Department of Mechanical Engineering and Materials Science, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States.
Nano Lett. 2013;13(12):6023-7. doi: 10.1021/nl403240r. Epub 2013 Nov 27.
In situ high-resolution transmission electron microscopy revealed the precipitation of the zinc-blende (ZB) structure InAs at the liquid/solid interface or liquid/solid/amorphous carbon triple point at high temperature. Subsequent to its precipitation, detailed analysis demonstrates unique solid to solid wurtzite (WZ) to ZB phase transition through gliding of sharp steps with Shockley partial dislocations. The most intriguing phenomenon was that each step is 6 {111} atomic layers high and the step migrated without any mechanical stress applied. We believe that this is the first direct in situ observation of WZ-ZB transition in semiconductor nanowires. A model was proposed in which three Shockley partial dislocations collectively glide on every two {0001} planes (corresponds to six atomic planes in an unit). The collective glide mechanism does not need any applied shear stress.
原位高分辨率透射电子显微镜揭示了在高温下，闪锌矿（ZB）结构的 InAs 在液/固界面或液/固/非晶碳三相点处析出。析出后，详细分析表明，通过具有 Shockley 部分位错的尖锐台阶的滑移，发生了独特的固-固纤锌矿（WZ）到 ZB 相转变。最有趣的现象是，每个台阶高 6 {111} 个原子层，台阶迁移时没有施加任何机械应力。我们相信这是首次在半导体纳米线中直接原位观察到 WZ-ZB 转变。提出了一个模型，其中三个 Shockley 部分位错集体在每两个{0001}平面上滑移（相当于一个单位中的六个原子层）。集体滑移机制不需要任何外加剪切应力。
