Effects of nitrogen precursor on the Au-assisted vapor-liquid-solid growth of GaAs(N) nanostructures

We investigated the effects of the use of a N precursor on the morphology of GaAs(N) nanostructures grown on GaAs (0 0 1) substrates via the vapor-liquid-solid (VLS) method while using Au particles as the catalyst. The synthesized nanostructures were characterized using scanning electron microscopy and X-ray diffraction analyses. When the N precursor was not used, GaAs nanowires grew, mainly along the <1 1 1>A directions, on the surface of the substrate. These nanowires consisted of zincblende (ZB) and wurtzite (WZ) structures, with a number of boundaries being formed at the {1 1 1} planes. When the N precursor was used, isotropic GaAsN nanodots in which 1~2% of the As atoms had been substituted by N atoms were formed. These nanodots consisted of ZB structures having twin boundaries; no WZ structures were formed in this case. Finally, although they remained isotropic in shape, the nanodots grew in a direction along which the substrate was oriented.