Thermally activated delayed fluorescent conducting organic polymers for OLED application

Thermally activated delayed fluorescence (TADF) polymers have emerged as a promising class of emissive materials for solution-processed organic light-emitting diodes (SP-OLEDs) due to their ability to utilize both singlet and triplet excitons for efficient light generation. Recent advances in molecular design, including main-chain donor-acceptor architectures, pendant-type systems, through-space charge transfer structures, and copolymer strategies, have enabled significant improvements in their photophysical and electroluminescent properties. These polymers exhibit favourable characteristics such as high photoluminescence quantum yields, small singlet-triplet energy gaps, and efficient delayed fluorescence, leading to encouraging device performances. In addition, their polymeric nature provides important advantages, including reduced aggregation-caused quenching, excellent film-forming ability, and compatibility with low-cost solution-processing techniques. Despite these benefits, TADF polymers still face limitations compared to small-molecule emitters, particularly in achieving higher external quantum efficiencies and superior colour purity with narrow emission bandwidths. Therefore, continued research focused on molecular engineering, structural optimization, and device design is essential to further enhance their performance and fully exploit their potential for next-generation, high-efficiency SP-OLED applications.