Abstract
Thermally stimulated current (TSC) and conductivity measurements were carried out on the composites of PE (polyethylene) and EVA ((ethylene-vinyl acetate) copolymer). When PE-EVA composite with Au electrodes was polarised with a positive voltage on the EVA side (PE-EVA(+)), a new TSC peak (P4) appeared which was not observed in PE, EVA or PE-EVA(-). The conduction currents in PE-EVA composites showed remarkable dependence on the polarity of the bias voltage and the electrode material. This led to the following conclusions. (i) Positive carriers are easily injected into EVA from the Au anode. (ii) Some of them trapped at the PE-EVA interface and give rise to the P4 peak. (iii) Most of the positive carriers can pass through the PE-EVA interface and move in the PE region, increasing the conduction current in PE by about two orders of magnitude.