OSA's Digital Library

Energy Express

Energy Express

  • Editor: Bernard Kippelen
  • Vol. 18, Iss. S4 — Nov. 8, 2010
  • pp: A631–A639

Improving the outcoupling efficiency of indium-tin-oxide-free organic light-emitting diodes via rough internal interfaces

Boris Riedel, Inga Kaiser, Julian Hauss, Uli Lemmer, and Martina Gerken  »View Author Affiliations

Optics Express, Vol. 18, Issue S4, pp. A631-A639 (2010)

View Full Text Article

Enhanced HTML    Acrobat PDF (925 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



We present low-cost texturing methods to produce different surface roughnesses on glass substrates. Using sand blasting, abrasion and wet etching we achieve roughnesses of about 50 nm to 250 nm (root mean squared roughness Rq). These textured substrates are used as extraction elements for guided modes and substrate modes in organic light-emitting diodes (OLEDs). We evaporate 50 nm of the high index material Ta2O5 on the textured substrate, which acts as waveguide layer, and flatten it with the transparent photoresist SU-8. On top of that, we fabricate indium tin oxide (ITO)-free OLEDs, which are characterized by electroluminescence and photoluminescence measurements. The devices with rough interfaces obtain an up to 37.4% and 15.5% (at 20 mA/cm2) enhanced emission and it is shown that the enhancement is due to an increased outcoupling efficiency.

© 2010 OSA

OCIS Codes
(240.5770) Optics at surfaces : Roughness
(250.3680) Optoelectronics : Light-emitting polymers
(260.3800) Physical optics : Luminescence
(290.5880) Scattering : Scattering, rough surfaces
(310.1860) Thin films : Deposition and fabrication
(310.6845) Thin films : Thin film devices and applications

ToC Category:
Light-Emitting Diodes

Original Manuscript: September 20, 2010
Manuscript Accepted: October 19, 2010
Published: October 28, 2010

