Charge carrier injection into insulating media: Single-particle versus mean-field approach

Self-consistent, mean-field description of charge injection into a dielectric medium is modified 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 that ensures validity of the model at both high and low injection rates including the barrier-dominated and the space-charge-dominated regimes. Comparison of the theory to experiment on a unipolar indium tin oxide-poly(phenylene vinylene)-Au device is presented.