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VA: Fachverband Vakuumphysik und Vakuumtechnik
VA 3: Vacuumnanoelectronics: fabrication, properties and applications
VA 3.2: Vortrag
Montag, 26. März 2007, 14:40–15:10, H9
Fabrication and electrical transport properties of bismuth nanowires — •Thomas Cornelius1, Maria Eugenia Toimil-Molares1, Shafqat Karim2, and Reinhard Neumann1 — 1Gesellschaft für Schwerionenforschung (GSI), Planckstr. 1, 64291 Darmstadt, Germany — 2Fachbereich Chemie, Marburg University, Hans-Meerwein-Str., 35032 Marburg, Germany
In recent years, nanowires attracted enormous interest due to their possible future applications, e.g. in vacuum-nanoelectronics. When the object size becomes comparable to the electronic mean free path and Fermi wavelength, classical and quantum size effects are expected [1], respectively. Both are large in Bi compared to conventional metals, making it an ideal material for studies on the nanoscale.
Single bismuth nanowires are deposited electrochemically in ion track-etched polycarbonate membranes and subsequently contacted electrically while left embedded in the template [2]. The specific electrical resistivity is a function of the wire crystallinity and increases for smaller mean grain size. The wire resistance is a non-monotonic function of temperature. In bulk bismuth the carrier mobility increases from 100 nm to 400 um when cooling down from 300 to 4 K. In contrast, in wires the mobility of charge carriers saturates at low temperatures, being one to two orders of magnitude smaller than in bulk bismuth. The saturation originates from finite-size effects [3].
[1] V.B Sandormirskii Sov. Phys. JETP 25 (1967) 101 [2] T.W. Cornelius et al. Nanotechnology 16 (2005) S246 [3] T.W. Cornelius et al. J. Appl. Phys. 100 (2006) 114307