Microstructural properties evaluation of SnSSe alloy films

Tin sulfoselenide (SnSSe) alloy films were electrosyntheized from an aqueous solution by potentiostatic method. SnSSe alloy films were characterized by stylus profilometer, X-ray diffraction (XRD), atomic force microscopy (AFM), photo luminescence and optical absorption techniques. The electrochemical growth reaction kinetics of the alloy formation were discussed. XRD patterns revealed that the deposited films exhibited in polycrystalline orthorhombic structure with preferred orientation along (111) crystallographic plane. Micro structural properties of SnSSe thin films such as crystallite size, dislocation density, micro strain, number of crystallites per unit area, stacking fault probability and texture coefficient were calculated from the predominant (111) diffraction lines. The theoretical route prepared microstructural properties were compared with graphical results. The optical band gap value was calculated from transmittance and absorption data. SnSSe thin film direct transition optical band gap found to be in the range of 1.08-1.25 eV. The 'x' value of SnSxSe1-x was estimated from Vegard's law and it was performed to fit with Gaussian curve fitting. The texture coefficients were calculated for polycrystalline SnSSe diffraction lines. The Lotgering factor were estimated for preferentially oriented diffraction line. The blue emission luminescence peak was observed at 460 nm for SnSSe alloy film. Surface topography and roughness were estimated using AFM micrographs.