cis-Quinacridone-Based Delayed Fluorescence Emitters: Seemingly Old but Renewed Functional Luminogens

Angew Chem Int Ed Engl. 2021 Mar 29;60(14):7643-7648. doi: 10.1002/anie.202016914. Epub 2021 Feb 24.

Abstract

Herein, we report a material design of linear cis-quinacridone (cis-QA) derivatives as delayed fluorescence luminogens. In contrast to the widely studied traditional trans-isomers, the functionality of cis-QA and its derivatives remains unexplored and unclarified. Through combined computational and experimental investigations, we revealed that cis-QA derivatives can function as fascinating narrowband deep-blue delayed fluorescence emitters for organic light-emitting diodes (OLEDs). The best-performing deep-blue OLEDs incorporating these cis-QA luminogens achieved high external electroluminescence quantum efficiencies of up to 19.0 % and high color purity with chromaticity coordinates of (0.13, 0.14).

Keywords: charge transfer; organic light-emitting diodes; quinacridones; spin-orbit coupling; thermally activated delayed fluorescence.