First colour-changing crystal glow could make for safer banknotes
New type of blue-to-orange luminescence discovered in organic material
A crystal that glows blue but changes colour to purple and then orange within a second could make banknotes more resistant to counterfeiting.
Fluorescence and phosphorescence – a type of delayed fluorescence – make materials glow a single colour. Now, a team of chemists in China has discovered the first single compound that has a colour-changing afterglow. Currently, to get a similar effect, researchers needed to build materials out of several different phosphorescent molecules.