Abstract
High-quality films are obtained by molecular beam epitaxy on a graphene substrate and investigated by in situ scanning tunneling microscopy and spectroscopy. Intrinsic defects responsible for the natural -type conductivity of are identified to be the Sb vacancies and antisites in agreement with first-principles calculations. By minimizing defect densities, coupled with a transfer doping by the graphene substrate, the Fermi level of thin films can be tuned over the entire range of the bulk band gap. This establishes the necessary condition to explore topological insulator behaviors near the Dirac point.
- Received 22 August 2011
DOI:https://doi.org/10.1103/PhysRevLett.108.066809
© 2012 American Physical Society