Interface dipole at metal-organic interfaces: Contribution of metal induced interface states

Despite the importance of interface dipole on the charge carrier injection at metal/organic contacts, there is yet no estimation of the various contributions to the overall dipole. We propose a simple approach to delineate and estimate the contribution of metal-induced interface states (MISs) toward the overall dipole. The relative contribution of the MIS was found to increase as the slope parameter decreases. By using published results, we estimate the relative MIS contributions in organic-silver contacts for various organic semiconductors to be -30%-80% of the overall dipole.