High-resolution detection of Au catalyst atoms in Si nanowires
High-resolution detection of Au catalyst atoms in Si nanowires
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DOI：
10.1038/nnano.2008.5
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发表时间：
2008-03-01
影响因子：
38.3
通讯作者：
Lauhon, Lincoln J.
中科院分区：
文献类型：
--
作者：
Allen, Jonathan E.;Hemesath, Eric R.;Lauhon, Lincoln J.
金属纳米催化剂污染气-液-固生长的半导体纳米线的可能性一直是长期关注的问题，因为最常见的催化剂材料Au对少数载流子电子器件的性能非常有害。我们已经检测到单个Au原子在硅纳米线生长使用Au纳米催化剂颗粒在汽液固过程。使用高角度环形暗场扫描透射电子显微镜，观察到Au原子的数量比预期的从一个简单的外推的体积溶解度的低生长温度。少数载流子扩散长度与纳米线直径的直接测量，然而，表明表面复合控制少数载流子输运在生长的n型纳米线，Au的影响是可以忽略不计的。这些结果推进了原子尺度结构与纳米材料性质的定量相关性，可以为基于纳米材料的器件技术的发展提供必要的指导。
The potential for the metal nanocatalyst to contaminate vapour-liquid-solid grown semiconductor nanowires has been a long-standing concern, because the most common catalyst material, Au, is highly detrimental to the performance of minority carrier electronic devices. We have detected single Au atoms in Si nanowires grown using Au nanocatalyst particles in a vapour liquid-solid process. Using high-angle annular dark-field scanning transmission electron microscopy, Au atoms were observed in higher numbers than expected from a simple extrapolation of the bulk solubility to the low growth temperature. Direct measurements of the minority carrier diffusion length versus nanowire diameter, however, demonstrate that surface recombination controls minority carrier transport in as-grown n-type nanowires; the influence of Au is negligible. These results advance the quantitative correlation of atomic-scale structure with the properties of nanomaterials and can provide essential guidance to the development of nanowire-based device technologies.