Abstract

We report on the characteristics of enhanced and balanced white-light emission from bi-directional organic light-emitting diodes (BiOLEDs) enabled by the introduction of micro-cavity effects. The insertion of an additional metal layer between the indium tin oxide anode and the hole transporting layer results in similar light output of our BiOLEDs in both top and bottom direction and in reduced distortion of the electroluminescence spectrum. Furthermore, we find that by utilizing MC effects, the overall current efficiency can be improved by 26.2% compared to that of a conventional device.

© 2013 Optical Society of America

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  1. S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, and K. Leo, “White organic light-emitting diodes with fluorescent tube efficiency,” Nature459(7244), 234–238 (2009).
    [CrossRef] [PubMed]
  2. M. C. Gather, A. Köhnen, and K. Meerholz, “White organic light-emitting diodes,” Adv. Mater.23(2), 233–248 (2011).
    [CrossRef] [PubMed]
  3. S. Chen, L. Deng, J. Xie, L. Peng, L. Xie, Q. Fan, and W. Huang, “Recent developments in top-emitting organic light-emitting diodes,” Adv. Mater.22(46), 5227–5239 (2010).
    [CrossRef] [PubMed]
  4. H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
    [CrossRef]
  5. K. S. Yook, S. O. Jeon, C. W. Joo, and J. Y. Lee, “Transparent organic light emitting diodes using a multilayer oxide as a low resistance transparent cathode,” Appl. Phys. Lett.93(1), 013301 (2008).
  6. H. Cho, J.-M. Choi, and S. Yoo, “Highly transparent organic light-emitting diodes with a metallic top electrode: the dual role of a Cs2CO3 layer,” Opt. Express19(2), 1113–1121 (2011).
    [CrossRef] [PubMed]
  7. J.-H. Lee, S. Lee, J.-B. Kim, J. Jang, and J.-J. Kim, “A high performance transparent inverted organic light emitting diode with 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile as an organic buffer layer,” J. Mater. Chem.22(30), 15262–15266 (2012).
    [CrossRef]
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    [CrossRef]
  9. J. Lee, S. Hofmann, M. Furno, M. Thomschke, Y. H. Kim, B. Lüssem, and K. Leo, “Influence of organic capping layers on the performance of transparent organic light-emitting diodes,” Opt. Lett.36(8), 1443–1445 (2011).
    [CrossRef] [PubMed]
  10. J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Increased and balanced light emission of transparent organic light-emitting diodes by enhanced microcavity effects,” Opt. Lett.36(15), 2931–2933 (2011).
    [CrossRef] [PubMed]
  11. J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Highly efficient bi-directional organic light-emitting diodes by strong micro-cavity effects,” Appl. Phys. Lett.99(7), 073303 (2011).
    [CrossRef]
  12. J. Lee, J. -I. Lee, J. -W. Lee, and H. Y. Chu, “Interlayer engineering with different host material properties in blue phosphorescent organic light-emitting diodes” ETRI. J. 32, 32-38 (2011).
  13. J.-I. Lee, J. Lee, J.-W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, and H. Y. Chu, “Dependence of light-emitting characteristics of blue phosphorescent organic light-emitting diodes on electron injection and transport materials,” ETRI J.34(5), 690–695 (2012).
    [CrossRef]
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    [CrossRef]
  15. M. Agrawal, Y. Sun, S. R. Forrest, and P. Peumans, “Enhanced outcoupling from organic light-emitting diodes using aperiodic dielectric mirrors,” Appl. Phys. Lett.90(24), 241112 (2007).
    [CrossRef]
  16. S. Hofmann, M. Thomschke, P. Freitag, M. Furno, B. Lüssem, and K. Leo, “Top-emitting organic light-emitting diodes: Influence of cavity design,” Appl. Phys. Lett.97(25), 253308 (2010).
    [CrossRef]
  17. R. Meerheim, M. Furno, S. Hofmann, B. Lüssem, and K. Leo, “Quantification of energy loss mechanisms in organic light-emitting diodes,” Appl. Phys. Lett.97(25), 253305 (2010).
    [CrossRef]
  18. T. Schwab, S. Schubert, S. Hofmann, M. Fröbel, M. Thomschke, L. Müller-Meskamp, K. Leo, and M. C. Gather, “Highly efficient color stable inverted white top-emitting OLEDs with ultra-thin wetting layer top electrodes,” Adv. Opt. Mater.in press., doi:.
    [CrossRef]
  19. C.-W. Chen, C.-L. Lin, and C.-C. Wu, “An effective cathode structure for inverted top-emitting organic light emitting devices,” Appl. Phys. Lett.85(13), 2469–2471 (2004).
    [CrossRef]
  20. M. Furno, R. Meerheim, S. Hofmann, B. Lüssem, and K. Leo, “Efficiency and rate of spontaneous emission in organic electroluminescent devices,” Phys. Rev. B85(11), 115205 (2012).
    [CrossRef]
  21. W. Brütting, J. Frischeisen, T. D. Schmidt, B. J. Scholz, and C. Mayr, “Device efficiency of organic light-emitting diodes: Progress by improved light outcoupling,” Phys. Status Solidi A210(1), 44–65 (2013).
    [CrossRef]
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  23. M. Furno, T. C. Rosenow, M. C. Gather, B. Lüssem, and K. Leo, “Analysis of the external and internal quantum efficiency of multi-emitter, white organic emitting diodes,” Appl. Phys. Lett.101(14), 143304 (2012).
    [CrossRef]

2013

H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
[CrossRef]

W. Brütting, J. Frischeisen, T. D. Schmidt, B. J. Scholz, and C. Mayr, “Device efficiency of organic light-emitting diodes: Progress by improved light outcoupling,” Phys. Status Solidi A210(1), 44–65 (2013).
[CrossRef]

