Multi‐channel charge transfer delayed fluorescence enabling high‐efficiency organic light‐emitting diodes

Abstract Thermally activated delayed fluorescence (TADF) materials have garnered extensive attention, as they can attain 100% exciton utilization without the necessity of introducing precious metal atoms. Since the breakthrough of electroluminescent devices based on pure organic TADF materials, this field has experienced rapid development with the design and synthesis of thousands of new TADF molecules in the past decade. Among them, TADF materials with multi‐channel charge transfer (MCCT) have become a research hotspot in recent years because of advantages such as the increased utilization rate of triplet excitons by opening more reverse intersystem crossing channels through degenerate molecular orbitals and the capability of obtaining emitted light with different wavelengths and spectral shapes by regulating the charge transfer processes of different channels. In this review, we have meticulously summarized the latest research accomplishments of TADF materials with MCCT reported in recent years by commencing from molecular design, photophysical properties and the performance of organic light‐emitting diodes (OLEDs). The objective is to clarify the relationship between structure and performance and to offer references for follow‐up work. Ultimately, the existing challenges of MCCT‐based TADF materials are presented and the prospects for their future development directions are also delineated.