Materials and Chemistry, SINTEF, NO-7465 Trondheim, Norway.
Department of Physics, Norwegian University of Science and Technology- NTNU, NO-7491 Trondheim, Norway.
Sci Rep. 2017 Mar 28;7:45376. doi: 10.1038/srep45376.
Geometric phase analysis has been applied to high resolution aberration corrected (scanning) transmission electron microscopy images of InAs/GaAs quantum dot (QD) materials. We show quantitatively how the lattice mismatch induced strain varies on the atomic scale and tetragonally distorts the lattice in a wide region that extends several nm into the GaAs spacer layer below and above the QDs. Finally, we show how V-shaped dislocations originating at the QD/GaAs interface efficiently remove most of the lattice mismatch induced tetragonal distortions in and around the QD.
几何相位分析已应用于高分辨率像差校正（扫描）的 InAs/GaAs 量子点（QD）材料的透射电子显微镜图像。我们定量地展示了晶格失配对应变的影响，在 QD 下方和上方 GaAs 间隔层中几个纳米宽的区域内，应变在原子尺度上变化，并使晶格发生了四方畸变。最后，我们展示了 V 型位错是如何从 QD/GaAs 界面开始，有效地消除了 QD 内及周围由晶格失配引起的大部分四方畸变。
