Measurements on the photo-induced discharge effects of ZnO semiconductor powder-resin binder layers show clearly their applicability as photoreceptors in low-volume xerographic machines. From the optical transmission characteristics, it can be confirmed that light is effectively guided down the binder layer as a result of multiple reflections at the semiconductor surface. An impurity or defect centre located at 1.61 eV below the conduction band of ZnO is found from the photoconductivity action spectrum and confirmed by cathodeluminescence data. The transit time results on these ZnO layers, obtained from xerographic time-of-flight measurements, lend support to the belief that the electron traps in these materials are essentially shallow in depth but likely to be present in large numbers.