Study of defect state chemistry of chalcogens elements (Se/Te) in binary Se100-xTex glassy system using lowtemperature d.c. conductivity measurements

Abstract

The density of defect states (DDS) has always been a subject of curiosity in electronic materials as the knowledge of this parameter is a key parameter for determining the applications of these materials. Chalcogenide glasses are well known as electronic materials because of their excellent electrical properties (e.g., resistive switching, thermally activated a.c. and d.c. conduction, dielectric relaxation, etc). In the present paper, the d.c. conductivity has been measured for chalcogens elements Se and Te based binary glasses in the low-temperature region to apply the Mott’s theory of electronic conduction. The conduction mechanism in this region follows the Mott’s temperature dependence. The further investigations provide the estimation of the density of defect states (DDS) in Se100-xTex alloys. The value of DDS is decreased with the increase in Te concentration. We have observed a correlation between the DDS and the electronegativity of the chalcogens elements Se and Te. The compositional dependence of the hopping parameters indicates that the condition becomes easier for the variable range hoping with the rise in the Te concentration. © 2020, National Institute of Optoelectronics. All rights reserved.