2012

M. Furno, T. C. Rosenow, M. C. Gather, B. Lüssem, and K. Leo, “Analysis of the external and internal quantum efficiency of multi-emitter, white organic emitting diodes,” Appl. Phys. Lett.101(14), 143304 (2012).
[CrossRef]

J.-I. Lee, J. Lee, J.-W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, and H. Y. Chu, “Dependence of light-emitting characteristics of blue phosphorescent organic light-emitting diodes on electron injection and transport materials,” ETRI J.34(5), 690–695 (2012).
[CrossRef]

J.-H. Lee, S. Lee, J.-B. Kim, J. Jang, and J.-J. Kim, “A high performance transparent inverted organic light emitting diode with 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile as an organic buffer layer,” J. Mater. Chem.22(30), 15262–15266 (2012).
[CrossRef]

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

M. Furno, R. Meerheim, S. Hofmann, B. Lüssem, and K. Leo, “Efficiency and rate of spontaneous emission in organic electroluminescent devices,” Phys. Rev. B85(11), 115205 (2012).
[CrossRef]

2011

J. Lee, S. Hofmann, M. Furno, M. Thomschke, Y. H. Kim, B. Lüssem, and K. Leo, “Influence of organic capping layers on the performance of transparent organic light-emitting diodes,” Opt. Lett.36(8), 1443–1445 (2011).
[CrossRef] [PubMed]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Increased and balanced light emission of transparent organic light-emitting diodes by enhanced microcavity effects,” Opt. Lett.36(15), 2931–2933 (2011).
[CrossRef] [PubMed]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Highly efficient bi-directional organic light-emitting diodes by strong micro-cavity effects,” Appl. Phys. Lett.99(7), 073303 (2011).
[CrossRef]

J. Lee, J. -I. Lee, J. -W. Lee, and H. Y. Chu, “Interlayer engineering with different host material properties in blue phosphorescent organic light-emitting diodes” ETRI. J. 32, 32-38 (2011).

M. C. Gather, A. Köhnen, and K. Meerholz, “White organic light-emitting diodes,” Adv. Mater.23(2), 233–248 (2011).
[CrossRef] [PubMed]

H. Cho, J.-M. Choi, and S. Yoo, “Highly transparent organic light-emitting diodes with a metallic top electrode: the dual role of a Cs2CO3 layer,” Opt. Express19(2), 1113–1121 (2011).
[CrossRef] [PubMed]

2010

S. Hofmann, M. Thomschke, P. Freitag, M. Furno, B. Lüssem, and K. Leo, “Top-emitting organic light-emitting diodes: Influence of cavity design,” Appl. Phys. Lett.97(25), 253308 (2010).
[CrossRef]

R. Meerheim, M. Furno, S. Hofmann, B. Lüssem, and K. Leo, “Quantification of energy loss mechanisms in organic light-emitting diodes,” Appl. Phys. Lett.97(25), 253305 (2010).
[CrossRef]

S. Chen, L. Deng, J. Xie, L. Peng, L. Xie, Q. Fan, and W. Huang, “Recent developments in top-emitting organic light-emitting diodes,” Adv. Mater.22(46), 5227–5239 (2010).
[CrossRef] [PubMed]

2009

S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, and K. Leo, “White organic light-emitting diodes with fluorescent tube efficiency,” Nature459(7244), 234–238 (2009).
[CrossRef] [PubMed]

S. Olthof, W. Tress, R. Meerheim, B. Lüssem, and K. Leo, “Photoelectron spectroscopy study of systematically varied doping concentrations in an organic semiconductor layer using a molecular p-dopant,” J. Appl. Phys.106(10), 103711 (2009).
[CrossRef]

2008

K. S. Yook, S. O. Jeon, C. W. Joo, and J. Y. Lee, “Transparent organic light emitting diodes using a multilayer oxide as a low resistance transparent cathode,” Appl. Phys. Lett.93(1), 013301 (2008).

2007

M. Agrawal, Y. Sun, S. R. Forrest, and P. Peumans, “Enhanced outcoupling from organic light-emitting diodes using aperiodic dielectric mirrors,” Appl. Phys. Lett.90(24), 241112 (2007).
[CrossRef]

2004

C.-W. Chen, C.-L. Lin, and C.-C. Wu, “An effective cathode structure for inverted top-emitting organic light emitting devices,” Appl. Phys. Lett.85(13), 2469–2471 (2004).
[CrossRef]

Agrawal, M.

M. Agrawal, Y. Sun, S. R. Forrest, and P. Peumans, “Enhanced outcoupling from organic light-emitting diodes using aperiodic dielectric mirrors,” Appl. Phys. Lett.90(24), 241112 (2007).
[CrossRef]

Brütting, W.

W. Brütting, J. Frischeisen, T. D. Schmidt, B. J. Scholz, and C. Mayr, “Device efficiency of organic light-emitting diodes: Progress by improved light outcoupling,” Phys. Status Solidi A210(1), 44–65 (2013).
[CrossRef]

Chang, H. W.

H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
[CrossRef]

Chen, C.-W.

C.-W. Chen, C.-L. Lin, and C.-C. Wu, “An effective cathode structure for inverted top-emitting organic light emitting devices,” Appl. Phys. Lett.85(13), 2469–2471 (2004).
[CrossRef]

Chen, S.

S. Chen, L. Deng, J. Xie, L. Peng, L. Xie, Q. Fan, and W. Huang, “Recent developments in top-emitting organic light-emitting diodes,” Adv. Mater.22(46), 5227–5239 (2010).
[CrossRef] [PubMed]

Cho, D.-H.

