Thermally Activated Delayed Fluorescence Enabled by Reversed Conformational Distortion for Blue Emitters
Yurong Guo, Hongwei Guan, Peng Li, Chao Wang, Zibo Wu, Yanan Wang, Zhenyi Yu, Zhen Zhang, Shiping Wang, G. Zhao
Abstract
In this work, we present for the first time a general strategy via molecular reversed conformational distortion for thermally activated delayed fluorescence (TADF). A model purely organic compound named BNNIO with a common fluorophore flexibly linked to benzene by an oxygen atom is rationally designed and successfully synthesized. Moreover, the rate constant of reverse intersystem crossing reaches 2.34 × 104 s–1 as determined by transient spectroscopy. As a result, TADF emission of BNNIO is observed with a photoluminescence quantum yield of 90.72% and a lifetime of 84.76 μs at 415 nm. This universal regulation strategy undoubtedly opens a new avenue for the development of novel purely organic blue light-emitting materials.