Patent ID: 7923628

Claim:
A method of forming a photovoltaic thin film cell, comprising: disposing a thin film on a substrate, wherein the thin film includes a chemical compound; coating the thin film with a protective layer to form a first coated thin film structure, wherein the protective layer prevents part of the chemical compound from escaping during an annealing process; annealing the coated thin film structure to form a coated photovoltaic thin film structure, wherein the coated photovoltaic thin film retains the part of the chemical compound that is prevented from escaping during the annealing by the protective layer; removing the protective layer from the coated photovoltaic thin film structure to form an uncoated photovoltaic thin film structure; disposing a contact grid on the uncoated photovoltaic thin film structure; disposing an anti-reflective coating on the contact grid; and disposing a cover glass on the anti-reflective coating to form a photovoltaic thin film cell, wherein the chemical compound of the thin film is selected from the group consisting of copper indium gallium diselenide (CuInGaSe 2 ), copper indium gallium disulfide (CuInGaS 2 ), copper gallium diselinide (CuGaSe 2 ), copper gallium disulfide (CuGaS 2 ) and copper indium disulfide (CuInS 2 ).