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

J.-I. Lee, J. Lee, J.-W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, and H. Y. Chu, “Dependence of light-emitting characteristics of blue phosphorescent organic light-emitting diodes on electron injection and transport materials,” ETRI J.34(5), 690–695 (2012).
[CrossRef]

Cho, H.

Choi, J.-M.

Chu, H. Y.

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

J.-I. Lee, J. Lee, J.-W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, and H. Y. Chu, “Dependence of light-emitting characteristics of blue phosphorescent organic light-emitting diodes on electron injection and transport materials,” ETRI J.34(5), 690–695 (2012).
[CrossRef]

J. Lee, J. -I. Lee, J. -W. Lee, and H. Y. Chu, “Interlayer engineering with different host material properties in blue phosphorescent organic light-emitting diodes” ETRI. J. 32, 32-38 (2011).

Deng, L.

S. Chen, L. Deng, J. Xie, L. Peng, L. Xie, Q. Fan, and W. Huang, “Recent developments in top-emitting organic light-emitting diodes,” Adv. Mater.22(46), 5227–5239 (2010).
[CrossRef] [PubMed]

Fan, Q.

S. Chen, L. Deng, J. Xie, L. Peng, L. Xie, Q. Fan, and W. Huang, “Recent developments in top-emitting organic light-emitting diodes,” Adv. Mater.22(46), 5227–5239 (2010).
[CrossRef] [PubMed]

Forrest, S. R.

M. Agrawal, Y. Sun, S. R. Forrest, and P. Peumans, “Enhanced outcoupling from organic light-emitting diodes using aperiodic dielectric mirrors,” Appl. Phys. Lett.90(24), 241112 (2007).
[CrossRef]

Freitag, P.

S. Hofmann, M. Thomschke, P. Freitag, M. Furno, B. Lüssem, and K. Leo, “Top-emitting organic light-emitting diodes: Influence of cavity design,” Appl. Phys. Lett.97(25), 253308 (2010).
[CrossRef]

Frischeisen, J.

W. Brütting, J. Frischeisen, T. D. Schmidt, B. J. Scholz, and C. Mayr, “Device efficiency of organic light-emitting diodes: Progress by improved light outcoupling,” Phys. Status Solidi A210(1), 44–65 (2013).
[CrossRef]

Fröbel, M.

T. Schwab, S. Schubert, S. Hofmann, M. Fröbel, M. Thomschke, L. Müller-Meskamp, K. Leo, and M. C. Gather, “Highly efficient color stable inverted white top-emitting OLEDs with ultra-thin wetting layer top electrodes,” Adv. Opt. Mater.in press., doi:.
[CrossRef]

Furno, M.

M. Furno, R. Meerheim, S. Hofmann, B. Lüssem, and K. Leo, “Efficiency and rate of spontaneous emission in organic electroluminescent devices,” Phys. Rev. B85(11), 115205 (2012).
[CrossRef]

M. Furno, T. C. Rosenow, M. C. Gather, B. Lüssem, and K. Leo, “Analysis of the external and internal quantum efficiency of multi-emitter, white organic emitting diodes,” Appl. Phys. Lett.101(14), 143304 (2012).
[CrossRef]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Highly efficient bi-directional organic light-emitting diodes by strong micro-cavity effects,” Appl. Phys. Lett.99(7), 073303 (2011).
[CrossRef]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Increased and balanced light emission of transparent organic light-emitting diodes by enhanced microcavity effects,” Opt. Lett.36(15), 2931–2933 (2011).
[CrossRef] [PubMed]

J. Lee, S. Hofmann, M. Furno, M. Thomschke, Y. H. Kim, B. Lüssem, and K. Leo, “Influence of organic capping layers on the performance of transparent organic light-emitting diodes,” Opt. Lett.36(8), 1443–1445 (2011).
[CrossRef] [PubMed]

S. Hofmann, M. Thomschke, P. Freitag, M. Furno, B. Lüssem, and K. Leo, “Top-emitting organic light-emitting diodes: Influence of cavity design,” Appl. Phys. Lett.97(25), 253308 (2010).
[CrossRef]

R. Meerheim, M. Furno, S. Hofmann, B. Lüssem, and K. Leo, “Quantification of energy loss mechanisms in organic light-emitting diodes,” Appl. Phys. Lett.97(25), 253305 (2010).
[CrossRef]

Gather, M. C.

H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
[CrossRef]

M. Furno, T. C. Rosenow, M. C. Gather, B. Lüssem, and K. Leo, “Analysis of the external and internal quantum efficiency of multi-emitter, white organic emitting diodes,” Appl. Phys. Lett.101(14), 143304 (2012).
[CrossRef]

M. C. Gather, A. Köhnen, and K. Meerholz, “White organic light-emitting diodes,” Adv. Mater.23(2), 233–248 (2011).
[CrossRef] [PubMed]

T. Schwab, S. Schubert, S. Hofmann, M. Fröbel, M. Thomschke, L. Müller-Meskamp, K. Leo, and M. C. Gather, “Highly efficient color stable inverted white top-emitting OLEDs with ultra-thin wetting layer top electrodes,” Adv. Opt. Mater.in press., doi:.
[CrossRef]

Han, J.-H.

J.-I. Lee, J. Lee, J.-W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, and H. Y. Chu, “Dependence of light-emitting characteristics of blue phosphorescent organic light-emitting diodes on electron injection and transport materials,” ETRI J.34(5), 690–695 (2012).
[CrossRef]

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

Hofmann, S.

