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MM: Fachverband Metall- und Materialphysik

MM 23: Nano structured materials I

MM 23.3: Vortrag

Mittwoch, 28. März 2007, 15:15–15:30, H4

Low temperature synthesis of Zn nanowires by physical vapor deposition — •Philipp Schroeder, Michael Kast, and Hubert Brückl — Austrian Research Centers GmbH ARC, Nano-Systemtechnologies, Donau-City-Straße 1, A-1220 Wien, Austria

We demonstrate catalytic growth of zinc nanowires by physical vapor deposition at modest temperatures of 125-175°C on various substrates. In contrast to conventional approaches using tube furnaces our home-built growth system allows to control the vapor sources and the substrate temperature separately. The silicon substrates were sputter coated with a thin gold layer as metal catalyst. The samples were heated to the growth temperature and subsequently exposed to the zinc vapor at high vacuum conditions. The work pressure was adjusted by the partial pressure of oxygen or argon flow gas. Scanning electron microscopy and atomic force microscopy characterizations revealed that the nanowires exhibit straight, uniform morphology and have diameters in the range of 50-350 nm and lengths up to 70 μm. The Zn nanowires grow independently of the substrates crystal orientation via a catalytic vapor-solid growth mechanism. Since no nanowire formation was observed without gold coating, we expect that the one-dimensional growth is initiated by a surface reactive Au seed. ZnO nanowires can be produced in the same preparation chamber by oxidation at 500°C in 1atm (80% Ar, 20% O2) for 1 hour. ZnO is highly attractive for sensor applications.