Wide‐Range Color Tuning of Narrowband Emission in Multi‐resonance Organoboron Delayed Fluorescence Materials through Rational Imine/Amine Functionalization
Minlang Yang, So Shikita, Hyukgi Min, In Seob Park, Hiromoto Shibata, Natsuki Amanokura, Takuma Yasuda
Abstract
Abstract Establishing a simple and versatile design strategy to finely modulate emission colors while retaining high luminescence efficiency and color purity remains an appealing yet challenging task for the development of multi‐resonance‐induced thermally activated delayed fluorescence (MR‐TADF) materials. Herein, we demonstrate that the strategic introduction of electron‐withdrawing imine and electron‐donating amine moieties into a versatile boron‐embedded 1,3‐bis(carbazol‐9‐yl)benzene skeleton enables systematic hypsochromic and bathochromic shifts of narrowband emissions, respectively. By this method, effective electroluminescence color tuning was accomplished over a wide visible range from deep‐blue to yellow (461–571 nm), using the same MR molecular system, without compromising very narrow spectral features. Deep‐blue to yellow organic light‐emitting diodes with maximum external quantum efficiencies as high as 19.0–29.2 % and superb color purity could be produced with this family of color‐tunable MR‐TADF emitters.