Optical and electronic properties for As-60 at.% S uniform thickness of thin films: Influence of Se content

Thin films of As40S60-xSex ((0 ≤ x ≥ 60) at. %) have been efficiently synthesized through the process of vacuum
thermal evaporation. The present framework analyzes the thin films to determine both optical and electronic
parameters as a function of change of Se concentrations. The thickness of the obtained films, d have been
mathematically determined utilizing Swanepoel’s computations and experimentally via an MII-4 interference
microscope with an accuracy of 1%. The thickness of the studied films has been closed to 500 ± 15 nm. Addi-
tionally, the optical properties of these films have been scrutinized from the transmittance and reflectance
spectra measured by a UV–Vis–NIR spectrophotometer. The transmission spectra, T (λ) of such films have been
documented in the spectral region 400–2500 nm. Based on the optical measurements, all of the linear optical
constants, the linear optical and dielectric parameters, the linear and non-linear optical susceptibility criteria,
and the material dispersion coefficient M(λ) have been computed. Besides, the nonlinear refractive index, en-
ergies of the electronic polarization have been determined.