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Energy Express

Energy Express

  • Editor: Christian Seassal
  • Vol. 22, Iss. S3 — May. 5, 2014
  • pp: A705–A714

Enhancement of light-extraction efficiency of organic light-emitting diodes using silica nanoparticles embedded in TiO2 matrices

Jooyoung Lee, Yun Young Kwon, Eun-Ho Choi, JeongWoo Park, Hong Yoon, and Hyunbin Kim  »View Author Affiliations

Optics Express, Vol. 22, Issue S3, pp. A705-A714 (2014)

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We investigate two types of internal light-extraction layer structures for organic light-emitting diodes (OLEDs) that consist of silica nanoparticles (NPs) embedded in high-refractive-index TiO2 matrices. The composite of silica NPs and TiO2 matrices was coated on the glass substrate and fabricated with and without a SiO2 planarization layer. An increase in the optical out-coupling efficiency by a factor of 2.0 was obtained at a high luminance of 3,000 cd/m2 from OLEDs containing the silica NPs embedded in TiO2 matrices between glass substrates and Zn-doped In2O3 (IZO) electrodes after additional planarization processes. This is consistent with the analytical result using the finite-difference time-domain (FDTD) method. Randomly distributed silica NPs acting as scattering centers could reduce the optical loss when extracting light. By using additional planarization processes with a PECVD-derived SiO2 layer, one can assure that smoother surfaces provide higher out-coupling efficiency, which attain 100% and 97% enhancements in power (lm/W) and current (cd/A) efficiencies, respectively.

© 2014 Optical Society of America

OCIS Codes
(230.3670) Optical devices : Light-emitting diodes
(290.5850) Scattering : Scattering, particles

ToC Category:
Light-Emitting Diodes

Original Manuscript: August 12, 2013
Revised Manuscript: March 7, 2014
Manuscript Accepted: March 15, 2014
Published: March 27, 2014

Jooyoung Lee, Yun Young Kwon, Eun-Ho Choi, JeongWoo Park, Hong Yoon, and Hyunbin Kim, "Enhancement of light-extraction efficiency of organic light-emitting diodes using silica nanoparticles embedded in TiO2 matrices," Opt. Express 22, A705-A714 (2014)

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