The carrier dynamics of Al‐rich AlGaN/AlN quantum well (QW) structures in the presence of strong carrier localization is reported. Excitation density‐dependent photoluminescence (PL) measurements at low temperatures reveal a clear correlation between the onset of efficiency droop and the broadening of the time‐integrated PL spectra. While the droop onset is heavily impacted by the localization strength, the PL emission broadening is observed almost exclusively on the high energy side of the emission spectrum. Spectrally resolved PL decay transient measurements reveal a strong dependency of the carrier lifetimes on the emission photon energy across the spectrum, consistent with a distribution of localized states, as well as on the temperature, depending on the localization strength of the investigated structure. The characteristic “S”‐shaped temperature dependence of the PL emission energy is shown to be directly correlated to the thermal redistribution of carriers between localized states. Based on these findings, the role of carrier localization in the recombination processes in AlGaN QW structures is underlined and its implications for efficiency droop are discussed.

中文翻译：

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载流子局部化控制富AlAlGaN / AlN量子阱结构中的载流子动力学

报道了在强载流子局部化的情况下富AlAlGaN / AlN量子阱（QW）结构的载流子动力学。低温下依赖于激发密度的光致发光（PL）测量表明，效率下降的发生与时间积分PL光谱的展宽之间存在明显的相关性。虽然下垂的开始受到定位强度的严重影响，但PL发射变宽几乎仅在发射光谱的高能侧观察到。光谱解析的PL衰减瞬态测量结果表明，载流子寿命对整个光谱上的发射光子能量有很强的依赖性，这与局部状态的分布以及温度有关，这取决于所研究结构的局部强度。PL发射能量的特征性的“ S”形温度依赖性被证明与载流子在局部状态之间的热再分布直接相关。基于这些发现，强调了载流子局部化在AlGaN QW结构的复合过程中的作用，并讨论了其对效率下降的影响。