Currents and charge profiles in electron beam irradiated samples under an applied voltage: exact numerical calculation and Sessler's conductivity approximation

In this paper the Sessler's treatment (ST) for radiation induced conductivity in open circuit, in which the material under electron beam irradiation is supposed to acquire a conductivity and to accumulate mobile as well as trapped charges, is applied to the case of irradiation under a voltage. We show that ST is an approximation of a more complex treatment where the generation-recombination process is explicitly considered while allowing a single species to move. ST leads to good results for the back electrode current and for charge profiles if the electric field is so directed as to drive the mobile charges into the sample bulk. In general, trapping causes the agreement to be worse. An implicit finite difference scheme was employed in the numerical integration to ensure greater accuracy.