Abstract In order to conduction-band engineer quantum cascade lasers (QCLs) for emission wavelength, specifically QCLs emitting at 4.6 µm, precise control over layer thicknesses and compositions is required. In this study, Al/Ga incorporation in a strain-balanced InAlAs/InGaAs superlattice (SL) on InP is characterized as a function of layer thickness, keeping the composition constant, using high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) and Atom Probe Tomography (APT). A SL structure was grown on an InP substrate by organometallic vapor phase epitaxy (OMVPE) at a temperature of 605 °C and a reactor pressure of 100 torr, with 5 sec interruption time between layers. The full growth thickness obtained from STEM images was used to calibrate the reconstruction of the atom probe data. From the APT results it was found that the Al and Ga incorporation in thin layers (

中文翻译：

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原子探针层析成像对应变 III-V 超晶格中成分的层厚依赖性

摘要 为了设计发射波长的导带量子级联激光器 (QCL)，特别是发射波长为 4.6 µm 的 QCL，需要精确控制层厚度和成分。在这项研究中，在 InP 上的应变平衡 InAlAs/InGaAs 超晶格 (SL) 中掺入 Al/Ga 被表征为层厚度的函数，使用高角度环形暗场 (HAADF) 扫描透射电子保持成分不变显微镜 (STEM) 和原子探针断层扫描 (APT)。在 605°C 的温度和 100 托的反应器压力下，通过有机金属气相外延 (OMVPE) 在 InP 衬底上生长 SL 结构，层间中断时间为 5 秒。从 STEM 图像获得的完整生长厚度用于校准原子探针数据的重建。