Experimental investigation of the radial growth mechanism on beta gallium oxide nanowires

8-Ga2O3 nanowires were fabricated on Au-coated sapphire substrates using the chemical vapor deposition technique. It is found that Au nanoparticles governed the alloying, nucleation and preferred growth of beta gallium oxide nanowires, which could be well demonstrated by vapor-liquid-solid mechanism. Mapping images of energy dispersive spectroscopy revealed the nanowires growth followed the bottom-up model due to Au nanoparticles located on the tips of 8-Ga2O3 nanowires. Further research on the mechanism of nanowire growth was carried out, images of scanning electron microscope indicated a dependent relation between nanowire diameters and growth time. Aimed to achieve the 8-Ga2O3 nanowires with tunable diameters, vapor-solid mechanism is discussed in the subsequent radial growth of nanowires. Band gap energy is an essential physical parameter for designating a wide band gap semiconductor, herein, the 8-Ga2O3 nanowires prepared at various growth time were studied, and a decrease in band gap values was found due to the band gap narrowing effect.