Transport properties of Ge30Sb10S60 chalcogenide glasses thin films

The AC electrical conductivity and dielectric relaxation of Ge30Sb10S60 chalcogenide glasses thin films in the frequency range 100 Hz-100 kHz and in the temperature span 290-450 K are reported for the first time. The DC conductivity and thermoelectric power of such system are also measured. From the DC data, a presence of a wide range of localization is predicted and conduction by hopping in the localized state is the dominant conduction mechanism. Thermoelectric power results are in reasonable agreement with the DC data. The AC conductivity, experimental results are explained by means of Elliott and Shimakawa models. Analysis of the results points to the conclusion that a single-polaron hopping mechanism could be a possible process of conduction in such case. The complex dielectric constant is calculated throughout the measurements of capacitance and loss factor. The temperature and frequency dependence of the real and imaginary parts of dielectric constant is measured. The dielectric loss peaks are shifted towards higher frequencies as temperature rises and its experimental observation is explained by the presence of intimate valence alteration pairs (IVAP). (C) 2000 Elsevier Science B.V. All rights reserved.