Structural and optical properties of SnS nanoparticles and electron-beam-evaporated SnS thin films

SnS nanoparticles were synthesised by the precipitation method using SnCl2.2H2O and Na2S.xH2O and the nanoparticles were characterised by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis. From the particles’ XRD pattern, a strong peak at 2θ = 31.5˚ was observed, which confirms the Herzenbergite orthorhombic crystal structure of SnS. The FTIR result also confirmed the SnS nanoparticles at 2354 cm−1 and 615 cm−1. Second, thin SnS films were prepared on a glass substrate by the electron beam evaporation technique at room temperature and annealed at 100°C, 200°C and 300°C. The effect of the annealing temperature on structural and optical properties of the SnS films was characterised by XRD and ultraviolet–visible (UV–Vis) analysis. From the experimental studies, optical absorption of SnS films increases with respect to the annealing temperature, while the values of band gap energy (Eg) get reduced from 1.77 to 1.57 eV.