Tandem injection of charge carriers across a metal-dielectric interface

A tandem mechanism of charge injection from a metal contact into an organic dielectric via an intermediate injection-facilitating layer is considered. It is shown that introducing such a layer can enhance charge injection considerably if the energy of transport states in this layer is in between the Fermi level of the contact and the energy of transport states in the bulk dielectric. The optimum energy of transport states in the intermediate layer and the minimum thickness thereof are calculated. (C) 2000 American Institute of Physics. [S0003-6951(00)04343-6].