The origin of yellow band emission and cathodoluminescence of Au-catalyzed wurtzite GaN nanowires

摘要

GaN nanowires with large yield are directly synthesized by simply ammoniating the gallium oxide powders in the presence of ammonia gas at 1000 degrees C, under the assistance of Au nanocatalysts. The microstructure and crystallinity of as-synthesized GaN nanowires are well studied by using high-resolution transmission electron microscope (HRTEM) and some structural defects such as stacking faults are found in the GaN nano-crystal. Cathodoluminescence measurement shows that a strong near-band edge (NBE) emission band centered at 384 nm and a broad yellow band in the range of 500-800 nm are observed. Finally, the growth mechanism and possible optical emission process of GaN nanowires are discussed. (C) 2016 Elsevier B.V. All rights reserved.