利用Pd催化合成单晶GaN纳米线的光学特性(英文)

Optical Properties of Single-Crystal GaN Nanowires Synthesized by Pd Catalysis

基于金属元素钯具有的催化特性,采用射频磁控溅射方法,在Si(111)衬底上沉积Pd:Ga2O3薄膜,然后在950℃下对薄膜进行氨化,制备出大量GaN纳米线.采用扫描电子显微镜(SEM)、X射线衍射(XRD)、透射电子显微镜(TEM)和高分辨透射电子显微镜(HRTEM)等技术手段对样品的结构、形貌和成分进行分析.结果表明,制备的样品为具有六方纤锌矿结构的单晶GaN纳米线,直径在20-60nm范围内,长度为几十微米,表面光滑无杂质,结晶质量较高.用光致发光光谱对样品的发光特性进行测试,分别在361.1、388.6和426.3nm处出现三个发光峰,且与GaN体材料相比近带边紫外发光峰发生了较弱的蓝移.对GaN纳米线的生长机制也进行了简单的讨论.

Based on the catalytic property of palladium, GaN nanowires were fabricated by ammoniating Pd：Ga2O3 thin films at 950℃, which were deposited onto a Si（111） substrate by radio frequency （RF） magnetron sputtering. Scanning electron microscopy （SEM）, X-ray diffraction （XRD）, transmission electron microscopy （TEM）, and high- resolution transmission electron microscopy （HRTEM） were used to characterize the structure, morphology, and composition of the samples. Results reveal that the nanowires are single-crystal GaN with a hexagonal wurtzite structure and they have diameters ranging from 20 to 60 nm with lengths of up to several tens of micrometers. Moreover, most of the GaN nanowires have a smooth surface without any impurities and are of high crystal quality. The optical properties of the samples were measured by photoluminescence spectroscopy and three emission bands with peaks at 361.1,388.6, and 426.3 nm were observed. Additionally, the bandgap UV light emission has a weak blue shift compared to the bulk GaN. We briefly discuss the growth mechanism of the GaN nanowires.