Regensburg 2004 – wissenschaftliches Programm
O 23.3: Vortrag
Dienstag, 9. März 2004, 16:15–16:30, H36
Local interfacial dipoles of alkali chloride thin films on Au(111) investigated with Kelvin probe force microscopy — •Ulrich Zerweck, Christian Loppacher, Stefan Grafström, and Lukas M. Eng — Institute of Applied Photophysics, University of Technology, D-01062 Dresden
Interface dipole formation of alkali chloride thin films on Au(111) is
investigated under ultrahigh vacuum conditions at room temperature by
noncontact atomic force microscopy in combination with Kelvin-probe force
microscopy (KPFM). Sample preparation is carried out in-situ and optimized
in order to achieve a sub-monolayer coverage on Au(111) with extended
alkali chloride islands.
The local surface potential for LiCl, NaCl, KCl, and RbCl thin films on Au(111) was determined by KPFM, with the bare Au(111) substrate serving as a reference. We thus directly probe the local and absolute change in the work function ΔΦ which is found to vary linearly as a function of the radius of the alkali ion. Furthermore, good agreement was obtained when checking our KPFM measurements with ultraviolet photoemission spectroscopy on a larger scale.