Directional emission control and increased light extraction in GaN photonic crystal light emitting diodes
Kelly McGroddy,Aurelien David,Elison Matioli,Michael Iza,Shuji Nakamura,Steven P. DenBaars,James S. Speck,Claude Weisbuch,Evelyn L. Hu +8 more
TLDR
In this paper, a two-dimensional photonic crystal (PhC) light emitting diodes (LEDs) design using both in-plane and index guiding layers (IGLs) in the vertical direction is proposed.Abstract:
Limitations in extraction efficiency of gallium nitride (GaN) photonic crystal (PhC) light emitting diodes (LEDs) are addressed by implementing an LED design using both two-dimensional PhCs in-plane and index guiding layers (IGLs) in the vertical direction. The effects of PhCs on light extraction and emission directionality from GaN LEDs are studied experimentally. Angular-resolved electroluminescence clearly shows the combined effect of controlling the vertical mode profile with the IGLs and tailoring the emission profile with the periodicity of the PhC lattice. Increases in directional emission as high as 3.5 times are achieved by taking advantage of this directionality and guided mode control.read more
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Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening
TL;DR: In this paper, an n-side-up GaN-based LED with a hexagonal "conelike" surface has been fabricated by using the laser lift-off technique followed by an anisotropic etching process to roughen the surface.
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Jonathan J. Wierer,Daniel A. Steigerwald,Michael R. Krames,J. O'Shea,M. J. Ludowise,G. Christenson,Y. C. Shen,C. H. Lowery,Paul S. Martin,S. Subramanya,W. Götz,Nathan F. Gardner,R. S. Kern,S. A. Stockman +13 more
TL;DR: In this article, the authors presented a flip-chip light-emitting diodes (FCLEDs) with a large emitting area (∼0.70 mm2) and an optimized contacting scheme allowing high current (200-1000 mA, J∼30-143 A/cm2) operation with low forward voltages.
Journal ArticleDOI
High-power truncated-inverted-pyramid (AlxGa1−x)0.5In0.5P/GaP light-emitting diodes exhibiting >50% external quantum efficiency
Michael R. Krames,M. Ochiai-Holcomb,Gloria E Hofler,Carrie Carter-Coman,E. I. Chen,I.-H. Tan,P.N. Grillot,Nathan F. Gardner,Herman C Chui,J.-W. Huang,S. A. Stockman,F. A. Kish,M. G. Craford,T. S. Tan,C. P. Kocot,M. Hueschen,J. Posselt,B. Loh,G. Sasser,D. Collins +19 more
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Impact of planar microcavity effects on light extraction-Part I: basic concepts and analytical trends
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