High-Efficiency Ag-In-S-Zn Quantum Dot/EVA Light-Conversion Films for Enhanced Plant Productivity

Developing novel materials to improve the global food supply is vital to combat hunger, achieve food security and promote sustainable agriculture. To address this issue, we employed red-emitting Ag-In-S-Zn (AISZ) quaternary quantum dots as light converters to fabricate AISZ QDs-loaded ethylene vinyl acetate (EVA) copolymers (AISZ/EVA) films to improve the light conditions for crop growth. The synthesis of AISZ QDs was optimized to achieve a high quantum yield (73%) and an emission band matching the absorption window of chlorophyll a and b. Using EVA resin as the matrix, efficient ultraviolet-to-red light-converting AISZ/EVA films with varying AISZ content were prepared by the solvent evaporation method. The fluorescence and transmittance of these light-conversion films along with a blank EVA control were characterized. Subsequent 28-day lettuce cultivation under controlled light illumination revealed that the 1.0 wt% AISZ/EVA film induced maximal growth enhancement. The fresh weight and dry weight were increased by 28.2% and 34.4% respectively, while the contents of total chlorophyll, chlorophyll a, chlorophyll b, carotenoid, soluble sugars and proteins were increased by 48.8%, 51.3%, 43.8%, 40.8%, 33.6%, and 37.2%, respectively. The results demonstrate that broad-emitting AISZ QDs served as efficient light converters to fabricate agricultural light-conversion films, highlighting their broad application prospects and promising commercial potential in controlled environment agriculture.