Influence of Mg doping on GaN nanowires

Magnesium-doped GaN nanowires with different dopant concentrations are synthesized by ammoniating Ga(2)O(3) thin films doped with Mg at 900 degrees C. Scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM), and room-temperature photoluminescence (PL) are employed to characterize the influences on the morphology, structure, crystallinity, and optical properties of Mg-doped GaN nanowires. The results demonstrate that the nanowires are single-crystalline with hexagonal wurzite structure. GaN nanowires doped with 5 atom % of Mg have the best morphology and crystallinity with a single-crystalline structure, and at this composition the PL spectrum with the strongest UV peak is observed. The growth mechanism of crystalline GaN nanowires is discussed briefly.