Materials Engineering, The University of Queensland, St. Lucia, Queensland 4072, Australia.
Nanoscale. 2017 Nov 9;9(43):16960-16967. doi: 10.1039/c7nr04606e.
The optoelectronic application of semiconductor nanowires largely depends on their nanostructures and related chemical characteristics. Although the spontaneously formed core-shell structure in ternary nanowires makes them often unpredictable, such versatile growth with varied chemical characteristics may open up opportunities for widening their applications. In this study, we present extraordinary phenomena observed during ternary InGaAs nanowire growth by molecular beam epitaxy. It was unexpectedly found that nanowires spontaneously formed the hierarchical structure during the growth: a pure core structure at the nanowire tip, a core-shell structure in the middle and a core-multishell structure in the bottom region. By careful electron microscopy investigations on nanowire growth at early stages, the growth mechanism of such a unique hierarchical structure was unveiled. This study provides new insights into ternary III-V nanowire growth with the hope of assistance in designing new nanomaterials and nanostructures for future optoelectronic devices.
半导体纳米线的光电应用在很大程度上取决于它们的纳米结构和相关的化学特性。尽管三元纳米线中自发形成的核壳结构使它们常常难以预测，但这种具有各种化学特性的多功能生长方式可能为拓宽它们的应用提供机会。在这项研究中，我们展示了在分子束外延生长过程中观察到的三元 InGaAs 纳米线的非凡现象。出乎意料的是，在生长过程中纳米线会自发形成分层结构：纳米线尖端为纯核结构，中部为核壳结构，底部为核多壳结构。通过对纳米线生长早期的电子显微镜研究，揭示了这种独特的分层结构的生长机制。这项研究为三元 III-V 纳米线的生长提供了新的见解，有望为未来的光电设备设计新型纳米材料和纳米结构提供帮助。
