Growth of niobium on the three-dimensional topological insulator Bi2Te1.95Se1.05

Abstract

While applying a new cleaving method, we investigated the growth of Nb on the three-dimensional (3D) topological insulator (TI) Bi2Te1.95Se1.05 by scanning tunneling microscopy and spectroscopy. After the deposition of nearly a full monolayer of Nb by high-energy electron-beam evaporation, we observed a downshift of the bands and the Dirac point on the TI surface, which is the result of an n-type doping of the TI by transition metal adatoms. Extra peaks in the spectroscopy results upon Nb deposition might indicate a Rashba-split of the bulk bands. Nb grew in small 10 nm wide islands upon sub-monolayer growth and in a layer-by-layer growth mode up to an annealing temperature of 450 °C. © 2015 Elsevier B.V. All rights reserved.