Effects Of Different Gallium Sources And Catalysts On The Morphology And Properties Of ?-Ga₂O₃ Nanostructures

Since 20th century,nano-materials?nanorods,nanowires,nano-bands,nano-chips?in the optoelectronic devices,sensors and other fields of applications have given great expectations.As one of the direct bandgap semiconductor materials,Ga₂O₃ is a wide bandgap?4.2-4.9EV?semiconductor structure with special and good electrical,optical,and photocatalytic properties,such as a high surface volume ratio,a high breakdown field strength?>8 mv/cm?,high optical visible transparency,ultraviolet radiation,High temperature stability,oxidation resistance and so on.Ga₂O₃ consists of five isomers,corundum crystal structure??-phase?,single oblique crystal structure??-phase?,spinel structure??-phase?,red beryl structure??-phase?,orthogonal crystal system structure??-phase?,wherein the thermal property is stable is expressed as the c2/m space group symmetry of beta Ga₂O₃.As a result of defects and oxygen vacancy,?-Ga₂O₃ are shown as n-type semiconductors.As a transparent conductive oxide?TCO?,?-Ga₂O₃ has a wide range of applications in many areas,such as deep ultraviolet photoelectric detectors,conductive windows,solar converters,high-temperature gas sensors,transparent field effect transistors,light-emitting diodes,etc.As with other low dimensional wide bandgap semiconductors such as ZnO,SiO₂,TiO₂,CeO₂,Al₂O₃,there are many methods of preparation,such as microwave plasma,arc plasma,physical evaporation method,oxide-assisted growth,chemical deposition,gas-phase epitaxial growth?VPE?,RF magnetron sputtering.The most frequently used chemical vapor deposition method?CVD?is because the CVD method has the advantages of low cost,lower temperature of growth environment,higher rate of growth sample.For the generation of Ga₂O₃ single crystal,there are two kinds of growth mechanisms,namely,gas-solid growth mechanism?VS?and gas-liquid-solid growth mechanism?VLS?,in the absence of a catalyst,the Ga₂O₃ powder is heated at high temperature,and the resulting Ga or Ga₂O vapor is transported to the SI substrate surface with the argon gas,Further reaction with ambient oxygen generates Ga₂O₃ deposited onto the substrate surface to form Ga₂O₃ nanostructures.Based on the above background,using chemical vapor deposition method,Ga₂O₃ powder and Ga simple element were used as Ga source to fabricate Ga₂O₃ nanomaterials on catalyst-free wafer and gold-plated wafer,and annealing treatment at different time in Ar atmosphere was done.Finally,using scanning electron microscope?SEM?,the samples were characterized by transmission electron microscopy?TEM?,X-ray diffraction?XRD?and Raman scattering?Ramman?,and the differences of the surface morphology of nano-materials with different gallium sources,different substrates and different time were compared.The main research contents of this paper can be divided into the following two parts:1.Take the right amount of Ga₂O₃ powder and active C powder evenly mixed,with high-purity argon gas for transport,with no catalyst si piece and gold-plated SI film as the substrate,respectively in 1100?environment heating 30min,60min,90min,120min,The surface morphology of the Ga₂O₃ nanometer material grown under two kinds of substrates is obviously different,the surface morphology of the sample is more dense after using the catalyst,the XRD test results show that the growth is a single phase?-Ga₂O₃ nanometer material with a preferred orientation?400?.2.Take the right amount of Ga as the source of gallium,using chemical vapor deposition method,the Ga elemental was heated at 1100?temperature condition and the Si piece of Au was sputtered,and the high purity argon was used as transport gas,annealing 30min,60min,90min,120min respectively,the growth nanometer material was columnar structure,The results of XRD test showed that the growth of single phase?-Ga₂O₃ nanomaterials with preferred orientation?111?.