Abstract

Thin microporous films were formed by dropcasting a toluene solution containing various ratios of polystyrene:polyethylene glycol blends on a glass substrate, with OLEDs on the ITO that coated the opposite side of that substrate. We demonstrate for the first time that such easily-fabricated films with surface and bulk micropores in the index-matching polystyrene can serve as random microlens-like arrays to improve forward OLED light extraction by up to ~60%. A theoretical interpretation of the angular emission profile of the device, considering the geometrical change at the substrate/air interface and the scattering by the pores within the films, was established in excellent agreement with the experiments. The use of such blended thin films provides an economical method, independent of the OLED fabrication technique, for improving the outcoupling efficiency.

© 2011 OSA

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    [CrossRef]
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    [CrossRef] [PubMed]
  23. J. S. Kim, D. S. Kim, J. J. Kang, J. D. Kim, and C. J. Hwang, “Replication and comparison of concave and convex microlens arrays of light guide plate for liquid crystal display in injection molding,” Polym. Eng. Sci.50(8), 1696–1704 (2010).
    [CrossRef]
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    [CrossRef]
  25. J. E. G. J. Wijnhoven and W. L. Vos, “Preparation of photonic crystals made of air spheres in titania,” Science281(5378), 802–804 (1998).
    [CrossRef] [PubMed]
  26. M. Ulbricht, “Advanced functional polymer membranes,” Polymer (Guildf.)47(7), 2217–2262 (2006).
    [CrossRef]
  27. G. K. Stylios, P. V. Giannoudis, and T. Wan, “Applications of nanotechnologies in medical practice,” Injury36(4Suppl 4), S6–S13 (2005).
    [CrossRef] [PubMed]
  28. J.-K. Kim, K. Taki, and M. Ohshima, “Preparation of a unique microporous structure via two step phase separation in the course of drying a ternary polymer solution,” Langmuir23(24), 12397–12405 (2007).
    [CrossRef] [PubMed]
  29. J.-K. Kim, K. Taki, S. Nagamine, and M. Ohshima, “Periodic porous stripe patterning in a polymer blend film induced by phase separation during spin-casting,” Langmuir24(16), 8898–8903 (2008).
    [CrossRef] [PubMed]
  30. K.-H. Wu, S.-Y. Lu, and H.-L. Chen, “Formation of parallel strips in thin films of polystyrene/poly(vinyl pyrrolidone) blends via spin coating on unpatterned substrates,” Langmuir22(19), 8029–8035 (2006).
    [CrossRef] [PubMed]
  31. 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]
  32. M. Cai, T. Xiao, R. Liu, Y. Chen, R. Shinar, and J. Shinar, “Indium tin oxide-free tris(8-hydroxyquinoline) Al OLEDs with 80% enhanced power efficiency,” Appl. Phys. Lett. (in press).

2011

J. Frischeisen, D. Yokoyama, A. Endo, C. Adachi, and W. Brütting, “Increased light outcoupling efficiency in dye-doped small molecule organic light-emitting diodes with horizontally oriented emitters,” Org. Electron.12(5), 809–817 (2011).
[CrossRef]

S.-H. Eom, E. Wrzesniewski, and J. Xue, “Close-packed hemispherical microlens arrays for light extraction enhancement in organic light-emitting devices,” Org. Electron.12(3), 472–476 (2011).
[CrossRef]

J.-M. Park, Z. Gan, W. Y. Leung, R. Liu, Z. Ye, K. Constant, J. Shinar, R. Shinar, and K.-M. Ho, “Soft holographic interference lithography microlens for enhanced organic light emitting diode light extraction,” Opt. Express19(S4Suppl 4), A786–A792 (2011).
[CrossRef] [PubMed]

2010

M. Slootsky and S. R. Forrest, “Enhancing waveguided light extraction in organic LEDs using an ultra-low-index grid,” Opt. Lett.35(7), 1052–1054 (2010).
[CrossRef] [PubMed]

L. Lu, F. Zhang, Z. Xu, S. Zhao, Z. Zhuo, D. Song, J. Li, and Y. Wang, “Characteristics of ZnS nanocolumn arrays and their effect on the light outcoupling of OLEDs,” Physica B405(17), 3728–3731 (2010).
[CrossRef]

J. S. Kim, D. S. Kim, J. J. Kang, J. D. Kim, and C. J. Hwang, “Replication and comparison of concave and convex microlens arrays of light guide plate for liquid crystal display in injection molding,” Polym. Eng. Sci.50(8), 1696–1704 (2010).
[CrossRef]

W. H. Koo, S. M. Jeong, F. Araoka, K. Ishikawa, S. Nishimura, T. Toyooka, and H. Takezoe, “Light extraction from organic light-emitting diodes enhanced by spontaneously formed buckles,” Nat. Photonics4(4), 222–226 (2010).
[CrossRef]

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

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. Mladenovski, K. Neyts, D. Pavicic, A. Werner, and C. Rothe, “Exceptionally efficient organic light emitting devices using high refractive index substrates,” Opt. Express17(9), 7562–7570 (2009).
[CrossRef] [PubMed]

