W-VO2/Cs0.32WO3 Composite Flexible Films: Promoted Metal–Insulator Transition and Enhanced Near-Infrared Shielding

VO2 is a promising candidate for smart energy-saving windows because of its unique thermochromism but suffers from a high transition temperature of 68 °C and poor thermochromic performance near room temperature. We fabricated a W-VO2/Cs0.32WO3 (CWO) composite flexible film, which shows a low transition temperature of 31.1 °C (W-VO2/CWO = 1:1) and much enhanced near-infrared shielding performance. The optimal W-VO2 + 0.5CWO reaches a desired near-infrared shielding efficiency of 76.34%. A model-house test under simulated solar irradiation further signifies the excellence of the W-VO2 + 0.5CWO composite flexible film under ambient conditions. The robust performance is attributed to the synergetic effects between W-VO2 and Cs0.32WO3, among which the former possesses a low MIT transition temperature and the latter possesses photo-thermal performance.