Deposition of transparent and electroconductive chalcogenide films at near-room temperatures

An economic and pollution-free technique for electroless chemical deposition of transparent and electrically conductive submicron films on the surfaces of glass, ceramics, transparent polyester films, metal, and ferroelectric thin films has been developed. The technique is based on hydrolytic decomposition of metal-thiosulfate or metal-selenosulfate complexes in aqueous solutions, and has been successfully used for deposition of transparent and electroconductive copper sulfide and copper selenide thin films of a variable composition. The basic optical and electrical characteristics of the as-deposited and annealed films are also reported.The Cu₂S films were highly transparent (Ⅵ 80 %) throughout the visible and nearinfrared region of the electromagnetic spectrum (0.5 to 2.5 μ,m wavelength), while the rest of the films exhibited stoichiometrically adjustable absorbance in the nearinfrared region (0.7 to 2.5 m wavelength). The sheet resistivities of the films were found to be between 15 and 1200 /sq. The most conductive among the chalcogenides were the Cu2Se films with sheet resistivities, R, of ~ 15 sq., while the Cu₂S films were the least conductive (R ~ 1200 /sq.).