Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong.
1] Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong [2] Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057, China.
Nat Commun. 2014 Oct 16;5:5249. doi: 10.1038/ncomms6249.
Although various device structures based on GaSb nanowires have been realized, further performance enhancement suffers from uncontrolled radial growth during the nanowire synthesis, resulting in non-uniform and tapered nanowires with diameters larger than few tens of nanometres. Here we report the use of sulfur surfactant in chemical vapour deposition to achieve very thin and uniform GaSb nanowires with diameters down to 20 nm. In contrast to surfactant effects typically employed in the liquid phase and thin-film technologies, the sulfur atoms contribute to form stable S-Sb bonds on the as-grown nanowire surface, effectively stabilizing sidewalls and minimizing unintentional radial nanowire growth. When configured into transistors, these devices exhibit impressive electrical properties with the peak hole mobility of ~200 cm(2 )V(-1 )s(-1), better than any mobility value reported for a GaSb nanowire device to date. These factors indicate the effectiveness of this surfactant-assisted growth for high-performance small-diameter GaSb nanowires.
尽管已经实现了各种基于 GaSb 纳米线的器件结构，但由于纳米线合成过程中不受控制的径向生长，进一步的性能提升受到了阻碍，导致纳米线不均匀且呈锥形，直径大于几十纳米。在这里，我们报告了在化学气相沉积中使用硫表面活性剂来实现非常细且均匀的 GaSb 纳米线，其直径可低至 20nm。与通常在液相和薄膜技术中使用的表面活性剂效应相反，硫原子有助于在生长的纳米线表面形成稳定的 S-Sb 键，有效地稳定侧壁并最小化非故意的径向纳米线生长。当这些纳米线被配置为晶体管时，它们表现出令人印象深刻的电学性能，峰值空穴迁移率约为 200cm²/V·s，优于迄今为止报道的任何 GaSb 纳米线器件的迁移率值。这些因素表明，这种表面活性剂辅助生长对于高性能小直径 GaSb 纳米线是有效的。
