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Chemistry

The Chemistry of Smart Windows: Electrochromic Materials and Their Limitations

Quick fact

Tungsten trioxide (WO3) is the most common electrochromic material: when lithium ions and electrons are injected into its crystal lattice, it turns deep blue—a color change driven by the reduction of W6+ to W5+.

Why this is interesting

Imagine a window that dims at the flick of a switch, without curtains or blinds. How can a pane of glass change its color on command?