Journal of the Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회논문지)

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
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Stable Blue Electroluminescence from Fluorine-containing Polymers

불소 함유된 고분자를 이용한 안정한 청색 발광 유기 EL

  • Published : 2006.06.01
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Abstract

We have synthesized new blue light emitting random copolymers, poly(9,9'-n-dioctylfluorene-co-perfluorobenzene-1,4-diyl)s (PFFBs), via Ni(0)-mediated coupling reactions. The weight-average molecular weights ($M_w$) of the PFFB copolymers ranged from 9,000 to 15,000. The PFFB copolymers dissolved in common organic solvents such as THF and toluene. The PL emission peaks of the PFFB copolymers were at around 420, 440, and 470 nm. EL devices were fabricated in ITO/PEDOT/polymer/Ca/Al configurations using these polymers. These EL devices were found to exhibit pure blue emission with approximate CIE coordinates of (0.15, 0.11) at $100cd/m^2$. The blue emissions of these devices might be due to the restriction of the polymer chains to aggregation by introducing of the highly electronegative fluorine moieties. The maximum brightnesses of the PFFB copolymer devices ranged from 140 to $3600cd/m^2$ with maximum efficiencies from 0.2 to 0.6 cd/A. The enhanced efficiency of the PFFB (8/2) copolymer device results from the inhibition of excimer formation by the introduction of the electronegative fluorine moieties into the copolymers.

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References

  1. A. Kraft, A. C. Grimsdale, and A. B. Holms, 'Electroluminescent conjugated polymers-seeing polymers in a new light', Angew. Chem., Int. Ed., Vol. 37, p. 402, 1998
  2. D. H. Hwang, S. K. Kim, M. J. Park, J. H. Lee, B. W. Koo, I. N. Kang, S. H. Kim, and T. Zyung, 'Conjugated polymers based on phenothiazine and fluorene in light-emtting diodes and field effect transistor', Chem. Mater., Vol. 16, p. 1298, 2004 https://doi.org/10.1021/cm035264+
  3. E. H. Lim, B. J. Jung, and H. K. Shim 'Synthesis and characterization of a new light-emitting fluorene-thieno[3,2-b] thiophene-based conjugated copolymer', Macromolecules, Vol. 36, p. 4288, 2003 https://doi.org/10.1021/ma034168r
  4. M. Inbasekaran, W. Wu, and E. P. Woo, 'Process for preparing conjugated polymers', US Patent, 5,777,070, 1998
  5. G. R. Roof, M. T. Bernius, W. Wu, M. Inbasekaran, W. R. Shiang, and E. P. Woo, 'Fluorene-containing polymers and compound useful in the preparation thereof', US Patent, 6,169,163, 2001
  6. U. Lemmer, S. Heun, R. F. Mahrt, U. Scherf, M. Hopmeier, U. Siegner, E. O. Gobel, K. Mullen, and H. Bassler, 'Aggregate fluorescence in conjugated polymers', Chem. Phys. Lett., Vol. 240, p. 373, 1995
  7. L. M. Herz and R. T. Phillips, 'Effects of interchain interactions, polarization anisotropy, and photo-oxidation on the ultrafast photo-luminescence decay from a polyfluorene', Phys. Rev. B, Vol. 61, p. 13691, 2000 https://doi.org/10.1103/PhysRevB.61.13691
  8. S. Xiao, M. Nguyen, X. Gong, Y. Cao, H. Wu, D. Mose, and A. J. Heeger, 'Stabilization of semiconducting polymers with silsesquioxane', Adv. Funct. Mater., Vol. 13, No.1, p. 25, 2005
  9. A. M. Assaka, P. C. Rodrigues, A. R. M. de Oliveira, L. Ding, B. Hu, F. E. Karasz, and L. Akcelrud, 'Novel fluorine containing polyfluorenes with blue electrolumine-scence', Polymer, Vol. 45, p. 7071, 2004 https://doi.org/10.1016/j.polymer.2004.07.072