Spectroscopic ellipsometry characterization of amorphous Se100-xTex films using the Cody–Lorentz parameterized model

The optical properties of a series of Se 100-x Te x ( x = 0, 1, 5, 10, 15, 20, 25 and 35) films have been determined using a variable angle spectroscopic ellipsometer in the photon energies range of 1–5 eV. Se 100-x Te x films were prepared by conventional vacuum deposition. The dielectric functions of this series are parameterized using a dielectric function model that applies two Cody–Lorentz (CL) and one Harmonic oscillator models. This parameterization scan is performed positively to define the changes in the optical properties with Te content. Lorentz oscillator amplitude ( A fun ), oscillator width ( C fun ), the extent of broadening E u fun and transition energy ( E p fun ) of the prepared films are enhanced with increasing Te content. While the CL peak transition energy ( E o fun ) and optical energy gap are gradually decreased as Te content is increased.