Faculty of Physics and Center for Nanointegration (CENIDE), University Duisburg-Essen , Lotharstrasse 1, 470 48 Duisburg, Germany.
Nano Lett. 2017 Jun 14;17(6):3634-3640. doi: 10.1021/acs.nanolett.7b00806. Epub 2017 May 31.
We study the surface diffusion and alloying of Sb into GaAs nanowires (NWs) with controlled axial stacking of wurtzite (Wz) and zinc blende (Zb) crystal phases. Using atomically resolved scanning tunneling microscopy, we find that Sb preferentially incorporates into the surface layer of the {110}-terminated Zb segments rather than the {112̅0}-terminated Wz segments. Density functional theory calculations verify the higher surface incorporation rate into the Zb phase and find that it is related to differences in the energy barrier of the Sb-for-As exchange reaction on the two surfaces. These findings demonstrate a simple processing-free route to compositional engineering at the monolayer level along NWs.
我们研究了 Sb 在具有控制的纤锌矿（Wz）和闪锌矿（Zb）晶体相轴向堆叠的 GaAs 纳米线（NWs）中的表面扩散和合金化。使用原子分辨扫描隧道显微镜，我们发现 Sb 优先掺入到 {110} 终止的 Zb 段的表面层中，而不是 {112̅0} 终止的 Wz 段中。密度泛函理论计算验证了 Sb 在 Zb 相中更高的表面掺入率，并发现这与 Sb 取代 As 交换反应在两个表面上的能垒差异有关。这些发现表明了一种在 NWs 上进行单层水平的组成工程的简单无处理途径。
