Enhancing Thermal Management Performance of Switchable Radiative Cooling Film by Multiple Wavelength Modulation

Abstract Passive radiative cooling (PRC) smart windows possess great potential in thermal management and reducing building energy consumption. Polymer‐dispersed liquid crystal (PDLC) films capable of modulating solar light transmittance are attractive in fabricating dynamic PRC smart windows. Considering the striking photothermal effect of near‐infrared (NIR) light, effectively NIR light shielding is of significance to improve the PRC performance. Herein, a general strategy to enhance thermal management performance of PRC PDLC film is achieved by synergistic modulation of mid‐infrared (MIR), NIR, and visible wavelength ranges. The SiO 2 doped fluorinated PDLC (FPDLC‐SiO 2 ) film exhibits MIR emissivity of 94.2% and achieves a temperature reduction of 8.7 °C compared to the FPDLC film. After further integration of poly‐(vinylpyrrolidone) (PVP) functionalized cesium tungsten bronze (Cs 0.33 WO 3 ) (CWO) nanoparticles, the nanoparticle‐doped (FPDLC‐SiO 2 ‐CWO) film demonstrates considerable NIR shielding ability (Δ T NIR = 21.9%), solar modulation efficiency (Δ T sol = 22.8%) and high MIR emissivity (over 94%) within the atmospheric window. Outdoor temperature decreases by 4.3 °C compared to the FPDLC‐SiO 2 film. Thanks to the multiple modulating functionalities, the FPDLC‐SiO 2 ‐CWO film achieves comprehensive thermal management capabilities and an HVAC energy saving efficiency of 35.52% compared to Low‐E glass, demonstrating a competent candidate in fabrication of energy‐saving smart windows.