Efficiency droop in high‐Al‐content AlGaN/AlGaN quantum wells
Efficiency droop in high‐Al‐content AlGaN/AlGaN quantum wells
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高铝含量 AlGaN/AlGaN 量子阱的效率下降
DOI：
10.1002/pssc.201000889
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
R. Gaska
中科院分区：
文献类型：
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作者：
G. Tamulaitis;J. Mickevičius;K. Kazlauskas;A. Zukauskas;M. Shur;J. Yang;R. Gaska
在8~300K温度范围内，研究了含有不同宽度量子阱的AlGaN多量子井结构的激发功率密度与光致发光效率的关系。观察到了发光效率的下降，并讨论了发光效率下降效应与势垒宽度和晶格温度的关系。光致发光带的形状显示出很强的载流子加热。结果表明，加热效应对光致发光效率有很大影响，特别是在较低的晶格温度下。用蒙特卡罗方法模拟载流子(激子)通过局域态跃迁得到的光致发光带宽与温度的关系表明：(I)用双标度势分布模型可以相当准确地描述势能起伏，(Ii)局域化在较窄的量子阱中变得更强。(2011Wiley-VCH Verlag GmbH&Co.KGaA，Weinheim)
Excitation power density dependence of photoluminescence (PL) efficiency is studied in the temperature range from 8 to 300 K for AlGaN multiple quantum well structures containing quantum wells of different width. PL efficiency droop is observed and dependence of the droop effect on the well width and lattice temperature is discussed. Photoluminescence band shape reveals strong carrier heating. It is shown that the heating effect has a substantial influence on the photoluminescence efficiency droop, especially at low lattice temperatures. Fitting of the temperature dependence of the PL band width with that obtained by the Monte Carlo simulation of carrier (exciton) hopping via localized states shows that (i) the potential fluctuations can be fairly accurately described using a double-scaled potential profile model, (ii) the localization becomes stronger in narrower quantum wells. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)