Numerical analysis of the radiation-induced conductivity in polymers in a large-signal regime
We made numerical calculations of the radiation-induced conductivity by computing current densities, carrier concentrations, and internal electric fields in a disordered sample biased by constant applied voltage under a pulsed or step-function irradiation in a large-signal regime. For this purpose, we used the multiple trapping model featuring an exponential trap distribution with the dispersion parameter α. Calculations of radiation-induced conductivity were done with traditional simplifications (1D-analysis, one-carrier polymer, diffusion currents neglected, and non-injecting electrodes). The nonlinear effects accompanying the large-signal radiation-induced conductivity, such as an internal field variation, the bimolecular recombination, and the charge carrier extraction by electrodes, have been consistently accounted for. Numerical analysis agrees satisfactorily with the results of previously published analytical calculations.