High-field AC dissipation current waveforms of nonpolar polymeric films superposed by DC ramp voltage

In this study, we studied the high-field AC dissipation current waveforms of an oxidized polypropylene (OPP) film under the superposition of DC ramp voltage at 27°C, 60°C and 90°C. To examine the carrier injection from the electrode, two kinds of metals, Au and Al, were used as the electrode materials. The observed results show the dissipation current waveforms depend largely on the electrode material in the high-field and high-temperature region. These results agree with our previous hypothesis where the carrier injection from the electrode is assisted by the hetero space charge in the vicinity of the electrodes. Based on these results, we discussed the AC conduction mechanisms of oxidized polypropylene in the high-field and high-temperature region