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Improved quality nonpolar a ‐plane GaN/AlGaN UV LEDs grown with sidewall lateral epitaxial overgrowth (SLEO)
Author(s) -
Imer Bilge,
Schmidt Matt,
Haskell Ben,
Rajan Siddharth,
Zhong Barry,
Kim Kwangchoong,
Wu Feng,
Mates Tom,
Keller Stacia,
Mishra Umesh K.,
Nakamura Shuji,
Speck James S.,
DenBaars Steven P.
Publication year - 2008
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200723403
Subject(s) - light emitting diode , optoelectronics , materials science , epitaxy , chemical vapor deposition , diode , planar , metalorganic vapour phase epitaxy , laser linewidth , plane (geometry) , optics , nanotechnology , physics , laser , geometry , computer graphics (images) , layer (electronics) , mathematics , computer science
Abstract High quality nonpolar a ‐plane GaN templates were grown by utilizing sidewall lateral epitaxial overgrowth (SLEO) technique with threading dislocation density of ∼10 6 –10 7 cm –2 . 360 nm GaN/AlGaN multiple quantum well ultraviolet light emitting diodes were grown with metalorganic chemical vapor deposition. Reduced defect density SLEO a‐ plane, planar a ‐plane, and planar c ‐plane templates were co‐loaded for device growth and processed together in order to make relative device performance comparison. For SLEO a ‐plane LEDs E EL peak position was measured at 360 nm and it was independent of drive current. The linewidth of the emission was 7 nm. The series resistance of these diodes was as low as 16.5 Ω and the forward voltage was measured as 4.08 V at 20 mA. The external quantum efficiency of the high quality SLEO a ‐plane devices was ∼275× higher than planar a ‐plane devices. The highest output power was realized at 200 mA as 65 μW. The effect of contact geometry on electrical and optical characteristics of the devices was also discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)