Abstract The site-controlled selective area growth of N-polar GaN nanorods (NR) was developed by plasma-assisted MBE (PA MBE) on micro-cone-patterned sapphire substrates (µ-CPSS) by using a two-stage growth process. A GaN nucleation layer grown by migration enhanced epitaxy provides the best selectivity for nucleation of NRs on the apexes of 3.5-µm-diameter cones, whereas the subsequent growth of 1-μm-high NRs with a constant diameter of about 100 nm proceeds by standard high-temperature PA MBE at nitrogen-rich conditions. These results are explained by anisotropy of the surface energy for GaN of different polarity and crystal orientation. The InGaN single quantum wells inserted in the GaN NRs grown on the µ-CPSS demonstrate photoluminescence at 510 nm with a spatially periodic variation of its intensity with a period of ∼6 µm equal to that of the substrate patterning profile.

中文翻译：

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通过等离子体辅助 MBE 在微锥形图案 c 蓝宝石衬底上选择性区域生长 N 极性 GaN 纳米棒

摘要 通过等离子体辅助 MBE (PA MBE) 在微锥形图案蓝宝石衬底 (μ-CPSS) 上使用两阶段生长工艺开发了 N 极性 GaN 纳米棒 (NR) 的位点控制选择性区域生长。通过迁移增强外延生长的 GaN 成核层为 3.5 µm 直径锥体顶点上的 NRs 成核提供了最佳选择性，而随后生长的 1 µm 高 NRs 的恒定直径约为 100 nm，按标准进行富氮条件下的高温 PA MBE。这些结果可以通过不同极性和晶体取向的 GaN 的表面能各向异性来解释。