Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014)
    Thin Films Tuesday Sessions
       Session TF-TuP

Paper TF-TuP15
Atomically-resolved Orientational Ordering of C60 Molecules on Epitaxial Graphene on Cu(111)

Tuesday, December 9, 2014, 4:00 pm, Room Mauka

Session: Thin Films Poster Session
Presenter: Hyung-Joon Shin, UNIST, Republic of Korea
Authors: M. Jung, UNIST
D. Shin, UNIST
S.-D. Sohn, UNIST
S.-Y. Kwon, UNIST
N. Park, UNIST
H.-J. Shin, UNIST, Republic of Korea
Correspondent: Click to Email
The interaction between molecular adsorbates and graphene is one of the fundamental issues for tailoring the properties of graphene-based molecular devices, because the electronic and structural properties of molecular layers on surfaces are determined by intermolecular and molecule-substrate interactions. Here, we present the atomically resolved experimental measurements of the self-assembled fullerene molecules on single-layer graphene on a Cu(111). Fullerene molecules form a (4 x 4) superstructure on graphene/Cu(111), revealing only single molecular orientation. We can resolve the exact adsorption site and the configuration of fullerene by means of low-temperature scanning tunnelling microscopy (LT-STM) and density functional theory (DFT) calculations. The adsorption orientation can be explained in terms of the competition between intermolecular interaction and molecule-substrate interaction, where strong Coulomb interactions among the fullerenes determine the in-plane orientation of the fullerene. Our results provide important implications for developing carbon- based organic devices using a graphene template in future.