Role of Deposition Potential on the Optical Properties of SnSSe Thin Films

Abstract

SnSSe solid solution thin films were electrosynthesized from an aqueous solution by potentiostatic method. Films were deposited at different potentials in the range of -700 mV to -1000 mV vs SCE. XRD patterns revealed that the deposited films exhibited polycrystalline orthorhombic structure with preferred orientation along (111) crystallographic plane. The optical band gap value was calculated from transmittance and absorption data and the films were found to have direct band gap found to be 1.08 eV-1.25 eV. The refractive index, extinction coefficient, real and imaginary part of dielectric constants and optical conductivity of the SnSSe thin films has been calculated. The value for the refractive index lies between 2.5 and 3.1 and value of extinction coefficient lies between 0.035 and 0.052. Surface morphological studies revealed pellet shaped grains occupying the entire surface of the film distributed homogeneity.