Submicron Metasurface Reconfigured Multiband Smart Windows
Guanya Wang, Shancheng Wang, Bin Li, Xinyi Tian, Rong Liu, Jian Chen, Zhendong Dai, Shouqin Tian, Yi LongABSTRACT
Improving the energy efficiency of windows holds great significance for global carbon emission reduction. Multiband thermochromic smart windows (MTSWs) based on vanadium dioxide (VO 2 ), which dynamically modulate indoor solar irradiation (Δ T sol ) and outdoor long‐wave heat radiation (Δ ε LWIR ), offer a promising pathway for passive building thermoregulation. However, limited by the intrinsic properties of materials and the complexity of multilayer architectures, current designs severely jeopardize luminous transmittance ( T lum ) when pursuing high regulation capabilities. Given that artificial lighting constitutes 17.4% of building electricity consumption, this trade‐off critically compromises their net energy‐saving potential. Here, we propose a submicron metasurface reconfigured MTSW (Meta‐MTSW), fabricated via template‐assisted nanoimprinting, to break this bottleneck by coupling subwavelength nanostructures. Theoretical and experimental analyses reveal that the gradient profile acts as an impedance‐matching layer to minimize the Fresnel reflection in the visible and near‐infrared bands without disrupting the Fabry−Perot resonance in the long‐wave infrared band. Consequently, Meta‐MTSWs enhance T lum by 60.1% compared to the state‐of‐the‐art reference, while maintaining uncompromised Δ T sol and Δ ε LWIR . Comprehensive building energy simulations across eight climate zones demonstrate that Meta‐MTSWs yield substantial reductions in annual energy consumption by up to 15.9% compared to commercial low‐emissivity glass, validating this nanoengineering paradigm as a compelling pathway for climate‐adaptive sustainable architecture.