Recently, Professor Chengyou Lin’s team from Mathematics and Physics published a research paper entitled "Synergistic solar spectrum and atmospheric window tunable VO₂/BaF₂ photonic structure for all-season smart thermal management". This research have created an innovative smart coating that automatically switches between cooling and heating modes based on the ambient temperature, offering a promising path to significant energy savings in buildings year-round. The study, published in the high-impact journal Optics Express, presents a breakthrough in dynamic thermal management technology.
While recent efforts have focused on developing dynamic thermal regulation, most prioritize modulating emissivity within the atmospheric window and often neglect the synergistic and active management of solar spectrum reflectance. To bridge this gap, Chengyou Lin’s team introduces a groundbreaking temperature-adaptive dual-mode smart radiative coating (DSRC). The innovation lies in its photonic structure composed of alternating vanadium dioxide (VO₂) and barium fluoride (BaF₂) layers, which is optimized using a genetic algorithm.
The genetically optimized 12-layer structure achieves remarkable modulation amplitudes: 35.6% in the solar spectrum and 69.9% within the atmospheric window. Specifically, in cooling mode, the coating exhibits high solar reflectance (52.3%) to minimize heat gain and a high selective emissivity (87.2%) for efficient radiative cooling. In heating mode, it switches to low solar reflectance (16.6%) to allow solar heating and low emissivity (17.3%) to suppress heat loss. Theoretical analyses confirm the structure's excellent angular insensitivity up to 75 degrees, which is crucial for real-world applications on building facades and roofs. Energy consumption simulations using EnergyPlus validate the DSRC's significant global energy-saving potential, with annual savings exceeding 60 MJ/m² in cold cities and a notable 5% reduction in warmer climates, proving its effectiveness for all-season thermal management across diverse climatic zones.
BUCT is the correspondence affiliation for this paper. Jiayu Liu (Master's candidate, Class of 2024) is the first author, and Professor Chengyou Lin is the corresponding author.
Paper link: https://doi.org/10.1364/OE.575223
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