title: Orientation-dependent growth mechanisms of graphene islands on Ir(111).
abstract: Using low-energy electron microscopy, we find that the mechanisms of graphene growth on Ir(111) depend sensitively on island orientation with respect to Ir. In the temperature range of 750-900 °C, we observe that growing rotated islands are more faceted than islands aligned with the substrate. Further, the growth velocity of rotated islands depends not only on the C adatom supersaturation but also on the geometry of the island edge. We deduce that the growth of rotated islands is kink-nucleation-limited, whereas aligned islands are kink-advancement-limited. These different growth mechanisms are attributed to differences in the graphene edge binding strength to the substrate.
authors.affiliation: Department of Materials Science and Engineering, University of California, Berkeley , Berkeley, California 94720, United States.
authors.forename: P C
authors.initials: PC
authors.lastname: Rogge
authors.forename: S
authors.initials: S
authors.lastname: Nie
authors.forename: K F
authors.initials: KF
authors.lastname: McCarty
authors.forename: N C
authors.initials: NC
authors.lastname: Bartelt
authors.forename: O D
authors.initials: OD
authors.lastname: Dubon
keywords: Graphene; crystal growth; kinks; low-energy electron microscopy; rotational variants