Regensburg 2013 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 81: Post-Deadline Session

O 81.4: Vortrag

Donnerstag, 14. März 2013, 20:45–21:00, H36

When hybridization makes chatty: adsorbate molecules communicating via the substrate — •Achim Schöll — Universität Würzburg, Exp.Physik VII, D-97074 Würzburg und Gemeinschaftslabor für Nanoanalytik, KIT, D-76021 Karlsruhe

Molecular condensates are generally characterized by small charge carrier mobilities, since coherent transport is impeded by disorder and the small intermolecular coupling. A significant band dispersion can only be observed in exceptional cases such as for pi-stacking of aromatic molecules in single crystals. Based on ARPES and STM we demonstrate that the hybridisation with a substrate can substantially increase the delocalization of the molecular states in selective directions along the surface. The influence of the interfacial bonding leads to novel phenomena [1] such as the generation of substrate-molecule hybrid states, which can be identified by analyzing the ARPES intensity distribution [2]. This method allows a mapping of electronic wave functions and thus provides unique information about molecular orbitals [3]. As a consequence of the mixing of molecular and substrate states the molecules communicate laterally via the substrate. This can be observed by a substantial band dispersion of the hybrid band and leads to a delocalization of molecular states mediated by the substrate [4]. Supported by DFT-calculations we show how this mechanism results in a four times larger in-plane charge carrier mobility.

[1] A. Schöll et al, Science 329,303 (2010). [2] J. Ziroff et al, PRL 104(23), (2010). [3] M. Dauth et al, PRL 107(19) (2011). [4] M. Wiessner et al, Nature Communications (in press).