TITLE

High-power and reliable operation of vertical light-emitting diodes on bulk GaN

AUTHOR(S)
Cao, X.A.; Arthur, S.D.
PUB. DATE
November 2004
SOURCE
Applied Physics Letters;11/1/2004, Vol. 85 Issue 18, p3971
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
InGaN/GaN light-emitting diodes (LEDs) with lateral and vertical geometries have been fabricated on free-standing GaN substrates. Current spreading was significantly enhanced in the vertical LED, leading to a reduced series resistance of 7 Ω compared to 12.2 and 14.2 Ω for the lateral LEDs on GaN and sapphire, respectively. As a result, the light output and power conversion efficiency of the vertical LED on GaN were greatly improved at high injection currents. The vertical LED was subjected to a stress test at 400 mA and showed minimal degradation of optical power, whereas the same stress resulted in the destruction of the lateral LED on sapphire due to increased current crowding and self-heating. However, lateral LEDs on sapphire with optimized current spreading exhibited excellent reliability, indicating the presence of a high density of dislocations (∼109 cm-2) in the heteroepitaxial device does not accelerate LED degradation at current densities up to 700 A/cm2.
ACCESSION #
14945531

 

Related Articles

  • Dislocation motion in GaN light-emitting devices and its effect on device lifetime. Sugiura, Lisa // Journal of Applied Physics;2/15/1997, Vol. 81 Issue 4, p1633 

    In this study, dislocation motions in GaN-based materials and devices were quantitatively estimated in order to determine why GaN-based light-emitting diodes have remarkable reliability and longevity in spite of extremely high dislocation density. The dislocation velocity of GaN-based materials...

  • Influence of a sapphire substrate on the emission spectra of gallium nitride light-emitting diodes. Kudryashov, V. E.; Mamakin, S. S.; Yunovich, A. É. // Technical Physics Letters;Jul99, Vol. 25 Issue 7, p536 

    The emission spectra of green light-emitting diodes based on InGaN/AlGaN/GaN heterostructures revealed a weak thin doublet line at the long-wavelength edge. This line is ascribed to luminescence of residual Cr[sup 3+] impurity ions in the sapphire substrate (similar to ruby, Al[sub 2]O[sub 3]...

  • The impact of trench defects in InGaN/GaN light emitting diodes and implications for the “green gap" problem. Massabuau, F. C. -P.; Davies, M. J.; Oehler, F.; Pamenter, S. K.; Thrush, E. J.; Kappers, M. J.; Kovács, A.; Williams, T.; Hopkins, M. A.; Humphreys, C. J.; Dawson, P.; Dunin-Borkowski, R. E.; Etheridge, J.; Allsopp, D. W. E.; Oliver, R. A. // Applied Physics Letters;9/15/2014, Vol. 105 Issue 11, p1 

    The impact of trench defects in blue InGaN/GaN light emitting diodes (LEDs) has been investigated. Two mechanisms responsible for the structural degradation of the multiple quantum well (MQW) active region were identified. It was found that during the growth of the p-type GaN capping layer, loss...

  • Occurrence of cubic GaN and strain relaxation in GaN buffer layers grown by low-pressure... Lisen Cheng; Kuan Zhou; Ze Zhang; Guoyi Zhang; Zhijian Yang; Yuzhen Tong // Applied Physics Letters;2/1/1999, Vol. 74 Issue 5, p661 

    Investigates the occurrence of cubic gallium nitride (GaN) and strain relaxation in GaN buffer layers grown by low-pressure metalorganic vapor phase epitaxy on (001) sapphire substrates. Preferential formation of cubic GaN under specific growth conditions; Existence of high density stacking...

  • Response to 'Comment on 'The effects of Si doping on dislocation movement and tensile stress in GaN films'' [J. Appl. Phys. 109, 073509 (2011)]. Moram, M. A.; Kappers, M. J.; Massabuau, F.; Oliver, R. A.; Humphreys, C. J. // Journal of Applied Physics;Nov2011, Vol. 110 Issue 9, p096102 

    A response to a commentary on the article "The Effects of Si Doping on Dislocation Movement and Tensile Stress in GaN Films," by M. A. Moran and colleagues, is presented. It defines climb as a movement of a dislocation in a plane that does not contain its burgers vector, influenced by in-plane...

  • Dislocation related droop in InGaN/GaN light emitting diodes investigated via cathodoluminescence. Pozina, Galia; Ciechonski, Rafal; Zhaoxia Bi; Samuelson, Lars; Monemar, Bo // Applied Physics Letters;12/21/2015, Vol. 107 Issue 25, p1 

    Today's energy saving solutions for general illumination rely on efficient white light emitting diodes(LEDs). However, the output efficiency droop experienced in InGaN based LEDs with increasing current injection is a serious limitation factor for future development of bright white LEDs. We show...

  • High efficiency light emitting diode with anisotropically etched GaN-sapphire interface. Lo, M. H.; Tu, P. M.; Wang, C. H.; Hung, C. W.; Hsu, S. C.; Cheng, Y. J.; Kuo, H. C.; Zan, H. W.; Wang, S. C.; Chang, C. Y.; Huang, S. C. // Applied Physics Letters;7/27/2009, Vol. 95 Issue 4, p041109 

    We report the fabrication and study of high efficiency ultraviolet light emitting diodes with inverted micropyramid structures at GaN-sapphire interface. The micropyramid structures were created by anisotropic chemical wet etching. The pyramid structures have significantly enhanced the light...

  • Confocal microscopic analysis of optical crosstalk in GaN micro-pixel light-emitting diodes. Li, K. H.; Cheung, Y. F.; Cheung, W. S.; Choi, H. W. // Applied Physics Letters;2015, Vol. 107 Issue 17, p1 

    The optical crosstalk phenomenon in GaN micro-pixel light-emitting diodes (LED) has been investigated by confocal microscopy. Depth-resolved confocal emission images indicate light channeling along the GaN and sapphire layers as the source of crosstalk. Thin-film micro-pixel devices are...

  • Is the use of GaN-on-Si for lighting LEDs just an impossible dream?  // Electronics Weekly;11/13/2013, Issue 2567, p16 

    The article discusses technical hurdles that should be addressed before substituting silicon for sapphire in manufacturing Light Emitting Diode (LEDs). It provides detail information on structure Lighting LED devices, which are fabricated on gallium nitride (GaN) semiconductor layers. The author...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics