Studies On The Chemical Vapor Deposition Growth And Characterization Of Nanostructured Ga₂O₃

We report the fabrication of ?-Ga2O3 nanostructures on(0001)sapphire substrate by chemical vapor deposition(CVD).A?10 nn thin layer of Au,deposited on the cleaned(0001)sapphire substrates by magnetron sputter first,is acted as catalyst.The well mixed Ga2O3 powder and graphite powder was used as Ga source by carbothermal reduction reaction,oxygen source came from O2/Ar mixed gases flow,residual O2 in the reactor or decomposed Ga2O3.High purity argon was served as carrier gas.The morphologies and structural properties of ?-Ga2O3 and the epitaxial relationship between substrate and ?-Ga2O3 were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD)and transmission electron microscopy(TEM).The deposition results of ?-Ga2O3 nanostructure on sapphire under different thickness of gold catalyst,different growth temperature,reaction pressure or gas flow rate were discussed,the results show that the ?-Ga2O3 nanostructure can be obtained when the experimental parameters remain at about Au 10 nm,970 ?,100 Torr,and 50sccm respectively.Different morphologies including nanowire,nanoflag and nanosheet were controllably synthesized by adjusting the important growth parameters of ambient source contents.And we also prepared horizontal,directional and about 20 ?m ?-Ga2O3 nanowires and the nanowires from horizontal growth to tilted growth nanowires.Moreover,the epitaxial relation between substrate and ?-Ga2O3 nanowires and transition mechanism of nanowire from horizontal growth to tilted growth was subjected.