Dependence of activation energy and pre-exponential factor on electric field in amorphous thin films of Se70Te30-xZnx

The present paper reports the effect of electric field on the electrical parameters (activation energy and pre-exponential factor) in amorphous thin films of Se70Te30-xZnx (x = 0, 6, 8). It is observed that, in a particular composition, at low electric field up to 10(3) V/cm neither activation energy nor pre-exponential factor depend on electric field as expected in case of ohmic region. However, at higher electric fields where non ohmic region is observed, activation energy and pre-exponential factor both vary with electric field. Similar behavior is observed in all the compositions used in this study. A correlation between activation energy and pre-exponential factor is also observed in these alloys, which is known as Meyer-Neldel rule (MN rule). Further MN rule is also observed in the present case which is explained by the model suggested by Yelon and Movaghar responsible for MN rule in chalcogenide glasses. (C) 2010 Elsevier B.V. All rights reserved.