Abstract: Photoreceptor used in this study was a single-layered ε-CuPc which was prepared bydispersing the photoconducting pigment in a polyester at different concentrations and coatingthe dispersion on aluminum substrate. Results showed that such prepared devices can be usedas positive and negative-charging photoreceptors and the negative-charging yields higher surface potential than positive-charging under identical corona-discharging-voltage,i.e.,V-V_T(V_T is the threshold corona-discharging-voltage).High ε-CuPc concentrations over 40%induced too fast dark-decay.Dark-decay was brought under control by reducing the loadingof ε-CuPc to below 20%,but at the sacrifice of photo decay speed,resulting in higher residualpotential. The loading of ε-CuPc in the range of 30 to 40%was considered most proper.

Key words: organic photoconductor, ε-CuPc, concentration of photoconducting center