Highly Efficient Circularly Polarized Electroluminescence Based on a Thermally Activated Delayed Fluorescence Mechanism

作者：Meng Li, Chuan‐Feng Chen · 发表于：Accounts of Chemical Research · 年份：2025 · DOI：10.1021/acs.accounts.5c00703 · 被引用次数：20 · 研究领域：Synthesis and Properties of Aromatic Compounds、Organic Light-Emitting Diodes Research、Perovskite Materials and Applications

Conspectus Circularly polarized electroluminescence (CPEL) is pivotal for next-generation photonic technologies, including 3D displays, optical data storage, and quantum communication. However, its practical application has long been hindered by two fundamental challenges: low device efficiency (external quantum efficiency, EQE) and a small luminescence dissymmetry factor ( g EL ), which quantifies the intensity of circular polarization. Traditional chiral fluorescent emitters suffer from limited exciton utilization of only 25%, while chiral phosphorescent emitters often rely on scarce metals. The emergence of thermally activated delayed fluorescence (TADF) offers a revolutionary pathway to overcome the device efficiency bottleneck by enabling full exciton harvesting through reverse intersystem crossing (RISC), yet integrating strong chirality into an efficient TADF molecular skeleton remains a significant hurdle. Our pioneering work established a comprehensive strategy to simultaneously boost EQE and g EL . We introduced TADF as a core mechanism to achieve high EQE by harnessing triplet excitons via RISC. Concurrently, we devised diverse chiral structures, which range from small molecules and polymers to assembled ionic systems, to effectively amplify the dissymmetry factor. For instance, chiral supramolecular assemblies with TADF emitters enhance chirality transfer through assembled structural ordering, leading to significantly amplified g EL values without compromising the...