An estimation of absorption parameters via optical characterization and theoretical analysis of (Ge₁S₂)_100−X(As₂Te₃)_X chalcogenides for Ir applications

The current investigation reports the optoelectronics studies for (Ge₂S₈)_100−x(As₂Te₃)_x (GSAT) (0 ≤ x ≤ 100) non-crystalline films. The GSAT glasses have been synthesised by using the conventional melt quench method. At 300 K and a vacuum of 10⁻⁵ Torr, the GAST films have been thermally evaporated on cleaned glass substrates. The XRD (X-ray diffraction) curves insist the non-crystalline state of the GAST samples. The transmittance and reflectance spectra have been used to evaluate the absorption parameters, optical band gap (E_g), and tailing constraints of the Ge-S-As-Te glasses. Both the values of E_g and the absorption edge energy are lessening; nevertheless, the energy of band tail width rises with the enhancement of As₂Te₃ ratio at the expense of Ge₂S₈ contents. Some of the physically criteria viz. glass densities (ρ), compactness (δ), and main atomic volume (V_m) were estimated for GAST glasses. Both the conductance and valance band positions have also been evaluated. The index of refraction (n) has been correlated with E_g values. The obtained results suggest that GSAT films are suitable for many optic devices.