Noncontact Atomic Force Microscopy - Yale School of Engineering ...

Self-assembled Boronitride Nanomesh on Rh(111)
Investigated by Means of Kelvin Probe Force Microscopy
P.I-10
Sascha Koch 1 , Markus Langer 1 , Jorge Lobo-Checa 1,3 , Thomas Brugger 2 , Shigeki
Kawai 1 , Bartosz Such 1 , Ernst Meyer 1 and Thilo Glatzel 1
1 Department of Physics, University of Basel, 4056 Basel, Switzerland
2 Department of Physics, University of Zurich, 8006 Zurich, Switzerland
3 Centre d'Investigaciò en Nanociència i Nanotecnologia (CIN2), Campus Universitat Autònoma de
Barcelona, Spain
By high temperature exposure of borazine [(HBNH)3], a self-assembled hexagonal
nanomesh with a periodicity of about 3nm and a hole size of 2nm is formed on Rh(111)
under UHV conditions [1]. The stable and periodic structure is perfectly suitable for
trapping single molecules at room temperature [2]. The determination of local work
function variations is a major requirement to understand the process of molecular
adsorption. NC-AFM combined with Kelvin probe force microscopy (KPFM) enables
imaging of the surface and simultaneous detection of the work function map with subnanometer
resolution [3].
Figure 1(a) shows the topography signal of the nanomesh which is in good agreement
with previous STM results [1,2,4]. The Rh(111) surface is found to be completely
covered with the mesh. Figure 1(b) shows the simultaneously obtained LCPD signal of
this superstructure clearly resolving a work function difference of the structure. Here a
variation of the LCPD of approximately 600mV was detected.
Figure 1: (a) AFM image of the bn-nanomesh (20x20nm 2 ). Parameters:
Δf=-35Hz, A=4nm, f0=153kHz; Δz=650pm. (b) Simultaneously measured
LCPD image. ΔLCPD=600mV, VAC=500mV, f1≈fAC=954kHz.
[1] M.Corso, W. Auwärter, M. Muntwiler, A. Tamai, T. Greber, J. Osterwalder, Science 303, 217 (2004)
[2] H. Dil, J. Lobo-Checa, R. Laskowski, et al., Science 319, 1824 (2008)
[3] Th. Glatzel, L. Zimmerli, S. Koch, S. Kawai, E. Meyer; Appl. Phys. Lett., 94, 3 (2009)
[4] S. Berner, M. Corso, R. Widmer et al., Ang. Chem. Int. Ed. 46, 5115 (2007)
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