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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 2 — Jan. 16, 2012
  • pp: 845–853

MgO nano-facet embedded silver-based dielectric/metal/dielectric transparent electrode

Sungjun Kim, Hak Ki Yu, Kihyon Hong, Kisoo Kim, Jun Ho Son, Illhwan Lee, Kyoung-Bo Kim, Tae-Yeob Kim, and Jong-Lam Lee  »View Author Affiliations


Optics Express, Vol. 20, Issue 2, pp. 845-853 (2012)
http://dx.doi.org/10.1364/OE.20.000845


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Abstract

We replace Indium Tin Oxide (ITO) with an MgO nano-facet Embedded WO3/Ag/WO3(WAW) multilayer for electrodes of high efficiency OLEDs. WAW shows higher values for transmittance (93%) and conductivity (1.3×105 S/cm) than those of ITO. Moreover, WAW shows higher transmittance (92.5%) than that of ITO (86.4%) in the blue region (<500 nm). However, due to the large difference in refractive indices (n) of glass (n=1.55) and WO3 (n=1.95), the incident light has a small critical angle (52°). Thus, the generated light is confined by the glass/WAW interface, resulting in low light outcoupling efficiency (~20%). This can be enhanced by using a nano-facet structured MgO (n=1.73) layer and a ZrO2 (n=1.84) layer as a graded index layer. Using these optimized electrodes, ITO-free, OLEDs with various emission wavelengths have been produced. The luminance of OLEDs using MgO/ZrO2/WAW layers is enhanced by 24% compared to that of devices with ITO.

© 2012 OSA

OCIS Codes
(250.0250) Optoelectronics : Optoelectronics
(310.7005) Thin films : Transparent conductive coatings

ToC Category:
Optoelectronics

History
Original Manuscript: October 18, 2011
Revised Manuscript: December 1, 2011
Manuscript Accepted: December 2, 2011
Published: January 3, 2012

Citation
Sungjun Kim, Hak Ki Yu, Kihyon Hong, Kisoo Kim, Jun Ho Son, Illhwan Lee, Kyoung-Bo Kim, Tae-Yeob Kim, and Jong-Lam Lee, "MgO nano-facet embedded silver-based dielectric/metal/dielectric transparent electrode," Opt. Express 20, 845-853 (2012)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-20-2-845


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