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Phosphorescence Quantum Efficiency and Intermolecular Interaction of Iridium(III) Complexes in Co-Deposited Films with Organic Semiconducting Hosts

  • Yuichiro Kawamura (a1), Kenichi Goushi (a2), Jason Brooks (a3), Julie J. Brown (a3), Hiroyuki Sasabe (a1) (a2) and Chihaya Adachi (a1) (a2)...

Abstract

We accurately measured the absolute photoluminescence (PL) quantum efficiency (ηPL) of organic solid-state thin films by using an integrating sphere. We measured the ηPL of conventional organic materials used in organic light emitting diodes, such as a tris (8-quinolionolato)aluminum(III) complex (Alq3), and a phosphorescent 1.5mol%-fac-tris(2-phenylpyridyl)iridium(III):4, 4'-bis(carbazol-9-yl)-2, 2'-biphenyl [Ir(ppy)3:CBP] co-deposited film. Alq3 and Ir(ppy)3:CBP showed a ηPL = 20 ± 1% and 97 ± 2%, which corresponded well to external electroluminescence efficiency using these materials. We also measured red emitting bis[2-(2'-benzothienyl)pyridinato-N, C 3'] (acetylacetonato) iridium(III) [Btp2Ir(acac)] with CBP, and the blue complex, bis[(4, 6-difluorophenyl)pyridinato-N, C 2](picolinato)iridium(III) [FIrpic], with m-bis(N -carbazolyl)benzene. The maximum ηPL values for Btp2Ir(acac), and FIrpic were 51±1% (at 1.4mol%), and 99±1% (1.2mol%), respectively. These results suggest that the ηEL of red phosphorescent OLEDs using Btp2Ir(acac) as the dopant can be as high as 10%, and blue devices using FIrpic can reach the theoretical limit of 20%.

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1. Tang, C. W. and VanSlyke, S. A., Appl. Phys. Lett. 51, 913 (1987).
2. Baldo, M. A., Lamansky, S., Burrows, P. E., Thomson, M. E. and Forrest, S. R., Appl. Phys. Lett. 75, 4 (1999).
3. Adachi, C., Baldo, M. A., Thompson, M. E. and Forrest, S. R., J. Appl. Phys. 90, 5048 (2001).
4. Ikai, M., Tokito, S., Sakamoto, Y., Suzuki, T. and Taga, Y., Appl. Phys. Lett. 79, 156 (2001).
5. Hide, F., Diaz-García, M. A., Schwartz, B. J., Andersonn, M. R., Pei, Q., and Heeger, A. J., Science 273, 1833 (1996).
6. Kozlov, V. G., Bulovic, V., Burrows, P. E., and Forrest, S. R., Nature (London) 389, 362 (1997).
7. Yamamoto, H., Oyamada, T., Sasabe, H. and Adachi, C., Appl. Phys. Lett. 84, 1401 (2004).
8. Kawamura, Y., Yamamoto, H., Goushi, K., Sasabe, H., Adachi, C. and Yoshizaki, H., Appl. Phys. Lett. 84, 2724 (2004).
9. Sakanoue, T., Fujiwara, E., Yamada, R. and Tada, H., Appl. Phys. Lett. 84, 3037 (2004).
10. Lamansky, S., Djurovich, P., Murphy, D., Abdel-Razzaq, F., Adachi, C., Burrows, P. E., Forrest, S. R. and Thompson, M. E., J. Am. Chem. Soc. 123, 4303 (2001).
11. Goushi, K., Kawamura, Y., Sasabe, H. and Adachi, C., Jpn. J. Appl. Phys. 43, L937 (2004).
12. Eckerle, K. L., Vanable, J. W. H. and Weidner, V. R., Appl. Opt. 15, 703 (1976).
13. Greenham, N. C., Samuel, I. D. W., Hayes, G. R., Phillips, R. T., Kessener, Y. A. R. R., Moratti, S. C., Holms, A. B. and Friend, R. H., Chem. Phys. Lett. 241, 89 (1995).
14. Mattoussi, H., Murata, H., Merritt, C. D., Iizumi, Y., Kido, J. and Kafafi, Z. H., J. Appl. Phys. 86, 4642 (1999).
15. Kawamura, Y., Sasabe, H. and Adachi, C., Jpn. J. Appl. Phys, 43, 7729 (2004)
16. Gu, G., Garbuzov, D. Z., Burows, P. E., Venkatesh, S., Forrest, S. R. and Thompson, M. E., Opt. Lett. 22, 396 (1997).
17. Vanslyke, S. A., Bryan, P. S. and Tang, C. W., Ext. Abstr. p.195 (The 8th International Workshop on Inorg. and Org. Electroluminescence/EL96 Berlin).
18. Kawamura, Y., Goushi, K., Brooks, J., Brown, J. J., Sasabe, H. and Adachi, C., Appl. Phys. Lett. (in press).
19. Adachi, C., Kwong, R. C., Djurovich, P., Adamovich, V., Baldo, M. A., Thompson, M. E. and Forrest, S. R., Appl. Phys. Lett. 79, 2082 (2001).
20. Holmes, R., Forrest, S. R., Tung, Y.-J., Kwong, R. C., Brown, J. J., Garon, S. and Thompson, M. E., Appl. Phys. Lett. 82, 2422 (2003).

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