Dresden 2017 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 73: Nanostructures at Surfaces: Metals, Oxides and Semiconductors III
O 73.7: Vortrag
Mittwoch, 22. März 2017, 12:00–12:15, REC/PHY C213
The bismuth bilayer on Bi2Se3(0001) prepared by atomic hydrogen etching studied by scanning tunneling microscopy — •Vasilii Sevriuk1, Holger Meyerheim1, Arthur Ernst1, Mikhail Otrokov2, Dirk Sander1, and Evgueni Chulkov2 — 1Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany — 2Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastian, Spain
Scanning tunneling microscopy (STM) and spectroscopy (STS) has been used to study a Bi bilayer (BL) on Bi2Se3(0001) prepared by atomic hydrogen etching of the Bi2Se3 substrate. This Bi BL has been previously characterized by surface x-ray diffraction [1]. STM images show predominantly an atomically flat surface of the Bi BL, which almost fully covers Bi2Se3. Ten percent of the surface area are covered by depressions, and protrusions are observed on 5% of the surface. The depressions are 0.4 nm deep, and this corresponds to the thickness of the Bi BL. The lateral size of the depressions is from 5 to 10 nm. There are mainly two types of the protrusions with heights of 0.35 and 0.08 nm. We ascribe this to a second Bi BL and to Se atoms on the Bi BL surface, respectively. STS spectra shows a signature of the surface Dirac cone in the electronic structure of the Bi BL/Bi2Se3 structure at -0.2 V sample bias. STS maps reveal the presence of surface areas with different electronic structures. We analyze this data with the help of the first principles calculations.