A Multimodal Smart Window with Visible-NIR-LWIR Electro-Modulation for All Weather.

Abstract

Intelligent modulation of solar and thermal radiation for a smart window, including visible, near-infrared (NIR), and long-wave infrared (LWIR) spectral tri-bands (0.38-25 µm), to achieve indoor comfort and energy efficiency is a critical frontier in sustainable building design. However, independent regulations of multi-functional radiation of visible lighting, NIR heating, and LWIR radiative cooling for dynamic operational requirements and weather conditions are not fully solved. A PET/ITO/PB/Pt-NPs electrode featuring separated reactions of ion insertion and metal electrodeposition for dual-band modulation of visible and NIR via precise potential control, enabling multifunctionalities such as illumination, glare reduction, and privacy protection is proposed. A multimodal smart window of lighting-heating-emitting electro-modulation device (LHE-ED), wherein electrochromism and dynamic emittance are delicately manipulated for tri-band modulation, possesses six independent electro-driven states of multi-scene lighting-heating-emitting regulations for the first time, exhibiting excellent wavelength selectivity of △T_Vis= 41.24%, △T_NIR= 53.95%, and Δε_8-13 µm= 0.35. Building energy simulations demonstrate the LHE-ED outperforms commercial low-E glass across diverse climate zones, showcasing a maximum reduction in CO₂ emissions of 34.01 kg (m²year)^-1 and a decrease in heating, ventilation and air conditioning (HVAC) energy consumption by 34.18% annually, which paves the way for next-generation smart window in terms of energy saving and environmental preservation.