An energy-efficient and low-driving-voltage flexible smart window enhanced by POSS and CsxWO3

Abstract

Smart windows with controllable visible and near-infrared (NIR) light transmittance are highly desirable for energy-saving buildings. Herein, we propose a hybrid polymer dispersed liquid crystal (PDLC) film for smart window applications, which combines dopants of polyhedral oligomeric silsesquioxane (POSS) and cesium tungsten bronze (Cs x WO 3 ). The low surface free energy of POSS and NIR absorption of Cs x WO 3 endow the film with enhanced electro-optical performance (ultra-low driving voltages, high contrast ratio and low optical haze value) and maneuverable light modulation in visible and NIR range. A model house equipped with the proposed film as smart windows reveals its outstanding light shielding and temperature regulating abilities that the indoor temperature rises less than 5 o C after irradiation for 10min under the experimental conditions. The research provides new opportunities for further development of energy-efficient smart windows, especially for cooling energy saving in buildings. • A hybrid PDLC film is proposed that can modulate the light passage in both visible and near-infrared ranges. • Cs x WO 3 is introduced to absorb the near-infrared radiation. • Both Cs x WO 3 and POSS can enhance the electro-optical properties of PDLC. • The as-fabricated film can regulate indoor temperature if used as smart windows.