Investigation of Two-Dimensional h-BCN Semiconductors

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This project is based on the hypothesis that the recently discovered 2D semiconductor h-BCN may replace graphene as a candidate material for 2D electronics. The 2D lattice structure of h-BN is identical to that of graphene, but with the graphenic sites occupied by atoms of boron, nitrogen and carbon. Hexagonal BCN exhibits a direct electronic band gap of 1.0 - 1.5 eV in preliminary measurements. However, the exact atomic structure of h-BCN is thus far unknown; computational modelling predicts that there are several possibilities to connect the precursor molecules, bis-BN cyclohexane, to form a covalent 2D layer after thermal dehydrogenation, which thus far have been indistinguishable in experimental studies. The goal of this project is to establish the materials-scientific basis of h-BCN. We will develop a fundamental understanding of the reaction kinetics during the h-BCN formation, the role of the supporting substrate during growth, the parameter space that determines the growth, local conductivities and the full k-space resolved electronic band structure. The experimental approach relies on state-of-the-art surface-scientific microscopy and spectroscopy methods under ultrahigh vacuum. The high risk and high reward component of this project are feasibility studies to exfoliate h-BCN from the substrate for prototype device fabrication. The suitability of h-BCN as nanotemplate for nanostructure growth will be explored. The impact of this study is expected to be huge, as the availability of graphene-like material with a moderate electronic bandgap, comparable to that of silicon and GaAs, could ultimately accelerate the development and implementation of 2D electronic devices.