Thermal Annealing Induced Ag Diffusion Into GeS Thin Film: Structural and Optical Property Study.

The present report shows the optical changes due to the top Ag layer inter diffusion into bottom GeS matrix prepared by thermal evaporation method. The thermal energy facilitates the Ag+ ion into GeS which enhances the Ag-Ge-S solid solution formation that brings changes in optical constants as probed by various experimental techniques. The drastic increase in transmission accompanied by increase in optical gap is explained on the basis of density of localized states and disorderness. The non linear refractive index is found to be reduced with decrease in absorption coefficient. The structural change is not noticed by the thermal induced diffusion mechanism and the surface morphology is influenced by this process. [ABSTRACT FROM AUTHOR]