Alonso-Orts Manuel, Hötzel Rudolfo, Grieb Tim, Auf der Maur Matthias, Ries Maximilian, Nippert Felix, März Benjamin, Müller-Caspary Knut, Wagner Markus R, Rosenauer Andreas, Eickhoff Martin
Institut für Festkörperphysik, Universität Bremen, Otto-Hahn-Allee, 28359, Bremen, Germany.
Department of Electronic Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133, Rome, Italy.
Discov Nano. 2023 Mar 1;18(1):27. doi: 10.1186/s11671-023-03808-6.
The influence of self-assembled short-period superlattices (SPSLs) on the structural and optical properties of InGaN/GaN nanowires (NWs) grown by PAMBE on Si (111) was investigated by STEM, EDXS, µ-PL analysis and k·p simulations. STEM analysis on single NWs indicates that in most of the studied nanostructures, SPSLs self-assemble during growth. The SPSLs display short-range ordering of In-rich and In-poor InGaN regions with a period of 2-3 nm that are covered by a GaN shell and that transition to a more homogenous InGaN core. Polarization- and temperature-resolved PL analysis performed on the same NWs shows that they exhibit a strong parallel polarized red-yellow emission and a predominantly perpendicular polarized blue emission, which are ascribed to different In-rich regions in the nanostructures. The correlation between STEM, µ-PL and k·p simulations provides better understanding of the rich optical emission of complex III-N nanostructures and how they are impacted by structural properties, yielding the significant impact of strain on self-assembly and spectral emission.
通过扫描透射电子显微镜（STEM）、能量色散X射线光谱（EDXS）、显微光致发光（µ-PL）分析和k·p模拟，研究了自组装短周期超晶格（SPSLs）对在Si（111）上通过等离子体辅助分子束外延（PAMBE）生长的InGaN/GaN纳米线（NWs）的结构和光学性质的影响。对单个纳米线的STEM分析表明，在大多数研究的纳米结构中，SPSLs在生长过程中自组装。SPSLs显示出富In和贫In的InGaN区域的短程有序，周期为2 - 3纳米，被GaN壳层覆盖，并过渡到更均匀的InGaN核心。对同一纳米线进行的偏振和温度分辨PL分析表明，它们表现出强烈的平行偏振红-黄发射和主要垂直偏振的蓝发射，这归因于纳米结构中不同的富In区域。STEM、µ-PL和k·p模拟之间的相关性有助于更好地理解复杂III族氮化物纳米结构丰富的光发射以及它们如何受到结构性质的影响，揭示了应变对自组装和光谱发射的重大影响。
