TY  - JOUR
A1  - Fiedler, Sebastian
A1  - El-Kareh, Lydia
A1  - Eremeev, Sergey V.
A1  - Tereshchenko, Oleg E.
A1  - Seibel, Christoph
A1  - Lutz, Peter
A1  - Kokh, Konstantin A.
A1  - Chulkov, Evgueni V.
A1  - Kuznetsova, Tatyana V.
A1  - Grebennikov, Vladimir I.
A1  - Bentmann, Hendrik
A1  - Bode, Matthias
A1  - Reinert, Friedrich
T1  - Defect and structural imperfection effects on the electronic properties of BiTeI surfaces
JF  - New Journal of Physics
N2  - The surface electronic structure of the narrow-gap seminconductor BiTeI exhibits a large Rashba-splitting which strongly depends on the surface termination. Here we report on a detailed investigation of the surface morphology and electronic properties of cleaved BiTeI single crystals by scanning tunneling microscopy, photoelectron spectroscopy (ARPES, XPS), electron diffraction (SPA-LEED) and density functional theory calculations. Our measurements confirm a previously reported coexistence of Te- and I-terminated surface areas originating from bulk stacking faults and find a characteristic length scale of ~100 nm for these areas. We show that the two terminations exhibit distinct types of atomic defects in the surface and subsurface layers. For electronic states resided on the I terminations we observe an energy shift depending on the time after cleavage. This aging effect is successfully mimicked by depositon of Cs adatoms found to accumulate on top of the I terminations. As shown theoretically on a microscopic scale, this preferential adsorbing behaviour results from considerably different energetics and surface diffusion lengths at the two terminations. Our investigations provide insight into the importance of structural imperfections as well as intrinsic and extrinsic defects on the electronic properties of BiTeI surfaces and their temporal stability.
KW  - electronic structure
KW  - spin–orbit coupling
KW  - surface morphology
KW  - semiconductor surfaces
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119467
SN  - 1367-2630
VL  - 16
IS  - 075013
ER  -