Patent ID: 8097305

Claim:
A method of producing a film of chalcopyrite composition on a substrate, the method comprising the steps of: preparing a substrate by depositing molybdenum in a thin layer on one of glass and a polymer substrate; preparing a metal mineral salt solution by mixing in a 1:2 ratio a solution A and a solution B, the solution A consisting of 5 mil of methanol containing 0.767 g of hydrated gallium nitrate (III), 0.885 g of anhydrous indium chloride (III), and 0.938 g of hemi-pentahydrate copper nitrate (II); and the solution B is prepared with 5 ml of 1-pentanol containing 0.767 g of hydrated gallium nitrate (III), 0.885 g of anhydrous indium chloride (III), 0.938 g of hemi-pentahydrate copper chloride (II), and 0.5 g of ethylcellulose with a standardized viscosity of 5-15 mPas (measured at 25° C. at a proportion of 5% in an 80:20 toluene/EtOH mixture); depositing the metal mineral salt solution on the substrate and spreading the metal mineral salt solution into a 100 micrometer thick liquid film; drying the liquid film of the metal mineral salt solution deposited on the molybdenum coated substrate at a temperature of between 100-120° C. for 2-3 minutes and further drying the liquid film at a temperature of 250° C. for 1-2 minutes to form a solid layer; forming chalcopyrite by placing the molybdenum coated substrate in a graphite environment containing 0.5 grams of sulfur for 10 minutes, the graphite environment being heated to a temperature of 500° C. to thermally react the metal mineral salts in the solid layer.