ABSTRACT
Self-consistent mean-field model of charge injection based on the matching of electric displacement and electrochemical potential in the electrode and the insulator is extended so as to account for discreteness of charge carriers. The improved scheme includes both the Schottky barrier lowering due to the individual image charge and the barrier change due to the field penetration into the injecting electrode. Applications of the theory to the cases of high-permittivity dielectric capacitors and organic light-emitting diodes are exemplarily presented.