Enhancing photosynthesis and light capture is a sustainable strategy to boost crop yields and address global food demand. Carbon dots (CDs) are promising light conversion nanomaterials with unique optical properties and aggregation-induced quenching (ACQ) alleviation ability. Herein, this study designed a novel light-manipulation composite film based on biomass-derived CDs for plant growth promotion. Biomass-based water-dispersible red solid-state luminescent CDs (CDs-HPC) were synthesized via a one-pot method, overcoming ACQ with emission spectrum matching chlorophyll absorption. Using poly(vinyl alcohol) (PVA) as a matrix, a novel light conversion composite film (ULC-CDs/PVA film) is constructed, featuring a surface microdome structure and abundant internal micronano scattering units. The film triple-regulates sunlight by converting ultraviolet, blue, and green light into red light, improving light extraction via surface microstructures, and homogenizing the spatial distribution of light internally. Spectral analysis showed a 12.4% increase in red-light (600–700 nm) photon flux density. Lettuce cultivation revealed 48.52% and 44.79% increases in fresh and dry weight vs pure PVA film, outperforming ordinary light conversion films by 15.90% and 14.34%. This work provides an innovative approach for high-performance, easily fabricated agricultural light-manipulation films, advancing green sustainable agriculture.
Wang et al. (Thu,) studied this question.