Abstract

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

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    [CrossRef]
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    [CrossRef]
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    [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]
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    [CrossRef]

2008 (1)

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]

2007 (2)

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]

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]

2006 (5)

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]

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]

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]

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]

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]

2005 (4)

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]

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]

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]

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]

2004 (1)

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]

2003 (3)

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]

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]

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]

2002 (1)

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]

2001 (1)

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]

2000 (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]

1999 (2)

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]

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]

1998 (2)

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]

K. Neyts, “Simulation of light emission from thin-film microcavities,” J. Opt. Soc. Am. A 15(4), 962–971 (1998).
[CrossRef]

1987 (1)

C. W. Tang and S. A. VanSlyke, “Organic electroluminescent diodes,” Appl. Phys. Lett. 51(12), 913–915 (1987).
[CrossRef]

Baik, K.-H.

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]

Baldo, M. A.

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]

Beirlein, T.

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]

Birnstock, J.

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]

Blochwitz, J.

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]

Burrows, P. E.

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]

Chang, C.-H.

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]

Cho, G. S.

Cho, S. H.

Cho, S.-H.

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]

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]

Cho, T.-Y.

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]

Choi, E. H.

Choi, W. K.

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]

Do, Y. R.

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]

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]

Elschner, A.

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]

Fehse, K.

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]

Forrest, S. R.

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]

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]

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]

Fritz, T.

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]

Fujii, H.

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]

Han, S. H.

Han, Y.-S.

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]

He, G.

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]

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]

Ho, Y. L.

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]

Hofmann, M.

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]

Huang, Q.

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]

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]

Huh, J.

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]

Juni, N.

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]

Kang, S. O.

Karg, S.

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]

Kawano, K.

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]

Kido, J.

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]

Kim, D. Y.

Kim, G.-H.

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]

Kim, I. T.

Kim, K.-B.

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]

Kim, S.-H.

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]

Kim, Y.-C.

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]

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]

Kwok, H.-S.

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]

Lamansky, S.

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]

Lee, M.-H.

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]

Lee, Y.-H.

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]

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]

Lee, Y.-J.

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]

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]

Leo, K.

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]

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]

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]

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]

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]

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]

Leung, L. M.

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]

Li, Y.-J.

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]

Lim, J.

Lin, C.-L.

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]

Lövenich, W.

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]

Lu, M.-H.

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]

Madigan, C. F.

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]

Marescaux, M.

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]

Meerheim, R.

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]

Möller, S.

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]

Nakamura, T.

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]

Neyts, K.

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]

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]

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]

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]

K. Neyts, “Simulation of light emission from thin-film microcavities,” J. Opt. Soc. Am. A 15(4), 962–971 (1998).
[CrossRef]

Nieto, A. U.

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]

Oh, S. S.

Park, B.

Peng, H.

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]

Pfeiffer, M.

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]

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]

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]

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]

Qin, D.

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]

Reineke, S.

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]

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]

Riel, H.

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]

Rieß, W.

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]

Sasabe, H.

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]

Schneider, O.

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]

Schwartz, G.

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]

Seo, Y. H.

So, S. K.

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]

Song, Y.-W.

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]

Sturm, J. C.

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]

Su, S.-J.

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]

Sun, Y.

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]

Tak, Y.-H.

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]

Takeda, T.

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]

Takezoe, H.

Tanaka, D.

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]

Tang, C. W.

C. W. Tang and S. A. VanSlyke, “Organic electroluminescent diodes,” Appl. Phys. Lett. 51(12), 913–915 (1987).
[CrossRef]

Thompson, M. E.

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]

Tsutsui, T.

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]

Tsutsumi, N.

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]

VanSlyke, S. A.

C. W. Tang and S. A. VanSlyke, “Organic electroluminescent diodes,” Appl. Phys. Lett. 51(12), 913–915 (1987).
[CrossRef]

Walzer, K.

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]

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]

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]

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]

Wellmann, P.

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]

Werner, A.

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]

Wong, M.

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]

Wu, C.-C.

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]

Yahiro, M.

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]

Yokogawa, H.

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]

Yokoyama, M.

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]

Yoon, M.-H.

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]

Yu, X.-J.

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]

Zeika, O.

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]

Zhou, X.

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]

Adv. Mater. (1)

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]

Appl. Phys. Lett. (10)

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]

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]

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]

C. W. Tang and S. A. VanSlyke, “Organic electroluminescent diodes,” Appl. Phys. Lett. 51(12), 913–915 (1987).
[CrossRef]

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]

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]

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]

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]

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]

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]

Appl. Surf. Sci. (1)

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]

IEEE J. Disp. Technol. (1)

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]

J. Appl. Phys. (5)

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]

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]

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]

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]

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]

J. Opt. Soc. Am. A (1)

J. Soc. Inf. Disp. (1)

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]

Jpn. J. Appl. Phys. (2)

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]

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]

Nat. Photonics (1)

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]

Opt. Express (1)

Other (3)

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).

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).

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).

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Figures (8)

Fig. 1
Fig. 1

Structure of the organic light-emitting device (OLED). Layers from top to bottom: silver cathode, electron-transport layer (ETL), hole-blocking layer (HBL), emission layers (EML2 & EML1), electron-blocking layer (EBL), hole-transport layer (HTL). Emitters are located at the EML1/EML2 interface. The distances of emitters from the cathode and the anode are d c and d a respectively.

Fig. 2
Fig. 2

Simulated outcoupling efficiency in air η o u t a i r (a) and in the substrate η o u t s u b s t r a t e (b) for OLEDs with a regular glass substrate as a function of d c and d a i.e. the distances between the emitters and the cathode and the anode respectively. The dashed line (d a = 60nm) indicates the parameters for the fabricated devices. The three crosses represent the parameters for which the angular distribution is shown in Fig. 4.

Fig. 3
Fig. 3

Measured luminous efficacy (points) in air and in the substrate and simulated outcoupling efficiency (lines) in air η o u t a i r and in the substrate η o u t s u b s t r a t e as a function of d c (with constant d a = 60nm).

Fig. 4
Fig. 4

Measured and simulated angle dependency of the luminance (in the substrate) for three different d c values: 55nm (a), 140nm (b) and 230nm (c).

Fig. 5
Fig. 5

Simulated outcoupling efficiency in air η o u t a i r (a) and in the substrate η o u t s u b s t r a t e (b) for OLEDs with a high index substrate as a function of dc and da i.e. the distances between the emitters and the cathode and the anode respectively. The dashed line (da = 60nm) indicates the parameter for which η o u t a i r and η o u t s u b s t r a t e are presented on Fig. 8. The cross represents the fabricated OLED with high index substrate with dc = 230nm and da = 60nm and for which the maximum luminous efficacy and quantum efficiency was measured (shown on Fig. 6).

Fig. 6
Fig. 6

Measured luminous efficacy (points) in air and in substrate for the best OLED sample on high index substrate with dc = 230nm and da = 60nm and simulated outcoupling efficiency (lines) in air η o u t a i r and in substrate η o u t s u b s t r a t e as a function of dc .

Fig. 7
Fig. 7

Simulated fractions emitted into air, trapped in the substrate, absorbed in the organic/ITO layers and absorbed in the silver electrode for an OLED structure (d c = 230nm and d a = 60nm) on regular glass and high index substrate.

Fig. 8
Fig. 8

Measured current- voltage characteristics of OLEDs on a regular glass substrate and on a high index substrate (d c = 230nm and d a = 60nm).

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