H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
[CrossRef]

M. Furno, R. Meerheim, S. Hofmann, B. Lüssem, and K. Leo, “Efficiency and rate of spontaneous emission in organic electroluminescent devices,” Phys. Rev. B85(11), 115205 (2012).
[CrossRef]

J. Lee, S. Hofmann, M. Furno, M. Thomschke, Y. H. Kim, B. Lüssem, and K. Leo, “Influence of organic capping layers on the performance of transparent organic light-emitting diodes,” Opt. Lett.36(8), 1443–1445 (2011).
[CrossRef] [PubMed]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Increased and balanced light emission of transparent organic light-emitting diodes by enhanced microcavity effects,” Opt. Lett.36(15), 2931–2933 (2011).
[CrossRef] [PubMed]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Highly efficient bi-directional organic light-emitting diodes by strong micro-cavity effects,” Appl. Phys. Lett.99(7), 073303 (2011).
[CrossRef]

S. Hofmann, M. Thomschke, P. Freitag, M. Furno, B. Lüssem, and K. Leo, “Top-emitting organic light-emitting diodes: Influence of cavity design,” Appl. Phys. Lett.97(25), 253308 (2010).
[CrossRef]

R. Meerheim, M. Furno, S. Hofmann, B. Lüssem, and K. Leo, “Quantification of energy loss mechanisms in organic light-emitting diodes,” Appl. Phys. Lett.97(25), 253305 (2010).
[CrossRef]

T. Schwab, S. Schubert, S. Hofmann, M. Fröbel, M. Thomschke, L. Müller-Meskamp, K. Leo, and M. C. Gather, “Highly efficient color stable inverted white top-emitting OLEDs with ultra-thin wetting layer top electrodes,” Adv. Opt. Mater.in press., doi:.
[CrossRef]

Huang, W.

S. Chen, L. Deng, J. Xie, L. Peng, L. Xie, Q. Fan, and W. Huang, “Recent developments in top-emitting organic light-emitting diodes,” Adv. Mater.22(46), 5227–5239 (2010).
[CrossRef] [PubMed]

Huh, J. W.

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

Hwang, J.

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

Jang, J.

J.-H. Lee, S. Lee, J.-B. Kim, J. Jang, and J.-J. Kim, “A high performance transparent inverted organic light emitting diode with 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile as an organic buffer layer,” J. Mater. Chem.22(30), 15262–15266 (2012).
[CrossRef]

Jeon, S. O.

K. S. Yook, S. O. Jeon, C. W. Joo, and J. Y. Lee, “Transparent organic light emitting diodes using a multilayer oxide as a low resistance transparent cathode,” Appl. Phys. Lett.93(1), 013301 (2008).

Joo, C. W.

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

K. S. Yook, S. O. Jeon, C. W. Joo, and J. Y. Lee, “Transparent organic light emitting diodes using a multilayer oxide as a low resistance transparent cathode,” Appl. Phys. Lett.93(1), 013301 (2008).

Kim, J.-B.

J.-H. Lee, S. Lee, J.-B. Kim, J. Jang, and J.-J. Kim, “A high performance transparent inverted organic light emitting diode with 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile as an organic buffer layer,” J. Mater. Chem.22(30), 15262–15266 (2012).
[CrossRef]

Kim, J.-J.

J.-H. Lee, S. Lee, J.-B. Kim, J. Jang, and J.-J. Kim, “A high performance transparent inverted organic light emitting diode with 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile as an organic buffer layer,” J. Mater. Chem.22(30), 15262–15266 (2012).
[CrossRef]

Kim, Y. H.

H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
[CrossRef]

J. Lee, S. Hofmann, M. Furno, M. Thomschke, Y. H. Kim, B. Lüssem, and K. Leo, “Influence of organic capping layers on the performance of transparent organic light-emitting diodes,” Opt. Lett.36(8), 1443–1445 (2011).
[CrossRef] [PubMed]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Highly efficient bi-directional organic light-emitting diodes by strong micro-cavity effects,” Appl. Phys. Lett.99(7), 073303 (2011).
[CrossRef]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Increased and balanced light emission of transparent organic light-emitting diodes by enhanced microcavity effects,” Opt. Lett.36(15), 2931–2933 (2011).
[CrossRef] [PubMed]

Köhnen, A.

M. C. Gather, A. Köhnen, and K. Meerholz, “White organic light-emitting diodes,” Adv. Mater.23(2), 233–248 (2011).
[CrossRef] [PubMed]

Lee, J.

J.-I. Lee, J. Lee, J.-W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, and H. Y. Chu, “Dependence of light-emitting characteristics of blue phosphorescent organic light-emitting diodes on electron injection and transport materials,” ETRI J.34(5), 690–695 (2012).
[CrossRef]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Highly efficient bi-directional organic light-emitting diodes by strong micro-cavity effects,” Appl. Phys. Lett.99(7), 073303 (2011).
[CrossRef]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Increased and balanced light emission of transparent organic light-emitting diodes by enhanced microcavity effects,” Opt. Lett.36(15), 2931–2933 (2011).
[CrossRef] [PubMed]

J. Lee, J. -I. Lee, J. -W. Lee, and H. Y. Chu, “Interlayer engineering with different host material properties in blue phosphorescent organic light-emitting diodes” ETRI. J. 32, 32-38 (2011).

J. Lee, S. Hofmann, M. Furno, M. Thomschke, Y. H. Kim, B. Lüssem, and K. Leo, “Influence of organic capping layers on the performance of transparent organic light-emitting diodes,” Opt. Lett.36(8), 1443–1445 (2011).
[CrossRef] [PubMed]

Lee, J. -I.

J. Lee, J. -I. Lee, J. -W. Lee, and H. Y. Chu, “Interlayer engineering with different host material properties in blue phosphorescent organic light-emitting diodes” ETRI. J. 32, 32-38 (2011).

Lee, J. W.

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

Lee, J. -W.

