Dresden 2006 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 25: C/diamond

HL 25.2: Vortrag

Dienstag, 28. März 2006, 18:15–18:30, POT 151

Thin films of metallic carbon nanotubes and their optical spectra — •Sabine Blatt¹, Frank Hennrich¹, Hilbert v. Löhneysen^2,3, and Ralph Krupke¹ — ¹Forschungszentrum Karlsruhe, Institut für Nanotechnologie, 76021 Karlsruhe — ²Physikalisches Institut, Universität Karlsruhe, 76128 Karlsruhe — ³Forschungszentrum Karlsruhe, Institut für Festkörperphysik, 76021 Karlsruhe

The exceptional electrical and structural properties of single-walled carbon nanotubes (SWNTs) open up a wide range of future applications provided that metallic and semiconducting nanotubes can be separated on a large scale. The separation through dielectrophoresis makes use of the different electric field-induced polarizabilities of the two types leading to a separation in ac electric fields [1, 2]. This method allows for the first time to produce thin films of only metallic SWNTs and to measure their optical absorption spectra [3]. Recent experiments address the dependence of the separation yield on the type and the concentration of the surfactant used to disperse the nanotubes and on the conductivity of the dispersion. For a better understanding of the dielectrophoretic forces finite elements simulations are performed additionally.

[1] Krupke,R.; Hennrich, F.; v. Löhneysen, H.; Kappes, M. M. Science 2003, 301, 344-347 [2] Krupke R.; Hennrich F.; Kappes M. M.; v. Löhneysen H. Nano Lett. 2004, 4, 1395-1399 [3] Krupke, R.; Linden, S.; Rapp, M.; Hennrich, F. cond-mat/0508418