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Optics Express

Optics Express

  • Editor: Andrew M. Weiner
  • Vol. 21, Iss. 12 — Jun. 17, 2013
  • pp: 14566–14572

Coherent vertical beaming using Bragg mirrors for high-efficiency GaN light-emitting diodes

Sun-Kyung Kim and Hong-Gyu Park  »View Author Affiliations

Optics Express, Vol. 21, Issue 12, pp. 14566-14572 (2013)

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We propose a dielectric Bragg mirror that utilizes coherent coupling with multiple quantum wells (MQWs) to significantly enhance light extraction from GaN light-emitting diode (LED). Full vectorial electromagnetic simulation showed that, under constructive interference conditions, the Bragg mirror consisting of two dielectric (SiO2/TiO2) stacks and a silver layer led to >30% enhancement in light extraction, as compared to a single silver mirror. Such significant enhancement by a pre-designed Bragg/metal mirror was ascribed to the vertically oriented radiation pattern and reduced plasmonic metal loss. In addition, the gap distance between the MQWs and a Bragg mirror at which the constructive interference takes place could be controlled by modulating the thickness of the first low-refractive-index layer. Moreover, a two-dimensional periodic pattern was incorporated into an upper GaN layer with the designed Bragg mirror and it was shown that a lattice constant of ~800 nm was optimal for light extraction. We believe that tailoring the radiation profile of light emitters by coherent coupling with designed high-reflectivity mirrors will be a promising route to overcome the efficiency limit of current semiconductor LED devices.

© 2013 OSA

OCIS Codes
(230.1480) Optical devices : Bragg reflectors
(230.3670) Optical devices : Light-emitting diodes
(260.3160) Physical optics : Interference

ToC Category:
Optical Devices

Original Manuscript: May 14, 2013
Manuscript Accepted: June 3, 2013
Published: June 11, 2013

Sun-Kyung Kim and Hong-Gyu Park, "Coherent vertical beaming using Bragg mirrors for high-efficiency GaN light-emitting diodes," Opt. Express 21, 14566-14572 (2013)

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