Self-organisation and growth of organic molecules on oxide surfaces

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funCOS4 aims at a deeper understanding of film growth and adsorption kinetics of medium-sized organic molecules on various single-crystalline oxide substrates, epitaxial oxide films on metal single crystals or nanoscaled oxidic systems (mainly nanoparticles). This includes aspects of various interactions, in particular the interplay of intermolecular interactions and molecule-substrate interactions, which are governing the growth of ultrathin organic films. Utilizing probes, which offer information ranging from the atomic to the mesoscopic length scales, the structural properties of the adsorbed organic film from the submonolayer to the multilayer regime can be accessed. Diffraction techniques (XRD, LEED, SAXS/SANS, GISAXS, XRR) deliver structural information with accuracies better than 0.1 Angström and in-situ studies will offer access to film formation kinetics. Surface-sensitive electron microscopic tools (PEEM, LEEM, XPEEM) will offer real-space information for both, oxide substrates and organic thin films. Two different preparation routes will be followed, i.e., preparation by vacuum sublimation and film deposition by wet chemical routes. The latter uses strong molecule-substrate-interactions to induce the formation of SAMs on planar substrates or nanoparticulate template structures. Thus, the project will bridge the gap from model systems prepared under UHV conditions to molecular depositions from solvents, thus offering potential pathways to prepare highly ordered molecular systems without costly hardware. Specifically, we will explore the perpendicular and lateral structures of adsorbed ultrathin films, the orientation of adsorbed molecules, the structural properties of the molecule-oxide interface, controlled substrate modifications and their influence on organic film formation, film growth modes, nucleation and long-range interactions on planar oxidic substrates and for nanoparticulate oxides. In-situ investigations will furthermore allow the insight into film formation kinetics. For optimum coherence with the other funCOS groups, the studies will concentrate on MgO, Co oxides and TiO2 as model systems including surface-modified substrates and the respective nanoparticulate systems.