Abstract

Compared to the OLED with planar substrate, the luminous current efficiency and luminous power efficiency of the device are shown 25% and 36% enhancement, respectively, by attaching the microlens array film (MAF) having a fill factor of 0.788 and a height ratio of 0.46. Both the luminous current efficiency and luminous power efficiency of the organic light-emitting device (OLED) increased monotonically with increasing the fill factor of MAFs, regardless of their arrangements. However, the curve-fitting equation of the luminous power efficiency has a negative second-order term, which shows a saturation phenomenon. Based on the experimentally verified configuration, simulation showed that the luminous current and power efficiencies also increase along with increasing height ratio and they were found to have more pronounced saturation phenomena. As for the spectral characteristics, the peak wavelength of the planar OLED spectra got blue-shift and the full-width-at-half-maximum (FWHM) of its spectra decreased with increasing the viewing angles due to the microcavity theories. After MAFs are attached to the OLED, the FWHM of the OLED spectra decreased linearly by increasing the fill factor of the MAFs. We also observe blue shifts at different viewing angles which is the evidence that the waveguiding modes are being extracted. The saturation phenomena of efficiency enhancement imply that high fill factor and large height ratio of MAFs will certainly benefit for efficiency enhancement, however, full factor cases are not always the most desirable. Optimal fill factor and height ratio, which may be less than unity, will gain the best efficiency enhancement, suffer from less color deviation, and make fabrication easier.

© 2011 IEEE

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2008 (3)

H. Y. Lin, "Patterned microlens array for efficiency improvement of small-pixelated organic light-emitting devices," Opt. Express 16, 11044-11051 (2008).

M.-K. Wei, "Efficiency improvement and spectral shift of an organic light-emitting device by attaching a hexagon-based microlens array," J. Opt. A: Pure Appl. Opt. 10, 055302-1055302 (2008).

M.-K. Wei, "Efficiency improvement and spectral shift of an organic light-emitting device with a square-based microlens array," Opt. Commun. 281, 5625-5632 (2008).

2007 (1)

H. Y. Lin, "Improvement of the outcoupling efficiency of an organic light-emitting device by attaching microstructured films," Opt. Commun. 275, 464-469 (2007).

2006 (4)

Y. Sun, S. Forrest, "Organic light emitting devices with enhanced outcoupling via microlenses fabricated by imprint lithography," J. Appl. Phys. 100, 073106-1073106 (2006).

M. Wei, I. Su, "The influence of a microlens array on planar organic light-emitting devices," J. Micromech. Microeng. 16, 368-374 (2006).

H.-C. Chen, J.-H. Lee, C.-C. Shiau, C. C. Yang, Y.-W. Kiang, "Electromagnetic modeling of organic light-emitting devices," J. Lightw. Technol. 24, 2450-2457 (2006).

J.-H. Lee, "Radiation simulations of top-emitting organic light-emitting devices with two-and three-microcavity structures," J. Display Technol. 2, 130-137 (2006).

2005 (1)

H. Peng, Y. Ho, X. Yu, M. Wong, H. Kwok, "Coupling efficiency enhancement in organic light-emitting devices using microlens array-theory and experiment," J Display Technol 1, 278-282 (2005).

2004 (2)

M.-K. Wei, I.-L. Su, "Method to evaluate the enhancement of luminance efficiency in planar OLED light emitting devices for microlens array," Opt. Express 12, 5777-5782 (2004).

J. J. Shiang, T. J. Faircloth, A. R. Duggal, "Experimental demonstration of increased organic light emitting device output via volumetric light scattering," J. Appl. Phys. 95, 2889-2895 (2004).

2003 (1)

Y. J. Lee, "A high-extraction-efficiency nanopatterned organic light-emitting diode," Appl. Phys. Lett. 82, 3779-3781 (2003).

2002 (2)

M. H. Lu, J. C. Sturm, "Optimization of external coupling and light emission in organic light-emitting devices: Modeling and experiment," J. Appl. Phys. 91, 595-604 (2002).

S. Moller, S. R. Forrest, "Improved light out-coupling in organic light emitting diodes employing ordered microlens arrays," J. Appl. Phys. 91, 3324-3327 (2002).

2001 (2)

T. Tsutsui, M. Yahiro, H. Yokogawa, K. Kawano, M. Yokoyama, "Doubling coupling-out efficiency in organic light-emitting devices using a thin silica aerogel layer," Adv Mater 13, 1149-1152 (2001).

B. Matterson, J. Lupton, A. Safonov, M. Salt, W. Barnes, I. Samuel, "Increased efficiency and controlled light output from a microstructured light-emitting diode," Adv Mater 13, 123-127 (2001).

2000 (4)

C. Madigan, M. Lu, J. Sturm, "Improvement of output coupling efficiency of organic light-emitting diodes by backside substrate modification," Appl. Phys. Lett. 76, 1650-1652 (2000).

T. Yamasaki, K. Sumioka, T. Tsutsui, "Organic light-emitting device with an ordered monolayer of silica microspheres as a scattering medium," Appl. Phys. Lett. 76, 1243-1245 (2000).

L. Lin, T. Shia, C. Chiu, "Silicon-processed plastic micropyramids for brightness enhancement applications," J. Micromech. Microeng. 10, 395-400 (2000).

