| Autor: |
Ha Park, Jun, Koh, Tae-Wook, Do, Youngkyu, Hyung Lee, Min, Yoo, Seunghyup |
| Zdroj: |
Journal of Polymer Science. Part A, Polymer Chemistry; Jun2012, Vol. 50 Issue 12, p2356-2365, 10p |
| Abstrakt: |
We report novel host polymers for a high-efficiency polymer-based solution-processed phosphorescent organic light-emitting diode with typical blue-emitting dopant bis(4,6-difluorophenylpyridinato-N,C2)iridium(III) picolinate (FIrpic). The host polymers, soluble polynorbornenes with pendant carbazole derivatives, N-phenyl-9 H-carbazole ( P1), N-biphenyl-9 H-carbazole ( P2), and 9,9′-(1,3-phenylene)bis-9 H-carbazole (mCP) ( P3) are efficiently synthesized by vinyl addition polymerization of norbornene monomers using Pd(II) catalyst in combination with 1-octene chain transfer agent. The polymers exhibit high thermal stability with high decomposition ( Td5 > 410 °C) and glass transition temperatures ( Tg ≈ 268 °C). The HOMO ( ca. −5.5 to −5.7 eV) and LUMO ( ca. −2.0 to −2.1 eV) levels with the high triplet energy of about 2.7-3.0 eV suggest that the polymers are suitable for a host material for blue emitters. Among the solution-processed devices that were fabricated based on the emissive layers containing the P1− P3 host doped with various concentrations of FIrpic (7-13 wt %), the best device with P3 host exhibits power efficiency of 3.0 lm W−1 and external quantum efficiency of 4.0% at a luminance of 1000 cd m−2 that is outstanding among the polymeric rivals. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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