The Luminescent Properties of Red OLED Devices Doped with Two Dopants

2원 첨가 적색 OLED 소자의 발광특성

  • Published : 2007.06.01


To invest the luminescent characteristics of red light emitting OLED device, a dual dopant system was incorporated into the emitting layer. The multiple layer OLED device structure was $ITO(1500\;{\AA})/HIL(200\;{\AA})/a-NPD(600\;{\AA})/EML(300\;{\AA})/Alq_3(200\;{\AA})/LiF(7\;{\AA})/Al(1800\;{\AA})$. The concentrations of the rubrene dopant were tested at 0 vol.%, 3 vol.%, 6 vol.% and 9 vol.%. The maximum device efficiency and life time were obtained at the rubrene dopant concentration of 6 vol.%. Emission spectrum and color coordinate of devices showed no relationship with rubrene dopant concentration. Experiment results show that rubrene dopant absorbs energy from $Alq_3$ host and transfer it to RD1 dopant acting as an energy intermediate and influencing the device efficiency, finally the red light is emitted from the RD1 dopant.



  1. C. W. Tang and S. A. VanSlyke, 'Organic electroluminescent diode', Appl, Phys, Lett., Vol. 51, p. 913, 1987
  2. H. H. Sung, I. H. Kim, K. N. Byun, and H. S. Yoo, 'Characterization of new red dopants for color OLED' , Current Applied Physics, Vol. 5, p. 345, 2005
  3. X. R. Wang, J. S. Chen, H. You, D. G. Ma, and R. G. Sun, 'Efficiency and color coordinate improvement using codopant in blue organic lightmitting diode', Japanese J. of Appl. Phys., Vol. 44, No. 12, p. 8480, 2005
  4. K. Okumoto, H. Kanno, Y. Hamaa, H. Takahashi, and K. Shibata, 'Green fluorescent organic light-emitting device with external quantum efficiency of nearly 10 %', Appl. Phys, Lett., Vol. 89, p. 63504, 2006
  5. Y. Hamada, H. Kanno, T. Tsujioka, H. Takahashi, and T. Usuki, 'Red organic light emitting diodes using an emitting assist dopant', Appl, Phys. Lett., Vol. 75, No. 12, p. 1682, 1999
  6. Y. Ohmori, H. Kajii, T. Sawatani, H. Ueta, and K. Yoshino, 'Enhancement of electroluminescence utilizing confined energy transfer for red light emission', Thin Solid Dilms, Vol. 393, p. 407, 2001
  7. H. Kanno, Y. Hamada, and H. Takahashi, 'Development of OLED with high stability and luminance efficiency by co-doping methods for full color displays', IEEE Journal of Selected Topics in Quantum Electronics, Vol. 10, No. 1, p. 30, 2004
  8. 박용규, 한정인, 곽민기, 한종근, 주성후, $ZnGa_2O_4:Mn,O$ 형광체의 휘도 및 색도 특성', 전기전자재료학회논문지, 10권, 3호, p.262, 1997

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