The growth and characterization of Au-catalyzed gallium oxide nanowires

Gallium oxide is a powerful and versatile wide band gap semiconductor, which has been gaining scientific interest in recent years due to its applications in power electronics. In this work, the growth of β-gallium oxide (Ga₂O₃) nanowires has been achieved by the vapor–solid–liquid method on silicon wafer, fused quartz, and gallium oxide thin-film substrates. In a chamber purged of ambient atmosphere, pure gallium was heated to produce gallium vapor, which was then oxidized by minute oxygen impurities in the backing gas to form gallium oxide nanowires on a substrate, inside a vertical tube furnace. On the silicon wafer substrates, β-Ga₂O₃ nanowires were observed to grow in a specific crystallographic direction via transmission electron microscopy. The resulting nanowires were highly faceted and had a unique polyhedral structure on the gold catalyst ‘cap’ of the nanowire. Time of growth and oxygen-level studies were conducted on nanowires grown on various substrates.