Efficient White Phosphorescent Organic Light-emitting Diodes for Solid-State Lighting Applications Using an Exciton-confining Emissive-Layer Structure

  • Lee, Jong-Hee (Convergence Components & Materials Research Laboratory, Electronics and Telecommunications Research Institute) ;
  • Lee, Jeong-Ik (Convergence Components & Materials Research Laboratory, Electronics and Telecommunications Research Institute) ;
  • Lee, Joo-Won (Convergence Components & Materials Research Laboratory, Electronics and Telecommunications Research Institute) ;
  • Lee, Jun-Yeob (Department of Polymer Science and Engineering, Dankook University) ;
  • Kang, Dong-Min (School of Materials Science and Engineering and Engineering Research Institute (ERI), Gyeongsang National University) ;
  • Yuanc, Wei (School of Materials Science and Engineering and Engineering Research Institute (ERI), Gyeongsang National University) ;
  • Kwon, Soon-Ki (School of Materials Science and Engineering and Engineering Research Institute (ERI), Gyeongsang National University) ;
  • Chu, Hye-Yong (Convergence Components & Materials Research Laboratory, Electronics and Telecommunications Research Institute)
  • Published : 2009.06.30

Abstract

Highly efficient blue and white phosphorescent organic light-emitting diodes (PHOLEDs) with an exciton-confining structure were investigated in this study. Effective charge confinement was achieved by stacking two emitting layers with different charge-transporting properties, and blue PHOLEDs with a maximum luminance efficiency of 47.9 lm/W were developed by using iridium(III) bis(4,6-(difluorophenyl) pyridinato-N,C2')picolinate (FIrpic) as an electrophosphorescent dopant. Moreover, when the optimized green and red emitting layers were sandwiched between the two stacked blue emitting layers, white PHOLEDs (WOLEDs) with peak external and luminance efficiencies of 19.0% coupling technique.and 54.0 lm/W, respectively, were obtained without the use of any out-coupling technique.

Keywords

References

  1. M. A. Baldo, D. F. O’Brien, Y. You, Shoustikov, S. Sibley, M. E. Thompson, and S. R. Forrest, Nature, 395, 151 (1998) https://doi.org/10.1038/25954
  2. G. He, M. Pfeiffer, K. Leo, M. Hofmann, J. Birnstock, R. Pudzich, and J. Salbeck, Appl. Phys. Lett. 85, 3911 (2004) https://doi.org/10.1063/1.1812378
  3. C. Adachi, M. A. Baldo, M. E. Thomposon, and S. R. Forrest, J. Appl. Phys. 90, 5048 (2001) https://doi.org/10.1063/1.1409582
  4. B. W. D'Andrade and S. R. Forrest. Adv. Mater. 16, 1595 (2004)
  5. J. Lee, J. -I. Lee, J. Y. Lee, and H. Y. Chu, Appl. Phys. Lett. 94, 193305 (2009) https://doi.org/10.1063/1.3136861
  6. Y. Sun, and S. R. Forrest, Appl. Phys. Lett. 91, 263503 (2007) https://doi.org/10.1063/1.2827178
  7. Y. -S. Park, J. -W. Kang, D. M. Kang, J. -W. Park, Y. -H. Kim, S. -K. Kwon, and J. -J. Kim, Adv. Mater. 20, 1957 (2008) https://doi.org/10.1002/adma.200702435
  8. Y. Shao, Y. Yang, Appl. Phys. Lett. 86, 073510 (2005) https://doi.org/10.1063/1.1866216
  9. K. S. Yook, S. O. Jeon, C. W. Joo, and J. Y. Lee, Appl. Phys. Lett. 93, 113301 (2008) https://doi.org/10.1063/1.2982917
  10. J. Y. Lee, J. H. Kwon, H. K. Chung, Org. Electron. 4, 143 (2003) https://doi.org/10.1016/j.orgel.2003.08.013
  11. S. -J. Su, E. Gonmori, H. Sasabe, and J. Kido, Adv. Mater. 20, 4189 (2008)
  12. C. Adachi, R. C. Kwong, P. Djurovich, V. Adamovich, M. A. Baldo, M. E. Thompson, and S. R. Forrest, Appl. Phys. Lett. 79, 2082 (2001) https://doi.org/10.1063/1.1400076
  13. R. J. Homes, S. R. Forrest, Y. -J. Tung, R. C. Kwong, J. J. Brown, S. Garon, and M. E. Thompson, Appl. Phys. Lett. 82, 2422 (2003) https://doi.org/10.1063/1.1568146
  14. J. Lee, J. -I. Lee, K. -I. Song, S. J. Lee, and H. Y. Chu, Appl. Phys. Lett. 92, 203305 (2008) https://doi.org/10.1063/1.2936837
  15. J. Lee, J. -I. Lee, K. -I. Song, S. J. Lee, and H. Y. Chu, Appl. Phys. Lett. 92, 133304 (2008) https://doi.org/10.1063/1.2904632
  16. S. O. Jeon, K. S. Yook, C. W. Joo, and J. Y. Lee, Appl. Phys. Lett. 94, 013301 (2009) https://doi.org/10.1063/1.3046288
  17. D. M. Kang, J.-W. Kang, S. O. Jung, J. W. Park, S.-H. Lee, H.-D. Park, Y.-H. Kim, S. C. Shin, J.-J. Kim, S.-K. Kwon, Adv. Mater., 20, 2003 (2008) https://doi.org/10.1002/adma.200702558
  18. RD is phosphorescent red dopant and the detailed information about this proprietary materials is disclosed later