Growth, characterization, and transport properties of ternary (Bi1-xSbx)2Te3 topological insulator layers

Ternary (Bi1-xSbx)2Te3 films with an Sb content between 0 and 100% were deposited on a Si(111) substrate by means of molecular beam epitaxy. X-ray diffraction measurements confirm single crystal growth in all cases. The Sb content is determined by X-ray photoelectron spectroscopy. Consistent values...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2016-10
Main Authors: Weyrich, C, Drögeler, M, Kampmeier, J, Eschbach, M, Mussler, G, Merzenich, T, Stoica, T, Batov, I E, Schubert, J, Plucinski, L, Beschoten, B, Schneider, C M, Stampfer, C, Grützmacher, D, Schäpers, Th
Format: Article
Language:English
Subjects:
Antimony
Conduction bands
Crystal growth
Electrons
Epitaxial growth
Fermi level
Fermi surfaces
Molecular beam epitaxy
Photoelectric emission
Photoelectrons
Protective coatings
Raman spectroscopy
Resistance
Silicon substrates
Single crystals
Spectrum analysis
Transport properties
Valence band
X-ray diffraction
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Ternary (Bi1-xSbx)2Te3 films with an Sb content between 0 and 100% were deposited on a Si(111) substrate by means of molecular beam epitaxy. X-ray diffraction measurements confirm single crystal growth in all cases. The Sb content is determined by X-ray photoelectron spectroscopy. Consistent values of the Sb content are obtained from Raman spectroscopy. Scanning Raman spectroscopy reveals that the (Bi1-xSbx)2Te3 layers with an intermediate Sb content show spatial composition inhomogeneities. The observed spectra broadening in angular-resolved photoemission spectroscopy (ARPES) is also attributed to this phenomena. Upon increasing the Sb content from x=0 to 1 the ARPES measurements show a shift of the Fermi level from the conduction band to the valence band. This shift is also confirmed by corresponding magnetotransport measurements where the conductance changes from n- to p-type. In this transition region, an increase of the resistivity is found, indicating a location of the Fermi level within the band gap region. More detailed measurements in the transition region reveals that the transport takes place in two independent channels. By means of a gate electrode the transport can be changed from n- to p-type, thus allowing a tuning of the Fermi level within the topologically protected surface states.
ISSN:2331-8422
DOI:10.48550/arxiv.1511.00965