Segura-Ruiz Jaime, Salomon Damien, Rogalev Andrei, Eymery Joël, Alén Benito, Martínez-Criado Gema
European Synchrotron Radiation Facility, 38043-Grenoble, France.
Univ. Grenoble Alpes, CEA, IRIG, MEM, NRS, 38000 Grenoble, France.
Nano Lett. 2021 Nov 24;21(22):9494-9501. doi: 10.1021/acs.nanolett.1c02760. Epub 2021 Nov 11.
Time-resolved cathodoluminescence is a key tool with high temporal and spatial resolution. However, optical spectroscopic information can be also extracted using synchrotron pulses in a hard X-ray nanoprobe, exploiting a phenomenon called X-ray excited optical luminescence. Here, with 20 ps time resolution and 80 nm lateral resolution, we applied this time-resolved X-ray microscopy technique to individual core-shell InGaN/GaN multiple quantum well heterostructures deposited on GaN wires. Our findings suggest that the -plane related multiple quantum well states govern the carrier dynamics. Likewise, our observations support not only the influence of In incorporation in the recombination rates, but also carrier localization phenomena at the hexagon wire apex. In addition, our experiment calls for further investigations of the spatiotemporal domain on the underlying mechanisms of optoelectronic nanodevices. Its great potential becomes more valuable when time-resolved X-ray excited optical luminescence microscopy is used in operando with other methods, such as X-ray absorption spectroscopy.
时间分辨阴极发光是一种具有高时间和空间分辨率的关键工具。然而，利用一种称为X射线激发光学发光的现象，也可以在硬X射线纳米探针中使用同步加速器脉冲提取光学光谱信息。在这里，我们以20皮秒的时间分辨率和80纳米的横向分辨率，将这种时间分辨X射线显微镜技术应用于沉积在氮化镓线（GaN线）上的单个核壳式氮化铟镓/氮化镓（InGaN/GaN）多量子阱异质结构。我们的研究结果表明，与c平面相关的多量子阱态主导着载流子动力学。同样，我们的观察结果不仅支持铟掺入对复合率的影响，还支持六边形线顶点处的载流子局域化现象。此外，我们的实验呼吁对光电子纳米器件的潜在机制在时空领域进行进一步研究。当时间分辨X射线激发光学发光显微镜与其他方法（如X射线吸收光谱法）一起用于原位操作时，其巨大潜力变得更有价值。
