Effect of SbSn additions on the physical characterization of amorphous Se

Different compositions of Se100−x(SbSn)x (0 ≤ x ≤ 14 at.%) glasses were prepared by the well-known melt quench technique. Thin films of these glasses were prepared by thermal evaporation onto ultrasonic cleaned glass substrate. Transmittance spectra of these films were measured in the wavelength range 400–2500 nm by using Jasco double beam spectrophotometer. A straight forward analysis proposed by Swanepoel, based on the maxima and minima of the transmittance spectra, allows to accurate determination of the film thickness and the complex index of refraction. Increasing SbSn content at the expense of Se atoms is found to affect the refractive index and the extinction coefficient of these films. The refractive indexes were discussed in terms of the single-oscillator Wemple–DiDomenico model. The compositional dependence of the optical band gap for the Se100−x(SbSn)x (0 ≤ x ≤ 14 at.%) thin films is discussed in terms of the chemical-bond approach.