| 摘要 |
PURPOSE:To form a thin inorganic insulating film without making holes by oxidizing a ferritic stainless sheet steel of less than 0.5 mm thick comprising 2 wt.% or more Al, thereby heating at a temp. 850 deg.C or more. CONSTITUTION:A ferritic stainless sheet steel of less than 0.5 mm thick comprising 2 wt.% or more Al is oxidized by heating at a temp. 850 deg.C or more and an insulation oxide layer mainly composed of Al oxide is formed at the surface of the above layer to have its thickness ranging 0.2 mum-10 mum. If its Al content does not come to the above inclusion level, the oxide layer that is formed by oxidizing with heat becomes porous and the defect appears at the surface of the oxide to cause a short-circuit of a solar cell. The thickness of sheet steel is restricted so that sufficient flexibility can be obtained even after manufacturing the solar cell and if it exceeds 0.5 mm thick, its rigity hinders achievement of satisfactory flexibility. Furthermore, when an oxidation treatment by heating is carried out at a temp. below 850 deg.C, the growth of an oxide film is so uneven that a complete covering of the defective stainless surface becomes impracticable. |
