Tornberg Marcus, Maliakkal Carina B, Jacobsson Daniel, Dick Kimberly A, Johansson Jonas
Solid State Physics, Lund University, Box 118, 22100 Lund, Sweden.
NanoLund, Lund University, 22100 Lund, Sweden.
J Phys Chem Lett. 2020 Apr 16;11(8):2949-2954. doi: 10.1021/acs.jpclett.0c00387. Epub 2020 Mar 31.
Crystal growth of semiconductor nanowires from a liquid droplet depends on the stability of this droplet's liquid-solid interface. Because of the assisting property of the droplet, growth will be hindered if the droplet is displaced onto the nanowire sidewalls. Using real-time observation of such growth by in situ transmission electron microscopy combined with theoretical analysis of the surface energies involved, we observe a reoccurring truncation at the edge of the droplet-nanowire interface. We demonstrate that creating a truncation widens the parameter range for having a droplet on the top facet, which allows continued nanowire growth. Combining experiment and theory provides an explanation for the previously reported truncation phenomenon of the growth interface based only on droplet wetting dynamics. In addition to determining the fundamental limits of droplet-assisted nanowire growth, this allows experimental estimation of the surface tension and the surface energies of the nanowire such as the otherwise metastable wurtzite GaAs {101̅0} facet.
半导体纳米线从液滴中生长取决于该液滴液 - 固界面的稳定性。由于液滴的辅助特性，如果液滴移位到纳米线侧壁上，生长将会受到阻碍。通过原位透射电子显微镜对这种生长进行实时观察，并结合对所涉及表面能的理论分析，我们观察到在液滴 - 纳米线界面边缘反复出现的截断现象。我们证明，产生截断会拓宽在顶面有液滴时的参数范围，从而使纳米线能够持续生长。将实验与理论相结合，为先前仅基于液滴润湿动力学报道的生长界面截断现象提供了解释。除了确定液滴辅助纳米线生长的基本限制外，这还允许对纳米线的表面张力和表面能进行实验估计，例如原本亚稳的纤锌矿GaAs {101̅0} 面。
