Influence of the InGaN/GaN quasi-superlattice underlying layer on photoluminescence in InGaN/GaN multiple quantum wells
Influence of the InGaN/GaN quasi-superlattice underlying layer on photoluminescence in InGaN/GaN multiple quantum wells
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InGaN/GaN准超晶格底层对InGaN/GaN多量子阱光致发光的影响
DOI：
10.1016/j.physe.2015.10.010
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发表时间：
2016-02-01
影响因子：
3.3
通讯作者：
Ji, Ziwu
中科院分区：
文献类型：
--
作者：
Mu, Qi;Xu, Mingsheng;Ji, Ziwu
研究了两种不同的InGaN/GaN多量子阱（MQW）结构的光致发光（PL）特性，包括在InGaN/GaN准超晶格（QSL）下的缓冲层和在QSL下的缓冲层。结果表明，在n-GaN和多量子阱之间插入QSL可以释放多量子阱区的应变，这是因为与没有QSL的样品相比，具有QSL的样品的峰值能量的蓝移随激发功率的变化较小。同时，插入QSL增强了载流子的局域化效应，这是从在低激发范围内峰值能量随激发功率增加而发生的异常红移以及峰值能量特性的更明显的“S形”温度依赖行为推断的：应变释放促进了InGaN阱层的轻微组分波动或相分离。应变释放导致量子限制斯塔克效应的降低和多量子阱局域化效应的增强，大大提高了多量子阱的辐射复合率。(C)2015 Elsevier B. V.版权所有。
Photoluminescence (PL) properties of two different InGaN/GaN multiple quantum well (MQW) structures, without and with an InGaN/GaN quasi-superlattice (QSL) underlying buffer layer, were investigated. The results show that inserting a QSL between the n-GaN and MQWs can release the strain in the MQW region, since the sample with a QSL shows a smaller excitation power-dependent blue-shift of its peak energy than that without. Meanwhile, inserting a QSL enhances the localization effect of the carriers inferred from an unusual red-shift of the peak energy with increasing excitation power in low excitation range, and from a more obvious "S-shaped" temperature-dependent behavior of the peak energy characteristic: the strain release facilitates the slight composition fluctuation or phase separation of the InGaN well layers. The reduction of the quantum-confined Stark effect and enhancement of the localization effect of the MQWs induced by the strain release, greatly enhance the radiative recombination rate of the MQWs. (C) 2015 Elsevier B.V. All rights reserved.