Thermally stimulated currents in poly-p-phenylene sulphide doped with tetracyanoethylene

Localised states in poly-p-phenylene sulphide (PPS) with an organic acceptor tetracyanoethylene (TCNE) were studied by the analysis of thermally stimulated currents (TSC). It is shown that shallow localised states with energy depths between 0.12 and 0.45 eV are introduced by doping with TCNE. The shallow localised states effectively capture charge carriers at low temperatures (-170-0 degrees C), while they act as effective hopping centres above room temperature.