Interfaces between conjugated organic molecules and metal surfaces: Correlating adsorption-induced distortion, electronic structure, and interface dipole

We will undertake a comprehensive study of conjugated organic adsorbates on metal substrates, focusing on the interplay between structural and electronic properties of the interface. Using complementary techniques, i.e., mainly photoelectron spectroscopy and the X-ray standing wave technique, our collaboration addresses fundamental issues of organic thin films. Specifically, the strength of the adsorbate-substrate interaction ( physisorption vs. chemisorption ), the orientation of the molecules on the surface, their bonding distances, molecular distortions and distortion-induced molecular dipoles will be studied in detail, in connection with the electronic properties (interface dipole, charge injection barrier). This work is a significant contribution towards the understanding of physical and chemical phenomena at interfaces between conjugated organic molecules and metals, which is a prerequisite for developing and optimizing devices that employ organic thin films.