P‐127: Student Poster: Highly Efficient Green Hyper‐fluorescent Organic Light‐Emitting Diodes using tetradentate Pt(II) Complex as Phosphorescent Sensitizer

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 N 9 ,N 9 ,N 10 ,N 10 ‐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/m 2 . It induced only 5.0% efficiency roll‐off, which is 6.4‐fold improvement compared to our previous work.