Graphene on atomically flat insulating substrates

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The project aims at preparing high quality graphene on clean, atomically ordered, electrically insulating substrates such as CaF2, CeO2, and diamond and a fundamental understanding of the physical properties of such systems. The focus of investigations is on the characterisation of graphene atomic scale structural properties as well as understanding and controlling the interaction of graphene with the underlying substrate. Graphene films are characterised by highest resolution dynamic scanning force microscopy operated in the non-contact mode (NC AFM) and Kelvin probe force microscopy (KPFM). From atomically resolved measurements at the border of flakes, we expect to reveal the registry between the graphene film and the substrate while force imaging and spectroscopy on the lake area is expected to yield information about the interaction between the graphene film and the substrate. The main goals for the project are (1) the improvement of the exfoliation of graphene in the ultra-high vacuum to produce large flakes of single layer graphene of highest structural perfection and uniformity on insulator surfaces, (2) the atomic scale characterisation of defects on or under the graphene flakes, and at their borders and (3) the study of the atomic structure and the local surface potential of folded graphene films as well as their registry with the underlying single layer film.