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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 17, Iss. 9 — Apr. 27, 2009
  • pp: 7562–7570

Exceptionally efficient organic light emitting devices using high refractive index substrates

Saso Mladenovski, Kristiaan Neyts, Domagoj Pavicic, Ansgar Werner, and Carsten Rothe  »View Author Affiliations

Optics Express, Vol. 17, Issue 9, pp. 7562-7570 (2009)

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Organic light emitting devices (OLEDs) are now used in commercial cell phones and flat screen displays, but may become even more successful in lighting applications, in which large area, high efficiency, long lifetime and low cost are essential. Due to the relatively high refractive index of the organic layers, conventional planar bottom emitting OLEDs have a low outcoupling efficiency. Various approaches for enhancing the optical outcoupling efficiency of bottom emitting OLEDs have been introduced in the literature. In this paper we demonstrate a green bottom emitting OLED with a record external quantum efficiency (42%) and luminous efficacy (183 lm/W). This OLED is based on a high index substrate and a thick electron transport layer (ETL) which uses electrical doping. The efficient light outcoupling is modeled by optical simulations.

© 2009 OSA

OCIS Codes
(160.4890) Materials : Organic materials
(230.3670) Optical devices : Light-emitting diodes
(310.6860) Thin films : Thin films, optical properties
(310.6845) Thin films : Thin film devices and applications

ToC Category:
Optical Devices

Original Manuscript: February 9, 2009
Revised Manuscript: April 15, 2009
Manuscript Accepted: April 19, 2009
Published: April 23, 2009

Saso Mladenovski, Kristiaan Neyts, Domagoj Pavicic, Ansgar Werner, and Carsten Rothe, "Exceptionally efficient organic light emitting devices using high refractive index substrates," Opt. Express 17, 7562-7570 (2009)

