A Dual‐Band Smart Window with Electrical‐Thermal Control for Visible and Near‐Infrared Light Modulation

Polymer dispersed liquid crystal (PDLC) exhibits excellent electro-optical properties for displays and smart windows but lacks sufficient near-infrared modulation for full solar management. Herein, a composite film with dual electrical-thermal control is designed for this purpose, which integrates PDLC film as an electrochromic layer and tungsten-doped vanadium dioxide (W/VO2) coating as a thermochromic layer. The composite film not only facilitates active regulation of visible light through electrical control, but also enables the modulation of near-infrared light via phase transitions in response to temperature changes. Furthermore, the diverse chemical bonding states within the PDLC film confer it with high emissivity in the atmospheric window (8-13 µm), demonstrating remarkable radiative cooling performance. The composite film achieves 13.90% solar modulation and 54.77% visible transmittance. MATLAB simulations reveal diurnal/nocturnal cooling powers of 59.55 and 109.01 W m-2 respectively. The solar simulator test demonstrates that the film achieves a significant temperature reduction of 12.5 °C relative to blank glass substrates, while the outdoor temperature test reveals that the film achieves a sub-ambient cooling performance of 2.3 °C below the surrounding air temperature. This innovative design represents a significant advancement in smart window technology, providing extensive light and thermal management capabilities.