Temperature-adaptive smart windows with passive transmittance and radiative cooling regulation.

The integration of radiative cooling and thermochromic technology methods, as a passive-regulating and environmental-friendly thermal management strategy, is highly desirable in reshaping the global energy landscape. However, the multispectral modulation based on the integration methods is challenging due to their low luminous transmissive and emissivity. Herein, we propose a transmittance passive-regulating radiative cooling thermochromic(T-PRCT) smart window using nano-storm technology based on phase change material, capable of adjusting its thermal management performance according to external temperature changes. With achieved luminous transmittance of 43.11% and solar modulation efficiency of 10.64% (from 50.90% to 40.26%) respectively, along with an emissivity positive modulation(∆ε) of 0.23 (from 0.71 to 0.94) in atmospheric windows, the cooling efficiency can be up to 56.52% improvement. The design is applicable in varying climates and holds the capacity to curtail the building's annual energy-saving by over 14.74%. Consequently, the simple and scalable approach-integrated phase change material may provide a promising way to expanding the multispectral manipulation ability of optical systems. Scheme 1. Illustrations of working principle of T-PRCT window in hot (up) and cool day (down). The pink arrows indicate the solar, the orange arrows indicate the Tsol and the red arrows represent heat radiation. On hot days, the NIR is blocked and luminous transmits through the window with thermal radiation enhanced. On cool days, the solar enter the room. Heat radiation is suppressed to minimize heat loss. [Display omitted] • A temperature-adaptive smart windows with passive transmittance and radiative cooling regulation without metal layer. • The emissivity was reversed due to the multiple light scattering effect at metal state of the W-VO 2. • High luminous transmittance(43.11%) and emissivity(0.94/90 °C) can be achieved through a W-doped VO 2 @SiO 2 core-shell structure. • The temperature-adaptive smart window has the ability to curtail the building's annual energy-saving more than low-E glass. [ABSTRACT FROM AUTHOR]