Fabrication and characteristics of N-doped β-Ga2O3 nanowires

Undoped and N-doped beta-Ga2O3 nanowires (NWs), using NH3 as the dopant source, were successfully fabricated by the CVD method on Si substrates. The microstructure, morphology, element composition and carrier concentration of the samples were characterized by XRD, SEM, TEM, and EDX. The results revealed that well-aligned undoped NWs were perpendicular to the substrates. Comparing with undoped beta-Ga2O3 NWs, the morphology of N-doped beta-Ga2O3 NWs showed a significant change and they were randomly oriented relative to the substrates. As the NH3 flow was increased, the microstructure of the sample presented a lot of branched-like and trumpet-shaped structures. Simultaneously, a rougher surface has been attained. PL spectrum measurements showed that N-doped beta-Ga2O3 NWs had ultraviolet (UV), blue and green emission peaks because of the N-doped process. Furthermore, micro-scale undoped beta-Ga2O3/N-doped beta-Ga2O3 homojunction structures were fabricated. The I-V property of the fabricated N-doped beta-Ga2O3 microwire and beta-Ga2O3/N-doped beta-Ga2O3 microwire homojunction were compared. I-V results testified that N-doped beta-Ga2O3 NWs showed p-type conductivity.