Agradecimentos: We acknowledge the Brazilian Nanotechnology Laboratory (LNNano/CNPEM) and Laboratory of Structural Characterization (LCS/UFSCAR) for granting access to their electron microscopy facilities. B.C.d.S. acknowledges FAEPEX-UNICAMP and CAPES for scholarships. We also acknowledge D. M. Ugarte for discussions on transmission electron microscopy, H.T. Obata for technical assistance with CBE system, and S. R. Araujo for lamella preparation. This work was financially supported by the Brazilian agencies CAPES, CNPq (Grants 479486/2012-3, 305769/2015-4, and 2012/10127-5), and FAPESP (Grants 2012/11382-9, 2013/02300-1, 2014/23399-9, 2015/16611-4, and 2016/16365-6) Ver menos

Abstract: Here we show a new nanowire growth procedure, exploring the thermally activated motion of Au droplets on III-V surfaces. We show that by setting a single growth parameter we can activate the crawling motion of Au droplets in vacuum and locally modify surface composition in order to enhance vapor solid (VS) growth along oxide-free areas on the trail of the metal particle. Asymmetric VS growth rates are comparable in magnitude to the vapor liquid solid growth, producing unconventional wurtzite GaP morphologies, which shows negligible defect density as well as optical signal in the green spectral region. Finally, we demonstrate that this effect can also be explored in different substrate compositions and orientations with the final shape finely tuned by group III flow and nanoparticle size. This distinct morphology for wurtzite GaP nanomaterials can be interesting for the design of nanophotonics devices Ver menos