Novel Deep‐Blue Hybridized Local and Charge‐Transfer Host Emitter for High‐Quality Fluorescence/Phosphor Hybrid Quasi‐White Organic Light‐Emitting Diode
Hao Zhang, Jianan Xue, Chenglong Li, Shitong Zhang, Bing Yang, Yu Liu, Yue Wang
Abstract
Abstract A new hybrid local and charge transfer (HLCT) molecule 2TPA‐PPI is obtained for constructing the high‐performance organic light‐emitting diodes (OLEDs) in this work. 2TPA‐PPI possesses the sufficient emission/charge‐transporting properties, thus it is used as a neat emitter achieving an efficient deep‐blue OLED with very high external quantum efficiency (EQE) up to 10.7%, as well as a multi‐functional emitting host matrix constructing the high‐performance phosphorescent OLEDs. More importantly, a high‐efficiency candle light‐style OLED adopting the HLCT/phosphor hybrid strategy is realized, where 2TPA‐PPI acts as not only a blue emitter, but also a universal host sensitizing both yellow and red phosphors. This quasi‐white OLED represents almost the highest EQE/PE level of 25.2%/49.7 lm W −1 at the practical luminance level of 1000 cd m −2 for the white OLEDs with the excellent color rendering index values of more than 80 reported.