Barettin Daniele, Sakharov Alexei V, Tsatsulnikov Andrey F, Nikolaev Andrey E, Pecchia Alessandro, Auf der Maur Matthias, Karpov Sergey Yu, Cherkashin Nikolay
Department of Electronic Engineering, Università Niccoló Cusano, 00133 Rome, Italy.
Ioffe Physico-Technical Institute RAS, 26 Polytekhnicheskaya str., 194021 St. Petersburg, Russia.
Nanomaterials (Basel). 2023 Apr 14;13(8):1367. doi: 10.3390/nano13081367.
A possible solution for the realization of high-efficiency visible light-emitting diodes (LEDs) exploits InGaN-quantum-dot-based active regions. However, the role of local composition fluctuations inside the quantum dots and their effect of the device characteristics have not yet been examined in sufficient detail. Here, we present numerical simulations of a quantum-dot structure restored from an experimental high-resolution transmission electron microscopy image. A single InGaN island with the size of ten nanometers and nonuniform indium content distribution is analyzed. A number of two- and three-dimensional models of the quantum dot are derived from the experimental image by a special numerical algorithm, which enables electromechanical, continuum k→·p→, and empirical tight-binding calculations, including emission spectra prediction. Effectiveness of continuous and atomistic approaches are compared, and the impact of InGaN composition fluctuations on the ground-state electron and hole wave functions and quantum dot emission spectrum is analyzed in detail. Finally, comparison of the predicted spectrum with the experimental one is performed to assess the applicability of various simulation approaches.
实现高效可见光发光二极管（LED）的一种可能解决方案是采用基于InGaN量子点的有源区。然而，量子点内部局部成分波动的作用及其对器件特性的影响尚未得到足够详细的研究。在此，我们展示了从实验高分辨率透射电子显微镜图像恢复的量子点结构的数值模拟。分析了一个尺寸为十纳米且铟含量分布不均匀的单个InGaN岛。通过一种特殊的数值算法从实验图像中导出了多个量子点的二维和三维模型，该算法能够进行机电、连续介质k→·p→和经验紧束缚计算，包括发射光谱预测。比较了连续和原子方法的有效性，并详细分析了InGaN成分波动对基态电子和空穴波函数以及量子点发射光谱的影响。最后，将预测光谱与实验光谱进行比较，以评估各种模拟方法的适用性。