2008

J.-K. Kim, K. Taki, S. Nagamine, and M. Ohshima, “Periodic porous stripe patterning in a polymer blend film induced by phase separation during spin-casting,” Langmuir24(16), 8898–8903 (2008).
[CrossRef] [PubMed]

H. Y. Lin, Y. H. Ho, J. H. Lee, K. Y. Chen, J. H. Fang, S. C. Hsu, M. K. Wei, H. Y. Lin, J. H. Tsai, and T. C. Wu, “Patterned microlens array for efficiency improvement of small-pixelated organic light-emitting devices,” Opt. Express16(15), 11044–11051 (2008).
[CrossRef] [PubMed]

P. Ruffieux, T. Scharf, I. Philipoussis, H. P. Herzig, R. Voelkel, and K. J. Weible, “Two step process for the fabrication of diffraction limited concave microlens arrays,” Opt. Express16(24), 19541–19549 (2008).
[CrossRef] [PubMed]

J. A. Zimberlin, P. Wadsworth, and A. J. Crosby, “Living microlens arrays,” Cell Motil. Cytoskeleton65(9), 762–767 (2008).
[CrossRef] [PubMed]

J. Shinar and R. Shinar, “Organic light-emitting devices (OLEDs) and OLED-based chemical and biological sensors: an overview,” J. Phys. D Appl. Phys.41(13), 133001 (2008).
[CrossRef]

Y. Sun and S. R. Forrest, “Enhanced light out-coupling of organic light-emitting devices using embedded low-index grids,” Nat. Photonics2(8), 483–487 (2008).
[CrossRef]

2007

J.-K. Kim, K. Taki, and M. Ohshima, “Preparation of a unique microporous structure via two step phase separation in the course of drying a ternary polymer solution,” Langmuir23(24), 12397–12405 (2007).
[CrossRef] [PubMed]

2006

Y. Sun and S. R. Forrest, “Organic light emitting devices with enhanced outcoupling via microlenses fabricated by imprint lithography,” J. Appl. Phys.100(7), 073106 (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. Express14(14), 6564–6571 (2006).
[CrossRef] [PubMed]

K.-H. Wu, S.-Y. Lu, and H.-L. Chen, “Formation of parallel strips in thin films of polystyrene/poly(vinyl pyrrolidone) blends via spin coating on unpatterned substrates,” Langmuir22(19), 8029–8035 (2006).
[CrossRef] [PubMed]

M. Ulbricht, “Advanced functional polymer membranes,” Polymer (Guildf.)47(7), 2217–2262 (2006).
[CrossRef]

B. W. D’Andrade and J. J. Brown, “Organic light-emitting device luminaire for illumination applications,” Appl. Phys. Lett.88(19), 192908 (2006).
[CrossRef]

W.-K. Huang, W.-S. Wang, H.-C. Kan, and F.-C. Chen, “Enhanced light out-coupling efficiency of organic light-emitting diodes with self-organized microlens arrays,” Jpn. J. Appl. Phys.45(41), L1100–L1102 (2006).
[CrossRef]

2005

G. K. Stylios, P. V. Giannoudis, and T. Wan, “Applications of nanotechnologies in medical practice,” Injury36(4Suppl 4), S6–S13 (2005).
[CrossRef] [PubMed]

2004

S. R. Forrest, “The path to ubiquitous and low-cost organic electronic appliances on plastic,” Nature428(6986), 911–918 (2004).
[CrossRef] [PubMed]

H. J. Peng, Y. L. Ho, X. J. Yu, and H. S. Kwok, “Enhanced coupling of light from organic light emitting diodes using nanoporous films,” J. Appl. Phys.96(3), 1649–1654 (2004).
[CrossRef]

2000

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]

1998

J. E. G. J. Wijnhoven and W. L. Vos, “Preparation of photonic crystals made of air spheres in titania,” Science281(5378), 802–804 (1998).
[CrossRef] [PubMed]

1997

S. Walheim, M. Böltau, J. Mlynek, G. Krausch, and U. Steiner, “Structure formation via polymer demixing in spin-cast films,” Macromolecules30(17), 4995–5003 (1997).
[CrossRef]

Adachi, C.

J. Frischeisen, D. Yokoyama, A. Endo, C. Adachi, and W. Brütting, “Increased light outcoupling efficiency in dye-doped small molecule organic light-emitting diodes with horizontally oriented emitters,” Org. Electron.12(5), 809–817 (2011).
[CrossRef]

Altun, A. O.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Araoka, F.

W. H. Koo, S. M. Jeong, F. Araoka, K. Ishikawa, S. Nishimura, T. Toyooka, and H. Takezoe, “Light extraction from organic light-emitting diodes enhanced by spontaneously formed buckles,” Nat. Photonics4(4), 222–226 (2010).
[CrossRef]

Böltau, M.

S. Walheim, M. Böltau, J. Mlynek, G. Krausch, and U. Steiner, “Structure formation via polymer demixing in spin-cast films,” Macromolecules30(17), 4995–5003 (1997).
[CrossRef]

Brown, J. J.

B. W. D’Andrade and J. J. Brown, “Organic light-emitting device luminaire for illumination applications,” Appl. Phys. Lett.88(19), 192908 (2006).
[CrossRef]

Brütting, W.

