Dual-band electrochromic smart windows towards building energy conservation

Windows play significant roles in today's buildings, allowing outside view and providing occupants with daylight. However, windows are also often considered to be one of the weakest building components with respect to high thermal losses, and therefore significant energy consumption is required to maintain a comfortable indoor environment. In comparison to traditional windows, dual-band electrochromic smart windows have the ability to independently regulate the transmittance of visible and near-infrared light, which will contribute to the optimal energy efficiency of building heating, cooling and artificial lighting systems. In this review, the basic concept, device structure, working principle and key factors affecting energy saving of dual-band electrochromism are briefly introduced. Next, recent advances in dual-band electrochromic materials including inorganic, organic, and composite materials are summarized in detail, with emphasis on device fabrication and applications in building energy conservation. Finally, some challenges and prospects of dual band electrochromic smart windows are introduced. It is anticipated that this review will provide new insights into the development of high-performance dual-band electrochromic smart windows toward applications in the green buildings.