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Proceedings Paper

InGaN based multi-double heterostructure light-emitting diodes with electron injector layers
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Paper Abstract

For high efficiency at high current injection InGaN light emitting diodes (LEDs) necessitate active regions that can mitigate the aggravating electron overflow. Multi double-heterostructures (DHs), 3D active regions separated by low energy barriers, were investigated as optimum solutions for high efficiency as they can accommodate a larger number of states compared to multiple quantum wells (MQWs). However, the number of DH active regions is limited as the material degrades with increasing thickness; therefore, carrier cooling should be partially achieved before the active region using staircase electron injector (SEI) layers. Using electroluminescence (EL) efficiency measurements supported by simulations, active regions and electron injectors were optimized to minimize the electron overflow and the associated efficiency drop at high injection. For a single 3 nm DH LED, the electron overflow was nearly eliminated by increasing the two-step staircase electron injector layer thickness from 4+4 nm to 20+20 nm, whereas the change in SEI thickness had nearly no effect for the DH LEDs with thicker active region. Temperature and excitation density dependent photoluminescence (PL) spectroscopy allowed determination of the material quality and the internal quantum efficiency of device structures with varying active region and SEI thickness.

Paper Details

Date Published: 4 March 2013
PDF: 8 pages
Proc. SPIE 8625, Gallium Nitride Materials and Devices VIII, 86251J (4 March 2013); doi: 10.1117/12.2003162
Show Author Affiliations
F. Zhang, Virginia Commonwealth Univ. (United States)
S. A. Hafiz, Virginia Commonwealth Univ. (United States)
X. Li, Virginia Commonwealth Univ. (United States)
S. Okur, Virginia Commonwealth Univ. (United States)
V. Avrutin, Virginia Commonwealth Univ. (United States)
Ü. Özgür, Virginia Commonwealth Univ. (United States)
H. Morkoç, Virginia Commonwealth Univ. (United States)


Published in SPIE Proceedings Vol. 8625:
Gallium Nitride Materials and Devices VIII
Jen-Inn Chyi; Yasushi Nanishi; Hadis Morkoç; Joachim Piprek; Euijoon Yoon; Hiroshi Fujioka, Editor(s)

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