J. Frischeisen, D. Yokoyama, A. Endo, C. Adachi, and W. Brütting, “Increased light outcoupling efficiency in dye-doped small molecule organic light-emitting diodes with horizontally oriented emitters,” Org. Electron.12(5), 809–817 (2011).
[CrossRef]

Cai, M.

M. Cai, T. Xiao, R. Liu, Y. Chen, R. Shinar, and J. Shinar, “Indium tin oxide-free tris(8-hydroxyquinoline) Al OLEDs with 80% enhanced power efficiency,” Appl. Phys. Lett. (in press).

Chen, F.-C.

W.-K. Huang, W.-S. Wang, H.-C. Kan, and F.-C. Chen, “Enhanced light out-coupling efficiency of organic light-emitting diodes with self-organized microlens arrays,” Jpn. J. Appl. Phys.45(41), L1100–L1102 (2006).
[CrossRef]

Chen, H.-L.

K.-H. Wu, S.-Y. Lu, and H.-L. Chen, “Formation of parallel strips in thin films of polystyrene/poly(vinyl pyrrolidone) blends via spin coating on unpatterned substrates,” Langmuir22(19), 8029–8035 (2006).
[CrossRef] [PubMed]

Chen, K. Y.

Chen, Y.

M. Cai, T. Xiao, R. Liu, Y. Chen, R. Shinar, and J. Shinar, “Indium tin oxide-free tris(8-hydroxyquinoline) Al OLEDs with 80% enhanced power efficiency,” Appl. Phys. Lett. (in press).

Cho, G. S.

Cho, S. H.

Choi, D.-G.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Choi, E. H.

Choi, J.-H.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Constant, K.

Crosby, A. J.

J. A. Zimberlin, P. Wadsworth, and A. J. Crosby, “Living microlens arrays,” Cell Motil. Cytoskeleton65(9), 762–767 (2008).
[CrossRef] [PubMed]

D’Andrade, B. W.

B. W. D’Andrade and J. J. Brown, “Organic light-emitting device luminaire for illumination applications,” Appl. Phys. Lett.88(19), 192908 (2006).
[CrossRef]

Endo, A.

J. Frischeisen, D. Yokoyama, A. Endo, C. Adachi, and W. Brütting, “Increased light outcoupling efficiency in dye-doped small molecule organic light-emitting diodes with horizontally oriented emitters,” Org. Electron.12(5), 809–817 (2011).
[CrossRef]

Eom, S.-H.

S.-H. Eom, E. Wrzesniewski, and J. Xue, “Close-packed hemispherical microlens arrays for light extraction enhancement in organic light-emitting devices,” Org. Electron.12(3), 472–476 (2011).
[CrossRef]

Fang, J. H.

Forrest, S. R.

M. Slootsky and S. R. Forrest, “Enhancing waveguided light extraction in organic LEDs using an ultra-low-index grid,” Opt. Lett.35(7), 1052–1054 (2010).
[CrossRef] [PubMed]

Y. Sun and S. R. Forrest, “Enhanced light out-coupling of organic light-emitting devices using embedded low-index grids,” Nat. Photonics2(8), 483–487 (2008).
[CrossRef]

Y. Sun and S. R. Forrest, “Organic light emitting devices with enhanced outcoupling via microlenses fabricated by imprint lithography,” J. Appl. Phys.100(7), 073106 (2006).
[CrossRef]

S. R. Forrest, “The path to ubiquitous and low-cost organic electronic appliances on plastic,” Nature428(6986), 911–918 (2004).
[CrossRef] [PubMed]

Frischeisen, J.

J. Frischeisen, D. Yokoyama, A. Endo, C. Adachi, and W. Brütting, “Increased light outcoupling efficiency in dye-doped small molecule organic light-emitting diodes with horizontally oriented emitters,” Org. Electron.12(5), 809–817 (2011).
[CrossRef]

Gan, Z.

Giannoudis, P. V.

G. K. Stylios, P. V. Giannoudis, and T. Wan, “Applications of nanotechnologies in medical practice,” Injury36(4Suppl 4), S6–S13 (2005).
[CrossRef] [PubMed]

Han, S. H.

Herzig, H. P.

Ho, K.-M.

Ho, Y. H.

Ho, Y. L.

H. J. Peng, Y. L. Ho, X. J. Yu, and H. S. Kwok, “Enhanced coupling of light from organic light emitting diodes using nanoporous films,” J. Appl. Phys.96(3), 1649–1654 (2004).
[CrossRef]

Hsu, S. C.

Huang, W.-K.

W.-K. Huang, W.-S. Wang, H.-C. Kan, and F.-C. Chen, “Enhanced light out-coupling efficiency of organic light-emitting diodes with self-organized microlens arrays,” Jpn. J. Appl. Phys.45(41), L1100–L1102 (2006).
[CrossRef]

Hwang, C. J.

J. S. Kim, D. S. Kim, J. J. Kang, J. D. Kim, and C. J. Hwang, “Replication and comparison of concave and convex microlens arrays of light guide plate for liquid crystal display in injection molding,” Polym. Eng. Sci.50(8), 1696–1704 (2010).
[CrossRef]

Ishikawa, K.

