Optical characteristics and dispersion parameters of thermally evaporated Ge50In4Ga13Se33 chalcogenide thin films

Abstract Ge50In4Ga13Se33 glassy composition was fabricated using the chemical composition and the melt quenching technique. Using X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis, the structural characterization of the thermally evaporated films with different thicknesses (126–745 nm) used in this study was determined. Transmittance T ( λ ) spectrum was obtained in the range of wavelength from 400 nm to 2500 nm at room temperature. Swanepoel’s method was employed to evaluate the optical constants, refractive index n and extinction coefficient k . From the obtained data of n , transmission coefficient T C and reflection loss factor R L were determined. Optical band gap E g opt and Urbach tail E u were determined using Tauc’s extrapolation method. The calculated value of the transition power factor p revealed the indirect optical transition indicated in this study. The Wemple-DiDomenico parameters are also reported for the composition under study. The dependency of real e 1 and imaginary e 2 components of dielectric constant, dissipation factor t a n δ , relaxation time τ volume and surface energy loss functions and the optical conductivity σ opt on photon energy h ν were studied also for Ge50In4Ga13Se33 films. In addition, the 3rd order non-linear optical susceptibility χ ( 3 ) and non-linear refractive index n 2 were determined.