Recombination from polar InGaN/GaN quantum well structures at high excitation carrier densities
Recombination from polar InGaN/GaN quantum well structures at high excitation carrier densities
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DOI：
10.1103/physrevb.98.155301
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发表时间：
2018-10-02
影响因子：
3.7
通讯作者：
Dawson, P.
中科院分区：
文献类型：
--
作者：
Christian, G. M.;Schulz, S.;Dawson, P.
在本文中，我们报告了极性 InGaN/GaN 单量子阱结构的低温光致发光光谱中高光激发载流子密度下出现的高能带。当局域基态的发射开始饱和时，在载流子密度处就会出现这种高能带。我们将这种高能带归因于涉及较高能量的不太强局域电子和空穴态的重组，一旦局域基态饱和，这些电子和空穴态就会出现。这一分配得到了原子紧束缚模型结果的支持。高载流子密度下复合的一个特殊特征是光致发光衰减曲线的整体形式与半导体量子点的光致发光衰减曲线非常相似。衰减曲线由平台组成，其中光致发光强度随时间恒定，这是由于高能局域态中的泡利态阻挡，一旦载流子密度足够低以致所涉及的态不再饱和，强度就会迅速下降。
In this paper we report on the emergence of a high energy band at high optically excited carrier densities in the low temperature photoluminescence spectra from polar InGaN/GaN single quantum well structures. This high energy band emerges at carrier densities when the emission from the localized ground states begins to saturate. We attribute this high energy band to recombination involving higher energy less strongly localized electron and hole states that are populated once the localized ground states become saturated; this assignment is supported by the results from an atomistic tight-binding model. A particular characteristic of the recombination at the high carrier densities is that the overall forms of the photoluminescence decay curves bear great similarity to those from semiconductor quantum dots. The decay curves consist of plateaus where the photoluminescence intensity is constant with time as a result of Pauli state blocking in the high energy localized states followed by a rapid decrease in intensity once the carrier density is sufficiently low that the states involved are no longer saturated.