Influence of bimolecular recombination on xerographic discharge process

Abstract

The photoinduced decay of surface potential, known as xerographic discharge, is analyzed as a method of determination of photogeneration quantum yield taking into account the recombination processes. The effects of slowing down the surface potential decay with time of illumination and nonzero residual potential are usually explained by trapping of the charge carriers in the bulk of the photoconductor. However, these effects can be explained also by bimolecular recombination in the illuminated thin surface layer occurring simultaneously with the photogeneration. In this work it is assumed that as a result of the illumination the mobile positive charge carriers and immobile negative recombination centers are generated. The critical value of the recombination cross section is determined for which the nonzero residual surface potential appears. This analysis allows also to determine an influence of the accumulated recombination centers on the photocurrent decay and build up of the residual potential in a series of subsequent xerographic discharge experiments.