Chinese scientists have turned copper–iodine cluster molecules into aggregated, highly luminescent nanostructures for use in light-emitting diodes (LEDs). The solid-state assemblies made of complexes of the copper–iodine cluster with phosphor–organic compounds as ligands are easily prepared, cheap, and can emit light in many colors, they report in the journal Angewandte Chemie. The nanoaggregates can be used as luminescent inks for invisible paintings and color coatings for LEDs.