Tunable Circularly Polarized Luminescence Through Chiral Dopant Dihedral Angle Modulation in Liquid Crystal Polymer...

Circularly polarized luminescence (CPL) film materials have garnered significant attention due to potential applications in chiral optical fields. While exogenous chiral binaphthyl dopants are widely employed to enhance CPL performance, the underlying connection between luminescence asymmetry factors (g_lum) and dihedral angles remains unclear. In this work, CPL films with tunable g_lum are prepared via co-assembly of fluorescent dye, liquid crystal (LC) polymer, and chiral binaphthyl inducers with varying dihedral angles. Experimental characterization and molecular simulation demonstrate that favorable π-π stacking and chiral LC phase drive efficient chiral amplification. The structures of chiral supramolecular assemblies can be modulated by precise control of dihedral angles, achieving tunable CPL properties. LC polymer doped with R/S-4 exhibited the best g_lum value of 0.61, attributed to the similar dihedral angles between binaphthyl inducers and LC units. Additionally, distinct chiral inversion phenomena are observed, attributed to CPL emission arising from selective reflection surpasses that induced by chiral emissive molecules. This study provides valuable insights into chiral amplification and inversion and establishes a versatile paradigm for designing high-g_lum CPL films with controllable chirality.