Electronic band structure of Sb2Te3
cond-mat.mtrl-sci
/ Authors
I. Mohelsky, J. Wyzula, F. Le Mardele, F. Abadizaman, O. Caha, A. Dubroka, X. D. Sun, C. W. Cho, B. A. Piot, M. F. Tanzim
and 4 more authors
/ Abstract
Here we report on Landau level spectroscopy of an epitaxially grown thin film of the topological insulator Sb2Te3, complemented by ellipsometry and magneto-transport measurements. The observed response suggests that Sb2Te3 is a direct-gap semiconductor with the fundamental band gap located at the Γpoint, or along the trigonal axis, and its width reaches Eg = 190 meV at low temperatures. Our data also indicate the presence of other low-energy extrema with a higher multiplicity in both the conduction and valence bands. The conclusions based on our experimental data are confronted with and to a great extent corroborated by the electronic band structure calculated using the GW method.