Supramolecular Charge‐Transfer Approach for Tunable and Efficient Circularly Polarized Delayed Fluorescence and Phosphorescence
Swadhin Garain, Anju Ajayan Kongasseri, Sopan M. Wagalgave, Rishika Konar, Darshana Deb, K. S. Narayan, Pralok K. Samanta, Subi J. George
Abstract
Abstract Achieving efficient circularly polarized luminescence (CPL) with a high luminescence dissymmetry factor (|g lum |) in purely organic systems is a vibrant and rapidly evolving field of research. Recently, the growing interest in ambient organic phosphors has offered a promising alternative for achieving CPL with remarkable quantum yields by utilizing triplet states. While supramolecular charge‐transfer (CT) interactions are well‐established to improve |g lum | by enhancing magnetic transition dipole components, their application to triplet‐harvesting organic systems remains unexplored. In this context, our current work introduces a supramolecular strategy to achieve highly efficient and tunable circularly polarized thermally activated delayed fluorescence (TADF) and phosphorescence by the involvement of intermolecular triplet CT states. Through‐space intermolecular CT interactions between heavy atom‐substituted bis‐chromophoric pyromellitic diimides (PmDIs) (acceptors) and achiral phenyl carbazole derivatives (donors) enable one of the most efficient circularly polarized delayed luminescent systems, characterized by a high quantum yield (∼46%) and a significant |g lum | ∼3.6 × 10⁻ 2 . Additionally, the modularity of this non‐covalent design allows for the tuning of emission from the orange to deep‐red regions by incorporating various donors. The strategy presented here opens new avenues for designing efficient CPL‐active organic phosphors.