Boris Riedel, Inga Kaiser, Julian Hauss, Uli Lemmer, and Martina Gerken, "Improving the outcoupling efficiency of indium-tin-oxide-free organic light-emitting diodes via rough internal interfaces," Opt. Express 18, A631-A639 (2010)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. F. So, J. Kido, and P. Burrows, “Organic light-emitting devices for solid-state lighting,” MRS Bull. 33, 663 (2008). [CrossRef]
  2. S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, and K. Leo, “White organic light-emitting diodes with fluorescent tube efficiency,” Nature 459, 234–238 (2009). [CrossRef] [PubMed]
  3. Y. Sun, N. Giebink, H. Kanno, B. Ma, M. Thompson, and S. Forrest, “Management of singlet and triplet excitons for efficient white organic light-emitting devices,” Nature 440, 908–912 (2006). [CrossRef] [PubMed]
  4. W. L. Barnes, “Electromagnetic crystals for surface plasmon polaritons and the extraction of light from emissive devices,” J. Lightwave Technol. 17, 2170 (1999). [CrossRef]
  5. K. Saxena, V. K. Jain, and D. Singh, “A review on the light extraction techniques in organic electroluminescent devices,” Opt. Mater. 32, 221–233 (2009). [CrossRef]
  6. J.-S. Kim, P. K. H. Ho, N. C. Greenham, and R. H. Friend, “Electroluminescence emission pattern of organic light-emitting diodes: implications for device efficiency calculations,” J. Appl. Phys. 88, 1073–1081 (2000). [CrossRef]
  7. S. Nowy, B. Krummacher, J. Frischeisen, N. Reinke, and W. Brütting, “Light extraction and optical loss mechanisms in organic light-emitting diodes: influence of the emitter quantum efficiency,” J. Appl. Phys. 104, 123109 (2008). [CrossRef]
  8. G. Gu, D. Garbuzov, P. Burrows, S. Venkatesh, and S. Forrest, “andM. Thompson, “High-external-quantum-efficiency organic light-emitting devices,” Opt. Lett. 22, 396–398 (1997). [CrossRef] [PubMed]
  9. D. K. Gifford and D. G. Hall, “Emission through one of two metal electrodes of an organic light-emitting diode via surface-plasmon cross coupling,” Appl. Phys. Lett. 81, 4315–4317 (2002). [CrossRef]
  10. M. Fujita, K. Ishihara, T. Ueno, T. Asano, S. Noda, H. Ohata, T. Tsuji, H. Nakada, and N. Shimoji, “Optical and electrical characteristics of organic light-emitting diodes with two-dimensional photonic crystals in organic/electrode layers,” Jpn. J. Appl. Phys. 44(Part 1), 3669–3677 (2005). [CrossRef]
  11. Y.-J. Lee, S.-H. Kim, J. Huh, G.-H. Kim, Y.-H. Lee, S.-H. Cho, Y.-C. Kim, and Y. R. Do, “A high-extraction-efficiency nanopatterned organic light-emitting diode,” Appl. Phys. Lett. 82, 3779 (2003). [CrossRef]
  12. S. M. Jeong, F. Araoka, Y. Machida, K. Ishikawa, H. Takezoe, S. Nishimura, and G. Suzaki, “Enhancement of normally directed light outcoupling from organic light-emitting diodes using nanoimprinted low-refractive-index layer,” Appl. Phys. Lett. 92, 083307 (2008). [CrossRef]
  13. U. Geyer, J. Hauss, B. Riedel, S. Gleiss, U. Lemmer, and M. Gerken, “Large-scale patterning of indium tin oxide electrodes for guided mode extraction from organic light-emitting diodes,” J. Appl. Phys. 104, 93111 (2008). [CrossRef]
  14. T. Tsutsui, M. Yahiro, H. Yokogawa, K. Kawano, and M. Yokoyama, “Doubling coupling-out efficiency in organic light-emitting devices using a thin silica aerogel layer,” Adv. Mater. 13, 1149–1152 (2001). [CrossRef]
  15. Y. Sun and S. R. Forrest, “Enhanced light out-coupling of organic light-emitting devices using embedded low-index grids,” Nat. Photonics 2, 483–487 (2008). [CrossRef]
  16. V. Bliznyuk, B. Ruhstaller, P. Brock, U. Scherf, and S. Carter, “Self-assembled nanocomposite polymer light-emitting diodes with improved efficiency and luminance,” Adv. Mater. 11, 1257–1261 (1999). [CrossRef]
  17. T. Yamasaki, K. Sumioka, and T. Tsutsui, “Organic light-emitting device with an ordered monolayer of silica microspheres as a scattering medium,” Appl. Phys. Lett. 76, 1243 (2000). [CrossRef]
  18. S. Moller and S. R. Forrest, “Improved light out-coupling in organic light emitting diodes employing ordered microlens arrays,” J. Appl. Phys. 91, 3324 (2002). [CrossRef]
  19. Y.-H. Cheng, J.-L. Wu, C.-H. Cheng, K.-C. Syao, and M.-C. M. Lee, “Enhanced light outcoupling in a thin film by texturing meshed surfaces,” Appl. Phys. Lett. 90, 091102 (2007). [CrossRef]
  20. S. Chen and H. S. Kwok, “Light extraction from organic light-emitting diodes for lighting applications by sandblasting substrates,” Opt. Express 18, 37–42 (2010). [CrossRef] [PubMed]
  21. H. Greiner, “Light extraction from organic light emitting diode substrates: simulation and experiment,” Jpn. J. Appl. Phys. 46(Part 1), 4125 (2007). [CrossRef]
  22. P. Bienstman, P. Vandersteegen, and R. Baets, “Modelling gratings on either side of the substrate for light extraction in light-emitting diodes,” Opt. Quantum Electron. 39, 797–804 (2007). [CrossRef]
  23. A. Colsmann, F. Stenzel, G. Balthasar, H. Do, and U. Lemmer, “Plasma patterning of Poly (3, 4-ethylenedioxythiophene): Poly (styrenesulfonate) anodes for efficient polymer solar cells,” Thin Solid Films 517, 1750 (2009). [CrossRef]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited