Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-11946 Wissenschaftlicher Artikel Fiedler, Sebastian; El-Kareh, Lydia; Eremeev, Sergey V.; Tereshchenko, Oleg E.; Seibel, Christoph; Lutz, Peter; Kokh, Konstantin A.; Chulkov, Evgueni V.; Kuznetsova, Tatyana V.; Grebennikov, Vladimir I.; Bentmann, Hendrik; Bode, Matthias; Reinert, Friedrich Defect and structural imperfection effects on the electronic properties of BiTeI surfaces 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. 2014 New Journal of Physics 16 075013 urn:nbn:de:bvb:20-opus-119467 10.1088/1367-2630/16/7/075013 Physikalisches Institut