Thermally Stimulated Currents in Polyethylene Terephthalate due to Injected Charge

Abstract

Thermally stimulated currents (TSC) from polyethylene terephthalate (PET) electrets have been investigated in the temperature range from -190 to +120°C. PET electrets were formed by applying a high field in a short time at various temperatures. Both dependencies of TSC on electrode metals (Au, Al) and the polarity of an applied field were remarkable in the temperature range above -40°C. The results indicate that electrons injected from the Al cathode greatly contribute to the TSC above -40°C and that the TSCs below -40°C for Al electrodes and at all temperatures for Au electrodes are mainly induced by the depolarization of dipoles.