Evaporated thin films of zinc sulfide (ZnS) have been deposited in a low ambient atmosphere of hydrogen sulfide (H2S similar to 10(-4) Torr). The H2S atmosphere was obtained by a controlled thermal decomposition of thiourea [CS(NH2)(2)] inside the vacuum chamber. It has been observed that at elevated substrates temperature of about 200 degrees C helps eject any sulfur atoms deposited due to thermal decomposition of ZnS during evaporation. The zinc ions promptly recombine with H2S to give better stoichiometry of the deposited films. Optical spectroscopy, X-ray diffraction patterns and scanning electron micrographs depict the better crystallites and uniformity of films deposited by this technique. These deposited films were found to be more adherent to the substrates and are pinhole free, which is a very vital factor in device fabrication. (c) 2007 Elsevier B.V. All rights reserved.