Optical Studies of Se80In5Te10Sb5 Nano Chalcogenide Thin Films of Different Thickness

This present study explores the effect of film thickness on the optical parameters of Se80In5Te10Sb5 nano-scale chalcogenide thin films deposited on glass/Si wafer substrates using the thermal evaporation technique under a vacuum of 10⁻⁶ Torr. The amorphous structure of the films was verified by High Resolution X-ray characterization, and their surface morphologies were subsequently investigated using FESEM. The optical constants of the thin films were evaluated from absorption spectra as a function of photon energy within the 400–1100 nm wavelength range. Chalcogenide glasses exhibit strong thickness-dependent optical properties such as changes in optical band gap, refractive index, and absorption coefficient. Experimental outcomes indicate that with the increase in film thickness, the optical band gap tends to decrease and other optical parameters differ methodically because of quantum confinement and structural disorder effects. The outcomes play a key role in enabling the rational design of chalcogenide films for advanced photonic and optoelectronic devices.