Investigating closely stacked GaN/AlN multiple quantum wells (MQWs) by means of cathodoluminescence spectroscopy directly performed in a scanning transmission electron microscope, we have reached an ultimate spatial resolution of σCL=1.8 nm. The pseudomorphically grown MQWs with high interface quality emit in the deep ultraviolet spectral range. Demonstrating the capability of resolving the 10.8 nm separated, ultra-thin quantum wells, a cathodoluminescence profile was taken across individual ones. Applying a diffusion model of excitons generated by a Gaussian-broadened electron probe, the spatial resolution of cathodoluminescence down to the free exciton Bohr radius scale has been determined.

中文翻译：

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来自紧密堆叠的 GaN/AlN 量子阱的单独分辨的发光

通过在扫描透射电子显微镜中直接执行的阴极发光光谱研究紧密堆叠的 GaN/AlN 多量子阱 (MQW)，我们已经达到了 σCL=1.8 nm 的最终空间分辨率。具有高界面质量的假晶生长的 MQW 在深紫外光谱范围内发射。展示解析 10.8 nm 分离的超薄量子阱的能力，对单个阱进行阴极发光分布。应用由高斯展宽电子探针产生的激子扩散模型，阴极发光的空间分辨率已确定到自由激子玻尔半径尺度。