Persson Axel R, Metaferia Wondwosen, Sivakumar Sudhakar, Samuelson Lars, Magnusson Martin H, Wallenberg Reine
Centre for Analysis and Synthesis and NanoLund, Lund University, P.O Box 124, SE-221 00, Lund, Sweden.
Solid State Physics and NanoLund, Lund University, P.O. Box 118, SE-221 00, Lund, Sweden.
Small. 2018 Jul 12:e1801285. doi: 10.1002/smll.201801285.
For the purpose of functionalizing III-V semiconductor nanowires using n-doping, Sn-doped GaAs zincblende nanowires are produced, using the growth method of Aerotaxy. The growth conditions used are such that Ga droplets, formed on the nanowire surface, increase in number and concentrations when the Sn-precursor concentration is increased. Droplet-covered wires grown with varying Sn concentrations are analyzed by transmission electron microscopy and electron tomography, which together establish the positioning of the droplets to be preferentially on {-111}B facets. These facets have the same polarity as the main wire growth direction, [-1-1-1]B. This means that the generated Ga particles can form nucleation sites for possible nanowire branch growth. The concept of azimuthal mapping is introduced as a useful tool for nanowire surface visualization and evaluation. It is demonstrated here that electron tomography is useful in revealing both the surface and internal morphologies of the nanowires, opening up for applications in the analysis of more structurally complicated systems like radially asymmetrical nanowires. The analysis also gives a further understanding of the limits of the dopants which can be used for Aerotaxy nanowires.
为了通过n型掺杂对III-V族半导体纳米线进行功能化处理，采用气相聚合法生长出了掺锡的闪锌矿结构GaAs纳米线。所使用的生长条件是，当增加锡前驱体浓度时，纳米线表面形成的镓液滴数量和浓度都会增加。通过透射电子显微镜和电子断层扫描对不同锡浓度下生长的被液滴覆盖的纳米线进行分析，二者共同确定了液滴优先位于{-111}B晶面上。这些晶面与纳米线的主要生长方向[-1-1-1]B具有相同的极性。这意味着所生成的镓颗粒可以形成可能的纳米线分支生长的成核位点。引入方位映射概念作为纳米线表面可视化和评估的有用工具。在此证明，电子断层扫描有助于揭示纳米线的表面和内部形态，为分析诸如径向不对称纳米线等结构更复杂的系统开辟了应用前景。该分析还进一步加深了对可用于气相聚合法纳米线的掺杂剂极限的理解。
