Investigation of the Optical Properties for Quaternary Se60−xGe35Ga5Sbx (x = 0, 5, and 10) Chalcogenide Glass

Abstract

A quenching technique was used to prepare the chalcogenide system of the (Formula presented.) (x = 0, 5, and 10 at. %), which was deposited as thin films onto glass substrates using a thermal evaporation technique. X-ray diffraction patterns were used for structure examination of the fabricated compositions, which exposes the amorphous nature of the deposited samples. Meanwhile, the chemical compositions of the prepared samples were evaluated and calculated via the energy-dispersive X-ray spectroscopy (EDX), which was in agreement with the measured compositional element percentages of the prepared samples. Based on the optical reflectance R and transmittance T spectra from the recorded spectrophotometric data ranging from 350 to 2500 nm, the influence of the Sb element on the (Formula presented.) thin films’ optical properties was studied. The film thickness and the refractive index were calculated via Swanepoel’s technique from optical transmittance data. It has been observed that the films’ refractive index increases with increasing x value over the spectral range. The refractive index data were used to evaluate the dielectric constants and estimate dispersion parameters (Formula presented.) and (Formula presented.) using the Wemple–DiDomenico model. The optical energy gap (Formula presented.) was calculated for the tested compositions. The result of the optical absorption analysis shows the presence of allowed direct and indirect transitions.