摘要： SnS (S1) and SnS0.4Se0.6 (S2) thin films were prepared using thermal evaporation on annealing at 523 K of the thermally deposited films. Compositional analysis of the films reveals the formation of SnS and SnS0.40Se0.60 phase. X-ray diffraction results demonstrate the formation of orthorhombic structure corresponding to SnS and SnS0.40Se0.60 phase. Moreover, a decrease in the intensity of SnS0.40Se0.60 peaks as compared to those of SnS was observed. Thus, causes insertion of selenium (Se) atoms in SnS lattice and results in the modification of lattice parameters. These structural modifications leads to variations in crystallite size, lattice strain and dislocation density, thus, confirms the formation of ternary SnS0.40Se0.60 phase. The changes corresponding to optical parameters are also observed in the films in the form of lower transmission, bandgap value and absorption coefficient on Se insertion. Moreover, both the films exhibit absorption coefficient >105 cm?1 with bandgap values of 1.44 and 1.23 eV and found suitable for absorption in solar cell.