Photodeposited Amorphous Oxide Films for Electrochromic Windows

Summary Electrochromic windows dynamically control solar irradiation to buildings by using transition-metal oxide films that change color in response to an electrical current. Electrochromic glass companies currently manufacture these films by physical deposition methods. We report here a solution-based protocol that forms layers of electrochromically active metal oxides (e.g., WO 3 , Nb 2 O 5 , MoO 3 , and V 2 O 5 ) on a timescale that rivals current industry practice. Indeed, the high-porosity WO 3 thin films prepared in this study displayed electrochromic performance parameters—including an optical modulation of 70% at 700 nm, colored and bleached interchange times on the order of seconds, and a coloration efficiency > 130 cm 2 /C—that are commensurate with the state of the art. This photodeposition method is scalable and therefore offers a potentially significant advancement for the large-scale deployment of electrochromic windows.