Time-dependent photoconductivity in the presence of light-induced recombination: application to atactic polystyrene

After introducing a novel recombination term representing light-induced bimolecular recombination processes the authors calculate time-dependent profiles for electron and hole density and electric field across a highly insulating material (atactic polystyrene) subjected to ultraviolet radiation and to the application of a potential at the illuminated electrode. The time-dependent current density is calculated for a wide range of parameters over arbitrary long intervals of time. In the weak-field limit the asymptotic behaviour of the photocurrent follows the Onsager electron-hole pair generation mechanism as observed experimentally in the strong-field case.