Atomic and electronic properties of graphene-on-diamond

Carbon, one of the most abundant elements, can exist in two inorganic crystal forms: as diamond, and as graphite. The electronic properties of diamond and graphene, a single layer of graphite, differ in two extremities. While the energy bandgap of about 6 eV in the diamond electronic structure leads to the electrical resistivity as high as 1018 Om, graphene shows a zero bandgap at Fermi level behaving as a semimetals with extraordinary electronic transport properties. A question arises what will happen when these two extremities meet in tight vicinity. The answer will be the aim of this collaborative project. We propose to synthesize graphene-on-diamond (GOD) systems and to investigate the electronic and atomic structure of their interface. The collaboration of the team from the Institute of Physics (IoP) at the Czech academy of sciences with the team from Physics of nanostructured materials (UW) at the University of Vienna brings together a perfectly matching expertise in the research fields of diamond (IoP) and of graphene (UW) including the complementarity of experimental scientific instruments needed for this research.

The aim of the project ATEGOD was to investigate the atomic mechanisms of graphitization at diamond surfaces. The main objective targeted a synthesis of graphene on diamond for superior electronic devices: graphene as a high carrier mobility active channel and diamond in the role of a substrate with very high electrical resistivity and outstanding thermal conductivity. The radio-frequency transistors and quantum spin sensors, for instance, could benefit of such a device architecture. Our team of the Physics of Nanostructured Materials department at the University of Vienna together with a team from the Academy of Sciences Czech Republic focused on a catalytically-mediated graphitization processes of diamond surfaces achieving deep understanding the mechanisms which may differ with the crystal size and orientation. The results were published in 10 open-access international scientific journals and presented in more than 20 international conferences. As for the education of young researchers, the multidisciplinary ATEGOD project was conducted in frame of the PhD thesis by MSc Semir Tulić: "Transformation of diamond surface to graphene - mechanisms and properties". Mr Tulić received the Dr. Tasilo Prnka Prize for outstanding presentation in the international NanoCon 2017 conference. There are still open problems related to direct diamond graphitization. First experiments have already been done in collaboration with the University of Cergy-Paris; in order to continue this research also related to quantum technology, we have proposed a follow-up bilateral FWF-ANR project QUEEN.