Direct synthesis of beta gallium oxide nanowires, nanobelts, nanosheets and nanograsses by microwave plasma

In this study, beta-gallium oxide (β-Ga2O3) nanowires, nanobelts, nanosheets, and nanograsses were synthesized through microwave plasma of liquid phase gallium containing H2O in Ar atmosphere using silicon as the substrate. The nanowires with diameters of about 20–30 nm were several tens of microns long and the nanobelts with thickness of about 20–30 nm were tens to hundreds of microns long. The morphology and structure of products were analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and X-ray diffraction (XRD). These results showed that multiple nucleation and growth of β-Ga2O3 nanostructures could easily occur directly out of liquid gallium exposed to appropriate H2O and Ar in the gas phase. The growth process of β-Ga2O3 nanostructures may be dominated by VS (vapor–solid) mechanism.