Abstract
The optical properties of Se
0.62Ge
0.38 and Se
0.62Ge
0.35X
0.03 where [X
=
In, Sb and Bi] thin films has been investigated. Thin films used in these studies were thermally evaporated on glass substrates. The structural characterization revealed that the as-deposited films were amorphous in nature. The chemical composition of the films has been checked using energy dispersive X-ray spectroscopy (EDX). The spectral distribution and optical parameters have been investigated using spectrophotometric measurements of transmittance and reflectance in the wavelength range (400–2500
nm). The optical constants were determined from the interference maxima and minima using the Swanepole method. The dispersion of the refractive index is discussed in terms of Wemple–Didomenico single oscillator model. The analysis of the optical absorption data indicates the existence of allowed indirect transitions. The optical dispersion parameters
E
o
and
E
d
were determined according to the above-mentioned model. The optical constants such as optical band gap
E
g
o
p
t
, complex dielectric constant and dissipation factor tan
δ were determined.