Abstract
The simultaneous realization of spectral selectivity and thermal management positions this innovation as a promising solution for modern greenhouse agriculture. This paper presents a polymer multilayer heterostructure greenhouse cladding material utilizing quarter-wave stacks (QWS) composed of polyethylene terephthalate (PET) and ethylene vinyl acetate copolymer (EVA). The structure comprises multiple EVA/PET quarter-wave stacks (QWS), with their geometric parameters optimized via a genetic algorithm (GA). Among them, the number of three quarter-wave stacks demonstrated excellent optical performance, the structure exhibits 97.95% average reflectivity in the green spectrum (520-580 nm), 88.16% average transmittance across visible wavelengths (400-520 nm & 580-780 nm), and 86.69% transmittance in near-infrared regions (780-2500 nm). Additionally, the film demonstrates 84.32% infrared blocking efficiency within the atmospheric window (7-14 μm). Notably, the designed structure demonstrates exceptional angular stability, with its reflectivity, transmittance, and infrared blocking rate showing minimal sensitivity to changes in incident light angle from 0 to 60°. Through leveraging the intrinsic absorption characteristics of polymeric materials and structural optimization of stacked multilayer structures, this structure exhibits infrared blocking capability and spectral modulation of sunlight wavelengths.
