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[摘要]:Two novel host materials based on carbazole derivatives were synthesized with benzo[b]thiophene (B2tCz) or dibenzothiophene (DB2tCz) for use in evaporation-processed blue phosphorescent organic light-emitting diodes. Both host materials exhibited high glass transition temperatures (T-g = 179 degrees C for B2tCz and T-g = 185 degrees C for DB2tCz) and triplet energy levels (E-T = 2.84 eV for B2tCz and E-T = 2.93 eV for DB2tCz). Multi layer devices fabricated using B2tCz or DB2tCz as hosts for the phosphorescence emitter, iridium(III)bis[(4,6-di-fluorophenyl)pyridinato-N,C2']picolinate (FIrpic), showed maximum current efficiencies of 43.3 and 35.6 cd A(-1), power efficiencies of 34.0 and 29.4 lm W-1, and external quantum efficiencies of 24.6% and 20.0%, respectively. |
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