Self-assembly of polar phthalocyanine molecules on graphene grown by chemical vapor deposition

Integration of functional organic molecules with graphene is expected to promote the development of graphene-based flexible electronics with novel properties. Here, the self-assembled structure of dipole phthalocyanine molecules, chloro-aluminum phthalocyanine (ClAlPc), on single-layer graphene grown by chemical vapor deposition (CVD) over a Cu film was characterized by low-temperature scanning tunneling microscopy (LT-STM). The phthalocyanine molecules show highly ordered assembled structures on the CVD graphene, and these molecular layers extend continuously over the steps of the Cu film. We also observe specific boundaries in the self-assembled molecule arrays, which can be explained by the presence of domain boundaries in the graphene. The STM results suggest that CVD graphene is as a good molecular assembly template for surface functionalization and that these molecular arrays facilitate the study of domain structures in CVD graphene.