W. H. Koo, S. M. Jeong, F. Araoka, K. Ishikawa, S. Nishimura, T. Toyooka, and H. Takezoe, “Light extraction from organic light-emitting diodes enhanced by spontaneously formed buckles,” Nat. Photonics4(4), 222–226 (2010).
[CrossRef]

Jeon, S.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Jeong, J.-H.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Jeong, S. M.

W. H. Koo, S. M. Jeong, F. Araoka, K. Ishikawa, S. Nishimura, T. Toyooka, and H. Takezoe, “Light extraction from organic light-emitting diodes enhanced by spontaneously formed buckles,” Nat. Photonics4(4), 222–226 (2010).
[CrossRef]

Kan, H.-C.

W.-K. Huang, W.-S. Wang, H.-C. Kan, and F.-C. Chen, “Enhanced light out-coupling efficiency of organic light-emitting diodes with self-organized microlens arrays,” Jpn. J. Appl. Phys.45(41), L1100–L1102 (2006).
[CrossRef]

Kang, J. J.

J. S. Kim, D. S. Kim, J. J. Kang, J. D. Kim, and C. J. Hwang, “Replication and comparison of concave and convex microlens arrays of light guide plate for liquid crystal display in injection molding,” Polym. Eng. Sci.50(8), 1696–1704 (2010).
[CrossRef]

Kang, J.-W.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Kang, S. O.

Kim, D. S.

J. S. Kim, D. S. Kim, J. J. Kang, J. D. Kim, and C. J. Hwang, “Replication and comparison of concave and convex microlens arrays of light guide plate for liquid crystal display in injection molding,” Polym. Eng. Sci.50(8), 1696–1704 (2010).
[CrossRef]

Kim, D. Y.

Kim, I. T.

Kim, J. D.

J. S. Kim, D. S. Kim, J. J. Kang, J. D. Kim, and C. J. Hwang, “Replication and comparison of concave and convex microlens arrays of light guide plate for liquid crystal display in injection molding,” Polym. Eng. Sci.50(8), 1696–1704 (2010).
[CrossRef]

Kim, J. S.

J. S. Kim, D. S. Kim, J. J. Kang, J. D. Kim, and C. J. Hwang, “Replication and comparison of concave and convex microlens arrays of light guide plate for liquid crystal display in injection molding,” Polym. Eng. Sci.50(8), 1696–1704 (2010).
[CrossRef]

Kim, J.-J.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Kim, J.-K.

J.-K. Kim, K. Taki, S. Nagamine, and M. Ohshima, “Periodic porous stripe patterning in a polymer blend film induced by phase separation during spin-casting,” Langmuir24(16), 8898–8903 (2008).
[CrossRef] [PubMed]

J.-K. Kim, K. Taki, and M. Ohshima, “Preparation of a unique microporous structure via two step phase separation in the course of drying a ternary polymer solution,” Langmuir23(24), 12397–12405 (2007).
[CrossRef] [PubMed]

Kim, K.-D.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Koo, W. H.

W. H. Koo, S. M. Jeong, F. Araoka, K. Ishikawa, S. Nishimura, T. Toyooka, and H. Takezoe, “Light extraction from organic light-emitting diodes enhanced by spontaneously formed buckles,” Nat. Photonics4(4), 222–226 (2010).
[CrossRef]

Krausch, G.

S. Walheim, M. Böltau, J. Mlynek, G. Krausch, and U. Steiner, “Structure formation via polymer demixing in spin-cast films,” Macromolecules30(17), 4995–5003 (1997).
[CrossRef]

Kwok, H. S.

H. J. Peng, Y. L. Ho, X. J. Yu, and H. S. Kwok, “Enhanced coupling of light from organic light emitting diodes using nanoporous films,” J. Appl. Phys.96(3), 1649–1654 (2004).
[CrossRef]

Lee, E.-S.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Lee, J. H.

Lee, S.-W.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Lee, Y.-H.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Leo, 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]

Leung, W. Y.

Li, J.

L. Lu, F. Zhang, Z. Xu, S. Zhao, Z. Zhuo, D. Song, J. Li, and Y. Wang, “Characteristics of ZnS nanocolumn arrays and their effect on the light outcoupling of OLEDs,” Physica B405(17), 3728–3731 (2010).
[CrossRef]

Lim, J.

Lin, H. Y.

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]

Liu, R.

J.-M. Park, Z. Gan, W. Y. Leung, R. Liu, Z. Ye, K. Constant, J. Shinar, R. Shinar, and K.-M. Ho, “Soft holographic interference lithography microlens for enhanced organic light emitting diode light extraction,” Opt. Express19(S4Suppl 4), A786–A792 (2011).
[CrossRef] [PubMed]

M. Cai, T. Xiao, R. Liu, Y. Chen, R. Shinar, and J. Shinar, “Indium tin oxide-free tris(8-hydroxyquinoline) Al OLEDs with 80% enhanced power efficiency,” Appl. Phys. Lett. (in press).

Lu, L.

L. Lu, F. Zhang, Z. Xu, S. Zhao, Z. Zhuo, D. Song, J. Li, and Y. Wang, “Characteristics of ZnS nanocolumn arrays and their effect on the light outcoupling of OLEDs,” Physica B405(17), 3728–3731 (2010).
[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]

Lu, S.-Y.

