Chiral co-assembly of quantum dots and organic emitters enables high-efficiency circularly polarized luminescence via FRET

Abstract

Circularly polarized luminescent quantum dots (CPL QDs) have demonstrated significant potential in applications such as three-dimensional displays, information encryption, optical communications, and biomedical technologies. The simultaneous achievement of high luminescence dissymmetry factors (g_lum) and high photoluminescence quantum yields (PLQYs), both essential for practical implementations, remains a critical challenge in this field. In this study, we developed a chiral co-assembly strategy integrating quantum dots (QDs) with organic polymeric chiral assemblies to address this challenge. Using poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) as the host matrix, a chiral binaphthyl derivative R/S-5011 was incorporated to induce helical structures, which were co-assembled with red-emitting CdSe/ZnSe QDs (RQDs). This configuration establishes a chiral donor–QD acceptor energy transfer framework through spectral matching and Förster resonance energy transfer (FRET), enabling directional modulation of QD luminescence. The resulting CPL QD thin films exhibit a g_lum value of 0.04 and a PLQY of 58%, outperforming conventional methods, such as direct synthesis and ligand exchange, which often compromise structural integrity. Our approach not only simplifies fabrication and enables tunable CPL performance but also preserves the pristine symmetrical configuration of QDs. This work provides a robust platform for developing high-performance, customizable CPL materials, advancing their applications in optical displays, information encryption, and related technologies.