Optimizing spectral quality with quantum dots to enhance crop yield in controlled environments

Bioregenerative life-support systems (BLSS) involving plants will be required to realize self-sustaining human settlements beyond Earth. To improve the plant photosynthetic efficiency of BLSS, the quality of the solar spectrum can be modified by low-weight, luminescent films. CuInS2/ZnS quantum dot (QD) films with peak emissions of 600 and 660 nm were used to redshift ultraviolet and blue photons to increase biomass accumulation in red romaine lettuce. All plant growth parameters except spectral quality were held constant between three equivalent plant environments. Compared with the control film, lettuce grown under the 600 and 660 nm-emitting QD films increased edible dry mass (13% and 9%), edible fresh mass (11% each), and total leaf area (8% and 13%), respectively. The spectral modifications by the QD films improved photosynthetic efficiency in lettuce and could be used to enhance crop productivity in greenhouses on Earth or on crewed space missions.