Tin sulfide thin films prepared by thermal evaporation and sulfurization

Tin sulfide thin films are prepared by a two-step process, thermally evaporated Tin and sulfurization. Five sulfurization temperatures are used to investigate the characteristics of SnS thin films. It is observed that Tin and Sulfur in the formation films decrease and increase with the increasing sulfurization temperature, respectively. Two main diffraction peaks appear at 2θ=32.04° and 66.8°, which are assign to SnS phase. A very weak peak of SnS₂ is observed at 2θ=62.96°. Raman spectra show a strong peak of SnS at 218 cm^-1 and a weak peak of SnS₂ at 315cm^-1. From transmittance measurement, two and three absorption transitions are observed at lower and higher sulfurization temperatures, respectively. Their corresponding bandgaps of these absorption edges are 1.27, 1.41 and 3,9 eV, respectively, which are determined by a linear fitting absorption curve.