A method of controlling variations in electrical characteristics in electrophotographic imaging devices by eliminating the effect of acidic or basic impurities in a photoconductive element. A solution of a weak acid or weak base and a conjugate salt of the weak acid and the weak base is incorporated into a layer of the photoconductive element. In a process for producing the photoconductive element, a substrate is coated with a first dispersion to form a charge generating layer, and then coated with a second dispersion to form a charge transporting layer, wherein there is incorporated in at least one of the first and second dispersions a solution of a weak acid or weak base and the conjugate salt of the weak acid and weak base in an amount effective to reduce variations in the dark development potential (VDDP) and background potential (VBG) characteristics of the imaging devices.