(417a) Edge-Epitaxial Growth of Graphene

Edge-epitaxial growth is a new type of the epitaxial growth that allows van der Waals (vdWs) layered structures to grow on various crystallographic plane of substrate. Here, we demonstrate that for graphene grown on Cu substrate, this type of growth can be achieved when graphene supply is restricted during the nucleation stage of the atmospheric pressure chemical vapor deposition process. Fundamentally, different from conventional vdWs growth, this new type of epitaxial growth benefits from the strong binding between the graphene edge and a metal step in a hydrogen-absent atmosphere. This interaction fixes the orientation of graphene grains in energetically preferable configurations at the early nucleation stage. Observation of this new type of edge-epitaxial growth helps to clarify many contradictory graphene growth phenomena that have been observed previously and may provide insights that will facilitate an understanding of the growth of other materials using the chemical vapor deposition method.