Structural and optical investigations of AlGaN MQWs grown on a relaxed AlGaN buffer on AlN templates for emission at 280 nm
Structural and optical investigations of AlGaN MQWs grown on a relaxed AlGaN buffer on AlN templates for emission at 280 nm
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DOI：
10.1016/j.jcrysgro.2015.09.013
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发表时间：
2015-12-15
影响因子：
1.8
通讯作者：
Ougazzaden, A.
中科院分区：
文献类型：
--
作者：
Li, X.;Le Gac, G.;Ougazzaden, A.
以AlN为模板在蓝宝石衬底上生长了10周期Al0.57Ga0.43N/Al0.38Ga0.62N多量子阱。分析了丝状位错和V型凹坑的特征，并对其成因进行了讨论。分析了V型凹坑对多量子阱结构质量和280 nm光发射的影响。观察到近表面的V型凹坑总是与晶界有关，晶界由源于AlN/Al_2O_3界面的边线位错组成。尽管V型凹坑的高密度破坏了MQW的生长，但即使当V型凹坑密度从7×10(7)cm(-2)增加到2×10(9)cm(-2)时，它也不影响内量子效率，在室温下测量的量子效率接近1%。这些结果有助于理解在AlN/Al_2O_3模板上生长的AlGaN多量子阱中典型缺陷的来源、扩展和影响，从而可能导致DUV器件性能的进一步提高。(C)2015爱思唯尔B.V.保留所有权利。
10-period Al0.57Ga0.43N/Al0.38Ga0.62N multi-quantum wells (MQWs) were grown on a relaxed Al0.58Ga0.42N buffer on AlN templates on sapphire. The threading dislocations and V-pits were characterized and their origin is discussed. The influence of V-pits on the structural quality of the MQWs and on optical emission at 280 nm was analyzed. It was observed that near-surface V-pits were always associated with grain boundaries consisting of edge threading dislocations originating from the AlN/Al2O3 interface. Although the high density of V-pits disrupted MQWs growth, it did not affect the internal quantum efficiency which was measured to be similar to 1% at room temperature even when V-pit density was increased from 7 x 10(7) cm(-2) to 2 x 10(9) cm(-2). The results help to understand the origin, propagation and influences of the typical defects in AlGaN MQWs grown on AlN/Al2O3 templates which may lead to further improvement of the performance of DUV devices. (C) 2015 Elsevier B.V. All rights reserved.