Journal of Information Display

The Korean Infomation Display Society (한국정보디스플레이학회)
권호 표지

Polymer Phosphorescence Device using a New Green Emitting Ir(III) Complex

  • Published : 2002.03.24
Download PDF
⟨ Previous Next ⟩

Abstract

We have synthesized a new green Ir(III) complex fac-tris-(3-methyl-2-phenyl pyridine)iridium(III) $Ir(mpp)_3$ and fabricated phosphorescent polymer light-emitting device using it as a triplet emissive dopant in PVK. $Ir(mpp)_3$ showed absorption centered at 388 nm corresponding to the $^1MLCT$ transition as .evidenced by its extinction coefficient of the order of $10^3{\cdot}$ From the PL and EL spectra of the $Ir(mpp)_3$ doped PVK film, the emission maximum was observed at 523 nm, due to the radiative decay from the $^3MLCT$ state to the ground state, confirming a complete energy transfer from PVK to $Ir(mpp)_3$. The methyl substitution has probably caused a red shift in the absorption and emission spectrum compared to $Ir(mpp)_3$. The device consisting of a 2 % doped PVK furnished 4.5 % external quantum efficiency at 72 $cd/m^2$ (current density of 0.45 $mA/cm^2$ and drive voltage of 13.9 V) and a peak luminance of 25,000 $cd/m^2$ at 23.4 V (494 $mA/cm^2$). This work demonstrates the impact of the presence of a methyl substituent at the 3-position of the pyridyl ring of 2-phenylpyridine on the photophysical and electroluminescence properties.

Keywords

References

  1. S. Sprouse, K. A, King, P. J. Spellane, and R. J. Watts, J. Am Chem. Soc., 106, 6647 (1984) https://doi.org/10.1021/ja00334a031
  2. R. J.Watts and G. A. Crosby, J. Am. Chem. Soc., 93, 3184(1971) https://doi.org/10.1021/ja00742a016
  3. K. Dedian, P. I. Jurovich, F.O. Graces, G. Carlson and R J. Watts, Inorg. Chem., 30, 1685 (1991) https://doi.org/10.1021/ic00008a003
  4. J. Kido, K. Hongawa, K. Okuyama, and K. Nagai, Appl. Phys. Lett, 64, 815 (1994) https://doi.org/10.1063/1.111023
  5. R. J. Watts, G. A. Crosby, and J. L. Sansregret, Interactions in Iridium(III) Complexes,' Inorg. Chem.,11, 1474 (1972) https://doi.org/10.1021/ic50113a006
  6. K. A. King, P. J. Spellane, and R. J. Watts, J. Am. Chem. Soc., 107,1431 (1985) https://doi.org/10.1021/ja00291a064
  7. M. Nishizawa, T. M. Suzuki, S. Sprouse, R. J. Watts, and P. C. Ford, Inorg. Chem., 23, 1837 (1984) https://doi.org/10.1021/ic00181a012
  8. H. H. Jaffe and M. Orchin, Theory and Applications of ultraviolet Spectroscopy(Wiley, New York, 1962), ch. 15
  9. C.-L. Lee, K. B. Lee, and J.-J. Kim, Appl. Phys. Lett., 77, 2280 (2000) https://doi.org/10.1063/1.1315629
  10. A. A. Shoustikov, Y. J. You, and M. E. Thompson, IEEE J. Sel. Top. Quant. Elect,, 4, 3 (1998) https://doi.org/10.1109/2944.669454