Journal of the Optical Society of Korea

Optical Society of Korea (한국광학회)
권호 표지
DOI QR코드

DOI QR Code

Optical Simulation Study on the Effect of Diffusing Substrate and Pillow Lenses on the Outcoupling Efficiency of Organic Light Emitting Diodes

  • Received : 2013.03.13
  • Accepted : 2013.05.27
  • Published : 2013.06.25
Download PDF
⟨ Previous Next ⟩

Abstract

The effect of diffusing substrate and pillow lenses on the outcoupling efficiency of organic light-emitting diodes (OLEDs) was studied by optical simulation based on the point-dipole model. The diffusing substrate included Mie scatterers by which the condition of total internal reflection could be broken. The finite-difference time-domain method was used to obtain the intensity distribution on the transparent electrode of an OLED, which was used as a light source to carry out a ray-tracing simulation of the OLED and the diffusing substrate. It was found that the outcoupling efficiency of the OLED was sensitive to the thickness of organic layers and could be increased by 21.0% by adopting a diffusing substrate in which Mie scatterers whose radius was $2.0{\mu}m$ were included at the density of $10^7mm^{-3}$ and by 65.5% by forming one pillow lens with the radius of 2 mm on the front surface of the glass substrate. This study revealed that the outcoupling efficiency could be improved by adopting diffusing substrate and pillow lenses along with the optimization of the thickness of each layer in the OLED.

Keywords

References

  1. K. Hong and J.-L. Lee, "Recent developments in light extraction technologies of organic light emitting diodes," Electron. Mater. Lett. 7, 77-91 (2011). https://doi.org/10.1007/s13391-011-0601-1
  2. 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 A 210, 44-65 (2012).
  3. G. Gu, D. Z. Garbuzov, P. E. Burrows, S. Venkatesh, and S. R. Forrest, "High-external-quantum-efficiency organic light-emitting devices," Opt. Lett. 22, 396-398 (1997). https://doi.org/10.1364/OL.22.000396
  4. J.-H. Jang, M.-C. Oh, T.-H. Yoon, and J. C. Kim, "Polymer grating imbedded organic light emitting diodes with improved out-coupling efficiency," Appl. Phys. Lett. 97, 123302 (2010). https://doi.org/10.1063/1.3491286
  5. C. S. Choi, S.-M. Lee, M. S. Lim, K. C. Choi, D. Kim, D. Y. Jeon, Y. Yang, and O. O. Park, "Improved light extraction efficiency in organic light emitting diodes with a perforated $WO_3$ hole injection layer fabricated by use of colloidal lithography," Opt. Express 20, A309-A318 (2012). https://doi.org/10.1364/OE.20.00A309
  6. Y.-H. Cheng, J.-L. Wu, C.-H. Cheng, K.-C. Syao, and M.-C. M. Lee, "Enhanced light outcoupling in a thin film by texturing meshed surfaces," Appl. Phys. Lett. 90, 091102 (2007). https://doi.org/10.1063/1.2709920
  7. C.-C. Liu, S.-H. Liu, K.-C. Tien, M.-H. Hsu, H.-W. Chang, C.-K. Chang, C.-J. Yang, and C.-C. Wu, "Microcavity top-emitting organic light-emitting devices integrated with diffusers for simultaneous enhancement of efficiencies and viewing characteristics," Appl. Phys. Lett. 94, 103302 (2009). https://doi.org/10.1063/1.3097354
  8. C.-H. Chang, K.-Y. Chang, Y.-J. Lo, S.-J. Chang, and H.-H. Chang, "Fourfold power efficiency improvement in organic light-emitting devices using an embedded nanocomposite scattering layer," Org. Electron. 13, 1073-1080 (2012). https://doi.org/10.1016/j.orgel.2012.02.017
  9. S. W. Liu, J. X. Wang, Y. Divayana, K. Dev, S. T. Tan, H. V. Demir, and X. W. Sun, "An efficient non-Lambertian organic light-emitting diode using imprinted submicron-size zinc oxide pillar arrays," Appl. Phys. Lett. 102, 053305 (2013). https://doi.org/10.1063/1.4791786
  10. S. S. Jeong and J.-H. Ko, "Simulation study on the optical structures for improving outcoupling efficiency of organic light emitting diodes," J. Inf. Disp. 13, 139-143 (2012). https://doi.org/10.1080/15980316.2012.734258
  11. Y.-J. Lee, S.-H. Kim, G.-H. Kim, and Y.-H. Lee, "Far-field radiation of photonic crystal organic light-emitting diode," Opt. Express 13, 5864-5870 (2005). https://doi.org/10.1364/OPEX.13.005864
  12. A. Chutinan, K. Ishihara, T. Asano, M. Fujita, and S. Noda, "Theoretical analysis on light-extraction efficiency of organic light-emitting diodes using FDTD and mode-expansion methods," Org. Electron. 6, 3-9 (2005). https://doi.org/10.1016/j.orgel.2004.12.001
  13. N. Nakamura, N. Fukumoto, F. Sinapi, N. Wada, Y. Aoki, and K. Maeda, "Glass substrates for OLED lighting with high out-coupling efficiency," in Proc. SID'09 Technical Digest (San Antonio, USA, 2009), pp. 603-607.
  14. R. Meerheim, M. Furno, S. Hofmann, B. Lussem, and K. Leo, "Quantification of energy loss mechanisms in organic light-emitting diodes," Appl. Phys. Lett. 97, 253305 (2010). https://doi.org/10.1063/1.3527936
  15. E. F. Schubert, N. E. J. Hunt, R. J. Malik, M. Micovic, and D. L. Miller, "Temperature and modulation characteristics of resonant-cavity light-emitting diodes," J. Lightwave Technol. 14, 1721-1729 (1996). https://doi.org/10.1109/50.507950
  16. D. G. Deppe, C. Lei, C. C. Lin, and L. Huffaker, "Spontaneous emission from planar microstructures," J. Modern Optics 41, 325-344 (1994). https://doi.org/10.1080/09500349414550361
  17. T. Nakamura, H. Fujii, N. Juni, and N. Tsutsumi, "Enhanced coupling of light from organic electroluminescent device using diffusive particle dispersed high refractive index resin substrate," Opt. Rev. 13, 104-110 (2006). https://doi.org/10.1007/s10043-006-0104-8
  18. R. Bathelt, D. Buchhauser, C. Garditz, R. Paetzold, and P. Wellmann, "Light extraction from OLEDs for lighting applications through light scattering," Org. Electron. 8, 293-299 (2007). https://doi.org/10.1016/j.orgel.2006.11.003
  19. 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, 1650-1652 (2000). https://doi.org/10.1063/1.126124
  20. Y. Sun and S. R. Forrest, "Organic light emitting devices with enhanced outcoupling via microlenses fabricated by imprint lithography," J. Appl. Phys. 100, 073106 (2006). https://doi.org/10.1063/1.2356904
  21. B. C. Krummacher, M. K. Mathai, V. Choong, S. A. Choulis, F. So, and A. Winnacker, "General method to evaluate substrate surface modification techniques for light extraction enhancement of organic light emitting diodes," J. Appl. Phys. 100, 054702 (2006). https://doi.org/10.1063/1.2234550
  22. S. S. Jeong and J.-H. Ko, "Far-field luminous intensity distribution depending on the outcoupling structure of organic light-emitting diodes," J. Inf. Disp., http://www.tandfonline.com/doi/full/10.1080/15980316.2013.801927.
  23. J. Kim, S. Jung, and I. Jeong, "Optical modeling for polarization- dependent optical power dissipation of thin-film organic solar cells at oblique incidence," J. Opt. Soc. Korea 16, 6-12 (2012). https://doi.org/10.3807/JOSK.2012.16.1.006

