Antimonite (Sb2S3) thin films have been synthesized through an annealing process in sulfur vapors at 300 degrees C of Sb thermal evaporated films. Deposited films have been characterized by X-ray diffraction, scanning electron microscopy and UV-vis-NIR spectroscopy. X-ray diagrams of these films have confirms that they were well crystallized in orthorhombic structure and some parameters such as the lattice parameter, crystallite size, microstrain and degree of preferred orientation have been reported and correlated with the effect of crystallite size. Optical properties of Sb2S3 films have been characterized by solid-state UV-visible absorption spectroscopy, and the band gap E-g was between 1.75 and 2.23 eV. Moreover, additional opto-thermal investigation and analyses within the framework of the Lattice Compatibility Theory provided plausible explanation for thickness-dependent incorporation of sulfur element inside antimony elaborated matrices. (C) 2014 Elsevier B.V. All rights reserved.