Growth mechanisms for GaAs nanowires grown in CBE
2004; Elsevier BV; Volume: 272; Issue: 1-4 Linguagem: Inglês
10.1016/j.jcrysgro.2004.08.106
ISSN1873-5002
AutoresAnn Persson, B. Jonas Ohlsson, S. Jeppesen, Lars Samuelson,
Tópico(s)Ga2O3 and related materials
ResumoWe have investigated the growth of GaAs nanowires as a function of temperatures and source pressures on (1 1 1) B-oriented substrates in chemical beam epitaxy (CBE), to establish the mechanisms that govern wire growth and to optimize growth conditions. The grown nanowires were characterized with a scanning electron microscope (SEM). We found two mechanisms to be of importance for wire growth: (i) sufficiently long diffusion length of the group-III material on the 2D substrate surface and on the side facets of the nanowire to obtain rod-shaped nanowires and (ii) growth conditions that suppress growth rate on adjacent surfaces to enhance the wire growth. Favorable conditions for these mechanisms are growth temperatures between 515 and 535 °C, and As-rich growth conditions. Furthermore, we suggest that the growth mechanism of nanowires in CBE is based on surface-selective-growth (SSG) with a solid seed particle rather than conventional vapor–liquid–solid (VLS) growth.
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