Gold flakes glow when they are bathed in light and now we know how

Wafer-thin gold flakes emit a faint glimmer after being hit with a laser, and researchers are starting to understand why. Gold flakes are widely used in nanoscience, so the new knowledge should give scientists more control over chemical reactions useful for energy storage and catalysis.

Gold owes its dazzling lustre to the way it reflects light. But ultra-thin gold flakes can also generate and emit their own light in a process called photoluminescence. This begins when the gold is …