在InGaN/GaN多量子阱(MQW)中存在较大的压电极化场,由此引起的量子限制斯塔克效应(QCSE)会造成电子空穴的辐射复合率下降。设计生长了具备InGaN应变层的MQW结构以减弱极化场,并进行了变温、变激发强度的光致发光谱实验,结果表明,引入应变层后的MQW内量子效率有所提高。对峰值能量蓝移量的分析表明,应变层有效减弱了QCSE,明显增加了对应电致发光谱的峰值强度。验证了InGaN应变插入层具有应力调制的作用,有利于提高MQW的发光效率,改善器件性能。

In InGaN/GaN multiple quantum well (MQW), the quantum-confined Stark effect (QCSE) induced by a strong piezoelectric polarization field decreases the electron-hole radiative recombination rate. We design and grow the MQW structure with an InGaN strained-layer to reduce the polarization field, and carry out the photoluminescence spectrum experiment with variable temperature and variable excitation intensity, the results indicate that the MQW internal quantum efficiency is increased by inserting an InGaN strained-layer.The analysis of the peak energy blue-shift shows that the strain-layer effectively weakens the QCSE and obviously increases the peak intensity of the corresponding electroluminescence spectrum. This verifies that the InGaN strained insertion layer has the effect of which is beneficial to improve the luminous efficiency of MQW and the performance of the device.