Copper sulfides CuS have been synthesized by a reaction between [C~(en),]~+ (en = ethylenediamine) and thiourea in alkaline solutions at different temperatures. The product obtained at 10 "C (CuS-10) was amorphous and showed semiconductive properties with an electrical conductivity of 0.1 S cm-' at 298 K and 3.6 x S cm-' at 108 K, whereas the product at 30 "C (CuS-30) was a crystalline CuS (covellite) that exhibited a metal-like temperature dependence with a conductivity of 92 S cm-' at 304 K and 101 S cm-' at 101 K. CuS-10 was changed to a crystalline CuS when annealed at 100-150°C. The resulting CuS had a higher crystallinity than that of CuS-30, and the electrical conductivity showed a metal-like temperature dependence: 27 S cm-at 299 K and 31 S cm-' at 98 K. When the reactions were conducted with an immersed polymer film in the solution, CuS films were formed on the substrate surface. The CuS-30 film and the annealed CuS-10 film were electroconductive and transparent in the visible spectral region. The synthesis of amorphous CuS followed by thermal treatment is a new method for the fabrication of metal sulfide films of high quality.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.