Electronic properties of organic semiconductor interfaces

Dr. M. Knupfer, FWI-Dresden, Germany

The electronic properties and the energy level alignment of interfaces between organic semiconductors and metals have been studied using photoemission spectroscopy in the valence as well the core level region. It is demonstrated that there are three different contributions to the interface properties, a reduced metal work function, image charge screening and a short-range interface dipole, which determine the energy level alignment in cases without chemical interactions at the interface. The implications of these contributions are discussed. In addition, it is shown that a number of technically relevant interfaces is not free from reactions at the interface.