This title appears in the Scientific Report : 2015 

Surface and Step Conductivities on Si(111) Surfaces
Just, Sven (Corresponding author)
Blab, Marcus / Korte, Stefan / Cherepanov, Vasily / Soltner, Helmut / Voigtländer, Bert (Corresponding author)
Funktionale Nanostrukturen an Oberflächen; PGI-3
Physical review letters, 115 (2015) 6, S. 066801
College Park, Md. APS 2015
Journal Article
Controlling Electron Charge-Based Phenomena
Please use the identifier: in citations.
Please use the identifier: in citations.
Four-point measurements using a multitip scanning tunneling microscope are carried out in order to determine surface and step conductivities on Si(111) surfaces. In a first step, distance-dependent four-point measurements in the linear configuration are used in combination with an analytical three-layer model for charge transport to disentangle the 2D surface conductivity from nonsurface contributions. A termination of the Si(111) surface with either Bi or H results in the two limiting cases of a pure 2D or 3D conductance, respectively. In order to further disentangle the surface conductivity of the step-free surface from the contribution due to atomic steps, a square four-probe configuration is applied as a function of the rotation angle. In total, this combined approach leads to an atomic step conductivity of σstep=(29±9)  Ω−1 m−1 and to a step-free surface conductivity of σsurf=(9±2)×10−6  Ω−1/□ for the Si(111)−(7×7) surface.