Effect of ammoniating temperature on microstructure and optical properties of one-dimensional GaN nanowires doped with magnesium

▶ Ammoniating temperature has great effect on the microstructure, morphology and optical properties of GaN nanowires, which are straight and smooth, of uniform thickness along spindle direction, and have the size of 50 nm in diameter and several tens of microns in length with high-quality crystalline synthesized at 900 °C for 15 min. ▶ PL spectra show that GaN nanowires ammoniating at 900 °C for 15 min have excellent optical properties and have a strong emission peak at 359 nm. The optical properties of the GaN nanowires are closely related to ammoniating temperatures because the strength of emission peaks changes with the variation of temperature while their locations do not change correspondingly. One-dimensional GaN nanowires doped with Mg element have been successfully prepared on Si (1 1 1) substrates by magnetron sputtering through ammoniating Ga 2O 3/Mg thin films, and the effect of the ammoniating temperatures on the microstructure and optical properties of the GaN nanowires was investigated in detail. X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS), FT-IR spectrophotometer, Scanning electron microscope (SEM), high-resolution transmission electron microscope (TEM), and photoluminescence (PL) spectrum were carried out to characterize the microstructure, morphology, and optical properties of GaN nanowires. The results demonstrate that ammoniating temperature has a significant effect on microstructure, morphology and optical properties of GaN nanowires. GaN nanowires after ammoniation at 900 °C for 15 min are straight, smooth and of uniform thickness along spindle direction with the highest crystalline quality. The growth direction of these nanowires is parallel to [1 0 0] orientation.