DOI QR코드

DOI QR Code

Emission Characteristics of White Organic Light-Emitting Diodes Using Ultra Wide Band-gap Phosphorescent Material

Ultra Wide Band-gap 인광체를 이용한 백색 OLED의 발광 특성

  • Chun, Hyun-Dong (Department of Advanced Materials Science & Engineering, Daejin University) ;
  • Na, Hyunseok (Department of Advanced Materials Science & Engineering, Daejin University) ;
  • Choo, Dong Chul (Cheorwon Plasma Research Institute) ;
  • Kang, Eu-Seok (Cheorwon Plasma Research Institute) ;
  • Yang, Jae-Woong (Department of Advanced Materials Science & Engineering, Daejin University) ;
  • Ju, Sung-Hoo (Department of Advanced Materials Science & Engineering, Daejin University)
  • 천현동 (대진대학교 신소재공학과) ;
  • 나현석 (대진대학교 신소재공학과) ;
  • 추동철 ((재)철원플라즈마산업기술연구원) ;
  • 강유석 ((재)철원플라즈마산업기술연구원) ;
  • 양재웅 (대진대학교 신소재공학과) ;
  • 주성후 (대진대학교 신소재공학과)
  • Received : 2012.07.31
  • Accepted : 2012.10.24
  • Published : 2012.11.01

Abstract

We studied the emission characteristics of white phosphorescent organic light-emitting diodes (PHOLEDs), which were fabricated using a two-wavelength method. The best blue emitting OLED and red emitting OLED characteristics were obtained at a concentration of 12 vol.% FIrpic and 1 vol.% $Bt_2Ir$(acac) in UGH3, respectively. And the optimum thickness of the total emitting layer was 25 nm. To optimize emission characteristics of white PHOLEDs, white PHOLEDs with red/blue/red, blue/red, red/blue and co-doping emitting layer structures were fabricated using a host-dopant system. In case of white PHOLEDs with co-doping structure, the best efficiency was obtained at a structure UGH3: 12 vol. % FIrpic: 1 vol.% $Bt_2Ir$(acac) (25 nm). The maximum brightness, current efficiency, power efficiency, external quantum efficiency, and CIE (x, y) coordinate were 13,430 $cd/m^2$, 40.5 cd/A, 25.3 lm/W, 17 % and (0.49, 0.47) at 1,000 $cd/m^2$, respectively.

Keywords

References

  1. Z. Liu, and N. Helena, Synth. Met., 111, 47 (2000). https://doi.org/10.1016/S0379-6779(99)00436-1
  2. F. Jing, L. Feng, G. Wenbao, and L. Shiyong, Appl. Phys. Lett., 78, 3947 (2001). https://doi.org/10.1063/1.1379788
  3. J. H. Lee, J. I. Lee, and H. Y. Chu, Synth. Met., 159, 991 (2009). https://doi.org/10.1016/j.synthmet.2008.12.031
  4. T. Tsuboi, H. Murayama, S. J. Yeh, and C. T. Chen, Opt. Mater., 29, 1299 (2007). https://doi.org/10.1016/j.optmat.2006.06.005
  5. V. Sivasubramaniam, F. Brodkorb, S. Hanning, H. P. Loebl, V. van Elsbergen, H. Boerner, U. Scherf, and M. Kreyenschmidt, J. Fluor. Chem., 130, 640 (2009). https://doi.org/10.1016/j.jfluchem.2009.04.009
  6. J. H. Seo, Y. K. Kim, and Y. Ha, Thin Solid Films, 517, 1807 (2009). https://doi.org/10.1016/j.tsf.2008.09.075
  7. H. I. Baek and C. H. Lee, J. Phys. D: Appl. Phys., 41, 105101 (2008). https://doi.org/10.1088/0022-3727/41/10/105101
  8. G. Lei, Wang, and Y. Qiu, Appl. Phys. Lett., 88, 103508 (2006). https://doi.org/10.1063/1.2185255
  9. R. J. Holmes, S. R. Forrest, Y. J. Tung, R. C. Kwog, J. J. Brown, S. Garon, and M. E. Thompson, Appl. Phys. Lett., 82, 2422 (2003). https://doi.org/10.1063/1.1568146
  10. M. A. Baldo, S. Lamansky, P. E. Burrows, M. E. Thompson, and S. R. Forrest, Appl. Phys. Lett., 75 (1999).
  11. J. W. Park, G. C. Choi, D. E. Kim, B. S. Kim, and Y. S. Kwon, Trans. KIEE, 7, 14 (2009).