Orthorhombic stannous sulfide (SnS) films were prepared by chemical bath deposition in which stannous dichloride (SnCl2), ammonium citrate (C6H5O7(NH4)(3)) and sodium thiosulfate (Na2S2O3) were used as tin source, chelating reagent and sulfur source, respectively. The influence of the deposition temperatures and the concentration ratios of Na2S2O3/SnCl2 on the morphologies, compositions and electrical and optical properties of the SnS films were investigated. The results show that the compactness of the SnS films gets worse when the deposition temperature increases, while the compactness of the films gets better when the concentration ratio of Na2S2O3/SnCl2 increases. The compositions of the films (the molar ratio of S/Sn ranges from 46.7:53.3 to 48.9:51.1) are all close to the stoichiometric ratio of SnS, and the molar ratio of S/Sn in the films increases as the deposition temperature and the concentration ratio of Na2S2O3/SnCl2 increase. The optical bandgaps of the SnS films are in the range of 1.01 eV-1.26 eV. The dark conductivities and photo conductivities of the SnS films all increase as the deposition temperature and the concentration ratio of Na2S2O3/ SnCl2 increase. (C) 2012 Elsevier B.V. All rights reserved.