Origin of huge photoluminescence efficiency improvement in InGaN/GaN multiple quantum wells with low-temperature GaN cap layer grown in N2/H2 mixture gas

The nominal internal quantum efficiency of InGaN/GaN multiple quantum wells significantly increases from 5.6 to 26.8%, as a low-temperature GaN cap layer is grown in N2/H2 mixture gas. Meanwhile, the room-temperature photoluminescence (PL) peak energy shows a merely 73 meV blue shift. On the basis o...

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Bibliographic Details
Published in:Applied physics express 2017-06, Vol.10 (6)
Main Authors: Zhu, Yadan, Lu, Taiping, Zhou, Xiaorun, Zhao, Guangzhou, Dong, Hailiang, Jia, Zhigang, Liu, Xuguang, Xu, Bingshe
Format: Article
Language:English
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Summary:The nominal internal quantum efficiency of InGaN/GaN multiple quantum wells significantly increases from 5.6 to 26.8%, as a low-temperature GaN cap layer is grown in N2/H2 mixture gas. Meanwhile, the room-temperature photoluminescence (PL) peak energy shows a merely 73 meV blue shift. On the basis of temperature-dependent PL characteristics analysis, the huge improvement in PL efficiency arises mainly from the "etching effect of hydrogen, which reduces the defect density and indium segregation at the upper well/barrier interface, and consequently contributes to the decrease in the number of nonradiative recombination centers and the enhancement of carrier localization.
ISSN:1882-0778
1882-0786
DOI:10.7567/APEX.10.061004