Helical Photonic Confinement of Narrowband-Emissive Carbon Quantum Dots Enables Amplified and Stimulus-Responsive Circularly Polarized Luminescence

Circularly polarized luminescence (CPL) materials that simultaneously exhibit large luminescence dissymmetry factors (glum), high photoluminescence quantum yields (PLQYs), and dynamic optical addressability remain highly sought after yet challenging to realize. Here, we establish a CQDs-CLCs photonic coupling platform via helical photonic confinement of narrowband-emissive carbon quantum dots (CQDs) in a chiral liquid crystal (CLC) host, enabling controlled emitter-photonic bandgap (PBG) spectral engineering. This yields amplified chiroptical signals with a glum of up to 1.12 and a figure of merit (FM = glum × PLQY) of 0.67. Beyond static performance, the helical photonic architecture allows dynamic CPL modulation by multiple stimuli, including temperature, light, electric field, mechanical pressure, viewing angle, and polarization. This work establishes helical photonic confinement as a material-photonic coupling strategy for decoupling dissymmetry amplification from emission efficiency while enabling multimodal stimulus-responsive modulation, offering potential applications in optical encryption, smart textiles, and photonic devices.