中文摘要：

采用金属Ga升华法在石墨烯/蓝宝石衬底上生长了高质量GaN纳米线,研究了不同的生长条件,如NH_3流量、反应时间、催化剂和缓冲层等对GaN纳米线形貌的影响,采用扫描电子显微镜（SEM）对GaN纳米线进行表征。研究发现,在适当的NH_3流量且无催化剂时,衬底上可以生长出粗细均匀的GaN纳米线。反应时间为5 min时,纳米线密集分布在衬底上,表面光滑。在石墨烯/蓝宝石上预先低温生长GaN缓冲层,然后升温至1 100℃进行GaN纳米线生长,获得了具有择优取向的GaN纳米线结构。研究表明,石墨烯和缓冲层对获得GaN纳米线结构有序阵列具有重要的作用。

英文摘要：

High-quality GaN nanowires were grown on graphene/sapphire substrates by metallic gallium sublimation method. The effects of different growth conditions on the morphology of GaN nanowires were investigated, such as the NH3 flow rate, the reaction time, the catalyst and the buffer layer. The GaN nanowires were characterized by the scanning electron microscopy （SEM）. The results show that GaN nanowires with uniform diameter can be grown on the graphene/sapphire substrate without catalyst with the proper NH3 flow rate. And the smooth GaN nanowires are densely distributed on the substrate when the reaction time is 5 min. The GaN buffer layer was grown on the surface of graphene/sapphire at a low temperature and then heated up to 1 100 ℃ for the growth of GaN nanowires, in order to obtain a nanowire structures with preferential orientation. The results show that the graphene and buffer layer play important roles in obtaining ordered arrays of GaN nanowire structures.