Al Hassan Ali, AlHumaidi Mahmoud, Kalt Jochen, Schneider Reinhard, Müller Erich, Anjum Taseer, Khadiev Azat, Novikov Dmitri V, Pietsch Ullrich, Baumbach Tilo
Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
Laboratory for Applications of Synchrotron Radiation, Karlsruhe Institute of Technology, Kaiserstraße 12, D-76131 Karlsruhe, Germany.
Nanotechnology. 2024 May 1;35(29). doi: 10.1088/1361-6528/ad3fc1.
We report on the fabrication of a novel design of GaAs/(In,Ga)As/GaAs radial nanowire heterostructures on a Si 111 substrate, where, for the first time, the growth of inhomogeneous shells on a lattice mismatched core results in straight nanowires instead of bent. Nanowire bending caused by axial tensile strain induced by the (In,Ga)As shell on the GaAs core is reversed by axial compressive strain caused by the GaAs outer shell on the (In,Ga)As shell. Progressive nanowire bending and reverse bending in addition to the axial strain evolution during the two processes are accessed byby x-ray diffraction. The diameter of the core, thicknesses of the shells, as well as the indium concentration and distribution within the (In,Ga)As quantum well are revealed by 2D energy dispersive x-ray spectroscopy using a transmission electron microscope. Shell(s) growth on one side of the core without substrate rotation results in planar-like radial heterostructures in the form of free standing straight nanowires.
我们报道了在硅111衬底上制备新型设计的砷化镓/(铟,镓)砷/砷化镓径向纳米线异质结构,首次在晶格失配的核心上生长不均匀壳层导致纳米线笔直而非弯曲。由砷化镓核心上的(铟,镓)砷壳层引起的轴向拉伸应变导致的纳米线弯曲,被(铟,镓)砷壳层上的砷化镓外壳引起的轴向压缩应变所逆转。通过X射线衍射可以观察到在这两个过程中除了轴向应变演变之外的纳米线逐渐弯曲和反向弯曲。使用透射电子显微镜的二维能量色散X射线光谱揭示了核心的直径、壳层的厚度以及(铟,镓)砷量子阱内的铟浓度和分布。在不进行衬底旋转的情况下在核心的一侧生长壳层会导致形成独立笔直纳米线形式的平面状径向异质结构。