A temperature and electric field responsive flexible hybrid composite film containing CsxWO3 nanocrystals for energy efficient smart window

Smart windows, which can dynamically adjust solar radiation transmittance in accordance with people's requirements and the ambient temperatures, play an important role in solving the problem of energy consumption in buildings. However, the polymer-dispersed liquid crystals, one of the representatives of smart window, are generally only optically modulated in the visible region, but not sensitive to the near-infrared light region, which has a thermal effect. Herein, we reported a hybrid composite film with both light and heat management by introducing inorganic CsxWO3 nanocrystals into the organic PDLC system. The optical modulation effect of this film covers the solar irradiation in the range of 400-2500 nm, including visible light and invisible near-infrared light. In addition, the optical state of the film could be switched between transparent and opaque by electric field when the temperature was below the phase transition temperature (45 degrees C), while the film remained transparent when the temperature was above the phase transition temperature. Simultaneously, about 60% to 95% of the NIR irradiation range of 800-2500 nm can be screened under the variations of the thermal and electric fields due to the local surface plasmon resonance of the CsxWO3 nanocrystals. The thermal insulation effect demonstrated by the model house fitted with this film gives it the potential to be used in energy-efficient smart windows.