Compositional effects on the optical properties of Gex Sb40−x Se60 thin films

摘要: Abstract Ge x Sb 40− Se 60 (  = 0, 2.42 and 23.41 at.%) thin chalcogenide films were deposited on glass quartz substrates by the conventional thermal evaporation technique at 300 K. The chemical composition of bulk material as-deposited determined energy dispersive analysis X-ray spectrometry (EDAX). diffraction pattern (XRD) indicates that they have amorphous structure. optical transmission reflection spectra measured in range 500 to 2500 nm. absorption coefficient studied for samples. It is observed edge shift higher range, as germanium content, , increases film. type electronic transition, responsible properties, indirect allowed transition. found band gap content increases. average coordination number N c ) increases, but atoms remains constant. – bonds bond system increase with number. gap, E g number, ). Also 04 discussed terms its relation composition. dispersion refractive index n Single Oscillator Model (SOM) (Wimple Didomenico model). single oscillator 0 ), d dielectric constant ɛ ∞ are also estimated.