Abstract: Provided are a solar cell substrate made of stainless steel foil which contains 7% to 40% by mass Cr and has a coefficient of linear expansion of 12.0×10?6/° C. or less at 0° C. to 100° C. and a thickness of 20 ?m to 200 ?m is subjected to the preparatory heat treatment for stress relief in an atmosphere consisting of one or more selected from an N2 gas, an H2 gas, an Ar gas, an AX gas, and an HN gas within the range of 250° C. to 1,050° C.; a back-contact made of a Mo layer is formed on a surface of the stainless steel foil subjected to the preparatory heat treatment or an insulating coating is formed on a surface of the stainless steel foil followed by forming the back-contact including the Mo layer thereon; and an absorber layer made of Cu(In1-xGax)Se2 is formed on the back-contact by performing coating formation heat treatment.

Abstract: A stainless steel foil contains, in percent by mass, 0.05% or less of C, 2.0% or less of Si, 1.0% or less of Mn, 0.003% or less of S, 0.05% or less of P, 25.0% to 35.0% of Cr, 0.05% to 0.30% of Ni, 3.0% to 10.0% of Al, 0.10% or less of N, 0.02% or less of Ti, 0.02% or less of Nb, 0.02% or less of Ta, 0.005% to 0.20% of Zr, 0.02% or less of Ce, 0.03% to 0.20% of REM excluding Ce, 0.5% to 6.0% in total of at least one of Mo and W, and the balance being Fe and incidental impurities.

Abstract: Provided are a solar cell substrate made of stainless steel foil which contains 7% to 40% by mass Cr and has a coefficient of linear expansion of 12.0×10?6/° C. or less at 0° C. to 100° C. and a thickness of 20 ?m to 200 ?m is subjected to the preparatory heat treatment for stress relief in an atmosphere consisting of one or more selected from an N2 gas, an H2 gas, an Ar gas, an AX gas, and an HN gas within the range of 250° C. to 1,050° C.; a back-contact made of a Mo layer is formed on a surface of the stainless steel foil subjected to the preparatory heat treatment or an insulating coating is formed on a surface of the stainless steel foil followed by forming the back-contact including the Mo layer thereon; and an absorber layer made of Cu(In1-xGax)Se2 is formed on the back-contact by performing coating formation heat treatment.

Abstract: A steel foil for a solar cell substrate includes 7% to 40% by mass of Cr and has a tensile strength of 930 MPa or more in a direction perpendicular to the rolling direction.

Abstract: A stainless steel foil contains, in percent by mass, 0.05% or less of C, 2.0% or less of Si, 1.0% or less of Mn, 0.003% or less of S, 0.05% or less of P, 25.0% to 35.0% of Cr, 0.05% to 0.30% of Ni, 3.0% to 10.0% of Al, 0.10% or less of N, 0.02% or less of Ti, 0.02% or less of Nb, 0.02% or less of Ta, 0.005% to 0.20% of Zr, 0.02% or less of Ce, 0.03% to 0.20% of REM excluding Ce, 0.5% to 6.0% in total of at least one of Mo and W, and the balance being Fe and incidental impurities.

Abstract: A stainless steel having good conductivity and ductility for use in a fuel cell separator is provided. In particular, the stainless steel has a composition of, in terms of % by mass, C: 0.01% or less, Si: 1.0% or less, Mn: 1.0% or less, S: 0.01% or less, P: 0.05% or less, Al: 0.20% or less, N: 0.02% or less, Cr: 20 to 40%, Mo: 4.0% or less, and at least one selected from Nb, Ti, and Zr: 0.05 to 0.60% in total, the balance being Fe and unavoidable impurities. At least one precipitate having an equivalent circle diameter of 0.1 ?m or more is present per 100 ?m2, a ratio of a thickness t (?m) to a maximum diameter Dmax (?m) of the precipitates satisfies formula (1) below 20?t/Dmax??(1) and the thickness is 200 ?m or less.

Abstract: A stainless steel having good conductivity and ductility for use in a fuel cell separator is provided. In particular, the stainless steel has a composition of, in terms of % by mass, C: 0.01% or less, Si: 1.0% or less, Mn: 1.0% or less, S: 0.01% or less, P: 0.05% or less, Al: 0.20% or less, N: 0.02% or less, Cr: 20 to 40%, Mo: 4.0% or less, and at least one selected from Nb, Ti, and Zr: 0.05 to 0.60% in total, the balance being Fe and unavoidable impurities. At least one precipitate having an equivalent circle diameter of 0.1 ?m or more is present per 100 ?m2, a ratio of a thickness t (?m) to a maximum diameter Dmax (?m) of the precipitates satisfies formula (1) below 20?t/Dmax??(1) and the thickness is 200 ?m or less.