Color Stability Enhancement of White Organic Light-Emitting Diodes Using a Charge Control Layer


  • Shui-Hsiang Su
  • Yu-Cheng Lin
  • Meiso Yokoyama


OLED, charge control layer (CCL)


Blue phosphorescent iridium complexes iridium(III)bis[(4,6-di-fluorophenyl)-pyridinato-N,C2'] (FIrpic) and yellow phosphorescent iridium complexes Iridium(III) bis (4-phenylthieno [3,2-c]pyridinato-N,C2′)acetylacetonate (PO-01) was doped into the small molecular phosphorescent host N, N_-dicarbazolyl-3, 5-benzene (mCP) to fabricate white phosphorescent organic light-emitting diodes (white PHOLEDs). Device current efficiency is enhanced by inserting a charge control layer (CCL) into the emitting layer.

The peaks of PHOLED electroluminescent (EL) spectrum locate at 472 nm (FIrpic) and 560 nm (PO-01). A high current efficiency white PHOLED has been fabricated by the use of FIrpic and Po-01 as the double emitting layer (EML), in which the mCP is used as the CCL inserted. The doping concentration of PO-01 is optimized and the carrier transport mechanism of CCL is discussed. The optimized current efficiency is 30.06 cd/A. The CIE coordinates locate at (0.33, 0.41) and vary within (±0.01, ±0.01) under driving voltage of 5-15V.


C. W. Joo, J. W. Shin, J. Moon, J. W. Huh, D. H. Cho, J. Lee, S. K. Park, N. S. Cho, J. H. Han, H. Y. Chu, J. I. Lee, “Highly efficient white transparent organic light emitting diodes with nano-structured substrate,” Org. Electron., vol. 29, pp. 72, 2016.

R. Joyce, K. Singh, S. Varghese, J. Akhtar, “Effective cleaning process and its influence on surface roughness in anodic bonding for semiconductor device packaging,” Mater. Sci. Semicond. Process., vol. 31, pp. 84, 2015.

B. Liu , J. Zou , Z. Zhou , L. Wang, M. Xu, H. Tao, D. Gao, L. Lan, H. Ning, J. Peng, “Efficient single-emitting layer hybrid white organic light-emitting diodes with low efficiency roll-off, stable color and extremely high luminance,” J. Ind. and Eng. Chem., vol. 30, pp. 85, 2015.

C. W. Tang and S. A. Vanslyke, “Organic electroluminescent diodes,” Appl. Phys. Lett., vol. 51,p p. 913, 1987.

G. T. Chen, S. H. Su, C. C. Hou, and M. Yokoyama, “Effects of Thermal Annealing on Performance of Organic Light-Emitting Diodes,” J. Electrochem. Soc., vol. 153, pp. J159, 2007.

J. F. Li, S. F. Chen, S. H. Su, K. A. Hwang, and M. Yokoyama, “Full-Wavelength White Organic Light-Emitting Diodes with Blue Fluorescence and Phosphorescent Iridium Complexes,“ J. Electrochem. Soc., vol. 153, pp. H195, 2006.

X. Du, Y. Huang, S. Tao, X. Yang, X Ding, X. Zhang, “Highly efficient white fluorescence/phosphorescence hybrid organic light emitting devices based on an efficient hole-transporting blue emitter,” Dyes Pigments, vol. 115, pp. 149, 2015.

Y. S. Tsai, A. Chittawanij, L. A. Hong, C. Y. Ou, F. S. Juang, C. C. Wang, S.H. Lai, “Adjusting dopant concentrations in solution process to optimize the white phosphorescent organic light-emitting diodes,” Microelectron. Eng., vol. 138, pp. 31, 2015.

B. S. Kim, J. Y. Lee, “Interlayer free hybrid white organic light-emitting diodes with red/blue phosphorescent emitters and a green thermally activated delayed fluorescent emitter,” Org. Electron., vol. 21, pp. 100, 2015.




How to Cite

S.-H. Su, Y.-C. Lin, and M. Yokoyama, “Color Stability Enhancement of White Organic Light-Emitting Diodes Using a Charge Control Layer”, Proc. eng. technol. innov., vol. 2, pp. 28–30, Jun. 2016.