Three InGaN/GaN MQWs samples with varying GaN cap layer thickness were grown by metalorganic chemical vapor deposition (MOCVD) to investigate the optical properties. We found that a thicker cap layer is more effective in preventing the evaporation of the In composition in the InGaN quantum well layer. Furthermore, the quantum-confined Stark effect (QCSE) is enhanced with increasing the thickness of GaN cap layer. In addition, compared with the electroluminescence measurement results, we focus on the difference of localization states and defects in three samples induced by various cap thickness to explain the anomalies in room temperature photoluminescence measurements. We found that too thin GaN cap layer will exacerbates the inhomogeneity of localization states in InGaN QW layer, and too thick GaN cap layer will generate more defects in GaN cap layer.

通过金属有机化学气相沉积（MOCVD）生长了三个具有变化的GaN盖层厚度的InGaN / GaN MQWs样品，以研究其光学性能。我们发现，较厚的覆盖层在防止InGaN量子阱层中In成分的蒸发方面更有效。此外，随着GaN盖层厚度的增加，量子限制的斯塔克效应（QCSE）得以增强。另外，与电致发光测量结果相比，我们着眼于不同盖厚度引起的三个样品的定位状态和缺陷的差异，以解释室温光致发光测量中的异常。我们发现，太薄的GaN盖层会加剧InGaN QW层中定位态的不均匀性，