Theoretical Investigation on Linear and Nonlinear Optical Properties of Solution-Processed GeTeBi Chalcogenide Films
Keywords:Chalcogenide, Nano colloid, Bandgap, Dispersion parameter, Refractive Index.
The optical study of Ge20Te75Bi5 nano colloids is presented in this paper. Bulk chalcogenide glass was prepared
by the well-known melt quenching method. Solution-based processing is proposed for nano colloid formation.
Using the spin coating technique, optical-grade thin films are deposited on glass slides. The optical bandgap of
films is estimated from absorbance spectra using the Tauc extrapolation method and Wemple and DiDomenico
(WDD) model is used to determine the optical dispersion parameters. Tichy and Ticha approach has been
employed to observe nonlinear refractive index (n2). An increase in optical parameters and a decrease in optical
bandgap with the increase in glass concentration may be attributed to cluster formation while dissolution.