[2PS-088]
Donor–Acceptor Positional Effects on Emission Performance and Roll-Off in Solution-Processed TADF OLEDs
발표자현예지 (경상국립대학교)
연구책임자김윤희 (경상국립대학교)
Abstract
TADF materials boost OLED efficiency by converting triplet excitons into singlet excitons, reducing quenching losses. We designed two donor–acceptor molecules, SiPhCzTrz and SiTrzPhCz, by altering the positions of donor (PhCz) and acceptor (Trz) units. Both include a tetraphenylsilyl (TPS) group to enhance solution-processability. SiTrzPhCz showed stronger TADF and higher efficiency but suffered from roll-off due to longer exciton lifetimes. Its twisted structure helped suppress aggregation-caused quenching (ACQ). SiPhCzTrz had weaker TADF but showed more stable efficiency and longer device lifetime. As sensitizers in phosphorescent OLEDs, they achieved efficiencies of 19.3 and 20 cd/A, respectively. Notably, SiPhCzTrz allowed a simplified two-component emitting layer, improving cost-effectiveness and durability. These results highlight the role of molecular design in optimizing TADF materials for stable OLED performance.