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Investigation of current density, recombination rate and space charge density in polyethylene thin films based on bipolar charge transport model

Bipolar charge transport model has been widely used to simulate the behavior of space charge in polymeric materials. In order to reduce the error of splitting method three-order flux limiter is adopted to solve the advection-reaction equations. The simulation results are compared with the experimental results and simulation results of Le Roy et al, validating the feasibility of the numerical scheme. The recombination rates and charge densities during polarization and depolarization are deeply analyzed for polyethylene at 40 kV mm−1. The effects of electric field on charge transport are also presented. It is found that the net charge density during polarization increases with the increase of the electric field. Negative charges are observed in the vicinity of the cathode, which disagrees with the experimental results.