Metal-organic interface and charge injection in organic electronic devices

521 An overview is given of the current understanding about the formation of metal-organic interfaces and how the properties of the interface affect charge injection. First an ideal interface, namely that between a clean metal surface and a van der Waals solid, where the molecular energy levels are such that one expects no chemical reaction is described. Following this, experimental data that relate to the energy level structure of the interface are reviewed. Finally, various theoretical approaches to the charge injection process are summarized and experiments designed to test the various theoretical predictions discussed.