Photodeposited Amorphous Oxide Films for Electrochromic Windows

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 photodeposition'' protocol that forms layers of electrochromically active metal oxides (e.g., WO3, Nb2O5, MoO3, and V2O5) on a timescale that rivals current industry practice. Indeed, the high-porosity WO3 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.