Band bending at the surface of Bi${}_2$Se${}_3$ studied from first principles

Abstract

The band bending (BB) effect on the surface of the second-generation topological insulators implies a serious challenge to design transport devices. The BB is triggered by the effective electric field generated by charged impurities close to the surface and by the inhomogeneous charge distribution of the occupied surface states. Our self-consistent calculations in the Korringa-Kohn-Rostoker framework showed that in contrast to the bulk bands, the spectrum of the surface states is not bent at the surface. In turn, it is possible to tune the energy level of the Dirac point via the deposited surface dopants. In addition, the electrostatic modifications induced by the charged impurities on the surface induce long range oscillations in the charge density. For dopants located beneath the surface, however, these oscillations become highly suppressed. Our findings are in good agreement with recent experiments, however, our results indicate that the concentration of the surface doping cannot be estimated from the energy shift of the Dirac cone within the scope of the effective continuous model for the protected surface states.

7 pages, 6 figures

References in corpus (8)

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Cited by in corpus (5)

• Band Structure of Topological Insulator BiSbTe1.25Se1.75
• Electronic and transport properties of the Mn-doped topological insulator Bi${}_2$Te${}_3$: A first-principles study
• Magnetic properties of Mn-doped Bi${}_2$Se${}_3$ topological insulators: ab initio calculations
• Proximity effect in a superconductor-topological insulator heterostructure based on first principles
• Observability of superconductivity in Sr-doped Bi2Se3 at the surface using scanning tunneling microscope