Space charge dynamics of low-density polyethylene

The space charge behavior in various low-density polyethylene (LDPE) has been investigated. The specimens are LDPE polymerized with high pressure method (h-LDPE), with Ziegler-Natta catalysts (LLDPE) or with methallocene catalysts (m-LDPE). The space charge distribution in a semicon/LDPE/Al specimen was measured by the Pulsed Electro-Acoustic (PEA) method. The space charge distributions were different among three kinds of LDPE, h-LDPE, LLDPE and m-LDPE. They also depended upon the electrode materials. Charge carriers were injected more easily from the semicon electrode than the Al or Au electrode. The formation and decay processes of space charge have been discussed considering the morphology of LDPE. The carrier mobility and the trap depth were also estimated from the space charge dynamics, formation and decay of space charge.