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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 17 — Aug. 13, 2012
  • pp: 19194–19199

Highly reliable Ag/Zn/Ag ohmic reflector for high-power GaN-based vertical light-emitting diode

Woong-Sun Yum, Joon-Woo Jeon, Jun-Suk Sung, and Tae-Yeon Seong  »View Author Affiliations


Optics Express, Vol. 20, Issue 17, pp. 19194-19199 (2012)
http://dx.doi.org/10.1364/OE.20.019194


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Abstract

We report the improved performance of InGaN/GaN-based light-emitting diodes (LEDs) through Ag reflectors combined with a Zn middle layer. It is shown that the Zn middle layer (5 nm thick) suppresses the agglomeration of Ag reflectors by forming ZnO and dissolving into Ag. The Ag/Zn/Ag contacts show a specific contact resistance of 6.2 × 10−5 Ωcm2 and reflectance of ~83% at a wavelength of 440 nm when annealed at 500 °C, which are much better than those of Ag only contacts. Blue LEDs fabricated with the 500 °C-annealed Ag/Zn/Ag reflectors show a forward voltage of 2.98 V at an injection current of 20 mA, which is lower than that (3.02 V) of LEDs with the annealed Ag only contacts. LEDs with the 500 °C-annealed Ag/Zn/Ag contacts exhibit 34% higher output power (at 20 mA) than LEDs with the annealed Ag only contacts.

© 2012 OSA

OCIS Codes
(230.3670) Optical devices : Light-emitting diodes
(230.4040) Optical devices : Mirrors

ToC Category:
Optical Devices

History
Original Manuscript: May 9, 2012
Revised Manuscript: July 11, 2012
Manuscript Accepted: July 16, 2012
Published: August 6, 2012

Citation
Woong-Sun Yum, Joon-Woo Jeon, Jun-Suk Sung, and Tae-Yeon Seong, "Highly reliable Ag/Zn/Ag ohmic reflector for high-power GaN-based vertical light-emitting diode," Opt. Express 20, 19194-19199 (2012)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-20-17-19194


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