垒层厚度对InGaN/GaN多量子阱电注入发光性能的影响及机理

研究了不同垒厚对InGaN/GaN多量子阱电注入发光性能的影响及机理。实验发现，当GaN垒层的厚度从6 nm增大到24 nm时，垒厚的样品发光强度更强，而且当注入电流增加时，适当增加垒厚，可以更显著增加发光强度。进一步结合发光峰位和光谱宽度的研究表明，由于应力和极化效应的存在，当垒层厚度在6~24 nm范围内时，适当增加垒层厚度不仅会使得能带的倾斜加剧，减少电子泄露，而且也会增加InGaN阱层的局域态深度，从而改善量子阱的发光性能。

Barrier Thickness Designing of InGaN/GaN Multiple Quantum Well for Electroluminescence

The effects of barrier layer thickness on the electroluminescence performance of InGaN/GaN multiple quantum wells(MQWs) were investigated, and the relevant physical mechanisms were discussed. It is found that the electroluminescence (EL) intensity of the samples which have thicker barrier layers is stronger under the same injection current condition, and their increase with the increase of injection current is more rapid. According to the analysis, a proper increase of barrier layer thickness can not only widen the potential barriers, but also increase the tilt of the energy band of MQWs due to the polarization effect and the localization potential due to in In-rich clusters, thus reducing the electron current leakage and increasing the carrier confinement ability, thereby improving the luminescence performance of the InGaN/GaN multiple quantum wells.