Barrier formation at organic-metal interfaces studied by density functional theory

The barrier formation at organic-metal interfaces was studied with density functional theory (DFT). We analyzed the induced density of states in the organic molecular gap and showed that it is high enough to control the barrier formation. We calculated the interface Fermi level for contact of BCP with various metals e.g. Ca, Mg, Al, Ag, and Au surfaces. We found our calculated result in consistent with experimental (UPS) result and concluded that the barrier formation is due to the charge transfer between the metal and the states induced in BCP molecular gap.