Dresden 2017 – scientific programme

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O: Fachverband Oberflächenphysik

O 32: Focus Session: Charge Transport at Surfaces and Nanostructures with Multi-probe Techniques I

O 32.7: Talk

Tuesday, March 21, 2017, 12:30–12:45, WIL C307

Interface Conductivity of Tellurium on Si(111) Investigated by in situ Charge Transport Measurements with a Multi-Tip STM — Felix Lüpke¹, •Sven Just¹, Martin Lanius¹, Gustav Bihlmayer¹, Jiri Dolezal², Martina Luysberg¹, Elmar Neumann¹, Vasily Cherepanov¹, Ivan Ostadal², Gregor Mussler¹, Detlev Grützmacher¹, and Bert Voigtländer¹ — ¹Peter Grünberg Institut (PGI) and JARA-FIT, Forschungszentrum Jülich — ²Departement of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University Prague, Czech Republic

A combined experimental and theoretical analysis of the structural and electrical transport properties of a Tellurium layer on Si(111) is presented. The Te forms a Te/Si(111)-(1×1) reconstruction saturating the substrate bonds and forming the template for van der Waals epitaxy, e.g. for the topological insulator Bi₂Te₃ based thin fim growth on Si(111). As DFT calculations propose a high carrier concentration in the Te layer, the interface layer might be highly conductive limiting the applicability of the on-top grown film. For determining the conductivity of the Te interface layer on differently reconstructed Si surfaces directly, in situ distance-dependent four-probe resistance measurements with a multi-tip STM are carried out. In a second part, further four-probe measurements on different material systems are presented, e.g. on semiconductors combined with an N-layer model for describing multiple interface layers arising from an approximation of the space-charge region, and on the weak topological insulator Bi₁₄Rh₃I₉ proposed to have one-dimensional edge-channels on the surface.