Highly Efficient Green Hyper-fluorescent Organic Light-Emitting Diodes using tetradentate Pt(Ⅱ) Complex as Phosphorescent Sensitizer

초록

We developed green hyper-fluorescent organic light-emitting diodes (OLEDs) using tetradentate Pt(Ⅱ) complex phosphorescent sensitizer to improve external quantum efficiency (EQE) and reduce efficiency roll-off through suppressed Deter energy transfer to green fluorescent emitter of N9,N9,N10,N10-tetrakis(4-(2-phenylpropan-2-yl)phenyl)anthracene-9,10-diamine (PhtBuPAD). The tetradentate Pt(Ⅱ) complex including bulky blocking unit prevented Dexter energy transferred into green fluorescent emitter. In the device evaluation, the hyper-fluorescent OLED is maintained the high EQE of 21.1% in spite of a high doping concentration of green fluorescent emitter of 3 wt%. As a result, the maximum EQE at optimized doping concentration 2 wt% shows 23.4% and 22.2% at 3000 cd/m2. It induced only 5.0% efficiency roll-off, which is 6.4-fold improvement compared to our previous work. © 2022. John Wiley and Sons Inc. AIAA. All rights reserved.

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