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Energy Express

  • Editor: Bernard Kippelen
  • Vol. 19, Iss. S4 — Jul. 4, 2011
  • pp: A793–A803

ITO-free large-area organic light-emitting diodes with an integrated metal grid

Seungkeun Choi, Sung-Jin Kim, Canek Fuentes-Hernandez, and Bernard Kippelen  »View Author Affiliations

Optics Express, Vol. 19, Issue S4, pp. A793-A803 (2011)

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We report on ITO-free large-area organic light-emitting diodes (OLEDs) fabricated on glass substrates comprising α-NPD as a hole transport layer (HTL) and coevaporated CBP:Ir(ppy)3 as the emission layer. Indium-tin-oxide (ITO) was replaced with a conductive polymer electrode and an electroplated thick metal grid was used to improve the homogeneity of the potential distribution over the transparent polymer electrode. An electrical model of a metal grid integrated OLED shows the benefits of the use of metal grids in terms of improving the uniformity of the light emitted as the area of the OLED increases as well as the conductivity of the transparent electrode decreases. By integrating metal grids with polymer electrodes, the luminance increases more than 24% at 6 V and 45% at 7 V compared to the polymer electrode devices without a metal grid. This implies that a lower voltage can be applied to achieve the same luminance, hence lowering the power consumption. Furthermore, metal grid integrated OLEDs exhibited less variation in light emission compared to devices without a metal grid.

© 2011 OSA

OCIS Codes
(160.0160) Materials : Materials
(250.3680) Optoelectronics : Light-emitting polymers
(260.3800) Physical optics : Luminescence
(310.6845) Thin films : Thin film devices and applications
(310.7005) Thin films : Transparent conductive coatings

ToC Category:
Light-Emitting Diodes

Original Manuscript: February 23, 2011
Revised Manuscript: April 15, 2011
Manuscript Accepted: April 21, 2011
Published: June 6, 2011

Seungkeun Choi, Sung-Jin Kim, Canek Fuentes-Hernandez, and Bernard Kippelen, "ITO-free large-area organic light-emitting diodes with an integrated metal grid," Opt. Express 19, A793-A803 (2011)

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