In organic diodes, usually a high work function transparent metal is used as anode (pa) for hole injection and a low work function metal as cathode (pc) for electron injection. at the metal-organic- metal contact, a non-negligible built-in potential vbi pbi/q is present across the organic layer. neglecting energy level shifts due to the interface dipoles, the built-in voltage is equal to: фа- фс фа + фс 0 2фс