K.-H. Wu, S.-Y. Lu, and H.-L. Chen, “Formation of parallel strips in thin films of polystyrene/poly(vinyl pyrrolidone) blends via spin coating on unpatterned substrates,” Langmuir22(19), 8029–8035 (2006).
[CrossRef] [PubMed]

Lüssem, B.

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]

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]

Mladenovski, S.

Mlynek, J.

S. Walheim, M. Böltau, J. Mlynek, G. Krausch, and U. Steiner, “Structure formation via polymer demixing in spin-cast films,” Macromolecules30(17), 4995–5003 (1997).
[CrossRef]

Nagamine, S.

J.-K. Kim, K. Taki, S. Nagamine, and M. Ohshima, “Periodic porous stripe patterning in a polymer blend film induced by phase separation during spin-casting,” Langmuir24(16), 8898–8903 (2008).
[CrossRef] [PubMed]

Neyts, K.

Nishimura, S.

W. H. Koo, S. M. Jeong, F. Araoka, K. Ishikawa, S. Nishimura, T. Toyooka, and H. Takezoe, “Light extraction from organic light-emitting diodes enhanced by spontaneously formed buckles,” Nat. Photonics4(4), 222–226 (2010).
[CrossRef]

Oh, S. S.

Ohshima, M.

J.-K. Kim, K. Taki, S. Nagamine, and M. Ohshima, “Periodic porous stripe patterning in a polymer blend film induced by phase separation during spin-casting,” Langmuir24(16), 8898–8903 (2008).
[CrossRef] [PubMed]

J.-K. Kim, K. Taki, and M. Ohshima, “Preparation of a unique microporous structure via two step phase separation in the course of drying a ternary polymer solution,” Langmuir23(24), 12397–12405 (2007).
[CrossRef] [PubMed]

Park, B.

Park, H.-D.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Park, J.-M.

Pavicic, D.

Peng, H. J.

H. J. Peng, Y. L. Ho, X. J. Yu, and H. S. Kwok, “Enhanced coupling of light from organic light emitting diodes using nanoporous films,” J. Appl. Phys.96(3), 1649–1654 (2004).
[CrossRef]

Philipoussis, I.

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]

Rothe, C.

Ruffieux, P.

Scharf, T.

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]

Seo, Y. H.

Shim, J.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Shinar, J.

J.-M. Park, Z. Gan, W. Y. Leung, R. Liu, Z. Ye, K. Constant, J. Shinar, R. Shinar, and K.-M. Ho, “Soft holographic interference lithography microlens for enhanced organic light emitting diode light extraction,” Opt. Express19(S4Suppl 4), A786–A792 (2011).
[CrossRef] [PubMed]

J. Shinar and R. Shinar, “Organic light-emitting devices (OLEDs) and OLED-based chemical and biological sensors: an overview,” J. Phys. D Appl. Phys.41(13), 133001 (2008).
[CrossRef]

M. Cai, T. Xiao, R. Liu, Y. Chen, R. Shinar, and J. Shinar, “Indium tin oxide-free tris(8-hydroxyquinoline) Al OLEDs with 80% enhanced power efficiency,” Appl. Phys. Lett. (in press).

Shinar, R.

J.-M. Park, Z. Gan, W. Y. Leung, R. Liu, Z. Ye, K. Constant, J. Shinar, R. Shinar, and K.-M. Ho, “Soft holographic interference lithography microlens for enhanced organic light emitting diode light extraction,” Opt. Express19(S4Suppl 4), A786–A792 (2011).
[CrossRef] [PubMed]

J. Shinar and R. Shinar, “Organic light-emitting devices (OLEDs) and OLED-based chemical and biological sensors: an overview,” J. Phys. D Appl. Phys.41(13), 133001 (2008).
[CrossRef]

M. Cai, T. Xiao, R. Liu, Y. Chen, R. Shinar, and J. Shinar, “Indium tin oxide-free tris(8-hydroxyquinoline) Al OLEDs with 80% enhanced power efficiency,” Appl. Phys. Lett. (in press).

Slootsky, M.

Song, D.

L. Lu, F. Zhang, Z. Xu, S. Zhao, Z. Zhuo, D. Song, J. Li, and Y. Wang, “Characteristics of ZnS nanocolumn arrays and their effect on the light outcoupling of OLEDs,” Physica B405(17), 3728–3731 (2010).
[CrossRef]

Steiner, U.

S. Walheim, M. Böltau, J. Mlynek, G. Krausch, and U. Steiner, “Structure formation via polymer demixing in spin-cast films,” Macromolecules30(17), 4995–5003 (1997).
[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]

Stylios, G. K.

G. K. Stylios, P. V. Giannoudis, and T. Wan, “Applications of nanotechnologies in medical practice,” Injury36(4Suppl 4), S6–S13 (2005).
[CrossRef] [PubMed]

Sun, Y.

Y. Sun and S. R. Forrest, “Enhanced light out-coupling of organic light-emitting devices using embedded low-index grids,” Nat. Photonics2(8), 483–487 (2008).
[CrossRef]

Y. Sun and S. R. Forrest, “Organic light emitting devices with enhanced outcoupling via microlenses fabricated by imprint lithography,” J. Appl. Phys.100(7), 073106 (2006).
[CrossRef]

Takezoe, H.

