Abstract: The detrapping currents from poly(2,6-ethylene naphthalene dicarboxylate) (PEN) films r-irradiated at doses ranged over 5× 10⁴ Gy were determined by means of Thermally Stimulated Current (TSC) technique, and the various electrode materials were used.The sign transition of main species of charge carriers in biaxial stretched PENfilm was observed.It is explained that this transition results from shifting of sub-Fermi levels of electrons and holes since the r-irra-diation causes decreasing of mean trap levels.The de-electreting phenomena of both amorphous and biaxial stretched PENelectrets have been investigated.The mechanism of moving of charge carriers during de-electreting process is discussed.

Key words: Electret, Specise of charge carriers, Localized energy level, Trap depth, Irradiation inducing