J. Lee, J. -I. Lee, J. -W. Lee, and H. Y. Chu, “Interlayer engineering with different host material properties in blue phosphorescent organic light-emitting diodes” ETRI. J. 32, 32-38 (2011).

Lee, J. Y.

K. S. Yook, S. O. Jeon, C. W. Joo, and J. Y. Lee, “Transparent organic light emitting diodes using a multilayer oxide as a low resistance transparent cathode,” Appl. Phys. Lett.93(1), 013301 (2008).

Lee, J.-H.

H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
[CrossRef]

J.-H. Lee, S. Lee, J.-B. Kim, J. Jang, and J.-J. Kim, “A high performance transparent inverted organic light emitting diode with 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile as an organic buffer layer,” J. Mater. Chem.22(30), 15262–15266 (2012).
[CrossRef]

Lee, J.-I.

J.-I. Lee, J. Lee, J.-W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, and H. Y. Chu, “Dependence of light-emitting characteristics of blue phosphorescent organic light-emitting diodes on electron injection and transport materials,” ETRI J.34(5), 690–695 (2012).
[CrossRef]

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

Lee, J.-W.

J.-I. Lee, J. Lee, J.-W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, and H. Y. Chu, “Dependence of light-emitting characteristics of blue phosphorescent organic light-emitting diodes on electron injection and transport materials,” ETRI J.34(5), 690–695 (2012).
[CrossRef]

Lee, S.

J.-H. Lee, S. Lee, J.-B. Kim, J. Jang, and J.-J. Kim, “A high performance transparent inverted organic light emitting diode with 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile as an organic buffer layer,” J. Mater. Chem.22(30), 15262–15266 (2012).
[CrossRef]

Leo, K.

H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
[CrossRef]

M. Furno, R. Meerheim, S. Hofmann, B. Lüssem, and K. Leo, “Efficiency and rate of spontaneous emission in organic electroluminescent devices,” Phys. Rev. B85(11), 115205 (2012).
[CrossRef]

M. Furno, T. C. Rosenow, M. C. Gather, B. Lüssem, and K. Leo, “Analysis of the external and internal quantum efficiency of multi-emitter, white organic emitting diodes,” Appl. Phys. Lett.101(14), 143304 (2012).
[CrossRef]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Highly efficient bi-directional organic light-emitting diodes by strong micro-cavity effects,” Appl. Phys. Lett.99(7), 073303 (2011).
[CrossRef]

J. Lee, S. Hofmann, M. Furno, M. Thomschke, Y. H. Kim, B. Lüssem, and K. Leo, “Influence of organic capping layers on the performance of transparent organic light-emitting diodes,” Opt. Lett.36(8), 1443–1445 (2011).
[CrossRef] [PubMed]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Increased and balanced light emission of transparent organic light-emitting diodes by enhanced microcavity effects,” Opt. Lett.36(15), 2931–2933 (2011).
[CrossRef] [PubMed]

R. Meerheim, M. Furno, S. Hofmann, B. Lüssem, and K. Leo, “Quantification of energy loss mechanisms in organic light-emitting diodes,” Appl. Phys. Lett.97(25), 253305 (2010).
[CrossRef]

S. Hofmann, M. Thomschke, P. Freitag, M. Furno, B. Lüssem, and K. Leo, “Top-emitting organic light-emitting diodes: Influence of cavity design,” Appl. Phys. Lett.97(25), 253308 (2010).
[CrossRef]

S. Olthof, W. Tress, R. Meerheim, B. Lüssem, and K. Leo, “Photoelectron spectroscopy study of systematically varied doping concentrations in an organic semiconductor layer using a molecular p-dopant,” J. Appl. Phys.106(10), 103711 (2009).
[CrossRef]

S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, and K. Leo, “White organic light-emitting diodes with fluorescent tube efficiency,” Nature459(7244), 234–238 (2009).
[CrossRef] [PubMed]

T. Schwab, S. Schubert, S. Hofmann, M. Fröbel, M. Thomschke, L. Müller-Meskamp, K. Leo, and M. C. Gather, “Highly efficient color stable inverted white top-emitting OLEDs with ultra-thin wetting layer top electrodes,” Adv. Opt. Mater.in press., doi:.
[CrossRef]

Lin, C.-L.

C.-W. Chen, C.-L. Lin, and C.-C. Wu, “An effective cathode structure for inverted top-emitting organic light emitting devices,” Appl. Phys. Lett.85(13), 2469–2471 (2004).
[CrossRef]

Lindner, F.

S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, and K. Leo, “White organic light-emitting diodes with fluorescent tube efficiency,” Nature459(7244), 234–238 (2009).
[CrossRef] [PubMed]

Lüssem, B.

H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
[CrossRef]

M. Furno, R. Meerheim, S. Hofmann, B. Lüssem, and K. Leo, “Efficiency and rate of spontaneous emission in organic electroluminescent devices,” Phys. Rev. B85(11), 115205 (2012).
[CrossRef]

M. Furno, T. C. Rosenow, M. C. Gather, B. Lüssem, and K. Leo, “Analysis of the external and internal quantum efficiency of multi-emitter, white organic emitting diodes,” Appl. Phys. Lett.101(14), 143304 (2012).
[CrossRef]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Increased and balanced light emission of transparent organic light-emitting diodes by enhanced microcavity effects,” Opt. Lett.36(15), 2931–2933 (2011).
[CrossRef] [PubMed]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Highly efficient bi-directional organic light-emitting diodes by strong micro-cavity effects,” Appl. Phys. Lett.99(7), 073303 (2011).
[CrossRef]

J. Lee, S. Hofmann, M. Furno, M. Thomschke, Y. H. Kim, B. Lüssem, and K. Leo, “Influence of organic capping layers on the performance of transparent organic light-emitting diodes,” Opt. Lett.36(8), 1443–1445 (2011).
[CrossRef] [PubMed]

