Fabrication And Characteristics Of The One-dimensional N-doped β-Ga₂O₃ Nanowires

As ammonia (NH3) gas is used as dopant source, the undoped and N-doped B-Ga2O3 nanowires (NWs) were successfully fabricated with chemical vapor deposition (CVD) method on (111) Si substrates. The microstructure, morphology and element composition of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and room-temperature photoluminescence (PL), respectively. Through control variate method, the best experimental parameter were available. And experimental result showed that the high quality N-doped B-Ga2O3 NWs can be attained as Au-coated Si substrates were loaded downstream with the deposition temperature was from 700 to 850℃as NH3 (99.999%) were introduced to the system with 40 ml/min flow rates for 1 or1.5 h. The investigations revealed that the single-crystalline N-dopedβ-Ga2O3 NWs are straight and smooth, with diameters ranging from 35 to 120 nm and length up to several tens of micrometers. Each NWs terminated in Au nanoparticle at the tip indicates that N-dopedβ-Ga2O3 NWs followed the vapor-liquid-solid (VLS) growth mechanism.The results showed that B-Ga2O3 NWs doping with N can create various kinds defects such as VO,VGa VGa:Vo and No, and these results induce that the PL spectra of N-dopedβ-Ga2O3 NWs is different from that of undoped sample. However phase separation ofβ-Ga2O3 and GaN haven't generated until the flow rate of NH3 reasech to 40 ml/min. PL spectrum measurements exhibited that N-dopedβ-Ga2O3 NWs had ultraviolet (UV), blue and green emission peaks because of N-doped process. The PL mechanism of N-dopedβ-Ga2O3 NWs is also discussed.Furthermore, micro-scale undopedβ-Ga2O3/N-dopedβ-Ga2O3 homojunction structures were fabricated. In the testing process, a single N-dopedβ-Ga2O3 microwire and undopedβ-Ga2O3/N-dopedβ-Ga2O3 microwire homojunction were connected by Pt electrode in the both ends. The IV property of the fabricated N-dopedβ-Ga2O3 microwire andβ-Ga2O3/N-dopedβ-Ga2O3 microwire homojunction were compared. IV results testified that N-dopedβ-Ga2O3NWs showed a p-type conductivity.