Recombination Pathways in Green InGaN/GaN Multiple Quantum Wells
Recombination Pathways in Green InGaN/GaN Multiple Quantum Wells
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绿色 InGaN/GaN 多量子阱中的复合路径
DOI：
10.1186/s11671-017-1922-2
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发表时间：
2017-02-21
影响因子：
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通讯作者：
Feng, Zhe Chuan
中科院分区：
文献类型：
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作者：
Lin, Tao;Kuo, Hao Chung;Feng, Zhe Chuan
报道了具有绿色发射的InGaN/GaN多量子阱(MQW)发光二极管的瞬时光致发光(PL)特性。局域激子复合是样品中绿光发射的主要微观机制。光致发光动力学可归结为激子复合的两条路径，分别对应于快衰变和慢衰变。慢衰变和快衰变的原因分别归结为铟的局部成分波动和InGaN层厚度的变化。此外，还发现在不同的发射光子能量下，两条衰变路径对绿色发光的贡献是不同的。快衰变路径的比例随着光子能量的降低而减小。深局域激子复合产生的慢辐射光致发光受到非辐射离域过程的抑制较小，因为要求的激活能较高。所有这些结果支持了绿色多量子阱LED结构激发-发射过程的一个清晰的微观机制。
This paper reports the transient photoluminescence (PL) properties of an InGaN/GaN multiple quantum well (MQW) light-emitting diode (LED) with green emission. Recombination of localized excitons was proved to be the main microscopic mechanism of green emission in the sample. The PL dynamics were ascribed to two pathways of the exciton recombination, corresponding to the fast decay and the slow decay, respectively. The origins of slow decay and fast decay were assigned to local compositional fluctuations of indium and thickness variations of InGaN layers, respectively. Furthermore, the contributions of two decay pathways to the green PL were found to vary at different emission photon energy. The fraction of fast decay pathway decreased with decreasing photon energy. The slow radiative PL from deep localized exciton recombination suffered less suppression from non-radiative delocalization process, for the higher requested activation energy. All these results supported a clear microscopy mechanism of excitation-emission process of the green MQW LED structure.