A Photo- and Electrochromic Dual-Responsive Smart Window for Full-Day Photothermal Management

Smart windows, which can intelligently regulate indoor temperature and improve living comfort provide a promising solution for reducing building energy consumption. Active and passive smart windows have their own advantages and disadvantages, yet it is a challenge to perfectly combine the two to achieve complementary advantages. In this work, photo- and electrical dual-responsive films containing WO₃, ethylene glycol (EG), and Ag are prepared, which can simultaneously realize photochromism and electrochromism. The EG and silver nanowires synergistically broaden the photoresponsive and electrochemical activities of the films and promote the electron transfer within the films and the interfacial ion transport. The WO₃-EG-Ag films exhibit an excellent dual-band (visible (vis) light and near-infrared (NIR) light) modulation capability (700 nm, 75.9%; 1000 nm, 76.7%; and 2000 nm, 69.2%), a fast responsive speed, and good reversibility. Finally, an all-solid-state photoelectric dual-responsive smart window with four operating modes (photochromic bright-cooling, photochromic dark-cooling, electrochromic bleaching, and photochromic self-bleaching) is assembled. The multiple operating modes can satisfy various individual demands of different people and also provide a more energy-saving and intelligent modulation of indoor temperature. This work provides a new direction for the development of next-generation smart windows.