Dresden 2006 – wissenschaftliches Programm

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O: Oberflächenphysik

O 29: Poster session II (Nanostructures, Magnetism, Particles and clusters, Scanning probe techniques, Time-resolved spectroscopy, Structure and dynamics, Semiconductor surfaces and interfaces, Oxides and insulators, Solid-liquid interfaces)

O 29.10: Poster

Mittwoch, 29. März 2006, 14:30–17:30, P2

IR-spectroscopy of Pb films and nanowires — •F. Kost¹, T. Kolb¹, R. Lovrincic¹, F. Neubrech¹, A. Pucci¹, M. Jalochowski², and G. Fahsold¹ — ¹Kirchhoff-Institut für Physik, Ruprecht-Karls-Universität, 69120 Heidelberg, Germany — ²Institute of Physics, Maria Curie-Sklodowska University, 20031 Lublin, Poland

The conductivity of metal films and nanowires can be specified via IR spectroscopic measurements which allow analysing these structures in a non-contact mode. The experimental setup enables in-situ investigation in an UHV chamber and therefore, the growth during lead evaporation to a silicon substrate can be investigated. Since the mean free path of electrons at Fermi energy and at room temperature for lead is roughly ten nanometers, classical size effects occur as the film thickness is of this order of magnitude. Quantum size effects are expected as well since the diameter of the nanostructure reaches the range of several ten times the Fermi wavelength [1]. Using a model for charge transport, we describe the measured spectra and explore the development of relaxation rate and plasma frequency and hence get information about scattering effects, band structure and film morphology [2]. In order to obtain nanowires for IR spectroscopic studies, lead is evaporated onto a single-domain stepped silicon substrate. Thereby, solid like nanowires of Pb align parallel to the step edges of the silicon due to self-organization processes [3].

[1] Trivedi, N. and Ashcroft, N.W., Phys. Rev. B 38 (1988), 12298 [2] G. Fahsold and A. Pucci, Adv. in Solid State Physics, Vol. 43, ed. by B. Kramer (Springer, 2003) 833. [3] M. Jalochowski, M. Strozak, R. Zdyb, Appl. Surf. Sci. 211 (2003) 209-215.