Temperature Dependence of Emission Properties of Self-Assembled InGaN Quantum Dots
Emission properties of self-assembled green-emitting InGaN quantum dots (QDs) grown on sapphire substrates by using metal organic chemical vapor deposition are studied by temperature-dependent photoluminescence (PL) measurements. As temperature increases (15-300K), the PL peak energy shows an anomal...
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Published in | Chinese physics letters Vol. 31; no. 11; pp. 70 - 73 |
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Main Author | |
Format | Journal Article |
Language | English |
Published |
01.11.2014
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Subjects | |
Online Access | Get full text |
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Summary: | Emission properties of self-assembled green-emitting InGaN quantum dots (QDs) grown on sapphire substrates by using metal organic chemical vapor deposition are studied by temperature-dependent photoluminescence (PL) measurements. As temperature increases (15-300K), the PL peak energy shows an anomalous V-shaped (redshift blueshift) variation instead of an S-shaped (redshift-blueshift-redshift) variation, as observed typically in green-emitting InGaN/GaN multi-quantum wells (MOWs). The PL full width at half maximum (FWHM) also shows a V-shaped (decrease-increase) variation. The temperature dependence of the PL peak energy and FWHM of QDs are well explained by a model similar to MOWs, in which carriers transferring in localized states play an important role, while the confinement energy of localized states in the QDs is significantly larger than that in MOWs. By analyzing the integrated PL intensity, the larger confinement energy of localized states in the QDs is estimated to be 105.9meV, which is well explained by taking into account the band-gap shrinkage and carrier thermalization with temperature. It is also found that the nonradiative combination centers in QD samples are much less than those in QW samples with the same In content. |
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Bibliography: | 11-1959/O4 Emission properties of self-assembled green-emitting InGaN quantum dots (QDs) grown on sapphire substrates by using metal organic chemical vapor deposition are studied by temperature-dependent photoluminescence (PL) measurements. As temperature increases (15-300K), the PL peak energy shows an anomalous V-shaped (redshift blueshift) variation instead of an S-shaped (redshift-blueshift-redshift) variation, as observed typically in green-emitting InGaN/GaN multi-quantum wells (MOWs). The PL full width at half maximum (FWHM) also shows a V-shaped (decrease-increase) variation. The temperature dependence of the PL peak energy and FWHM of QDs are well explained by a model similar to MOWs, in which carriers transferring in localized states play an important role, while the confinement energy of localized states in the QDs is significantly larger than that in MOWs. By analyzing the integrated PL intensity, the larger confinement energy of localized states in the QDs is estimated to be 105.9meV, which is well explained by taking into account the band-gap shrinkage and carrier thermalization with temperature. It is also found that the nonradiative combination centers in QD samples are much less than those in QW samples with the same In content. ZHAO Wan-Ru, WENG Guo-En, LIANG Ming-Ming, LI Zeng-Cheng, LIU Jian-Ping, ZHANG Jiang-Yong,ZHANG Bao-Ping(1. Optoelectronics Engineering Research Center, Department of Electronic Engineering, Xiamen University, Xiamen 361005; 2.Department of Physics, Xiamen University, Xiamen 361005; 3.Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123) ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0256-307X 1741-3540 |
DOI: | 10.1088/0256-307X/31/11/114205 |