In recent technology exciting advances have been made in developing new alloys to comply with the requirements of research and development. One of the most promising materials is GaAs alloys. In this paper, a review of recent advances in preparing stoichiometric single-crystal GaAs and its amorphous alloys by thermal and flash evaporation is presented. The resulting materials showed better composition, electrical and optical properties as compared with published data. (C) 2002 Elsevier Science Ltd. All rights reserved.