Interface Study of the Intermediate Connectors in Tandem Organic Devices

  • Tang, Jian-Xin (Functional Nano & Soft Materials Laboratory (FUNSOM) & Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Soochow University) ;
  • Fung, Man-Keung (Center of Superdiamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong) ;
  • Lee, Chun-Sing (Center of Superdiamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong) ;
  • Lee, Shuit-Tong (Center of Superdiamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong)
  • Received : 2009.11.16
  • Accepted : 2010.02.24
  • Published : 2010.03.31

Abstract

The intermediate connectors play crucial roles in the performance of tandem organic light-emitting diodes (OLEDs) because they are required to facilitate charge carrier transport and to guarantee transparency for light transmission and deposition compatibility. Understanding the physical properties of the intermediate connector is not only fundamentally important but is also crucial to developing high-efficiency organic devices with a tandem structure. In this study, several effective intermediate connectors in tandem OLEDs using a doped or non-doped organic p-n heterojunction were systematically investigated by studying their interfacial electronic structures and corresponding device characteristics. The working mechanisms of the intermediate connectors are discussed herein by referring to their relevant energy levels with respect to those of the neighboring organic layers. The factors affecting the operation of the intermediate connectors in tandem OLEDs, as demonstrated herein, provide guidance for the identification of new materials and device architectures for high-performance devices.

Keywords

References

  1. C. W. Tang and S. A. VanSlyke, Appl. Phys. Lett. 51, 913 (1987). https://doi.org/10.1063/1.98799
  2. L. S. Hung and C. H. Chen, Mater. Sci. Eng. R 39, 143 (2002).
  3. B. W. D'Andrade and S. R. Forrest, Adv. Mater. 16, 1585 (2004). https://doi.org/10.1002/adma.200400684
  4. Y. Gao, I. D. Parker, G. Yu, C. Zhang, and A. J. Heeger, Nature 397, 414 (1999). https://doi.org/10.1038/17087
  5. R. H. Friend, R. W. Gymer, A. B. Holmes, J. H. Burroughes, R. N. Marks, C. Taliani, D. D. C. Bradley, D. A. Dos Santos, J. L. Bredas, M. Logdlund, and W. R. Salaneck, Nature 397, 121 (1999). https://doi.org/10.1038/16393
  6. T. Matsumoto, T. Nakada, J. Endo, K. Mori, N. Kavamura, A. Yokoi, and J. Kido, SID Int. Symp. Digest Tech. Papers, 34, 979 (2003).
  7. C. W. Chen, Y. J. Lu, C. C. Wu, E. H. E. Wu, C. W. Chu, and Y. Yang, Appl. Phys. Lett. 87, 241121 (2005). https://doi.org/10.1063/1.2141718
  8. L. S. Liao, K. P. Klubek, and C. W. Tang, Appl. Phys. Lett. 84, 167 (2004). https://doi.org/10.1063/1.1638624
  9. J. Drechsel, M. Pfeiffer, X. Zhou, A. Nollau, and K. Leo, Synth. Met. 127, 201 (2002). https://doi.org/10.1016/S0379-6779(01)00623-3
  10. X. D. Gao, J. Zhou, Z. T. Xie, B. F. Ding, Y. C. Qian, X. M. Ding, and X. Y. Hou, Appl. Phys. Lett. 93, 083304 (2008). https://doi.org/10.1063/1.2969293
  11. C. C. Chang, S. W. Hwang, C. H. Chen, and J. F. Chen, Jpn. J. Appl. Phys. Part 1 43, 6418 (2004). https://doi.org/10.1143/JJAP.43.6418
  12. C. C. Chang, J. F. Chen, S. W. Hwang, and C. H. Chen, Appl. Phys. Lett. 87, 253501 (2005). https://doi.org/10.1063/1.2147730
  13. H. Kanno, R. J. Holmes, Y. Sun, S. K. Cohen, and S. R. Forrest, Adv. Mater. 18, 339 (2006). https://doi.org/10.1002/adma.200501915
  14. H. Kanno, N. C. Giebink, Y. Sun, and S. R. Forrest, Appl. Phys. Lett. 89, 023503 (2006). https://doi.org/10.1063/1.2219725
  15. L. S. Liao, X. F. Ren, W. J. Begley, Y. S. Tyan, and C. A. Pellow, SID 08 DIGEST 2008, p. 818.
  16. J. Kido, T. Nakada, J. Endo, N. Kawamura, K. Mori, A. Yokoi, and T. Matsumoto, in Proceedings of the 11th International Workshop on Inorganic and Organic Electrolumi
  17. nescence and 2002 International Conference on the Science and Technology of Emissive Displays and Lighting (2002), p. 539.
  18. P. E. Burrows, S. R. Forrest, S. P. Sibley, and M. E. Thompson, Appl. Phys. Lett. 69, 2959 (1995).
  19. T. Y. Cho, C. L. Lin, and C. C. Wu, Appl. Phys. Lett. 88, 111106 (2006). https://doi.org/10.1063/1.2185077
  20. T. Tsutsui and M. Terai, Appl. Phys. Lett. 84, 440 (2004). https://doi.org/10.1063/1.1640470
  21. C. W. Law, K. W. Lau, M. K. Fung, M. Y. Chan, F. L. Wong, C. S. Lee, and S. T. Lee, Appl. Phys. Lett. 89, 133511 (2006). https://doi.org/10.1063/1.2357846
  22. M. K. Fung, K. M. Lau, S. L. Lai, C. W. Law, M. Y. Chan, C. S. Lee, and S. T. Lee, J. Appl. Phys. 104, 034509 (2008). https://doi.org/10.1063/1.2942408
  23. M. Y. Chan, S. L. Lai, K. M. Lau, M. K. Fung, C. S. Lee, and S. T. Lee, Adv. Funct. Mater. 17, 2509 (2007). https://doi.org/10.1002/adfm.200600642
  24. S. L. Lai, M. Y. Chan, M. K. Fung, C. S. Lee, and S. T. Lee, J. Appl. Phys. 101, 014509 (2007). https://doi.org/10.1063/1.2426338
  25. C. Shen, A. Kahn, and I. G. Hill, in Conjugated Polymer and Molecular Interfaces, edited by A. Kahn, J.-J. Pireaux, W. R. Salaneck, and K. Seki (Dekker, New York, 2001), p. 351.
  26. A. J. Makinen, M. Uchida, and Z. H. Kafafi, Appl. Phys. Lett. 82, 3889 (2003). https://doi.org/10.1063/1.1579558
  27. S. Naka, H. Okada, H. Onnagawa, and T. Tsutsui, Appl. Phys. Lett. 76, 197 (2000). https://doi.org/10.1063/1.125701
  28. S. L. Lai, M. K. Fung, S. N. Bao, S. W. Tong, M. Y. Chan, C. S. Lee, and S. T. Lee, Chem. Phys. Lett. 367, 753 (2003). https://doi.org/10.1016/S0009-2614(02)01790-6
  29. T. C. Wong, J. Kovac, C. S. Lee, L. S. Hung, and S. T. Lee, Chem. Phys. Lett. 334, 61 (2001). https://doi.org/10.1016/S0009-2614(00)01442-1
  30. J. Wang, H. Wang, X. Yan, H. Huang, and D. Yan, Appl. Phys. Lett. 87, 093507 (2005). https://doi.org/10.1063/1.2037204
  31. K. M. Lau, J. X. Tang, H. Y. Sun, C. S. Lee, S. T. Lee, and D. Yan, Appl. Phys. Lett. 88, 173513 (2006). https://doi.org/10.1063/1.2198484