Self-adaptive energy-efficient windows with enhanced synergistic regulation of broadband infrared thermal radiation

Abstract

Effective management of both near-infrared (NIR) radiation and long-wavelength infrared (LWIR) thermal emission through window design holds tremendous promise for achieving carbon neutrality in the building sector. Compared to the traditional static low emissivity (Low-E) and solar regulating windows, emerging emissivity-altering windows can better adapt to varied weather. However, dynamic windows with self-adaptive solar radiation and emissivity control have long been challenging, primarily due to the intricate broadband spectrum manipulation requiring sophisticated material design. Herein, by employing the NIR transparent hydrogen-doped In2O3 (IHO) as a function layer (ε = 0.13, TNIR = 79.8 %), we present a broadband self-adaptive radiative thermal management (SRTM) window based on Fabry-Perot resonator. Compared to the common tin-indium oxide (ITO)-based counterpart, the IHO-based SRTM window shows a 70 % enhancement in NIR power regulation ability (10.9 %) with remaining emissivity regulation ability (0.26). It contributes significantly to energy conservation offering an annual energy saving and equivalent CO2 emissions reduction of up to 20 % (411 MJ·m−2) and 244 tons/yr, compared to traditional Low-E windows globally.