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Optimization of InGaN/(In,Al,Ga)N based near UV‐LEDs by MQW strain balancing with in‐situ wafer bow sensor
Author(s) -
Knauer A.,
Kolbe T.,
Einfeldt S.,
Weyers M.,
Kneissl M.,
Zettler T.
Publication year - 2009
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.200880403
Subject(s) - light emitting diode , optoelectronics , materials science , heterojunction , wafer , epitaxy , diode , quantum well , quantum efficiency , optics , nanotechnology , physics , laser , layer (electronics)
A high resolution curvature sensor was used for in‐situ monitoring of the strain state during the growth of the InGaN multiple‐quantum‐well (MQW) for near UV light emitting diodes (LEDs). The LED heterostructures were grown by metal‐organic vapor phase epitaxy. LEDs containing different In x Al 0.16 Ga 0.84– x N barrier layers were compared. The results were correlated with the external quantum efficiency (EQE) and the current induced shift of the emission wavelength of the LEDs. It was found that strain‐compensated or slightly compressively strained In x Al 0.16 Ga 0.84– x N barrier layers in the MQW, for which the net polarization in the InGaN quantum wells is close to zero, result in the highest EQE and in a stable emission wavelength independent of the drive current. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)