标题： 原子探针组成和外延量子点集合的原位电子结构 显示英文标题

标题： Atom probe composition and in situ electronic structure of epitaxial quantum dot ensembles

摘要： 密集的半导体量子点阵列目前被用于高效量子点激光器，用于数据通信和其他应用。 传统上，这些量子纳米结构的电子特性被视为孤立物体，相邻量子点和湿润层之间的杂化程度未被研究。 在这里，我们使用原子探针断层扫描和透射电子显微镜来揭示外延InAs/GaAs量子点高密度集合的三维组成剖面。 亚纳米级的组成数据被用来构建三维局部能带结构，并使用有限元方法模拟密集量子点集合内的电子本征态。 这种原位电子模拟揭示了相邻量子点和湿润层之间高度的杂化，这与通常的孤立量子纳米结构图像形成鲜明对比。 模拟的跃迁能量与低温光致发光进行比较。 这项工作在量子点激光器设计中具有重要的应用，并为工程量子点激光器和其他量子纳米结构中的集合效应铺平了道路。 显示英文摘要

摘要： Dense arrays of semiconductor quantum dots are currently employed in highly efficient quantum dot lasers for data communications and other applications. Traditionally, the electronic properties of such quantum nanostructures have been treated as isolated objects, with the degree of hybridization between neighboring quantum dots and the wetting layer left unexplored. Here, we use atom probe tomography and transmission electron microscopy to uncover the three-dimensional composition profile of a high-density ensemble of epitaxial InAs/GaAs quantum dots. The sub-nanometer compositional data is used to construct the 3D local band structure and simulate the electronic eigenstates within the dense quantum dot ensemble using finite element method. This in situ electronic simulation reveals a high degree of hybridization between neighboring quantum dots and the wetting layer, in stark contrast to the usual picture of isolated quantum nanostructures. The simulated transition energies are compared with low temperature photoluminescence. This work has important applications for quantum dot laser design and paves the way to engineering ensemble effects in quantum dot lasers and other quantum nanostructures.