S. Hofmann, M. Thomschke, P. Freitag, M. Furno, B. Lüssem, and K. Leo, “Top-emitting organic light-emitting diodes: Influence of cavity design,” Appl. Phys. Lett.97(25), 253308 (2010).
[CrossRef]

R. Meerheim, M. Furno, S. Hofmann, B. Lüssem, and K. Leo, “Quantification of energy loss mechanisms in organic light-emitting diodes,” Appl. Phys. Lett.97(25), 253305 (2010).
[CrossRef]

S. Olthof, W. Tress, R. Meerheim, B. Lüssem, and K. Leo, “Photoelectron spectroscopy study of systematically varied doping concentrations in an organic semiconductor layer using a molecular p-dopant,” J. Appl. Phys.106(10), 103711 (2009).
[CrossRef]

S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, and K. Leo, “White organic light-emitting diodes with fluorescent tube efficiency,” Nature459(7244), 234–238 (2009).
[CrossRef] [PubMed]

Mayr, C.

W. Brütting, J. Frischeisen, T. D. Schmidt, B. J. Scholz, and C. Mayr, “Device efficiency of organic light-emitting diodes: Progress by improved light outcoupling,” Phys. Status Solidi A210(1), 44–65 (2013).
[CrossRef]

Meerheim, R.

M. Furno, R. Meerheim, S. Hofmann, B. Lüssem, and K. Leo, “Efficiency and rate of spontaneous emission in organic electroluminescent devices,” Phys. Rev. B85(11), 115205 (2012).
[CrossRef]

R. Meerheim, M. Furno, S. Hofmann, B. Lüssem, and K. Leo, “Quantification of energy loss mechanisms in organic light-emitting diodes,” Appl. Phys. Lett.97(25), 253305 (2010).
[CrossRef]

S. Olthof, W. Tress, R. Meerheim, B. Lüssem, and K. Leo, “Photoelectron spectroscopy study of systematically varied doping concentrations in an organic semiconductor layer using a molecular p-dopant,” J. Appl. Phys.106(10), 103711 (2009).
[CrossRef]

Meerholz, K.

M. C. Gather, A. Köhnen, and K. Meerholz, “White organic light-emitting diodes,” Adv. Mater.23(2), 233–248 (2011).
[CrossRef] [PubMed]

Moon, J.

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

Müller-Meskamp, L.

H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
[CrossRef]

T. Schwab, S. Schubert, S. Hofmann, M. Fröbel, M. Thomschke, L. Müller-Meskamp, K. Leo, and M. C. Gather, “Highly efficient color stable inverted white top-emitting OLEDs with ultra-thin wetting layer top electrodes,” Adv. Opt. Mater.in press., doi:.
[CrossRef]

Olthof, S.

S. Olthof, W. Tress, R. Meerheim, B. Lüssem, and K. Leo, “Photoelectron spectroscopy study of systematically varied doping concentrations in an organic semiconductor layer using a molecular p-dopant,” J. Appl. Phys.106(10), 103711 (2009).
[CrossRef]

Peng, L.

S. Chen, L. Deng, J. Xie, L. Peng, L. Xie, Q. Fan, and W. Huang, “Recent developments in top-emitting organic light-emitting diodes,” Adv. Mater.22(46), 5227–5239 (2010).
[CrossRef] [PubMed]

Peumans, P.

M. Agrawal, Y. Sun, S. R. Forrest, and P. Peumans, “Enhanced outcoupling from organic light-emitting diodes using aperiodic dielectric mirrors,” Appl. Phys. Lett.90(24), 241112 (2007).
[CrossRef]

Reineke, S.

S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, and K. Leo, “White organic light-emitting diodes with fluorescent tube efficiency,” Nature459(7244), 234–238 (2009).
[CrossRef] [PubMed]

Rosenow, T. C.

M. Furno, T. C. Rosenow, M. C. Gather, B. Lüssem, and K. Leo, “Analysis of the external and internal quantum efficiency of multi-emitter, white organic emitting diodes,” Appl. Phys. Lett.101(14), 143304 (2012).
[CrossRef]

Schmidt, T. D.

W. Brütting, J. Frischeisen, T. D. Schmidt, B. J. Scholz, and C. Mayr, “Device efficiency of organic light-emitting diodes: Progress by improved light outcoupling,” Phys. Status Solidi A210(1), 44–65 (2013).
[CrossRef]

Scholz, B. J.

W. Brütting, J. Frischeisen, T. D. Schmidt, B. J. Scholz, and C. Mayr, “Device efficiency of organic light-emitting diodes: Progress by improved light outcoupling,” Phys. Status Solidi A210(1), 44–65 (2013).
[CrossRef]

Schubert, S.

T. Schwab, S. Schubert, S. Hofmann, M. Fröbel, M. Thomschke, L. Müller-Meskamp, K. Leo, and M. C. Gather, “Highly efficient color stable inverted white top-emitting OLEDs with ultra-thin wetting layer top electrodes,” Adv. Opt. Mater.in press., doi:.
[CrossRef]

Schwab, T.

T. Schwab, S. Schubert, S. Hofmann, M. Fröbel, M. Thomschke, L. Müller-Meskamp, K. Leo, and M. C. Gather, “Highly efficient color stable inverted white top-emitting OLEDs with ultra-thin wetting layer top electrodes,” Adv. Opt. Mater.in press., doi:.
[CrossRef]

Schwartz, G.

S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, and K. Leo, “White organic light-emitting diodes with fluorescent tube efficiency,” Nature459(7244), 234–238 (2009).
[CrossRef] [PubMed]

Seidler, N.

