Charge transfer at photoconductor–liquid interfaces

The electrical properties of a photoconductor–liquid interface are investigated by a study of transient photostimulated charge transfer from phthalocyanine into an insulating hydrocarbon liquid. The dependence of charge transfer on electric field, light intensity, and concentration of impurities added to the liquid was measured. A theoretical rate constant model is developed for the various processes which contribute to the transient current. Comparing this to the measurements, we find evidence for surface traps at the interface. A model for the desorption rate of ions from the interface is used to obtain an estimate of the adsorption energy of the ion at the interface. Finally, a discussion of probable charge transfer mechanisms is presented.