The morphology, structure and phonon properties of well-aligned and kink-free GaAs nanowires grown on (1̄ 1̄ 1̄)B GaAs are reported. The nanowires were grown at temperatures down to 400 °C by Au-catalysed MOVPE usingtBuAsH2and Me3Ga in H2ambient. Colloidal Au nanoparticles (NPs) with average size of 60-70 nm were used as catalyst. Below 425 °C the nanowires consist of almost cylindrical segments, their average diameter closely matching that of the original Au NPs. At higher temperatures, the nanowires show a large tapering. The structural analysis of nanowire samples grown at 450 °C evidences that residual catalyst droplets at the nanowire tips consist of crystalline fcc Au, with a preferred (1 1 1) crystallographic orientation, and orthorhombic GaAu2alloy (γ phase). Non-resonant Raman scattering experiments carried out on GaAs nanowires showed no evidence of phonon confinement effects. However, new strong LO phonon contributions arise in the Raman spectra with respect to bulk GaAs, likely due to the nanowire large surface-to-volume ratio. © 2006 Elsevier B.V. All rights reserved.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
Paiano, P., Prete, P., Speiser, E., Lovergine, N., Richter, W., Tapfer, L., & Mancini, A. M. (2007). GaAs nanowires grown by Au-catalyst-assisted MOVPE using tertiarybutylarsine as group-V precursor. Journal of Crystal Growth, 298(SPEC. ISS), 620 - 624. https://doi.org/10.1016/j.jcrysgro.2006.10.107