J. Kim, P. Ho, N. Greenham, R. Friend, "Electroluminescence emission pattern of organic light-emitting diodes: Implications for device efficiency calculations," J. Appl. Phys. 88, 1073-1081 (2000).

1995 (1)

H. Wittmann, J. Gruner, R. Friend, G. Spencer, S. Moratti, A. Holmes, "Microcavity effect in a single-layer polymer light-emitting diode," Adv. Mater. 7, 541-544 (1995).

1994 (1)

A. Dodabalapur, L. Rothberg, T. Miller, E. Kwock, "Microcavity effects in organic semiconductors," Appl. Phys. Lett. 64, 2486-2488 (1994).

1993 (1)

N. Takada, T. Tsutsui, S. Saito, "Control of emission characteristics in organic thin film electroluminescent diodes using an optical microcavity structure," Appl. Phys. Lett. 63, 2032-2034 (1993).

Adv Mater (2)

T. Tsutsui, M. Yahiro, H. Yokogawa, K. Kawano, M. Yokoyama, "Doubling coupling-out efficiency in organic light-emitting devices using a thin silica aerogel layer," Adv Mater 13, 1149-1152 (2001).

B. Matterson, J. Lupton, A. Safonov, M. Salt, W. Barnes, I. Samuel, "Increased efficiency and controlled light output from a microstructured light-emitting diode," Adv Mater 13, 123-127 (2001).

Adv. Mater. (1)

H. Wittmann, J. Gruner, R. Friend, G. Spencer, S. Moratti, A. Holmes, "Microcavity effect in a single-layer polymer light-emitting diode," Adv. Mater. 7, 541-544 (1995).

Appl. Phys. Lett. (5)

N. Takada, T. Tsutsui, S. Saito, "Control of emission characteristics in organic thin film electroluminescent diodes using an optical microcavity structure," Appl. Phys. Lett. 63, 2032-2034 (1993).

A. Dodabalapur, L. Rothberg, T. Miller, E. Kwock, "Microcavity effects in organic semiconductors," Appl. Phys. Lett. 64, 2486-2488 (1994).

C. Madigan, M. Lu, J. Sturm, "Improvement of output coupling efficiency of organic light-emitting diodes by backside substrate modification," Appl. Phys. Lett. 76, 1650-1652 (2000).

T. Yamasaki, K. Sumioka, T. Tsutsui, "Organic light-emitting device with an ordered monolayer of silica microspheres as a scattering medium," Appl. Phys. Lett. 76, 1243-1245 (2000).

Y. J. Lee, "A high-extraction-efficiency nanopatterned organic light-emitting diode," Appl. Phys. Lett. 82, 3779-3781 (2003).

J Display Technol (1)

H. Peng, Y. Ho, X. Yu, M. Wong, H. Kwok, "Coupling efficiency enhancement in organic light-emitting devices using microlens array-theory and experiment," J Display Technol 1, 278-282 (2005).

J. Appl. Phys. (5)

Y. Sun, S. Forrest, "Organic light emitting devices with enhanced outcoupling via microlenses fabricated by imprint lithography," J. Appl. Phys. 100, 073106-1073106 (2006).

J. Kim, P. Ho, N. Greenham, R. Friend, "Electroluminescence emission pattern of organic light-emitting diodes: Implications for device efficiency calculations," J. Appl. Phys. 88, 1073-1081 (2000).

J. J. Shiang, T. J. Faircloth, A. R. Duggal, "Experimental demonstration of increased organic light emitting device output via volumetric light scattering," J. Appl. Phys. 95, 2889-2895 (2004).

S. Moller, S. R. Forrest, "Improved light out-coupling in organic light emitting diodes employing ordered microlens arrays," J. Appl. Phys. 91, 3324-3327 (2002).

M. H. Lu, J. C. Sturm, "Optimization of external coupling and light emission in organic light-emitting devices: Modeling and experiment," J. Appl. Phys. 91, 595-604 (2002).

J. Display Technol. (1)

J. Lightw. Technol. (1)

H.-C. Chen, J.-H. Lee, C.-C. Shiau, C. C. Yang, Y.-W. Kiang, "Electromagnetic modeling of organic light-emitting devices," J. Lightw. Technol. 24, 2450-2457 (2006).

J. Micromech. Microeng. (2)

M. Wei, I. Su, "The influence of a microlens array on planar organic light-emitting devices," J. Micromech. Microeng. 16, 368-374 (2006).

L. Lin, T. Shia, C. Chiu, "Silicon-processed plastic micropyramids for brightness enhancement applications," J. Micromech. Microeng. 10, 395-400 (2000).

J. Opt. A: Pure Appl. Opt. (1)

M.-K. Wei, "Efficiency improvement and spectral shift of an organic light-emitting device by attaching a hexagon-based microlens array," J. Opt. A: Pure Appl. Opt. 10, 055302-1055302 (2008).

Opt. Commun. (2)

M.-K. Wei, "Efficiency improvement and spectral shift of an organic light-emitting device with a square-based microlens array," Opt. Commun. 281, 5625-5632 (2008).

H. Y. Lin, "Improvement of the outcoupling efficiency of an organic light-emitting device by attaching microstructured films," Opt. Commun. 275, 464-469 (2007).

Opt. Express (2)

Other (1)

S. Sinzinger, J. Jahns, Microoptics (Wiley-VCH, 2003).

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