%0 Journal Article
%A Myslivecek, J.
%A Dvorak, F.
%A Strozecka, A.
%A Voigtländer, B.
%T Scanning tunneling microscopy contrast in lateral Ge-Si nanostructures on Si(111)-3x3-Bi
%J Physical review / B
%V 81
%N 24
%@ 1098-0121
%C College Park, Md.
%I APS
%M PreJuSER-10295
%P 245427
%D 2010
%Z We would like to thank Vasily Cherepanov, Neelima Paul, and Kurt Schroeder for many helpful discussions and Helmut Stollwerk and Peter Coenen for the expert technical assistance. J.M. acknowledges the support of the research Program No. MSM 0021620834 of the Ministry of Education of the Czech Republic. F. D. acknowledges the support of the research Program No. GAUK 92209 of the Grant Agency of the Charles University. A. S. acknowledges the support of European Union FP6 project NANOCAGE (Grant No. MEST-CT-2004-50-6854)
%X We investigate the origin of scanning tunneling microscope (STM) contrast in lateral Ge-Si nanostructures prepared on the Si(111)-root 3x root 3-Bi surface [M. Kawamura, N. Paul, V. Cherepanov, and B. Voigtlander, Phys. Rev. Lett. 91, 096102 (2003)]. At low sample bias, the voltage-dependent apparent height difference between Si-and Ge-terminated areas in STM images corresponds exceptionally well to the difference in voltage-integrated scanning tunneling spectroscopy (STS) curves measured in Si-and Ge-terminated areas. The STS curves and the STM contrast reflect both differences in local density of states and in tip-induced effects in Si- and Ge-terminated areas. At higher bias voltage, the tunneling into unoccupied states on Ge-terminated areas is strongly influenced by lowering of the local height of the tunneling barrier with respect to Si. The lowering of the local tunneling barrier height vanishes for the occupied states and can be traced back to different tip-induced band bending on Si-and Ge-terminated areas.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000279145200001
%R 10.1103/PhysRevB.81.245427
%U https://juser.fz-juelich.de/record/10295