Study of space charge effects in polyethylene by thermal-pulse current techniques

Effects of oxidation on space-charge formation, carrier injection, and electrical conduction in polyethylene (PE) are studied by using thermal pulse current and thermally stimulated current (TSC) techniques. Oxidation increases the conduction current by a few orders of magnitude and negative homo space charge is formed near the cathode. The introduction of an oxidized PE layer on the surface of unoxidized PE enhances both electron and hole injection. The enhanced electron injection predominates over the hole injection and plays an important role in the increase of conduction with oxidation. The negative homo space charge is released at ≈40°C and gives rise to a TSC peak