Intense Left‐handed Circularly Polarized Luminescence in Chiral Nematic Hydroxypropyl Cellulose Composite Films

Abstract Integrating optically active components into chiral photonic cellulose to fabricate circularly polarized luminescent materials has transformative potential in disease detection, asymmetric reactions, and anticounterfeiting techniques. However, the lack of cellulose‐based left‐handed circularly polarized light (L‐CPL) emissions hampers the progress of these chiral functionalizations. Here, this work proposes an unprecedented strategy: incorporating a chiral nematic organization of hydroxypropyl cellulose with robust aggregation‐induced emission luminogens to generate intense L‐CPL emission. By utilizing N,N‐dimethylformamide as a good solvent for fluorescent components and cellulose matrices, this work produces a right‐handed chiral nematic structure film with a uniform appearance in reflective and fluorescent states. Remarkably, this system integrates a high asymmetric factor (0.51) and an impressive emission quantum yield (55.8%) into one fascinating composite. More meaningfully, this approach is versatile, allowing for the incorporation of luminogen derivatives emitting multicolored L‐CPL. These chiral fluorescent films possess exceptional mechanical flexibility (toughness up to 0.9 MJ m⁻³) and structural stability even under harsh environmental exposures, making them promising for the fabrication of various products. Additionally, these films can be cast on the fabrics to reveal multilevel and durable anticounterfeiting capabilities or used as a chiral light source to induce enantioselective photopolymerization, thereby offering significant potential for diverse practical applications.