Physico-chemical characterization of β-In2S3 thin films synthesized by solid-state reaction, induced by annealing, of the constituents sequentially deposited in thin layers

beta-In2S3 thin films have been obtained by solid-state reaction, induced by annealing for half an hour under constant argon flow, between the constituents sequentially deposited in thin layers by vacuum thermal evaporation. The films obtained after annealing at 623, 673 and 723 K are crystallized in beta-In2S3 tetragonal structure without any preferential orientation. The crystallization of the samples annealed at 523 and 573 K is only initiated. It has been shown by XPS study that the films are contaminated by oxygen during annealing. This contamination increases slightly with the annealing temperature but the oxygen atomic percentage never exceeds 3% in the samples annealed at 623 and 673 K. The SEM visualization of the films has shown that they exhibit very good covering efficiency. In order to obtain In2S3 films with the best crystalline properties and the best purity, the optimum temperature has been found to be 673 K. (C) 2000 Elsevier Science:Ltd. All rights reserved.