Electrical conduction mechanism in films of Se80-xTe20Bix (0 ≤ x ≤ 12) glassy alloys

This paper reports the study of DC electrical conductivity of films of Se80-xTe20Bix (0 <= x <= 12) glasses prepared using physical vapor deposition method. The films were structurally characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM results indicate the formation of nanorods within the films. The electrical conductivity of the samples was studied using Keithley electrometer in the temperature range 303-373 K. The results show that conduction in these samples takes place via thermally assisted tunnelling and variable range hopping of charge carriers corresponding to higher and lower temperature ranges, respectively. Further, it was found that the conductivity increases with increase in Bi concentration in Se-Te system. This has been explained on the basis of chemically ordered network model. It was also found that nanorod formation improves the electrical conductivity of Se-Te-Bi system compared to bulk Se-Te-Bi system.