Gallium nitride nanowires doped with magnesium

GaN nanowires doped with Mg have been synthesized on Si (111) substrate through ammoniating Ga2O3 films doped with Mg under flowing ammonia atmosphere. The Mg-doped GaN nanowires were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM) and photoluminescence (PL). The results demonstrate that the nanowires were single crystalline with hexagonal wurzite structure. The diameters of the nanowires ranged 20–30 nm and the lengths were about hundreds of micrometers. The intense PL peak at 359 nm showed a blueshift from the bulk band gap emission, attributed to Burstein–Moss effect. The growth mechanism of the crystalline GaN nanowires is discussed briefly.