Center for Functional Nanomaterials Seminar

The determination of the structure and electronic properties of organic thin films grown on inorganic substrates is highly relevant for the application of these systems in organic electronic devices. Likewise the interaction of biomolecules with inorganic materials has recently attracted a lot of interest with the aim of determining the characteristics of bio-active surfaces for biotechnological applications. In these films, characterized by a large number of degrees of freedom, structure, morphology and electronic properties are strongly interrelated and often depend critically from the growth conditions and therefore should be studied in situ and in the same experimental system. With the aim of reaching a better understanding of the above-mentioned film properties and of related effects like molecule substrate bond formation, charge transfer processes at the interface and in the films, our group studies the growth of organic thin films by means of various experimental techniques mostly using synchrotron radiation; our experimental apparatus combines structural techniques like Grazing Incidence X-ray Diffraction (GIXD) and He Atom Scattering (HAS) with spectroscopic techniques like High resolution X-ray Photoemission Spectroscopy (HRXPS), X-ray Absorption Spectroscopy (XAS) and most importantly Resonant Photoemission (RESPES). Example of phenomena like substrate induced modification of the electronic states of the organic molecules at the interface, film induced structural rearrangements of the substrate and electron charge transfer processes will be presented referring to thin films of large planar molecules like Cu-phthalocyanine, PTCDA but also small biomolecules like L-cysteine and L-methionine.