Luminescent Characteristics of Near Ultraviolet InGaN/GaN MQWs Grown on Grooved Sapphire Substrates Fabricated by Wet Chemical Etching
Yu Nai-Sen; Guo Li-Wei; Chen Hong; Xing Zhi-Gang; Wang Jing; Zhu Xue-Liang; Peng Ming-Zheng; Yan Jian-Feng; Jia Hai-Qiang; Zhou Jun-Ming; Yu Nai-Sen; State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080; Guo Li-Wei; State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080; Chen Hong; State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080; Xing Zhi-Gang; State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080; Wang Jing; State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080; Zhu Xue-Liang; State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080; Peng Ming-Zheng; State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080; Yan Jian-Feng; State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080; Jia Hai-Qiang; State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080; Zhou Jun-Ming; State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080
Журнал:
Chinese Physics Letters
Дата:
2006-08-01
Аннотация:
InGaN/GaN multiple quantum wells (MQWs) are grown on planar and maskless periodically grooved sapphires by metal organic vapour phase epitaxy (MOCVD). High-resolution x-ray rocking curves and transmission electron microscopy (TEM) are adopted to characterize the film quality. Compared with the MQWs grown on planar sapphire, the sample grown on grooved sapphire shows better crystalline quality: a remarkable reduction of dislocation densities is achieved. Meanwhile, the MQWs grown on grooved sapphire show two times larger PL intensity at room temperature. Temperature-dependent PL measurements are adopted to investigate the luminescence properties. The luminescence thermal quenching based on a fit to the Arrhenius plot of the normalized integrated PL intensity over the measured temperature range suggests that the nonradiative recombination centres (NRCs) are greatly reduced for the sample grown on grooved sapphire. We assume that the reduction of dislocations which act as NRCs is the main reason for the sample grown on pattern sapphire having higher PL intensity.
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