W. H. Koo, S. M. Jeong, F. Araoka, K. Ishikawa, S. Nishimura, T. Toyooka, and H. Takezoe, “Light extraction from organic light-emitting diodes enhanced by spontaneously formed buckles,” Nat. Photonics4(4), 222–226 (2010).
[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. Express14(14), 6564–6571 (2006).
[CrossRef] [PubMed]

Taki, K.

J.-K. Kim, K. Taki, S. Nagamine, and M. Ohshima, “Periodic porous stripe patterning in a polymer blend film induced by phase separation during spin-casting,” Langmuir24(16), 8898–8903 (2008).
[CrossRef] [PubMed]

J.-K. Kim, K. Taki, and M. Ohshima, “Preparation of a unique microporous structure via two step phase separation in the course of drying a ternary polymer solution,” Langmuir23(24), 12397–12405 (2007).
[CrossRef] [PubMed]

Toyooka, T.

W. H. Koo, S. M. Jeong, F. Araoka, K. Ishikawa, S. Nishimura, T. Toyooka, and H. Takezoe, “Light extraction from organic light-emitting diodes enhanced by spontaneously formed buckles,” Nat. Photonics4(4), 222–226 (2010).
[CrossRef]

Tsai, J. H.

Ulbricht, M.

M. Ulbricht, “Advanced functional polymer membranes,” Polymer (Guildf.)47(7), 2217–2262 (2006).
[CrossRef]

Voelkel, R.

Vos, W. L.

J. E. G. J. Wijnhoven and W. L. Vos, “Preparation of photonic crystals made of air spheres in titania,” Science281(5378), 802–804 (1998).
[CrossRef] [PubMed]

Wadsworth, P.

J. A. Zimberlin, P. Wadsworth, and A. J. Crosby, “Living microlens arrays,” Cell Motil. Cytoskeleton65(9), 762–767 (2008).
[CrossRef] [PubMed]

Walheim, S.

S. Walheim, M. Böltau, J. Mlynek, G. Krausch, and U. Steiner, “Structure formation via polymer demixing in spin-cast films,” Macromolecules30(17), 4995–5003 (1997).
[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]

Wan, T.

G. K. Stylios, P. V. Giannoudis, and T. Wan, “Applications of nanotechnologies in medical practice,” Injury36(4Suppl 4), S6–S13 (2005).
[CrossRef] [PubMed]

Wang, W.-S.

W.-K. Huang, W.-S. Wang, H.-C. Kan, and F.-C. Chen, “Enhanced light out-coupling efficiency of organic light-emitting diodes with self-organized microlens arrays,” Jpn. J. Appl. Phys.45(41), L1100–L1102 (2006).
[CrossRef]

Wang, Y.

L. Lu, F. Zhang, Z. Xu, S. Zhao, Z. Zhuo, D. Song, J. Li, and Y. Wang, “Characteristics of ZnS nanocolumn arrays and their effect on the light outcoupling of OLEDs,” Physica B405(17), 3728–3731 (2010).
[CrossRef]

Wei, M. K.

Weible, K. J.

Werner, A.

Wijnhoven, J. E. G. J.

J. E. G. J. Wijnhoven and W. L. Vos, “Preparation of photonic crystals made of air spheres in titania,” Science281(5378), 802–804 (1998).
[CrossRef] [PubMed]

Wrzesniewski, E.

S.-H. Eom, E. Wrzesniewski, and J. Xue, “Close-packed hemispherical microlens arrays for light extraction enhancement in organic light-emitting devices,” Org. Electron.12(3), 472–476 (2011).
[CrossRef]

Wu, K.-H.

K.-H. Wu, S.-Y. Lu, and H.-L. Chen, “Formation of parallel strips in thin films of polystyrene/poly(vinyl pyrrolidone) blends via spin coating on unpatterned substrates,” Langmuir22(19), 8029–8035 (2006).
[CrossRef] [PubMed]

Wu, T. C.

Xiao, T.

M. Cai, T. Xiao, R. Liu, Y. Chen, R. Shinar, and J. Shinar, “Indium tin oxide-free tris(8-hydroxyquinoline) Al OLEDs with 80% enhanced power efficiency,” Appl. Phys. Lett. (in press).

Xu, Z.

L. Lu, F. Zhang, Z. Xu, S. Zhao, Z. Zhuo, D. Song, J. Li, and Y. Wang, “Characteristics of ZnS nanocolumn arrays and their effect on the light outcoupling of OLEDs,” Physica B405(17), 3728–3731 (2010).
[CrossRef]

Xue, J.

S.-H. Eom, E. Wrzesniewski, and J. Xue, “Close-packed hemispherical microlens arrays for light extraction enhancement in organic light-emitting devices,” Org. Electron.12(3), 472–476 (2011).
[CrossRef]

Ye, Z.

Yokoyama, D.

J. Frischeisen, D. Yokoyama, A. Endo, C. Adachi, and W. Brütting, “Increased light outcoupling efficiency in dye-doped small molecule organic light-emitting diodes with horizontally oriented emitters,” Org. Electron.12(5), 809–817 (2011).
[CrossRef]

Youn, J. R.

