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EP-4742859-A1 - LAMINATED BODY, SOLAR CELL, MULTI-JUNCTION SOLAR CELL, SOLAR CELL MODULE, AND MANUFACTURING METHOD FOR LAMINATED BODY

EP4742859A1EP 4742859 A1EP4742859 A1EP 4742859A1EP-4742859-A1

Abstract

A laminated body according to an embodiment includes a transparent substrate, a p-electrode on the substrate, including a transparent conductive oxide film, and a p-type light-absorbing layer on the p-electrode, including a cuprous oxide compound. A crystal grain size of the cuprous oxide compound is 1.2 times or more a thickness of the p-type light-absorbing layer. A carrier concentration of the p-type light-absorbing layer is 5.0×10 14 [cm -3 ] or more. The cuprous oxide compound comprises Cu, oxygen, and optionally an element represented by M1. The element represented by M1 is one or more elements selected from the group consisting of Li, Na, K, Al, Ga, In, C, Si, Ge, Sn, N, P, Sb, and Bi.

Inventors

  • HONISHI, Yuya
  • SHIBASAKI, Soichiro
  • NAKAGAWA, NAOYUKI
  • YAMAMOTO, KAZUSHIGE

Assignees

  • KABUSHIKI KAISHA TOSHIBA

Dates

Publication Date
20260513
Application Date
20250912

Claims (15)

  1. A laminated body (10) comprising: a transparent substrate (1); a p-electrode (2) on the substrate (1), including a transparent conductive oxide film; and a p-type light-absorbing layer (3) on the p-electrode (2), including a cuprous oxide compound, wherein a crystal grain size of the cuprous oxide compound is 1.2 times or more a thickness of the p-type light-absorbing layer (3), a carrier concentration of the p-type light-absorbing layer (3) is 5.0×10 14 [cm -3 ] or more, the cuprous oxide compound comprises Cu, oxygen, and optionally an element represented by M1, and the element represented by M1 is one or more elements selected from the group consisting of Li, Na, K, Al, Ga, In, C, Si, Ge, Sn, N, P, Sb, and Bi.
  2. The laminated body (10) according to claim 1, wherein the element represented by M1 is Si or/and N.
  3. The laminated body (10) according to claim 1 or 2, wherein the carrier concentration of the p-type light-absorbing layer (3) is 1.0×10 18 [cm -3 ] or less.
  4. The laminated body (10) according to any one of claims 1 to 3, wherein the thickness of the p-type light-absorbing layer (3) is 500 [nm] or more and 10 [µm] or less.
  5. The laminated body (10) according to any one of claims 1 to 4, wherein the mobility of the p-type light-absorbing layer (3) is 10 [cm 2 /(V·s)] or more.
  6. The laminated body (10) according to any one of claims 1 to 5, wherein when an atomic ratio of the copper element included in the p-type light-absorbing layer (3) is set to 100 [%], a total amount of the element represented by M1 included in the p-type light-absorbing layer (3) is 0.00001 [%] or more and 1 [%] or less.
  7. A solar cell (100) according comprising: the laminated body (10) according to any one of claims 1 to 6; an n-type layer (4) provided on the p-type light-absorbing layer (3) of the laminated body (10); and an n-type electrode (5).
  8. A multi-junction solar cell (200) comprising: the solar cell (100) according to claim 7.
  9. A manufacturing method for a laminated body (10) comprising: forming a layer mainly composed of a cuprous oxide compound on a p-electrode (2) of the base member comprising a substrate (1) and the p-electrode (2) including a transparent conductive oxide film on the substrate (1), by sputtering using a target primarily composed of copper, wherein the sputtering for the cuprous oxide compound is carried out continuously in a low-temperature range and then in a high-temperature range, temperature of the base member during sputtering in the low-temperature range is 25 [°C] or more and 600 [°C] or less and is at least 50 [°C] lower than the maximum temperature in the high-temperature range, and temperature of the base member during sputtering in the high-temperature range is more than 600 [°C] and 1000 [°C] or less.
  10. The manufacturing method according to claim 9, wherein the sputtering duration in the low-temperature range is 5% or more and 200% or less of the sputtering duration in the high-temperature range.
  11. The manufacturing method according to claim 9 or 10, wherein an average temperature of the base member during the low-temperature range sputtering is at least 100 [°C] lower than an average temperature of the base member during the high-temperature range sputtering.
  12. The manufacturing method according to any one of claims 9 to 11, wherein the minimum temperature of the base member during the low-temperature range sputtering is 550 [°C] or less.
  13. The manufacturing method according to any one of claims 9 to 12, wherein the minimum temperature of the base member during the low-temperature range sputtering is 450 [°C] or less.
  14. The manufacturing method according to any one of claims 9 to 13, wherein the copper element, oxygen, and the element represented by M1 are continuously supplied from the start of the sputtering reaction until the end of the sputtering process.
  15. The manufacturing method according to any one of claims 9 to 14, wherein an oxygen partial pressure in a chamber during sputtering is 0.01 [Pa] or more and 0.10 [Pa] or less.

