Abstract
We have fabricated white organic light-emitting devices by using the phosphorescent material fac tris (2-phenylpyridine) iridium [Ir(ppy3)] as a sensitizer, as a result, the efficiency of these devices is improved dramatically. Ir(ppy)3 and the fluorescent dye 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7- tetramethyljulolidyl-9-enyl)(DCJTB) are co-doped into 4,4′-N,N′-dicarbazole-biphenyl (CBP) host, whose thickness affects both color and efficiency of the devices. Tris (8-hydroxyquinoline) aluminum (Alq) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (bathocuproine or BCP) are used as electron-transporting and exciton-blocking layers, respectively, and N,N′-diphenyl-N,N′-bis(1-naphthyl)-(1,1′-biphenyl)-4,4′-diamine (NPB) as a blue light-emitting as well as hole-transporting layer. The maximum efficiencies of the devices with 15 and 20 nm co-doped BCP tuning layer are 7.5 and 8.6 cd/A, respectively, and the former presents fairly pure white emission with CIE coordinates of (0.33, 0.32) at 10 V, which is very stable at various biases (10–19 V).
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Baldo, M.A., D.F. O'Brien, M.E. Thompson and S.R. Forrest. Phys. Rev. B 60 14422, 1999a.
Baldo, M.A., M.E. Thompson and S.R. Forrest. Nature 403 750, 2000.
Baldo, M.A., S. Lamansky, P.E. Burrows, M.E. Thompson and S.R. Forrest. Appl. Phys. Lett. 75 4, 1999b.
Burrows, P.E., S.R. Forrest, T.X. Zhou and L. Michalski. Appl. Phys. Lett. 76 2493, 2000.
Chao, C.-L. and S.-A. Chen. Appl. Phys. Lett. 73 426, 1998.
Chen, C.H., C.W. Tang, J. Shi and K.P. Klubek. Macromol. Symp. 125 49, 1997.
D'Andrade, B.W., J. Brooks, V. Adamovich, M.E. Thompson and S.R. Forrest. Adv. Mater. 14 1032, 2002a.
D'Andrade, B.W., M.A. Baldo, C. Adachi, J. Brooks, M.E. Thompson and S.R. Forrest. Appl. Phys. Lett. 79 1045, 2001.
D'Andrade, B.W., M.E. Thompson and S.R. Forrest. Adv. Mater. 14 147, 2002b.
Deshpande, R.S., V. Bulović and S.R. Forrest. Appl. Phys. Lett. 75 888, 1999.
Dodabalapur, A., L.J. Rothberg and T.M. Miller. Appl. Phys. Lett. 65 2308, 1994.
Feng, J., F. Li, W.B. Gao, S.Y. Liu, Y. Liu and Y. Wang. Appl. Phys. Lett. 78 3947, 2001.
Kido, J., H. Shionoya and K. Nagai. Appl. Phys. Lett. 67 2281, 1995a.
Kido, J., M. Kimura and K. Nagai. Science 267 1332, 1995b.
Tasch, S., E.J.W. List, O. Ekström, W. Granpner, G. Leising, P. Schlichting, U. Rohr, Y. Geerts, U. Scherf and K. Müllen. Appl. Phys. Lett. 71 2883, 1997.
Xie, Z.Y., J. Feng, J.S. Huang, Y. Wang and J.C. Shen. Synth. Met. 108 81, 2000.
Yang, K., W. Gao, J. Zhao, J. Sun, S. Lu and S. Liu. Synth. Met. 132 43, 2002.
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Cheng, G., Zaho, Y., Xie, W. et al. High-Efficiency White Light Emission Using a Phosphorescent Sensitizer in Organic Light-Emitting Devices. Optical and Quantum Electronics 36, 659–664 (2004). https://doi.org/10.1023/B:OQEL.0000034727.28657.76
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DOI: https://doi.org/10.1023/B:OQEL.0000034727.28657.76