Recent Progress in Molecular Design of Boron/Nitrogen‐Based Multi‐Resonance Materials for Narrowband Organic Light‐Emitting Diodes

Abstract Luminescent boron‐nitrogen (BN)‐type multi‐resonance (MR) materials have been first reported by Hatakeyama and co‐workers in 2016. BN‐type MR materials have attracted a lot of attention, because of their unique photophysical properties, including narrowband emissions, high photoluminescent quantum yields, and thermally activated delayed fluorescent (TADF) properties. BN‐type MR‐TADF materials are considered as the next‐generation luminescent materials for efficient, stable, and narrow‐emission organic light‐emitting diodes (OLEDs). Herein, a comprehensive review of the recent progress in BN‐type MR‐TADF materials is provided by highlighting the structures, photophysical properties, and device performances. Moreover, the future perspective for the development of BN‐type MR‐TADF materials will be discussed.