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  1. C. W. Tang and S. A. VanSlyke, “Organic electroluminescent diodes,” Appl. Phys. Lett. 51(12), 913–915 (1987). [CrossRef]
  2. 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,” IEEE J. Disp. Technol. 1(2), 278–282 (2005). [CrossRef]
  3. 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]
  4. 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]
  5. 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]
  6. 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(15), 1149–1152 (2001). [CrossRef]
  7. S. K. So, W. K. Choi, L. M. Leung, and K. Neyts, “Interference effects in bilayer organic light-emitting diodes,” Appl. Phys. Lett. 74(14), 1939–1941 (1999). [CrossRef]
  8. Y.-C. Kim, S.-H. Cho, Y.-W. Song, Y.-J. Lee, Y.-H. Lee, and Y. R. Do, “Planarized SiNx/spin-on-glass photonic crystal organic light-emitting diodes,” Appl. Phys. Lett. 89(17), 173502 (2006). [CrossRef]
  9. 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(21), 3779–3781 (2003). [CrossRef]
  10. 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]
  11. T. Nakamura, N. Tsutsumi, N. Juni, and H. Fujii, “Thin-film waveguiding mode light extraction in organic electroluminescent device using high refractive index substrate,” J. Appl. Phys. 97(5), 054505 (2005). [CrossRef]
  12. H. J. Peng, Y.L. Ho, C. F. Qui, M. Wong and H.S. Kwok, “Coupling Efficiency Enhancement of Organic Light Emitting Devices with Refractive Microlens Array on High Index Glass Substrate,” SID’ 04 Digest, 35, 158–161 (2004).
  13. D. Tanaka, H. Sasabe, Y.-J. Li, S.-J. Su, T. Takeda, and J. Kido, “Ultra High Efficiency Green Organic Light-Emitting Devices,” Jpn. J. Appl. Phys. 46(1), L10–L12 (2007). [CrossRef]
  14. K. Neyts, “Simulation of light emission from thin-film microcavities,” J. Opt. Soc. Am. A 15(4), 962–971 (1998). [CrossRef]
  15. K. Neyts, “Microcavity effects and the outcoupling of light in displays and lighting applications based on thin emitting films,” Appl. Surf. Sci. 244(1-4), 517–523 (2005). [CrossRef]
  16. H. Riel, S. Karg, T. Beirlein, W. Rieß, and K. Neyts, “Tuning the emission characteristics of top-emitting organic light-emitting devices by means of a dielectric capping layer: An experimental and theoretical study,” J. Appl. Phys. 94(8), 5290–5296 (2003). [CrossRef]
  17. J. Blochwitz, M. Pfeiffer, T. Fritz, and K. Leo, “Low voltage organic light emitting diodes featuring doped phthalocyanine as hole transport material,” Appl. Phys. Lett. 73(6), 729–731 (1998). [CrossRef]
  18. M. A. Baldo, S. Lamansky, P. E. Burrows, M. E. Thompson, and S. R. Forrest, “Very high efficiency green organic light-emitting devices based on electrophosphorescence,” Appl. Phys. Lett. 75(1), 4–6 (1999). [CrossRef]
  19. G. He, O. Schneider, D. Qin, X. Zhou, M. Pfeiffer, and K. Leo, “Very high-efficiency and low voltage phosphorescent organic light-emitting diodes based on a p-i-n junction,” J. Appl. Phys. 95(10), 5773–5777 (2004). [CrossRef]
  20. C.-L. Lin, T.-Y. Cho, C.-H. Chang, and C.-C. Wu, “Enhancing light outcoupling of organic light-emitting devices by locating emitters around the second antinode of the reflective metal electrode,” Appl. Phys. Lett. 88(8), 081114 (2006). [CrossRef]
  21. P. Wellmann, M. Hofmann, O. Zeika, A. Werner, J. Birnstock, R. Meerheim, G. He, K. Walzer, M. Pfeiffer, and K. Leo, “High-efficiency p-i-n organic light-emitting diodes with long lifetime,” J. Soc. Inf. Disp. 13(5), 393–397 (2005). [CrossRef]
  22. J. Birnstock, M. Hofmann, S. Murano, M. Vehse, J. Blochwitz-Nimoth, Q. Huang, G. He, M. Pfeiffer and K. Leo, “Novel OLEDs for Full Color Display with Highest Power Efficiencies and Long Lifetime,” SID’ 05 Dig. 36, 40–43 (2005).
  23. J. Birnstock, A. Lux, M. Ammann, P. Wellmann, M. Hofmann and T. Stübinger, “Novel Materials and Structures for Highly-Efficient, Temperature-Stable, and Long-Living AM OLED Displays,” SID‘ 06 Dig. 37, 1866–1869 (2006).
  24. K. Neyts, M. Marescaux, A. U. Nieto, A. Elschner, W. Lövenich, K. Fehse, Q. Huang, K. Walzer, and K. Leo, “Inhomogeneous luminance in organic light emitting diodes related to electrode resistivity,” J. Appl. Phys. 100(11), 114513 (2006). [CrossRef]
  25. S. Reineke, G. Schwartz, K. Walzer, and K. Leo, “Reduced efficiency roll-off in phosphorescent organic light emitting diodes by suppression of triplet-triplet annihilation,” Appl. Phys. Lett. 91(12), 123508 (2007). [CrossRef]
  26. Q. Huang, S. Reineke, K. Walzer, M. Pfeiffer, and K. Leo, “Quantum efficiency enhancement in top-emitting organic light-emitting diodes as a result of enhanced intrinsic quantum yield,” Appl. Phys. Lett. 89(26), 263512 (2006). [CrossRef]
  27. K.-B. Kim, Y.-H. Tak, Y.-S. Han, K.-H. Baik, M.-H. Yoon, and M.-H. Lee, “Relationship between Surface Roughness of Indium Tin Oxide and Leakage Current of Organic Light-Emitting Diode,” Jpn. J. Appl. Phys. 42(Part 2, No. 4B), L438–L440 (2003). [CrossRef]

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