Abstract
The adsorption of alkali metals (AMs) on single layer graphene is studied using first principles methods. We observe a common trend in the binding distance, the charge transfer, and the work function at certain coverage of AMs with increase in the proportion (adatom/C atom) of the graphene covered by the AM. A dip in these properties occurs at for all AMs except Li, for which it occurs at . This behavior is due to a transition of adsorbed metals from individual atoms to two-dimensional metallic sheets that exert a depolarization effect. of graphene exhibits asymmetric dependence on : a dip in the adatom layer side but saturation on the graphene side, which is in contrast to the case of bulk graphite.
- Received 21 April 2010
DOI:https://doi.org/10.1103/PhysRevB.82.033414
©2010 American Physical Society