Optically Tunable Dynamic Windows based on Reversible Metal Electrodeposition

Optically tunable dynamic windows demonstrate many advantages over static lighting controls, such as blinds and shades. This technology allows users to control both heat and light flow into and out of buildings, without sacrificing their comfort or view. Dynamic windows based on reversible metal electrodeposition (RME) offer an exciting alternative to traditional electrochromic technologies. The usage of metals is an attractive option for electrochromic applications due to their high optical extinction coefficients, color neutral metallic state, chemical inertness, and high solubility. Our group has developed windows that demonstrate color-neutral, fast switching speeds (60%) over thousands of cycles with minimal degradation.1 These windows traditionally operate by the reversible, electrochemical movement of metallic ions from a transparent conducting electrode to a metal counter electrode through an electrolytic medium, usually consisting of Ag+, Bi3+, and/or Cu2+ ions.2 To enable uniform electrodeposition over a large working electrode area, transparent conducting oxides are modified with a self-assembled monolayer of Pt nanoparticles, which serves as an inert metal seed layer for metal nucleation and enhances electrodeposit morphology.3 Finally, this RME-based electrochromic mechanism can also be coupled with an ion-insertion based metal oxide counter electrode to increase the scalability and functionality of these windows.