Compositional dependence of structural, physical, and, in particular, optical parameters of Se50–x Te30Sn20Sb x chalcogenide glassy systems

Highlights: • Quaternary chacogenide glassy system have been prepared by melt quenching method. • Compositional dependence of several physiochemical, structural and optical properties are studied. • Tauc-plot method has been deployed to determine optical band gap energy. • The location shift of the CB and VB potential have been studied and discussed. • Compositional dependence of Transition temperature has been observed. Through this paper, we describe the compositional dependency on physical, structural and optical properties of Se_50–xTe₃₀Sn₂₀Sb_x (x = 2, 4, 6, and 8) chalcogenide bulk glassy systems, synthesized via the melt quenching method. X-ray diffraction patterns of all the samples conspicuously confirm the formation of the amorphous structure. Various structural parameters like density, molar volume, compactness, atomic density and other associated parameters have been evaluated and the effect of Sb incorporation within the network has been discussed. The studied glass is rigidly connected, as suggested by the gradual increment in the values of estimated average coordination. Tauc's extrapolation method has been employed to determine optical bandgap energy from UV–Vis spectroscopic data, which reveal that optical bandgap energy decreases as Sb content increases. The bond distribution within the glassy network has been studied and discussed. The Mean bond energy and cohesive energy of the glassy systems have been estimated by using the chemical bond approach (CBA). The glass transition temperature varies with composition. The position of the valence band edge and conduction band edge has been determined to inspect the applicability of the as-prepared samples in designing semiconductor devices.