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Title: Enhancing the quantum efficiency of InGaN yellow-green light-emitting diodes by growth interruption

We studied the effect of multiple interruptions during the quantum well growth on emission-efficiency enhancement of InGaN-based yellow-green light emitting diodes on c-plane sapphire substrate. The output power and dominant wavelength at 20 mA are 0.24 mW and 556.3 nm. High resolution x-ray diffraction, photoluminescence, and electroluminescence measurements demonstrate that efficiency enhancement could be partially attributed to crystal quality improvement of the active region resulted from reduced In clusters and relevant defects on the surface of InGaN layer by introducing interruptions. The less tilted energy band in the quantum well is also caused by the decrease of In-content gradient along c-axis resulted from In segregation during the interruptions, which increases spatial overlap of electron-hole wavefunction and thus the internal quantum efficiency. The latter also leads to smaller blueshift of dominant wavelength with current increasing.
Authors:
; ; ; ; ; ; ;  [1]
  1. Key Laboratory for Renewable Energy, Chinese Academy of Sciences, Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condense Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)
Publication Date:
OSTI Identifier:
22310864
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CRYSTAL DEFECTS; CRYSTALS; CURRENTS; ELECTROLUMINESCENCE; GALLIUM COMPOUNDS; INDIUM COMPOUNDS; LAYERS; LIGHT EMITTING DIODES; NITROGEN COMPOUNDS; PHOTOLUMINESCENCE; QUANTUM EFFICIENCY; QUANTUM WELLS; RESOLUTION; SAPPHIRE; SUBSTRATES; SURFACES; WAVE FUNCTIONS; WAVELENGTHS; X-RAY DIFFRACTION