Densely packed overlayer of iron phthalocyanine molecules grown on single-layer graphene

The formation of densely packed overlayer of iron phthalocyanine （FePc） molecules on single-layer graphene （SLG） epitaxially grown on Ru（0001） is studied by means of low temperature scanning tunneling microscopy. We show that the FePc molecules form single molecular arrays, ordered honeycomb lattice, Kagome lattice and square lattice with increasing molecular coverage. The densely packed square lattice of the molecular layer is modulated by the moire pattern of SLGJRu（O001）. The superposition of the square lattice of the molecular layer on the hexagonal lattice of SLG molte pattern leads to the formation of a larger strip moire pattern. This coverage-dependent self-assembling behavior of FePc on SLG/Ru（0001 ） is mainly driven by the inhomogeneous electronic structure of graphene moire oattern, due to soatial-deoendent interracial charge transfer between SLG and Ru（0001 ） substrate.