Transient and steady-state currents in disordered polyethylene film under charge packet effects

Transient and steady-state currents in disordered polyethylene are presented for low and high dc voltages. For this subject, the charge dynamics, within an additive-free low density polyethylene film, are studied by a bipolar charge transport model. The computational procedures for the external and the conduction currents are based on the Poisson, the continuity and the transport equations with the appropriate physical conditions. The numerical models are chosen to overcome the difficulty due to the nonlinear recombination source terms in continuity equation. Under high dc voltages, the results show the effects of the generated charge packets on the transient and steady-state currents. Indeed, these charge packets induce a conduction regime controlled by the interface electrode-insulator and provoke some oscillations in the transient conduction current. These obtained phenomena are revealed for the first time in modelling although they have been already observed in some experiments.