Structural and compositional analyses on indium sulfide thin films deposited in aqueous chemical bath containing indium chloride and thioacetamide

Chemical bath deposition of indium sulfide thin films from aqueous mixtures containing indium chloride and thioacetamide under the two extreme reaction conditions, namely, at 30 and 70 degreesC, has been examined in order to obtain further insights for understanding the reaction mechanism. The S/In ratio of both the films and the precipitates was low at the early stage of the reaction and it gradually increases to 1.5, which corresponds to the stoichiometric composition of In2S3. X-ray analyses of the films have indicated the formation of amorphous indium hydroxysulfide in the early stage, followed by the formation of nanocrystalline indium sulfide in the late stage of the film growth. The films deposited at 30 degreesC had a cauliflower-like morphology, whereas the fibrous structure was observed at 70 degreesC. It is inferred that the rate-determining step for the film growth at the higher temperature is not identical to that at the lower temperature. (C) 2003 Elsevier Science B.V. All rights reserved.