Fast Electrochromic Switching with Nanocrystalline Oxide Semiconductor Films

Forward biasing of transparent nanocrystalline (anatase) films in lithium ion‐containing organic electrolytes leads to rapid and reversible coloration due to electron accumulation and Li + intercalation in the anatase lattice. Absorption of >90% light throughout the visible and near IR can be switched on and off within a few seconds. The nanocrystalline morphology of the film plays a primary role in enhancing the electrochromic process.