Light emitting diodes represent a key technology that can be found in many areas of everydays life. Therefore, the improvement of the efficiency of such structures offers a high economic and ecological potential. One approach is electrostatic screening of the quantum-confined Stark effect (QCSE) in polar III-V heterostructures by n-type doping in order to increase the oscillator strength of electronic transitions in quantum structures. In this study, we analyzed the cathodoluminescene (CL) spectra of different functional parts of individual AlN/GaN nanowire superlattices and studied their decay characteristics with sub-nanosecond time resolution. This allows us to extract information about strain and electric fields in such heterostructures with an overall spatial resolution <100 nm. The samples, which were investigated in a temperature range from 10 to 300 K by using time-integrated cathodoluminescence spectroscopy (TICL) and time-resolved cathodoluminescence spectroscopy (TRCL) consist of GaN bottom and top layer and a 40-fold stack of GaN nanodiscs, embedded in AlN barriers that were doped with Ge. We show, that the QCSE is reduced with increasing doping concentration due to a screening of the internal electric fields inside GaN nanodiscs, resulting in a reduction of the carrier lifetimes and a blue shift of the emitted light. Due to the small diameter of the electron excitation beam CL offers the possibility to individually analyze the different functional parts of the nanowires.

发光二极管代表了一种可以在日常生活的许多领域中找到的关键技术。因此，这种结构效率的提高提供了很高的经济和生态潜力。一种方法是通过 n 型掺杂对极性 III-V 异质结构中的量子限制斯塔克效应 (QCSE) 进行静电屏蔽，以增加量子结构中电子跃迁的振荡器强度。在这项研究中，我们分析了单个 AlN/GaN 纳米线超晶格的不同功能部分的阴极发光 (CL) 光谱，并以亚纳秒时间分辨率研究了它们的衰减特性。这使我们能够以 <100 nm 的整体空间分辨率提取有关此类异质结构中应变和电场的信息。样品，通过使用时间积分阴极发光光谱 (TICL) 和时间分辨阴极发光光谱 (TRCL) 在 10 到 300 K 的温度范围内研究了由 GaN 底层和顶层以及 40 倍堆叠的 GaN 纳米圆盘组成，嵌入在掺杂 Ge 的 AlN 势垒。我们表明，由于 GaN 纳米盘内部的内部电场屏蔽，QCSE 随着掺杂浓度的增加而降低，导致载流子寿命缩短和发射光蓝移。由于电子激发束的小直径，CL 提供了单独分析纳米线不同功能部分的可能性。