研究了具有InGaN/GaN超晶格(SL)插入结构的绿光InGaN/GaN多量子阱(MQW)的发光特性。结构测试表明, SL插入结构并没有引起MQW中平均In组份的增加, 而是改变了In组份的分布, 形成了高In组份的量子点和低In组份量子阱。其电致发光(EL)谱和光致发光(PL)谱均出现了双发光峰。我们认为这两个峰分别来自于量子点和量子阱, 且存在着载流子从阱向点转移的输运机制。最后变温PL积分强度的Arrhenius拟合表明, SL插入结构并没有在MQW中引入新的缺陷, 使其发光效率下降。

Green InGaN/GaN multiple quantum well(MQW) LEDs employing InGaN/GaN superlattice(SL) structure were studied. The distribution of indium within the MQWs is changed by inserting the InGaN/GaN SL. Meanwhile, the average indium content of MQW does not change. Two InGaN-related peaks that were clearly found in the electroluminescence(EL) and photoluminescence(PL) spectrum, which are assigned to In-rich quantum dots(QD) and the InGaN matrix, respectively. It is suggested that the carrier drifts from the InGaN matrix to the In-rich QD. It could be concluded that employing SL structures is an effective way to adjust the wavelength of InGaN/GaN MQW without introducing new defects in the MQWs.