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Title: Interplay of point defects, extended defects, and carrier localization in the efficiency droop of InGaN quantum wells light-emitting diodes investigated using spatially resolved electroluminescence and photoluminescence

Abstract

We perform both spatially resolved electroluminescence (SREL) as a function of injection current and spatially resolved photoluminescence (SRPL) as a function of excitation power on InGaN quantum well blue light-emitting diodes to investigate the underlying physics for the phenomenon of the external quantum efficiency (EQE) droop. SREL allows us to study two most commonly observed but distinctly different droop behaviors on a single device, minimizing the ambiguity trying to compare independently fabricated devices. Two representative devices are studied: one with macroscopic scale material non-uniformity, the other being macroscopically uniform, but both with microscopic scale fluctuations. We suggest that the EQE–current curve reflects the interplay of three effects: nonradiative recombination through point defects, carrier localization due to either In composition or well width fluctuation, and nonradiative recombination of the extended defects, which is common to various optoelectronic devices. By comparing SREL and SRPL, two very different excitation/detection modes, we show that individual singular sites exhibiting either particularly strong or weak emission in SRPL do not usually play any significant and direct role in the EQE droop. We introduce a two-level model that can capture the basic physical processes that dictate the EQE–current dependence and describe the whole operating range of themore » device from 0.01 to 100 A/cm{sup 2}.« less

Authors:
 [1]; ;  [1]; ;  [2]; ;  [3]
  1. Electrical and Computer Engineering Department and Energy Production and Infrastructure Center, University of North Carolina at Charlotte, Charlotte, North Carolina 28223 (United States)
  2. R and D Center for Semiconductor Lighting, Chinese Academy of Sciences, Beijing 100083 (China)
  3. Department of Electronic Science and Fujian Engineering Research Center for Solid-State Lighting, Xiamen University, Xiamen, Fujian 361005 (China)
Publication Date:
OSTI Identifier:
22271251
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 115; Journal Issue: 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; CAPTURE; CHARGE CARRIERS; COMPARATIVE EVALUATIONS; ELECTRIC CURRENTS; ELECTROLUMINESCENCE; EXCITATION; FLUCTUATIONS; GALLIUM NITRIDES; INDIUM COMPOUNDS; LIGHT EMITTING DIODES; PHOTOLUMINESCENCE; POINT DEFECTS; QUANTUM EFFICIENCY; QUANTUM WELLS; RECOMBINATION

Citation Formats

Lin, Yue, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, Department of Electronic Science and Fujian Engineering Research Center for Solid-State Lighting, Xiamen University, Xiamen, Fujian 361005, Zhang, Yong, Su, Liqin, Liu, Zhiqiang, Wei, Tongbo, Zhang, Jihong, and Chen, Zhong. Interplay of point defects, extended defects, and carrier localization in the efficiency droop of InGaN quantum wells light-emitting diodes investigated using spatially resolved electroluminescence and photoluminescence. United States: N. p., 2014. Web. doi:10.1063/1.4861150.
Lin, Yue, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, Department of Electronic Science and Fujian Engineering Research Center for Solid-State Lighting, Xiamen University, Xiamen, Fujian 361005, Zhang, Yong, Su, Liqin, Liu, Zhiqiang, Wei, Tongbo, Zhang, Jihong, & Chen, Zhong. Interplay of point defects, extended defects, and carrier localization in the efficiency droop of InGaN quantum wells light-emitting diodes investigated using spatially resolved electroluminescence and photoluminescence. United States. https://doi.org/10.1063/1.4861150
Lin, Yue, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, Department of Electronic Science and Fujian Engineering Research Center for Solid-State Lighting, Xiamen University, Xiamen, Fujian 361005, Zhang, Yong, Su, Liqin, Liu, Zhiqiang, Wei, Tongbo, Zhang, Jihong, and Chen, Zhong. Tue . "Interplay of point defects, extended defects, and carrier localization in the efficiency droop of InGaN quantum wells light-emitting diodes investigated using spatially resolved electroluminescence and photoluminescence". United States. https://doi.org/10.1063/1.4861150.
@article{osti_22271251,
title = {Interplay of point defects, extended defects, and carrier localization in the efficiency droop of InGaN quantum wells light-emitting diodes investigated using spatially resolved electroluminescence and photoluminescence},
author = {Lin, Yue and Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 and Department of Electronic Science and Fujian Engineering Research Center for Solid-State Lighting, Xiamen University, Xiamen, Fujian 361005 and Zhang, Yong and Su, Liqin and Liu, Zhiqiang and Wei, Tongbo and Zhang, Jihong and Chen, Zhong},
abstractNote = {We perform both spatially resolved electroluminescence (SREL) as a function of injection current and spatially resolved photoluminescence (SRPL) as a function of excitation power on InGaN quantum well blue light-emitting diodes to investigate the underlying physics for the phenomenon of the external quantum efficiency (EQE) droop. SREL allows us to study two most commonly observed but distinctly different droop behaviors on a single device, minimizing the ambiguity trying to compare independently fabricated devices. Two representative devices are studied: one with macroscopic scale material non-uniformity, the other being macroscopically uniform, but both with microscopic scale fluctuations. We suggest that the EQE–current curve reflects the interplay of three effects: nonradiative recombination through point defects, carrier localization due to either In composition or well width fluctuation, and nonradiative recombination of the extended defects, which is common to various optoelectronic devices. By comparing SREL and SRPL, two very different excitation/detection modes, we show that individual singular sites exhibiting either particularly strong or weak emission in SRPL do not usually play any significant and direct role in the EQE droop. We introduce a two-level model that can capture the basic physical processes that dictate the EQE–current dependence and describe the whole operating range of the device from 0.01 to 100 A/cm{sup 2}.},
doi = {10.1063/1.4861150},
url = {https://www.osti.gov/biblio/22271251}, journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 2,
volume = 115,
place = {United States},
year = {2014},
month = {1}
}