Topological Insulator Bi2Te3: The Effect of Doping with Elements from the VIII B Column of the Periodic Table

Abstract

We studied the doping of a Bi2Te3 single crystal using angle-resolved photoemission and ab initio electronic structure calculations. We find that at the surface, the typical bulk p-type conductivity is transformed to the n-type. The dopants from the VIII B column (Fe, Ru, and Os) give rise to the shift of the Dirac cone at the surface in the direction from the valence band maximum to the conductivity band minimum. The rearrangement of the Bi2Te3 surface electronic structure caused by doping is linked to the pinning of the Fermi level in the bulk gap, and its comparison with experimental data indicates that the dopants substitute Bi atoms rather than they occupy interstitial positions.