The mean depth of trap level of oriented, crystallized and γ-irradiated poly(ethylene terephthalate) electrets

The mean depth of trap level is increased with increasing degree of planar orientation, crystallinity, and irradiation done in oriented, crystallized, and γ-irradiated PET electrets. The order of variation range for the trap depth is drawn, γ-irradiated, and annealed sample. Three kinds of trap models are proposed corresponding to the three methods of sample treatment on the basis of the depth of trap level, the current maximum of detrapping charge carriers, and the initial density of charge carriers