Optical properties of spin-coated SnS2 thin films

This paper reports optical properties of n-type SnS₂ thin films, prepared by spin-coating of a sol-gel based on the lowcost and environmentally friendly solvent dimethyl sulfoxide (DMSO). The effect of a short-term low-temperature treatment in air and final annealing under low vacuum (0.1 Pa) on the synthesis of tin disulfide films was tested and analyzed. The dynamics of changes of optical properties of the films on the parameters of spin-coating and heat treatment was established. The value of the band gap E_g ≈ 2.25 – 2.54 eV for Sn_S2 and E_g ≈ 1.99 eV for Sn₂S₃ was determined from the analysis of optical characteristics.