Ac conductivity and dielectric properties of Ge20Se75In5 films

作者：Bekheet A E^*; Hegab N A

来源：Vacuum, 2008, 83(2): 391-396.

DOI：10.1016/j.vacuum.2008.05.023

• Ac conductivity
• Dielectric properties
• Ge-Se-In films

Amorphous films of Ge20Se75In5 chalcogenide glass were prepared using a thermal evaporation technique. The chemical composition of the deposited films was examined using energy dispersive X-ray spectroscopy (EDX). The ac conductivity and dielectric properties of the prepared films have been studied as a function of temperature in the range from 300 to 423 K and frequency in the range from 1 02 to 10(5) Hz. The experimental results indicate that ac conductivity sigma(ac)((omega)) is proportional to omega(5) where s equals 0.902 at room temperature and decreases with increasing temperature. The results obtained are discussed in terms of the correlated barrier hopping (CBH) model. The density of localized states N(E-F) at the Fermi level is found to have values of the order 10(19) eV(-1) cm(-3), which increase with temperature. The dielectric constant epsilon(1) and dielectric loss epsilon(2) were found to decrease with increasing frequency and to increase with increasing temperature over the ranges studied. The maximum barrier height W-m was estimated from an analysis of the dielectric loss,2 according to Giuntini equation, its value for the deposited films (0.43 eV) agrees with that proposed by the theory of hopping of charge carrier over a potential barrier as suggested by Elliott for chalcogenide glasses.

• 出版日期2008-9-26