Efficiency breakthrough for radical LEDs

Light-emitting devices made from organic materials have the potential to be thin, flexible and lightweight, and might therefore be used in a variety of applications — including foldable display screens, ‘smart’ wallpaper incorporating digital devices, and windows that could be converted into illuminated panels at the flick of a switch. The efficiencies of other types of OLED are generally limited by quantum-mechanical effects, but radical-based OLEDs (ROLEDs) don’t have this constraint, owing to the electronic state of the radicals. The authors’ ROLEDs have the highest emission efficiency obtained so far among LEDs that emit light in the deep-red and infrared regions of the electro-magnetic spectrum.