Transient Conductivity Measurements in a Molecularly Doped Polymer Over Wide Dynamic Ranges

Abstract

Transient conductivity measurements have been carried out in a hydrazone-polycarbonate molecularly doped polymer over wide dynamic ranges of time and current as a function of the applied electric field. These data are plotted using both linear−linear and log−log axes. The plots on linear−linear axes give familiar results: an initial spike followed by a relatively flat current before the transit time; a mobility that equals published values and precisely follows the Poole−Frenkel law, being exponential in the square root of the electric field; and a current after the transit time that falls much more slowly than can be accounted for using Gaussian statistics. The same data plotted using log−log axes reveals the behavior over long times and low currents. Before the transit time, the decrease of the current can be characterized by two power laws, but it only decreases by about a factor of 2 from 10− 2 of the transit time to the transit time and is almost independent of electric field from 5 to 80 V/μm. After...