Analysis of conductivity of glasses from the (As(2)S(3))(100-x)Bi(x) system in direct and alternating regimes

• Published in: Journal of Optoelectronics and Advanced Materials 2009-12, Vol.11 (12), p.2049-2052
• Main Authors: Siljegovic, M V, Lukic, S R, Skuban, F, Petrovic, D M, Slankamenac, M
• Format: Article
• Language: English
• ISSN: 1454-4164

The work presents results of the conductivity measurements in both direct and alternating regimes for a series of samples from the system (As(2)S(3))(100-x) Bi(x), x=0.5, 2, 6 and 8 at.%. Temperature dependence in the dc regime indicates a semiconducting character of all investigated glasses. A linear fit of experimental results was used to determine the pre-exponential factor and energy of activation. On the basis of the analysis of these parameters it was possible to establish a dominant mechanism of conduction, as well as an increased participation of localized states in the transfer processes with an increase in Bi concentration. Conductivity measurements in the ac regime were performed with the aim of studying the nature of defect centers. The glasses with 0.5, 2 and 6 at.% Bi showed a frequency dependence of the ac conductivity that is typical for amorphous semiconducting materials. The absence of frequency dependence for the glass with 8 at.% Bi at higher temperatures in the major part of the measuring interval, significantly higher conductivity, as well as its temperature dependence, compared to the other glass samples, indicate the possibility of treating this sample as an inhomogeneous double-layer structure, an indication of this being also the results of x-ray analysis.