Study on Electron Traps in Polyethylene Terephthalate by Thermally Stimulated Current and Photo-Stimulated Detrapping Current Analyses

Electron traps in PET photoelectret were investigated by the analyses of the thermally stimulated current (TSC) and the photo-stimulated detrapping current (PSDC). A broad peak of TSC was observed around -100°C at which the motion of the COO group was released and a plateau was observed around 0°C. The apparent activation energy of the former peak was estimated at about 0.23 eV by the partial heating technique. On the other hand, PSDC spectra at -185°C showed an existence of deep traps at 2.3 eV, which could be thermally cleaned by heating only up to -70°C. These facts clearly show the effect of molecular motions on the carrier detrapping process during heating.