Growth of CuInSe ~2 thin films by a single-step electrodeposition technique using acetonitrile as complexing agent

摘要

Thin films of CuInSe _2 were grown on SnO _2 coated glass microslides using a single-step electrodeposition technique. The bath was made up of a mixture of aqueous solutions of CuCl _2, InCl _3, and SeO _2 with acetonitrile (CH _3CN) acting as a complexing agent. Voltametric studies suggest that acetonitrile is a suitable complexing agent, which helps in bringing the deposition potentials of Cu, In, and Se close to each other. The films were characterized by EDAX, SIMS, X-ray diffraction, and optical studies, which show that the material is CuInSe _2, with a direct band gap of about 1 eV. The films were annealed in a Se atmosphere to improve their crystalline properties. X-ray diffractograms show that the peaks of CuInSe _2, which are broad and of low intensity for as-grown films, become sharp and intense after annealing in Se atmosphere. SIMS depth profiles show that the films have a fairly uniform composition along the depth of the films.