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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 17, Iss. 20 — Sep. 28, 2009
  • pp: 17269–17278

Highly efficient inverted top-emitting organic light-emitting diodes using a lead monoxide electron injection layer

Qiang Wang, Zhaoqi Deng, and Dongge Ma  »View Author Affiliations


Optics Express, Vol. 17, Issue 20, pp. 17269-17278 (2009)
http://dx.doi.org/10.1364/OE.17.017269


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Abstract

By introducing an effective electron injection layer (EIL) material, i.e., lead monoxide (PbO), combined with the optical design in device structure, a high efficiency inverted top-emitting organic light-emitting diode (ITOLED) with saturated and quite stable colors for different viewing angles is demonstrated. The green ITOLED based on 10-(2-benzothiazolyl)-1, 1, 7, 7-tetramethyl-2, 3, 6, 7-tetrahydro-1H, 5H, 11H-[1] benzopyrano [6, 7, 8-ij] quinolizin-11-one exhibits a maximum current efficiency of 33.8 cd/A and a maximum power efficiency of 16.6 lm/W, accompanied by a nearly Lambertian distribution as well as hardly detectable color variation in the 140° forward viewing cone. A detailed analysis on the role mechanism of PbO in electron injection demonstrates that the insertion of the PbO EIL significantly reduces operational voltage, thus greatly improving the device efficiency. More importantly, the optically optimized device structure by setting the resonant wavelength at the peak wavelength of the intrinsic emission of the emitter and adding an effective outcoupling layer further enhances the device efficiency, at the same time, also reduces the color shift with viewing angles, leading to the simultaneous optimization in efficiency and angular emission characteristics in the fabricated ITOLEDs.

© 2009 OSA

OCIS Codes
(220.0220) Optical design and fabrication : Optical design and fabrication
(230.3670) Optical devices : Light-emitting diodes

ToC Category:
Optical Devices

History
Original Manuscript: June 22, 2009
Revised Manuscript: September 1, 2009
Manuscript Accepted: September 5, 2009
Published: September 14, 2009

Citation
Qiang Wang, Zhaoqi Deng, and Dongge Ma, "Highly efficient inverted top-emitting organic light-emitting diodes using a lead monoxide electron injection layer," Opt. Express 17, 17269-17278 (2009)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-17-20-17269


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