Abstract
Scanning tunneling microscopy (STM) studies of the fullerene C molecule adsorbed on the silicon carbide SiC(0001)- surface, combined with density functional theory (DFT) calculations, show that chemisorption of individual C molecules occurs through the formation of one bond to one silicon adatom only in contrast to multiple bond formation on other semiconducting surfaces. We observe three stable adsorption sites with respect to the Si adatoms of the surface unit cell. Comprehensive DFT calculations give different adsorption energies for the three most abundant sites showing that van der Waals forces between the C molecule and the neighboring surface atoms need to be considered. The C molecules are observed to form small clusters even at low coverage indicating the presence of a mobile molecular precursor state and nonnegligible intermolecular interactions.
- Received 15 May 2012
DOI:https://doi.org/10.1103/PhysRevB.87.155421
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