A comparison of the optical properties of InGaN/GaN multiple quantum well structures grown with and without Si-doped InGaN prelayers
A comparison of the optical properties of InGaN/GaN multiple quantum well structures grown with and without Si-doped InGaN prelayers
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DOI：
10.1063/1.4941321
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发表时间：
2016-02-07
影响因子：
3.2
通讯作者：
Humphreys, C. J.
中科院分区：
文献类型：
--
作者：
Davies, M. J.;Hammersley, S.;Humphreys, C. J.
在本文中，我们报告的InGaN/GaN多量子阱结构的光学性质的详细光谱研究，无论是有和没有Si掺杂的InGaN预层。在光致发光和光致发光激发光谱中，在含有InGaN预层的多量子阱结构的光谱中识别出在较高能量下发生的第二发射带，其源自堆叠中的第一量子阱。能带结构的计算表明，在所产生的电场中发生的减少，在量子阱中紧邻的InGaN预层，因此导致在该量子阱中的量子限制斯塔克效应的强度的减少。在该量子阱中的量子限制斯塔克效应的部分抑制导致修改的（更高的）发射能量和增加的辐射复合率。因此，我们将高能量发射带的起源归因于结构中第一个量子阱的复合。两个样品的温度依赖性复合动力学的研究表明，在整个光谱上测量的衰减时间受到堆叠中的第一量子阱（在包含预层的样品中）的强烈影响，导致该样品中的平均室温寿命较短。发现含有样品的预层的室温内部量子效率高于参考样品（36%与25%相比），这因此归因于第一量子阱的更快的辐射复合速率，提供了与非辐射复合过程更具竞争力的复合途径。(C)2016年作者。除非另有说明，否则所有文章内容均根据Creative Commons Attribution 3.0 Unported License许可。
In this paper, we report on a detailed spectroscopic study of the optical properties of InGaN/GaN multiple quantum well structures, both with and without a Si-doped InGaN prelayer. In photoluminescence and photoluminescence excitation spectroscopy, a 2nd emission band, occurring at a higher energy, was identified in the spectrum of the multiple quantum well structure containing the InGaN prelayer, originating from the first quantum well in the stack. Band structure calculations revealed that a reduction in the resultant electric field occurred in the quantum well immediately adjacent to the InGaN prelayer, therefore leading to a reduction in the strength of the quantum confined Stark effect in this quantum well. The partial suppression of the quantum confined Stark effect in this quantum well led to a modified (higher) emission energy and increased radiative recombination rate. Therefore, we ascribed the origin of the high energy emission band to recombination from the 1st quantum well in the structure. Study of the temperature dependent recombination dynamics of both samples showed that the decay time measured across the spectrum was strongly influenced by the 1st quantum well in the stack (in the sample containing the prelayer) leading to a shorter average room temperature lifetime in this sample. The room temperature internal quantum efficiency of the prelayer containing sample was found to be higher than the reference sample (36% compared to 25%) which was thus attributed to the faster radiative recombination rate of the 1st quantum well providing a recombination pathway that is more competitive with non-radiative recombination processes. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.