Department of Engineering Physics, Centre for Emerging Device Technologies, McMaster University , Hamilton, Ontario Canada , L8S 4L7.
Center for Electron Nanoscopy, Technical University of Denmark , DK-2800 Kongens Lyngby, Denmark.
Nano Lett. 2017 Oct 11;17(10):5875-5882. doi: 10.1021/acs.nanolett.7b00794. Epub 2017 Sep 20.
A new dopant incorporation mechanism in Ga-assisted GaAs nanowires grown by molecular beam epitaxy is reported. Off-axis electron holography revealed that p-type Be dopants introduced in situ during molecular beam epitaxy growth of the nanowires were distributed inhomogeneously in the nanowire cross-section, perpendicular to the growth direction. The active dopants showed a remarkable azimuthal distribution along the (111)B flat top of the nanowires, which is attributed to preferred incorporation along 3-fold symmetric truncated facets under the Ga droplet. A diffusion model is presented to explain the unique radial and azimuthal variation of the active dopants in the GaAs nanowires.
报道了一种在分子束外延生长 Ga 辅助 GaAs 纳米线中掺入新掺杂剂的机制。偏轴电子全息术显示，在纳米线生长过程中原位引入的 p 型 Be 掺杂剂在纳米线横截面上沿垂直于生长方向呈不均匀分布。活性掺杂剂沿纳米线（111）B 平坦顶部表现出显著的各向异性分布，这归因于在 Ga 液滴下优先沿 3 重对称截断面掺入。提出了一个扩散模型来解释 GaAs 纳米线中活性掺杂剂的独特径向和各向异性变化。
