DC and AC conductivities of (As<inf>2</inf>S<inf>3</inf>)<inf>100-x</inf>(AsSe<inf> 0.5</inf>Te<inf>0.5</inf>I)<inf>x</inf> chalcogenide glasses

Abstract

The DC and AC conductivities of samples from the system (As2S3)100-x(AsSe 0.5Te0.5I)x, where x=0, 5, 10, 15, 20, 25, 30, 35, 50, 70 and 90 mol%, were measured as a function of temperature. Besides, the AC conductivities of the samples with x=10 and 30 were measured as a function of frequency from room temperature to the glass transition temperature. The DC conductivity dependence on temperature is of the Arrhenius type, whereas the value of the pre-exponential factor suggests the electrical conduction by localized states in the band tails and by localized states near the Fermi level. The small values of the conduction activation energy (10-2-10-1 eV) obtained at higher frequencies suggest that the conduction in these materials is due to hopping of charge carriers between close defect states near the Fermi level. © 2008 Elsevier B.V. All rights reserved.