الفهرس 
Amorphous semiconductorsOnly 14 pages are availabe for public view
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Abstract
Structure identification for the compositions under test, in both powder and thin film forms is confirmed by X-ray diffraction patterns (XRD), energy dispersive X-ray analysis (EDX) and differential thermal analysis (DTA).
The crystallization kinetics of Se0.62Ge0.38 and Se0.62Ge0.35X0.03(X=In, Sb and Bi) chalcogenide glasses has been discussed under non-isothermal conditions using differential thermal analysis DTA. from the heating rate dependence of the glass transition temperature and crystallization temperature , the values of the activation energy of glass transition and the activation energy of crystallization are evaluated.
The optical properties of the studied samples were studied by using spectrophotometric measurements of transmittance and reflectance. The optical constants were determined from the interference using Swanepole method. The optical absorption edge and the optical band gap are estimated from the absorption coefficient values using the non direct transition model by Tauc,s extrapolation procedure.
Dc conductivity measurements of the investigated compositions in thin film form were carried out as a function of temperature in the range [303-433 K] for the thickness 495 nm. The dc conductivity of Se0.62Ge0.38 increases with increasing temperature as well as with metal additives. The observed increasing sequence is in the order (SeGe)< (In) < (Sb)< (Bi). The obtained results showed that conduction activation energy has two values and indicating the presence of two different conduction mechanisms through the investigated range of temperature.
Ac conductivity and dielectric constant measurements were carried out for the investigated compositions at different frequencies in the range [50 Hz-5 MHZ] and in the temperature range [303-433 K]. The ac conductivity for all investigated compositions is temperature dependent, it obeys law. The obtained results are explained on the basis of correlated barrier hopping [CBH] model.