No Access Submitted: 04 April 2008 Accepted: 19 July 2008 Published Online: 02 September 2008
Appl. Phys. Lett. 93, 093301 (2008); https://doi.org/10.1063/1.2976782
more...View Affiliations
View Contributors
  • J. Mezyk
  • F. Meinardi
  • R. Tubino
  • M. Cocchi
We have investigated the mechanism of exciton dissociation in organometallic phosphorescent emitters by measuring the electric field-dependent time-resolved photoluminescence for thin vacuum-evaporated films of a model compound—tris(2-phenylpyridine) iridium (III) [Ir(ppy)3]. We have shown that the dissociation occurs from higher lying spin-mixed states before their relaxation to the lowest emissive levels, the lifetime of the latter not being significantly affected by external electric field. Knowledge about the mechanism of exciton dissociation in this class of materials is relevant for theoretical simulations of exciton kinetics in phosphorescent diodes as well as for optimization of the performances of these devices.
This work was supported by funds from the Italian MURST (FIRB Project RBNE03S7XZ “SYNERGY”) and the CARIPLO foundation. The contribution from Dr. M. Cocchi was supported by funds of CNR Project No. PM-P04-010 (MACOL).
  1. 1. M. A. Baldo, D. F. O’Brien, Y. You, A. Shoustikov, S. Silbey, M. E. Thompson, and S. R. Forrest, Nature (London) https://doi.org/10.1038/25954 395, 151 (1998). Google ScholarCrossref, ISI
  2. 2. J. Kalinowski, Organic Light Emitting Diodes: Principles, Characteristics, and Processes (Dekker, New York, 2005). Google Scholar
  3. 3. M. A. Baldo, C. Adachi, and S. R. Forrest, Phys. Rev. B https://doi.org/10.1103/PhysRevB.62.10967 62, 10967 (2000). Google ScholarCrossref, ISI
  4. 4. J. Kalinowski, W. Stampor, J. Mezyk, M. Cocchi, D. Virgili, and P. Di Marco, Phys. Rev. B https://doi.org/10.1103/PhysRevB.66.235321 66, 235321 (2002). Google ScholarCrossref, ISI
  5. 5. Y. B. Li, Y. B. Hou, F. Teng, and X. R. Xu, Chin. Phys. Lett. https://doi.org/10.1088/0256-307X/21/7/050 21, 1362 (2004). Google ScholarCrossref
  6. 6. J. Kalinowski, J. Mezyk, F. Meinardi, R. Tubino, M. Cocchi, and D. Virgili, J. Appl. Phys. https://doi.org/10.1063/1.2060955 98, 063532 (2005). Google ScholarScitation
  7. 7. R. J. Holmes, S. R. Forrest, T. Sajoto, A. Tamayo, P. I. Djurovich, and M. E. Thompson, Org. Electron. https://doi.org/10.1016/j.orgel.2006.03.009 7, 163 (2006). Google ScholarCrossref
  8. 8. J. Kalinowski, W. Stampor, J. Szmytkowski, D. Virgili, M. Cocchi, V. Fattori, and C. Sabatini, Phys. Rev. B https://doi.org/10.1103/PhysRevB.74.085316 74, 085316 (2006). Google ScholarCrossref
  9. 9. S. Reineke, K. Walzer, and K. Leo, Phys. Rev. B https://doi.org/10.1103/PhysRevB.75.125328 75, 125328 (2006). Google ScholarCrossref
  10. 10. W. Stampor and J. Mezyk, Chem. Phys. https://doi.org/10.1016/j.chemphys.2007.07.016 337, 151 (2007). Google ScholarCrossref
  11. 11. R. Kersting, U. Lemmer, M. Deussen, H. J. Bakker, R. F. Mahrt, H. Kurz, V. I. Arkhipov, H. Bässler, and E. O. Göbel, Phys. Rev. Lett. https://doi.org/10.1103/PhysRevLett.73.1440 73, 1440 (1994). Google ScholarCrossref
  12. 12. Z. D. Popovic, M. I. Khan, A. M. Hor, J. L. Goodman, and J. F. Graham, J. Phys. Chem. B https://doi.org/10.1021/jp020700l 106, 8625 (2002). Google ScholarCrossref
  13. 13. J. Kalinowski, J. Mezyk, F. Meinardi, R. Tubino, M. Cocchi, and D. Virgili, J. Chem. Phys. https://doi.org/10.1063/1.2841458 128, 124712 (2008). Google ScholarScitation
  14. 14. J. Szmytkowski, W. Stampor, J. Kalinowski, and Z. H. Kafafi, Appl. Phys. Lett. https://doi.org/10.1063/1.1450055 80, 1465 (2002). Google ScholarScitation, ISI
  15. 15. J. Kalinowski, W. Stampor, J. Szmytkowski, M. Cocchi, D. Virgili, V. Fattori, and P. Di Marco, J. Chem. Phys. https://doi.org/10.1063/1.1878612 122, 154710 (2005). Google ScholarScitation
  16. 16. J. Cabanillas-Gonzalez, M. R. Antognazza, T. Virgili, G. Lanzani, C. Gadermaier, M. Sonntag, and P. Strohriegl, Phys. Rev. B https://doi.org/10.1103/PhysRevB.71.155207 71, 155207 (2005). Google ScholarCrossref
  17. 17. J. Kalinowski, M. Cocchi, V. Fattori, P. Di Marco, and G. Giro, Jpn. J. Appl. Phys. 40, L282 (2001). Google ScholarCrossref
  18. 18. J. Kalinowski, M. Cocchi, D. Virgili, and C. Sabatini, Appl. Phys. Lett. https://doi.org/10.1063/1.2218821 89, 011105 (2006). Google ScholarScitation
  19. 19. T. Matsushita, T. Asada, and S. Koseki, J. Phys. Chem. C https://doi.org/10.1021/jp0708796 111, 6897 (2007). Google ScholarCrossref
  20. 20. K. -C. Tang, K. L. Liu, and I. -C. Chen, Chem. Phys. Lett. https://doi.org/10.1016/j.cplett.2004.01.098 386, 437 (2004). Google ScholarCrossref, ISI
  21. 21. L. Onsager, Phys. Rev. https://doi.org/10.1103/PhysRev.54.554 54, 554 (1938). Google ScholarCrossref
  22. 22. W. Stampor, Chem. Phys. https://doi.org/10.1016/S0301-0104(00)00123-3 256, 351 (2000). Google ScholarCrossref
  23. 23. W. Stampor, Chem. Phys. https://doi.org/10.1016/j.chemphys.2005.03.034 315, 259 (2005). Google ScholarCrossref
  1. © 2008 American Institute of Physics.