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HL: Fachverband Halbleiterphysik
HL 33: Quantum wires: preparation and characterization
HL 33.3: Vortrag
Mittwoch, 25. März 2009, 14:30–14:45, BEY 81
Ga-assisted growth of GaAs nanowires by molecular beam epitaxy — •Sonja Heiderich1,2, Mihail Ion Lepsa1, and Detlev Grützmnacher1 — 1Institute of Bio- and Nanosystems (IBN-1) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich GmbH, D-52425 Jülich — 2Universität Hamburg, Institut für Angewandte Physik, Jungiusstr. 11, D-20355 Hamburg
An important aim of many research activities is the integration of III-V semiconductor nanowires in the established and cheaper silicon technology to get novel electronic and optoelectronic devices. Until now, III-V semiconductor nanowires have been typically synthesized using Au nanoparticles (catalyst) as a seed and the vapor-liquid-solid (VLS) or vapor-solid-solid (VSS) mechanisms. However, the Au can diffuse into the wire during the growth and affect the electronic transport properties. Therefore the growth of nanowires using the group III element as a seed represent the ideal option. In this report, we present data about the Ga-assisted growth of GaAs nanowires by molecular beam epitaxy (MBE). The nanowires have been grown on (100) or (111) GaAs substrates covered with a thin hydrogen silsesquioxan (HSQ) film. A study varying the growth conditions has been realized. From the analysis of the nanowire diameter and length (growth rate) in different growth conditions, we propose a phenomenological growth model. The model take into account that the growth proceeds via VLS mechanism from Ga droplets which develop at the beginning and are situated over preexisting pinholes in HSQ.