the p-electrode 2 opposite to the p-type light-absorbing layer 3 side, but the substrate 1 may be provided on a side of the n-electrode 5 opposite to the n-type layer 4 side. Hereinafter, although a mode illustrated in FIG. 1 will be described, a mode in which the substrate 1 is provided on the n-electrode 5 side except that a position of the substrate 1 is different is also used. In the solar cell 100 of the embodiment, light is incident from the n-electrode 5 side toward the p-electrode 2 side. The substrate 1 is a transparent substrate. A transparent organic substrates such as acrylic, polyimide, polycarbonate, polyethylene terephthalate (PET), polypropylene (PP), fluorine-based resins (polytetrafluoroethylene (PTFE), perfluoroethylene propene copolymer (FEP), ethylene tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), perfluoroalkoxy alkane (PFA), and the like), polyarylate, polysulfone, poly