Investigation of the Effect of Film Thickness and Heat Treatment on the Optical Properties of TeSeSn Thin Films

Abstract

Glassy substrates TeSeSn thin films were thermally evaporated onto chemically cleaned glass. The as-deposited (as-prepared) and annealed thin films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and optical transmission. The optical absorption of the as-prepared and annealed TeSeSn thin films is studied in the wavelength range of 300 nm - 900 nm. The direct optical energy gap ( E g ) increases from 1.989 to 2.143 eV with increasing the thickness of the as-prepared films from 100 to 200 nm. The annealed TeSeSn films showed a decrease in the optical energy gap with increasing the annealing temperature. The effect of heat treatment on the lattice dielectric constant ( ε L ) and carrier concentration ( N ) are also studied.