Chirality Inducing Units in Organic TADF Molecules: A Way to Circularly Polarized Luminescence

Abstract

The circularly polarized luminescence (CPL) emission has become a hot topic due to its applications in optical data storage, optical spintronics, and 3D displays. The CP-OLEDs, being a highly efficient source of CP light, open new possibilities for CP electroluminescence technology in the future. Various types of small and large chiral organic molecules, metal complexes, and macromolecules with decent efficiencies have been developed in this regard. The present literature also includes different approaches for inducing chirality in the organic molecules. TADF technology has been regarded as a promising technique thanks to its 100% internal quantum efficiency and precious metal-free emitters. Therefore, inducing chirality to the TADF molecules to generate CP-EL remains one of the efficient techniques for the future of the CP-OLEDs. This review summarizes various methods or organic moieties utilized in literature to induce chirality in the small organic TADF molecules. We discuss the different moieties to develop the TADF molecule and the organic units to bestow it with the chirality. In addition, their theoretical analysis, photo-physics, chiroptical properties, and chiral-EL efficiencies have also been summarized and discussed. We firmly believe that this review would benefit researchers working in the area of chirality and contribute its share to the future of display technology.