Modeling of thermally stimulated currents in polytetrafluoroethylene

A phenomenological model has been derived for thermally stimulated open-circuit current measured on negatively charged polytetrafluoroethylene electret film. The model is based on trap controlled release of negative charge carriers using approximations justified by thermally stimulated current and mean charge depth results. To describe the open-circuit current, a minimum of five traps was necessary including surface and bulk traps with activation energies of 1.3 (2), 1.4, 1.5, and 1.7 eV. In addition, attempt-to-escape frequencies were calculated and found in the range 1011–1013 s−1.