Description

FIELD Embodiments described herein relate generally to a laminated body, an electronic device, a solar cell, a multi-junction solar cell, a solar cell module, a photovoltaic power generation system, and a manufacturing method for a laminated body. 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 which presents abundantly on the earth and oxygen, it is expected that a low-cost solar cell with high-efficiency can be realized. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional diagram of a laminated body according to an embodiment;FIG. 2 shows analysis spots of a laminated body according to an embodiment;FIG. 3 is a schematic diagram of a surface of a p-type light-absorbing layer according to an embodiment;FIG. 4 is a flowchart of a manufacturing method of a laminated body according to an embodiment;FIG. 5 is a schematic diagram of a manufacturing apparatus according to an embodiment;FIG. 6 is a schematic cross-sectional diagram of a solar cell according to an embodiment;FIG. 7 is a schematic cross-sectional diagram of a multi-junction solar cell according to an embodiment;FIG. 8 is a perspective diagram of a solar cell module according to an embodiment;FIG. 9 is a schematic cross-sectional diagram of a solar cell module according to an embodiment;FIG. 10 is a configuration diagram of a photovoltaic power generation system according to an embodiment;FIG. 11 is a conceptual diagram of a vehicle according to an embodiment;FIG. 12 is a schematic diagram of a drone according to an embodiment;FIG. 13 is a table relating to examples;FIG. 14 is a table relating to examples;FIG. 15 is a cross-sectional SEM image of a laminated body of an example; andFIG. 16 is a table relating to examples. DETAILED DESCRIPTION A laminated body according to an embodiment includes a transparent substrate, a p-electrode on the substrate, including a transparent conductive oxide film, and a p-type light-absorbing layer on the p-electrode, including a cuprous oxide compound. A crystal grain size of the cuprous oxide compound is 1.2 times or more a thickness of the p-type light-absorbing layer. A carrier concentration of the p-type light-absorbing layer is 5.0×1014 [cm-3] or more. The cuprous oxide compound comprises Cu, oxygen, and optionally an element represented by M1. The element represented by M1 is one or more elements selected from the group consisting of Li, Na, K, Al, Ga, In, C, Si, Ge, Sn, N, P, Sb, and Bi. 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 described. An average represents an arithmetic mean value. Each concentration is an average concentration in the region or layer of interest. In each layer, the presence of a specific element is, for example, an element whose presence can be confirmed by SIMS (Secondary Ion Mass Spectrometry), and the absence of a specific element is, for example, an element whose presence cannot be confirmed by SIMS. In the specification, "/" (slash) represents the division sign excluding "/" of "and/or" representing "or". In the specification, "·" (middle dot, dot operator) and "×" represent a multiplication sign. In the specification, "." (period) of a numerical value represents a decimal point. The thickness and structure of members described in the specification can be known, for example, from one or more of images obtained by SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), HAADF-STEM: High-Angle Annular Dark Field Scanning Transmission Electron Microscopy), and the like. The boundaries of the members described in the specification can be determined from one or more images obtained by scanning electron microscopy or transmission electron microscopy, SEM-EDS (Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy) or TEM-EDX (Transmission Electron Microscopy with Energy Dispersive X-ray Spectroscopy), SIMS (Secondary Ion Mass Spectrometry), and the like. The composition of the members described in the specification can be determined by one SIMS, ICP-MS (Inductively Coupled Plasma Mass Spectrometry), SEM-EDX, TEM-EDX, or the like. The crystallinity of the members described in the specification can be evaluated, for example, from XRD (X-ray Diffraction), EBSD (Electron Backscatter Diffraction), images obtained by HAADF-STEM, SEM, TEM or the like. Materials included in the members described in the specification (crystal defects, bonding states, etc.) can be evaluated from HAADF-STEP, PL (Photoluminescence), XPS (X-ray Photoelectron Spectroscopy), or the like. These analysis methods are examples and do not negate the specific analytical methods described in the specification. (FIRST EMBODIMENT) A first embodiment relates to a laminated body. FIG. 1 shows a schematic diag