Tailoring of physical, optical, and thermal properties of Se50-xTe30Ge20Sbx chalcogenide glasses: Influence of metalloids

Abstract

The compositional dependence on physical and spectroscopic characteristics of chalcogenide Se50-xTe30Ge20Sbx (x = 5, 10, 15, and 20 at. wt%) bulk glassy systems has been explored in this communication. Numerous physical and optical features are rigorously examined by using the best glass sample among all the prepared samples. The XRD pattern reveals the amorphous character of the synthesized materials. Some of the physical parameters like density, and compactness are gradually increasing with the Sb addition, while the free volume percentage and excess volume follow the decreasing trend. The optical properties have been precisely inspected by UV-Vis spectroscopy in the (200–800) nm spectral range. The optical bandgap (Eopt) values are found to decline from (1.09–0.85) eV with Sb content. The observed refractive index, n values experience a subsequent decline with incident energy. By using the Wemple and DiDomenico (WDD) single oscillator model, the refractive index dispersion curve has been studied, and the dispersion parameters are discussed. The valence band (VB) and conduction band (CB) locations are estimated, and the obtained result reveals the VB potential increases from −15,089 eV to −1.3899 eV, while that of CB decreases from −0.4113 eV to −0.5303 eV with the rise of Sb-concentration. The cohesive energy (CE) values have been estimated by using the chemical bond approach (CBA). Investigation reveals the CE of the system decreases from 45.237 kcal/mole to 44.229 kcal/mole justifying the decrement in obtained band gap energy values of the studied glassy systems. Furthermore, the compositional dependency of various thermal parameters is investigated by using the DSC approach. The glass transition (Tg), and peak crystallization (Tp) were significantly affected by Sb addition. The obtained values of Tg are found to decrease from (337–305 K), while the thermal stability is found to increase with the Sb incorporation.