The effect of annealing time on thermally stimulated discharge current of corona-charged ethyl cellulose

Short circuit thermally stimulated discharge current (TSDC) has been recorded in corona-charged ethyl cellulose foil samples at different annealing time. An analysis of the data reveals significant changes in the TSDC curves of the samples as a function of annealing time. The possible relaxation processes accounting for the changes are discussed, not only a shift of peak temperature of the observed peak to higher temperatures, but also a lowering in its height has been observed with increase in annealing time. Peak temperature higher than 343 K did not arise even for the annealing time of 240 h. The activation energy (A) has been found to increase, while the trapped charge carrier n (t) decrease with increase in annealing time. Linear relationship between ln A and n (t) indicated an exponential distribution of traps.