Patent ID: 8759142

Claim:
A method for producing thin-film light-absorbing layer of a copper indium selenium (CIS) or copper indium gallium selenium (CIGS), the method comprising: applying a coating slurry comprising a copper indium selenium (CIS) or copper indium gallium selenium (CIGS) powder to a substrate to form a slurry coat layer; heating the slurry coat layer in an inert or reducing gas atmosphere to form a powder coat layer, followed by pressing the powder coat layer to increase its particle packing density, or pressing the slurry coat layer to form a powder coat layer, followed by heating the powder coat layer In an inert or reducing gas atmosphere to increase its particle packing density; followed by heating the powder coat layer with improved packing density in an inert or reducing gas atmosphere to form a dense thin film, wherein the thin film is formed by heat treatment at 250 to 600° C. of the pressed powder coat layer together with a powder mixture of a selenium or sulfur powder and a ceramic powder in a selenium or sulfur atmosphere.