CuS

Copper sulfide (CuS) is an inorganic compound belonging to the chalcogenide family, existing naturally as the mineral covellite and also produced synthetically for industrial applications. It is primarily used in photovoltaic devices, photodetectors, and thin-film solar cells due to its semiconductor properties, as well as in catalysis, lubricants, and historical pigment applications. Engineers select CuS-based materials for optoelectronic and energy conversion applications where earth-abundant, non-toxic alternatives to cadmium or lead-based compounds are required, though it remains largely confined to research and specialized industrial contexts rather than commodity applications.