Thermally Stimulated Current from Polyethylene in High-Temperature Region

Abstract

Thermally stimulated current (TSC) is obtained with a small external electric field from low and high density polyethylenes which have been treated by a high-field application. Two peaks, P1 and P2, appear at about 85° and 50°C, respectively. The decay time constant of trapped charges is also obtained from the isothermal decay experiment which is compared with that estimated from the TSC curve. For the peak P1, a consideration on both the activation energies and the relation between the apparent capture cross section and the nature of life-time suggests that the trap is surrounded by a potential barrier. For the peak P2, the traps exist in the amorphous-crystalline interface and the release of the trapped charges is enhanced by the molecular motion.