Cited by

  1. Simulation of the Combined Effects of Dipole Emitter Orientation, Mie Scatterers, and Pillow Lenses on the Outcoupling Efficiency of an OLED vol.25, pp.4, 2014, https://doi.org/10.3807/KJOP.2014.25.4.193
  2. Outcoupling efficiency of organic light-emitting diodes depending on the fill factor and size of the microlens array vol.211, pp.8, 2014, https://doi.org/10.1002/pssa.201330613
  3. Effects of a Dielectric Multilayer Mirror on the Lighting Efficiency of Organic Light-Emitting Diodes Studied by Optical Simulation vol.26, pp.3, 2015, https://doi.org/10.3807/KJOP.2015.26.3.139
  4. Effect of the finite pixel boundary on the angular emission characteristics of top-emitting organic light-emitting diodes vol.23, pp.11, 2015, https://doi.org/10.1364/OE.23.00A709
  5. Simulation Study on the Effect of the Emitter Orientation and Photonic Crystals on the Outcoupling Efficiency of Organic Light-Emitting Diodes vol.18, pp.6, 2014, https://doi.org/10.3807/JOSK.2014.18.6.732
  6. Dielectric nanoparticles for the enhancement of OLED light extraction efficiency vol.387, 2017, https://doi.org/10.1016/j.optcom.2016.11.059
  7. Parametrization of the Optical Constants of AlAsxSb1-x Alloys in the Range 0.74-6.0 eV vol.18, pp.4, 2014, https://doi.org/10.3807/JOSK.2014.18.4.359
  8. A hybrid simulated method for analyzing the optical efficiency of a head-mounted display with a quasi-crystal OLED panel vol.22, pp.S2, 2014, https://doi.org/10.1364/OE.22.00A567
  9. The elliptical micro-lens array in the application of the LDA beam shaping vol.125, pp.24, 2014, https://doi.org/10.1016/j.ijleo.2014.07.114
  10. Theoretical comparison of the excitation efficiency of waveguide and surface plasmon modes between quantum-mechanical and electromagnetic optical models of organic light-emitting diodes vol.26, pp.22, 2018, https://doi.org/10.1364/OE.26.00A955
  11. Improvement of light-extraction efficiency of organic light-emitting diodes using dielectric nanoparticles vol.11, pp.03, 2017, https://doi.org/10.1117/1.JNP.11.036010
  12. Theoretical Modeling of the Internal Power Flow and Absorption Loss of the Air Mode Based on the Proposed Poynting Vector Analysis in Top-emitting Organic Light-emitting Diodes vol.73, pp.11, 2018, https://doi.org/10.3938/jkps.73.1663