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2018 Vol.29, Issue 6 Preview Page
December 2018. pp. 262-267

In this paper, we designed a new antireflective film to improve the optical efficiency of organic light-emitting diode displays (OLEDs). The reflection characteristics in the normal and side viewing directions of OLEDs with the antireflective film were calculated, depending on the degree of polarization and transmittance of the currently used polarizer when used in the antireflective film of an OLED. The results showed that when the polarization degree of the commercial polarizer (99.990~99.995%) is lowered to 99.900%, the average reflectance of the antireflective film is increased by about 0.1% (2.5% in terms of rate of increase) which is difficult to notice with the human eye, while the transmittance is increased by 1.63~3.34% (4.2~8.2% in terms of rate of increase). This study provides an optimal design for high-light-efficiency OLEDs with good antireflection properties.

본 논문에서는 유기발광다이오드 디스플레이(OLED)의 광 효율을 향상시키기 위해 방사방지필름을 새롭게 디자인하였다. 현재 상용화되고 있는 편광판의 편광도와 투과율을 변화시켜 OLED 반사방지필름에 사용하였을 경우 정면과 측면방향의 반사특성을 계산하였다. 그 결과 편광도가 99.995%나 99.990%인 상용화된 편광판의 편광도를 99.9% 수준으로 떨어뜨릴 경우, 반사방지필름의 평균 시감반사율은 사람의 눈으로 알아차리기 힘든 약 0.1% (증가율 환산 2.5%) 상승한 반면, 투과율은 기존보다 약 1.63~3.34% (증가율 환산 4.2~8.2%) 상승하였다. 이 결과는 기존 OLED에서 저반사율을 유지하면서 광효율을 상승시킬 수 있는 광학설계 조건을 제시하였다.

  1. C. W. Tang and S. A. Vanslyke, "Organic electroluminescent diodes," Appl. Phys. Lett. 51, 913-915 (1987).10.1063/1.98799
  2. J. Shi and C. W. Tang, "Doped organic electroluminescent devices with improved stability," Appl. Phys. Lett. 70, 1665-1667 (1997).10.1063/1.118664
  3. G. Rajeswaran, M. Itoh, M. Boroson, S. Barry, T. K. Hatwar, K. B. Kahen, K. Yoneda, R. Yokoyama, T. Yamada, N. Komiya, H. Kanno, and H. Takahashi, "Active matrix low temperature poly-si TFT/OLED full color displays: Development status," SID Symposium Digest of Technical Papers 31, 947-977 (2000).
  4. Y. Wang, N. Herron, V. V. Grushin, D. LeCloux, and V. Petrov, "Highly efficient electroluminescent materials base on fluorinated organometallic iridium compounds," Appl. Phys. Lett. 79, 449-451 (2001).10.1063/1.1384903
  5. L. S. Hung, C. W. Tang, M. G. Mason, P. Raychaudhuri, and J. Madathil, "Application of an ultrathin LiF/Al bilayer in organic surface-emitting diodes," Appl. Phys. Lett. 78, 544-546 (2001).10.1063/1.1327273
  6. K. Mameno, R. Nishikawa, K. Suzuki, S. Matsumoto, T. Yamaguchi, K. Yoneda, Y. Hamada, H. Kanno, Y. Nishio, H. Matsuoka, Y. Saito, S. Oima, N. Mori, G. Rajeswaran, S. Mizukoshi, and T. K. Hatwar, "Development of 2.2-inch full color AM-OLED display for mobile applications," in Proc. 9th International Display Workshop (Society for Information Display, 2002), pp. 235-238.
  7. V. Bulovic, G. Gu, P. E. Burrows, S. R. Forrest, and M. E. Thompson, "Transparent light-emitting devices," Nature 380, 29 (1996).10.1038/380029a0
  8. G. Parthasarathy, P. E. Burrows, V. Khalfin, V. G. Kozlov, and S. R. Forrest, "A metal-free cathode for organic semiconductor devices," Appl. Phys. Lett. 72, 2138-2140 (1998).10.1063/1.121301
  9. T. Sasaoka, M. Sekiya, A. Yumoto, J. Yamada, T. Hirano, Y. Iwase, T. Yamada, T. Ishibashi, T. Mori, M. Asano, S. Tamura, and T. Urabe, "A 13.0-inch AM-OLED display with top emitting structure and adaptive current mode programmed pixel circuit (TAC)," SID Symposium Digest of Technical Papers 32, 384-387 (2001).
  10. M.-H. Lu, M. S. Weaver, T. X. Zhou, M. Rothman, R. C. Kwong, M. Hack, and J. J. Brown, "High-efficiency top-emitting organic light-emitting devices," Appl. Phys. Lett. 81, 3921-3923 (2002).10.1063/1.1523150
  11. C.-J. Yang, C.-L. Lin, C.-C. Wu, Y.-H. Yeh, C.-C. Cheng, Y.-H. Kuo, and T.-H. Chen, "High-contrast top-emitting organic light-emitting devices for active-matrix displays," Appl. Phys. Lett. 87, 143507 (2005).10.1063/1.2081137
  12. Q. Li, Self-Organized Organic Semiconductors: From Materials to Device Application (John Wiley & Sons, 2011).10.1002/9780470949122
  13. Q. Li, Liquid Crystals Beyond Displays: Chemistry, Physics, and Applications (John Wiley & Sons, 2012).10.1002/9781118259993
  14. A. Uchiyama and T. Yatabe, "Wide-band retardation films with reverse wavelength dispersion," in Proc. 7th International Display Workshop (Society for Information Display, 2000), pp. 407-410.
  15. A. Uchiyama and T. Yatabe, "Characteristics and application of new wide-band retardation films," SID Symposium Digest of Technical Papers 32, 566-569 (2001).
  16. M. Okamoto, K. Minoura, and S. Mitsui, "Optical design of the LC layer on reflective LCDs with a single polarizer," in Proc. 6th International Display Workshop (Society for Information Display, 1999), 49-52.
  17. T.-H. Yoon, G.-D. Lee, and J. C. Kim, "Nontwist quarter-wave liquid-crystal cell for a high-contrast reflective display," Opt. Lett. 25, 1547-1549 (2000).10.1364/OL.25.00154718066274
  18. B. C. Kim, Y. J. Lim, J. H. Song, J. H. Lee, K.-U. Jeong, J. H. Lee, G.-D. Lee, and S. H. Lee, "Wideband antireflective circular polarizer exhibiting a perfect dark state in organic light-emitting-diode disply," Opt. Express 22, A1725-A1730 (2014).10.1364/OE.22.0A172525607486
  19. P. Yeh and C. Gu, Optics of Liquid Crystal Displays (Wiley, Hoboken, NJ, USA, 2010).
  20. S. S. Kim, H. J. Kim, and S. D. Lee, Display Engineering 1 (Cheongbeom Publishing Company, Korea, 2005).
  • Publisher :Optical Society of Korea
  • Publisher(Ko) :한국광학회
  • Journal Title :Korean Journal of Optics and Photonics
  • Journal Title(Ko) :한국광학회지
  • Volume : 29
  • No :6
  • Pages :262-267
  • Received Date :2018. 09. 07
  • Accepted Date : 2018. 10. 15