Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, D-01328 Dresden, Germany. Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, D-01062 Dresden, Germany.
Nanotechnology. 2018 Dec 14;29(50):504004. doi: 10.1088/1361-6528/aae361. Epub 2018 Sep 21.
We demonstrate a simple route to grow ensembles of self-catalyzed GaAs nanowires with a remarkably narrow statistical distribution of lengths on natively oxidized Si(111) substrates. The fitting of the nanowire length distribution (LD) with a theoretical model reveals that the key requirements for narrow LDs are the synchronized nucleation of all nanowires on the substrate and the absence of beam shadowing from adjacent nanowires. Both requirements are fulfilled by controlling the size and number density of the openings in SiO , where the nanowires nucleate. This is achieved by using a pre-growth treatment of the substrate with Ga droplets and two annealing cycles. The narrowest nanowire LDs are markedly sub-Poissonian, which validates the theoretical predictions about temporally anti-correlated nucleation events in individual nanowires, the so-called nucleation antibunching. Finally, the reproducibility of sub-Poissonian LDs attests the reliability of our growth method.
我们展示了一种简单的方法，即在 native 氧化的 Si(111)衬底上生长具有显著窄统计分布长度的自催化 GaAs 纳米线的集合体。通过将纳米线长度分布（LD）与理论模型拟合，揭示了获得窄 LD 的关键要求是衬底上所有纳米线的同步成核以及相邻纳米线的束阴影不存在。通过控制在纳米线成核的 SiO2 中的开口的大小和密度，可以满足这两个要求。这是通过使用 Ga 液滴对衬底进行预生长处理和两次退火循环来实现的。最窄的纳米线 LD 明显是亚泊松分布的，这验证了关于单个纳米线中时间反相关成核事件的理论预测，即所谓的成核反聚束。最后，亚泊松 LD 的可重复性证明了我们生长方法的可靠性。