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Yu, X. J.

H. J. Peng, Y. L. Ho, X. J. Yu, and H. S. Kwok, “Enhanced coupling of light from organic light emitting diodes using nanoporous films,” J. Appl. Phys.96(3), 1649–1654 (2004).
[CrossRef]

Zhang, F.

L. Lu, F. Zhang, Z. Xu, S. Zhao, Z. Zhuo, D. Song, J. Li, and Y. Wang, “Characteristics of ZnS nanocolumn arrays and their effect on the light outcoupling of OLEDs,” Physica B405(17), 3728–3731 (2010).
[CrossRef]

Zhao, S.

L. Lu, F. Zhang, Z. Xu, S. Zhao, Z. Zhuo, D. Song, J. Li, and Y. Wang, “Characteristics of ZnS nanocolumn arrays and their effect on the light outcoupling of OLEDs,” Physica B405(17), 3728–3731 (2010).
[CrossRef]

Zhuo, Z.

L. Lu, F. Zhang, Z. Xu, S. Zhao, Z. Zhuo, D. Song, J. Li, and Y. Wang, “Characteristics of ZnS nanocolumn arrays and their effect on the light outcoupling of OLEDs,” Physica B405(17), 3728–3731 (2010).
[CrossRef]

Zimberlin, J. A.

J. A. Zimberlin, P. Wadsworth, and A. J. Crosby, “Living microlens arrays,” Cell Motil. Cytoskeleton65(9), 762–767 (2008).
[CrossRef] [PubMed]

Appl. Phys. Lett.

B. W. D’Andrade and J. J. Brown, “Organic light-emitting device luminaire for illumination applications,” Appl. Phys. Lett.88(19), 192908 (2006).
[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]

M. Cai, T. Xiao, R. Liu, Y. Chen, R. Shinar, and J. Shinar, “Indium tin oxide-free tris(8-hydroxyquinoline) Al OLEDs with 80% enhanced power efficiency,” Appl. Phys. Lett. (in press).

Cell Motil. Cytoskeleton

J. A. Zimberlin, P. Wadsworth, and A. J. Crosby, “Living microlens arrays,” Cell Motil. Cytoskeleton65(9), 762–767 (2008).
[CrossRef] [PubMed]

Injury

G. K. Stylios, P. V. Giannoudis, and T. Wan, “Applications of nanotechnologies in medical practice,” Injury36(4Suppl 4), S6–S13 (2005).
[CrossRef] [PubMed]

J. Appl. Phys.

Y. Sun and S. R. Forrest, “Organic light emitting devices with enhanced outcoupling via microlenses fabricated by imprint lithography,” J. Appl. Phys.100(7), 073106 (2006).
[CrossRef]

H. J. Peng, Y. L. Ho, X. J. Yu, and H. S. Kwok, “Enhanced coupling of light from organic light emitting diodes using nanoporous films,” J. Appl. Phys.96(3), 1649–1654 (2004).
[CrossRef]

J. Phys. D Appl. Phys.

J. Shinar and R. Shinar, “Organic light-emitting devices (OLEDs) and OLED-based chemical and biological sensors: an overview,” J. Phys. D Appl. Phys.41(13), 133001 (2008).
[CrossRef]

Jpn. J. Appl. Phys.

W.-K. Huang, W.-S. Wang, H.-C. Kan, and F.-C. Chen, “Enhanced light out-coupling efficiency of organic light-emitting diodes with self-organized microlens arrays,” Jpn. J. Appl. Phys.45(41), L1100–L1102 (2006).
[CrossRef]

Langmuir

J.-K. Kim, K. Taki, and M. Ohshima, “Preparation of a unique microporous structure via two step phase separation in the course of drying a ternary polymer solution,” Langmuir23(24), 12397–12405 (2007).
[CrossRef] [PubMed]

J.-K. Kim, K. Taki, S. Nagamine, and M. Ohshima, “Periodic porous stripe patterning in a polymer blend film induced by phase separation during spin-casting,” Langmuir24(16), 8898–8903 (2008).
[CrossRef] [PubMed]

K.-H. Wu, S.-Y. Lu, and H.-L. Chen, “Formation of parallel strips in thin films of polystyrene/poly(vinyl pyrrolidone) blends via spin coating on unpatterned substrates,” Langmuir22(19), 8029–8035 (2006).
[CrossRef] [PubMed]

Macromolecules

S. Walheim, M. Böltau, J. Mlynek, G. Krausch, and U. Steiner, “Structure formation via polymer demixing in spin-cast films,” Macromolecules30(17), 4995–5003 (1997).
[CrossRef]

Nat. Photonics

Y. Sun and S. R. Forrest, “Enhanced light out-coupling of organic light-emitting devices using embedded low-index grids,” Nat. Photonics2(8), 483–487 (2008).
[CrossRef]

W. H. Koo, S. M. Jeong, F. Araoka, K. Ishikawa, S. Nishimura, T. Toyooka, and H. Takezoe, “Light extraction from organic light-emitting diodes enhanced by spontaneously formed buckles,” Nat. Photonics4(4), 222–226 (2010).
[CrossRef]

Nature

S. R. Forrest, “The path to ubiquitous and low-cost organic electronic appliances on plastic,” Nature428(6986), 911–918 (2004).
[CrossRef] [PubMed]

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.

