Fermi level engineering of topological insulator films by tuning the substrates.

The Fermi level of the topological insulators (TIs) Bi2Se3 and Bi2Te3 is usually well above the Dirac points, which is ascribed to the intrinsic donor defects, such as antisites and anion vacancies. We show here by first-principles calculations that the substrates can modulate the Fermi level of TIs considerably. It is found that in Bi2Se3/graphene and… CONTINUE READING