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Energy Express

  • Editor: Bernard Kippelen
  • Vol. 20, Iss. S1 — Jan. 2, 2012
  • pp: A13–A19

High efficiency white LEDs with single-crystal ZnO current spreading layers deposited by aqueous solution epitaxy

Arthur H. Reading, Jacob J. Richardson, Chih-Chien Pan, Shuji Nakamura, and Steven P. DenBaars  »View Author Affiliations

Optics Express, Vol. 20, Issue S1, pp. A13-A19 (2012)

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Heteroepitaxial ZnO transparent current spreading layers with low sheet resistances were deposited on GaN-based light emitting diodes using aqueous solution phase epitaxy at temperatures below 90°C. The performance of the LEDs was analyzed and compared to identical devices using electron-beam evaporated indium tin oxide transparent current spreading layers. White LEDs with ZnO layers provided high luminous efficacy–157 lm/W at 0.5A/cm2, and 84.8 lm/W at 35A/cm2, 24% and 50% higher, respectively, than devices with ITO layers. The improvement appears to be due to the enhanced current spreading and low optical absorption provided by the ZnO.

© 2011 OSA

OCIS Codes
(230.3670) Optical devices : Light-emitting diodes
(310.7005) Thin films : Transparent conductive coatings

ToC Category:
Light-Emitting Diodes

Original Manuscript: August 16, 2011
Revised Manuscript: September 28, 2011
Manuscript Accepted: October 28, 2011
Published: November 14, 2011

Arthur H. Reading, Jacob J. Richardson, Chih-Chien Pan, Shuji Nakamura, and Steven P. DenBaars, "High efficiency white LEDs with single-crystal ZnO current spreading layers deposited by aqueous solution epitaxy," Opt. Express 20, A13-A19 (2012)

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