S.-H. Eom, E. Wrzesniewski, and J. Xue, “Close-packed hemispherical microlens arrays for light extraction enhancement in organic light-emitting devices,” Org. Electron.12(3), 472–476 (2011).
[CrossRef]

J. Frischeisen, D. Yokoyama, A. Endo, C. Adachi, and W. Brütting, “Increased light outcoupling efficiency in dye-doped small molecule organic light-emitting diodes with horizontally oriented emitters,” Org. Electron.12(5), 809–817 (2011).
[CrossRef]

A. O. Altun, S. Jeon, J. Shim, J.-H. Jeong, D.-G. Choi, K.-D. Kim, J.-H. Choi, S.-W. Lee, E.-S. Lee, H.-D. Park, J. R. Youn, J.-J. Kim, Y.-H. Lee, and J.-W. Kang, “Corrugated organic light emitting diodes for enhanced light extraction,” Org. Electron.11(5), 711–716 (2010).
[CrossRef]

Physica B

L. Lu, F. Zhang, Z. Xu, S. Zhao, Z. Zhuo, D. Song, J. Li, and Y. Wang, “Characteristics of ZnS nanocolumn arrays and their effect on the light outcoupling of OLEDs,” Physica B405(17), 3728–3731 (2010).
[CrossRef]

Polym. Eng. Sci.

J. S. Kim, D. S. Kim, J. J. Kang, J. D. Kim, and C. J. Hwang, “Replication and comparison of concave and convex microlens arrays of light guide plate for liquid crystal display in injection molding,” Polym. Eng. Sci.50(8), 1696–1704 (2010).
[CrossRef]

Polymer (Guildf.)

M. Ulbricht, “Advanced functional polymer membranes,” Polymer (Guildf.)47(7), 2217–2262 (2006).
[CrossRef]

Science

J. E. G. J. Wijnhoven and W. L. Vos, “Preparation of photonic crystals made of air spheres in titania,” Science281(5378), 802–804 (1998).
[CrossRef] [PubMed]

Other

Organic Electronics: Materials, Processing, Devices and Applications, F. So, ed. (CRC, 2010)

Organic Electronics in Sensors and Biotechnology, R. Shinar and J. Shinar, eds., (McGraw-Hill, 2009)

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Figures (3)

Fig. 1
Fig. 1

(a) Schematic demonstration of the microporous structure formation of the PS:PEG mixed film during the drying process following dropcasting; note that the actual pore density is not uniform. (b) SEM images of the surface and cross section of a film with 48:12 mg/mL PS:PEG. (c) The principle of the OLED outcoupling enhancement by the PS:PEG film.

Fig. 2
Fig. 2

Effect of 200 μL PS:PEG 54:6 mg/mL in toluene that were dropcast on the backside of the OLED’s ITO/glass substrate. (a) Images of two pixels with and without the PS:PEG film, each biased at 6 V. The dropcast area is 1 × 1 in.2 (b) Overall emission spectra of the devices with (red open circles) and without (black solid squares) the PS:PEG film. The current density in each device was J = 55 mA/cm2 (c) Angular emission intensity profile of the device with (red open circles) and without (black solid squares) the PS:PEG film. In each device J = 5.5 mA/cm2 The solid lines are the Lambertian emission profiles. The dashed purple line is the simulated emission profile. We note that the enhancement was essentially independent of J and consequently, of course, the brightness L, in agreement with other studies [16].

Fig. 3
Fig. 3

The surface SEM images of the PS:PEG films with different weight ratios, but constant total concentration of 60 mg/mL. The scale bar in the insets is 10 μm.

Tables (1)

Tables Icon

Table 1 Comparison of Outcoupling Enhancement Factor by PS:PEG Films with Different Weight Ratios Total Concentration: 60 mg/mL) a

Equations (5)

Equations on this page are rendered with MathJax. Learn more.

I 1 ( θ 1 ) = I 0 ( θ 0 ) sin θ 0 d θ 0 sin θ 1 d θ 1 = n P S : P E G 2 cos θ 1 n o r g 2 cos θ 0 I 0 ( θ 0 ) = n P S : P E G 2 cos θ 1 n o r g 2 1 ( n P S : P E G n o r g sin θ 1 ) 2 I 0 ( θ 0 )
I 2 ( θ 2 ) = n a i r 2 cos θ 2 n o r g 2 1 ( n a i r n o r g sin θ 2 ) 2 I 0 ( θ 0 ) ,
I 2 ( θ 2 ) = 1 2 π n a i r 2 cos θ 2 n o r g 2 1 ( n a i r n o r g sin θ 2 ) 2 ,
I 1 ' ( θ 1 ) = { C 1 w h e n θ 1 θ c C 2 w h e n θ 1 > θ c ,
I 2 ' ( θ 2 ) = C 1 n a i r 2 cos θ 2 n P S : P E G 2 1 ( n a i r n P S : P E G sin θ 2 ) 2 .

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