S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, and K. Leo, “White organic light-emitting diodes with fluorescent tube efficiency,” Nature459(7244), 234–238 (2009).
[CrossRef] [PubMed]

Shin, J.-W.

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

J.-I. Lee, J. Lee, J.-W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, and H. Y. Chu, “Dependence of light-emitting characteristics of blue phosphorescent organic light-emitting diodes on electron injection and transport materials,” ETRI J.34(5), 690–695 (2012).
[CrossRef]

Sun, Y.

M. Agrawal, Y. Sun, S. R. Forrest, and P. Peumans, “Enhanced outcoupling from organic light-emitting diodes using aperiodic dielectric mirrors,” Appl. Phys. Lett.90(24), 241112 (2007).
[CrossRef]

Thomschke, M.

J. Lee, S. Hofmann, M. Furno, M. Thomschke, Y. H. Kim, B. Lüssem, and K. Leo, “Influence of organic capping layers on the performance of transparent organic light-emitting diodes,” Opt. Lett.36(8), 1443–1445 (2011).
[CrossRef] [PubMed]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Highly efficient bi-directional organic light-emitting diodes by strong micro-cavity effects,” Appl. Phys. Lett.99(7), 073303 (2011).
[CrossRef]

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Increased and balanced light emission of transparent organic light-emitting diodes by enhanced microcavity effects,” Opt. Lett.36(15), 2931–2933 (2011).
[CrossRef] [PubMed]

S. Hofmann, M. Thomschke, P. Freitag, M. Furno, B. Lüssem, and K. Leo, “Top-emitting organic light-emitting diodes: Influence of cavity design,” Appl. Phys. Lett.97(25), 253308 (2010).
[CrossRef]

T. Schwab, S. Schubert, S. Hofmann, M. Fröbel, M. Thomschke, L. Müller-Meskamp, K. Leo, and M. C. Gather, “Highly efficient color stable inverted white top-emitting OLEDs with ultra-thin wetting layer top electrodes,” Adv. Opt. Mater.in press., doi:.
[CrossRef]

Tress, W.

S. Olthof, W. Tress, R. Meerheim, B. Lüssem, and K. Leo, “Photoelectron spectroscopy study of systematically varied doping concentrations in an organic semiconductor layer using a molecular p-dopant,” J. Appl. Phys.106(10), 103711 (2009).
[CrossRef]

Walzer, K.

S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, and K. Leo, “White organic light-emitting diodes with fluorescent tube efficiency,” Nature459(7244), 234–238 (2009).
[CrossRef] [PubMed]

Wu, C.-C.

H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
[CrossRef]

C.-W. Chen, C.-L. Lin, and C.-C. Wu, “An effective cathode structure for inverted top-emitting organic light emitting devices,” Appl. Phys. Lett.85(13), 2469–2471 (2004).
[CrossRef]

Xie, J.

S. Chen, L. Deng, J. Xie, L. Peng, L. Xie, Q. Fan, and W. Huang, “Recent developments in top-emitting organic light-emitting diodes,” Adv. Mater.22(46), 5227–5239 (2010).
[CrossRef] [PubMed]

Xie, L.

S. Chen, L. Deng, J. Xie, L. Peng, L. Xie, Q. Fan, and W. Huang, “Recent developments in top-emitting organic light-emitting diodes,” Adv. Mater.22(46), 5227–5239 (2010).
[CrossRef] [PubMed]

Yoo, S.

Yook, K. S.

K. S. Yook, S. O. Jeon, C. W. Joo, and J. Y. Lee, “Transparent organic light emitting diodes using a multilayer oxide as a low resistance transparent cathode,” Appl. Phys. Lett.93(1), 013301 (2008).

Adv. Mater.

M. C. Gather, A. Köhnen, and K. Meerholz, “White organic light-emitting diodes,” Adv. Mater.23(2), 233–248 (2011).
[CrossRef] [PubMed]

S. Chen, L. Deng, J. Xie, L. Peng, L. Xie, Q. Fan, and W. Huang, “Recent developments in top-emitting organic light-emitting diodes,” Adv. Mater.22(46), 5227–5239 (2010).
[CrossRef] [PubMed]

Appl. Phys. Lett.

K. S. Yook, S. O. Jeon, C. W. Joo, and J. Y. Lee, “Transparent organic light emitting diodes using a multilayer oxide as a low resistance transparent cathode,” Appl. Phys. Lett.93(1), 013301 (2008).

J. Lee, S. Hofmann, M. Thomschke, M. Furno, Y. H. Kim, B. Lüssem, and K. Leo, “Highly efficient bi-directional organic light-emitting diodes by strong micro-cavity effects,” Appl. Phys. Lett.99(7), 073303 (2011).
[CrossRef]

M. Agrawal, Y. Sun, S. R. Forrest, and P. Peumans, “Enhanced outcoupling from organic light-emitting diodes using aperiodic dielectric mirrors,” Appl. Phys. Lett.90(24), 241112 (2007).
[CrossRef]

S. Hofmann, M. Thomschke, P. Freitag, M. Furno, B. Lüssem, and K. Leo, “Top-emitting organic light-emitting diodes: Influence of cavity design,” Appl. Phys. Lett.97(25), 253308 (2010).
[CrossRef]

R. Meerheim, M. Furno, S. Hofmann, B. Lüssem, and K. Leo, “Quantification of energy loss mechanisms in organic light-emitting diodes,” Appl. Phys. Lett.97(25), 253305 (2010).
[CrossRef]

C.-W. Chen, C.-L. Lin, and C.-C. Wu, “An effective cathode structure for inverted top-emitting organic light emitting devices,” Appl. Phys. Lett.85(13), 2469–2471 (2004).
[CrossRef]

M. Furno, T. C. Rosenow, M. C. Gather, B. Lüssem, and K. Leo, “Analysis of the external and internal quantum efficiency of multi-emitter, white organic emitting diodes,” Appl. Phys. Lett.101(14), 143304 (2012).
[CrossRef]

ETRI J.

