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Energy Express

  • Editor: Bernard Kippelen
  • Vol. 19, Iss. S4 — Jul. 4, 2011
  • pp: A786–A792

Soft holographic interference lithography microlens for enhanced organic light emitting diode light extraction

Joong-Mok Park, Zhengqing Gan, Wai Y. Leung, Rui Liu, Zhuo Ye, Kristen Constant, Joseph Shinar, Ruth Shinar, and Kai-Ming Ho  »View Author Affiliations

Optics Express, Vol. 19, Issue S4, pp. A786-A792 (2011)

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Very uniform 2 μm-pitch square microlens arrays (μLAs), embossed on the blank glass side of an indium-tin-oxide (ITO)-coated 1.1 mm-thick glass, are used to enhance light extraction from organic light-emitting diodes (OLEDs) by ~100%, significantly higher than enhancements reported previously. The array design and size relative to the OLED pixel size appear to be responsible for this enhancement. The arrays are fabricated by very economical soft lithography imprinting of a polydimethylsiloxane (PDMS) mold (itself obtained from a Ni master stamp that is generated from holographic interference lithography of a photoresist) on a UV-curable polyurethane drop placed on the glass. Green and blue OLEDs are then fabricated on the ITO to complete the device. When the μLA is ~15 × 15 mm2, i.e., much larger than the ~3 × 3 mm2 OLED pixel, the electroluminescence (EL) in the forward direction is enhanced by ~100%. Similarly, a 19 × 25 mm2 μLA enhances the EL extracted from a 3 × 3 array of 2 × 2 mm2 OLED pixels by 96%. Simulations that include the effects of absorption in the organic and ITO layers are in accordance with the experimental results and indicate that a thinner 0.7 mm thick glass would yield a ~140% enhancement.

© 2011 OSA

OCIS Codes
(080.3630) Geometric optics : Lenses
(230.3990) Optical devices : Micro-optical devices

ToC Category:
Light-Emitting Diodes

Original Manuscript: March 16, 2011
Revised Manuscript: April 22, 2011
Manuscript Accepted: April 23, 2011
Published: June 6, 2011

Joong-Mok Park, Zhengqing Gan, Wai Y. Leung, Rui Liu, Zhuo Ye, Kristen Constant, Joseph Shinar, Ruth Shinar, and Kai-Ming Ho, "Soft holographic interference lithography microlens for enhanced organic light emitting diode light extraction," Opt. Express 19, A786-A792 (2011)

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  1. C. F. Madigan, M.-H. Lu, and J. C. Sturm, “Improvement of output coupling efficiency of organic light-emitting diodes by backside substrate modification,” Appl. Phys. Lett. 76(13), 1650–1652 (2000). [CrossRef]
  2. S. Möller and S. R. Forrest, “Improved light out-coupling in organic light emitting diodes employing ordered microlens arrays,” J. Appl. Phys. 91(5), 3324–3327 (2002). [CrossRef]
  3. M.-K. Wei and I.-L. Su, “Method to evaluate the enhancement of luminance efficiency in planar OLED light emitting devices for microlens array,” Opt. Express 12(23), 5777–5782 (2004). [CrossRef] [PubMed]
  4. Y. Sun and S. R. Forrest, “Enhanced light out-coupling of organic light-emitting devices using embedded low-index grids,” Nat. Photonics 2(8), 483–487 (2008). [CrossRef]
  5. H. J. Peng, Y. L. Ho, C. F. Qiu, M. Wong, and H. S. Kwok, “Coupling efficiency enhancement of organic light emitting devices with refractive microlens array on high index glass substrate,” SID J. 11(4), 158–161 (2004). [CrossRef]
  6. H. Peng, Y. L. Ho, X.-J. Yu, M. Wong, and H. S. Kwok, “Coupling efficiency enhancement in organic light-emitting devices using microlens array—theory and experiment,” J. Displ. Technol. 1(2), 278–282 (2005). [CrossRef]
  7. J. Lim, S. S. Oh, D. Y. Kim, S. H. Cho, I. T. Kim, S. H. Han, H. Takezoe, E. H. Choi, G. S. Cho, Y. H. Seo, S. O. Kang, and B. Park, “Enhanced out-coupling factor of microcavity organic light-emitting devices with irregular microlens array,” Opt. Express 14(14), 6564–6571 (2006). [CrossRef] [PubMed]
  8. H.-Y. Lin, Y.-H. Ho, J.-H. Lee, K.-Y. Chen, J.-H. Fang, S.-C. Hsu, M.-K. Wei, H.-Y. Lin, J.-H. Tsai, and T.-C. Wu, “Patterned microlens array for efficiency improvement of small-pixelated organic light-emitting devices,” Opt. Express 16(15), 11044–11051 (2008). [CrossRef] [PubMed]
  9. Y. Sun and S. R. Forrest, “Organic light emitting devices with enhanced outcoupling via microlenses fabricated by imprint lithography,” J. Appl. Phys. 100, 073106 (2006). [CrossRef]
  10. S.-H. Eom, E. Wrzesniewski, and J. Xue, “Periodic nanostructuring for guided mode extraction in organic light-emitting diodes,” Int. J. Photoenergy 1, 011002 (2011).
  11. J.-H. Lee, W. Leung, J. Ahn, T. Lee, I.-S. Park, K. Constant, and K.-M. Ho, “Layer-by-layer photonic crystal fabricated by low-temperature atomic layer deposition,” Appl. Phys. Lett. 90, 151101 (2007). [CrossRef]
  12. X.-M. Zhao, Y. Xia, and G. M. Whitesides, “Fabrication of three-dimensional micro-structures: microtransfer molding,” Adv. Mater. 8(10), 837–840 (1996). [CrossRef]
  13. J.-M. Park, K. S. Nalwa, W. Leung, K. Constant, S. Chaudhary, and K.-M. Ho, “Fabrication of metallic nanowires and nanoribbons using laser interference lithography and shadow lithography,” Nanotechnology 21, 215301 (2010). [CrossRef] [PubMed]
  14. Y.-K. Ee, P. Kumnorkaew, R. A. Arif, H. Tong, J. F. Gilchrist, and N. Tansu, “Light extraction efficiency enhancement of InGaN quantum wells light-emitting diodes with polydimethylsiloxane concave microstructures,” Opt. Express 17(16), 13747–13757 (2009). [CrossRef] [PubMed]
  15. L. Zou, V. Savvate’ev, J. Booher, C. H. Kim, and J. Shinar, “Combinatorial fabrication and studies of intense efficient ultraviolet–violet organic light-emitting device arrays,” Appl. Phys. Lett. 79(14), 2282 (2001). [CrossRef]
  16. B. Choudhury, R. Shinar, and J. Shinar, “Glucose biosensors based on organic light-emitting devices structurally integrated with a luminescent sensing element,” J. Appl. Phys. 96(5), 2949–2954 (2004). [CrossRef]
  17. J. Shinar and R. Shinar, “Organic light-emitting devices (OLEDs) and OLED-based chemical and biological sensors: an overview,” J. Phys. D Appl. Phys. 41(13), 133001 (2008). [CrossRef]

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