Abstract
High-resolution transmission electron microscopy (HRTEM) studies show the dynamics of small
graphene platelets on larger graphene layers. The platelets move nearly freely to eventually lock in at
well-defined positions close to the edges of the larger underlying graphene sheet. While such
movement is driven by a shallow potential energy surface described by an interplane interaction, the
lock-in position occurs by via edge-edge interactions of the platelet and the graphene surface located
underneath. Here we quantitatively study this behavior using van der Waals density functional
calculations. Local interactions at the open edges are found to dictate stacking configurations that are
different from Bernal (AB) stacking. These stacking configurations are known to be otherwise absent in
edge-free two-dimensional (2D) graphene. The results explain the experimentally observed platelet
dynamics and provide a detailed account of the new electronic properties of these combined systems.