J.-I. Lee, J. Lee, J.-W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, and H. Y. Chu, “Dependence of light-emitting characteristics of blue phosphorescent organic light-emitting diodes on electron injection and transport materials,” ETRI J.34(5), 690–695 (2012).
[CrossRef]

Interlayer engineering with different host material properties in blue phosphorescent organic light-emitting diodes

J. Lee, J. -I. Lee, J. -W. Lee, and H. Y. Chu, “Interlayer engineering with different host material properties in blue phosphorescent organic light-emitting diodes” ETRI. J. 32, 32-38 (2011).

J. Appl. Phys.

S. Olthof, W. Tress, R. Meerheim, B. Lüssem, and K. Leo, “Photoelectron spectroscopy study of systematically varied doping concentrations in an organic semiconductor layer using a molecular p-dopant,” J. Appl. Phys.106(10), 103711 (2009).
[CrossRef]

H. W. Chang, J.-H. Lee, S. Hofmann, Y. H. Kim, L. Müller-Meskamp, B. Lüssem, C.-C. Wu, K. Leo, and M. C. Gather, “Nano-particle based scattering layers for optical efficiency enhancement of organic light-emitting diodes and organic solar cells,” J. Appl. Phys.113(20), 204502 (2013).
[CrossRef]

J. Mater. Chem.

J.-H. Lee, S. Lee, J.-B. Kim, J. Jang, and J.-J. Kim, “A high performance transparent inverted organic light emitting diode with 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile as an organic buffer layer,” J. Mater. Chem.22(30), 15262–15266 (2012).
[CrossRef]

Nature

S. Reineke, F. Lindner, G. Schwartz, N. Seidler, K. Walzer, B. Lüssem, and K. Leo, “White organic light-emitting diodes with fluorescent tube efficiency,” Nature459(7244), 234–238 (2009).
[CrossRef] [PubMed]

Opt. Express

Opt. Lett.

Org. Electron.

J. W. Huh, J. Moon, J. W. Lee, D.-H. Cho, J.-W. Shin, J.-H. Han, J. Hwang, C. W. Joo, H. Y. Chu, and J.-I. Lee, “Directed emissive high efficient white transparent organic light emitting diodes with double layered capping layer,” Org. Electron.13(8), 1386–1391 (2012).
[CrossRef]

Phys. Rev. B

M. Furno, R. Meerheim, S. Hofmann, B. Lüssem, and K. Leo, “Efficiency and rate of spontaneous emission in organic electroluminescent devices,” Phys. Rev. B85(11), 115205 (2012).
[CrossRef]

Phys. Status Solidi A

W. Brütting, J. Frischeisen, T. D. Schmidt, B. J. Scholz, and C. Mayr, “Device efficiency of organic light-emitting diodes: Progress by improved light outcoupling,” Phys. Status Solidi A210(1), 44–65 (2013).
[CrossRef]

Other

“ENERGY STAR ® Program Requirements for Solid State Lighting Luminaires Eligibility Criteria – Version 1.1” 1–23 (2008).

T. Schwab, S. Schubert, S. Hofmann, M. Fröbel, M. Thomschke, L. Müller-Meskamp, K. Leo, and M. C. Gather, “Highly efficient color stable inverted white top-emitting OLEDs with ultra-thin wetting layer top electrodes,” Adv. Opt. Mater.in press., doi:.
[CrossRef]

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Figures (6)

Fig. 1
Fig. 1

Device structures of the bi-directional OLEDs tested in this study.

Fig. 2
Fig. 2

Current density versus voltage (J-V) and voltage versus bottom- and top-luminance (V-L) for Devices B1 and B2.

Fig. 3
Fig. 3

Current efficiency of bottom- and top-emission versus current density of (a) Devices A1 and A2 and (b) Devices B1 and B2.

Fig. 4
Fig. 4

Calculated enhancement in multiple-beam resonance [gres(λ)] and two-beam interference [fTB(λ)] terms due to the additional Ag layer in the bottom electrode of the white BiOLEDs under study. Calculation was based on Fabry-Perot formalism in a simplified structure of front electrode/ organic layer/ rear electrode using Eqs. (1)-(3).

Fig. 5
Fig. 5

Electroluminescence spectra emitted in bottom and top-direction for (a) Devices A1 and A2 and (b) Devices B1 and B2 at a driving current density of 15 mA/cm2.

Fig. 6
Fig. 6

(a) The overall enhancement ratio of the forward intensity I(λ) due to the additional Ag layer in the bottom electrode of white BiOLEDs: comparison between experimental data (Device A) and simulation results. (b)-(c) Simulated intensity for various thickness values of the bottom Ag layer ( = dAg(bott.)) for the thickness of the top Ag layer of 15 nm (b) and 30 nm (c). Shown in (b) and (c) are the values obtained for top-emission direction. Simulation in Fig. 6 was done using the full classical electromagnetic model considering dipole emitters embedded in a microcavity structure as described in Ref. 20 with the unity radiative quantum efficiency assumed.

Tables (1)

Tables Icon

Table 1 Performance parameters of the white BiOLEDs under study*

Equations (4)

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I(λ)= g res ( λ )× f TB ( λ )× I 0 (λ),
g res ( λ )= T f ( 1 R f R r ) 2 +4 R f R r sin 2 ( Δϕ(λ) 2 ) ,
f TB ( λ )=1+ R r +2 R r cos{ ϕ r + 4π λ n org z EM },
Δϕ(λ)= ϕ f ϕ r + 4π n org d org λ ,

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