Simple synthesis of copper sulfide film using self-reducible copper formate-amine-sulfur complex paste at less than 200 °C

Copper sulfide films were synthesized via a simple calcination process using self-reducible pastes of copper formate, amine and sulfur with various ratios of sulfur to copper formate at less than 200 °C. The film was a mixture of CuS and Cu1.8S. CuS alone was synthesized from the paste with sulfur ratios of 1.1 at 140 °C and 1.2 at 160 °C. Analysis of the crystal size of the film revealed the formation of CuS particles via calcination of the paste, which was followed by evaporation of the sulfur in CuS, which resulted in a transformation to Cu1.8S.