Sn-induced changes in the structure and optical properties of amorphous As-Se-Sn thin films for optical devices

The present framework is primarily concerned with the optical properties of As40Se60-xSnx thin films. The bulk form has been synthesized by the melt quenching technique. The thin films have been prepared by thermal evaporation technique. The XRD and the SEM techniques showed the non-crystalline nature of the prepared glasses. The refractive index n, energy gap, energy loss functions and other optical constants have been determined. The findings refer to increase of the refractive index of thin films with the increase of Sn content. The energy gap decreases to 1.4 eV with the increasing of Sn content for the investigated films. Further explanation of the physical characteristics of the investigated films made following the approach of chemical bond. Additionally, the optical dispersion dn/d lambda, phase velocity v(p) and group velocity U-g have been discussed in detail.