Korean and Spanish scientists have pulled off a neat trick–they’ve discovered a new molecule that will make white LEDs pretty much a certainty for replacing compact fluorescent bulbs. The invention replaces two previous molecules with a single one.
White LEDs and OLEDs typically achieve their color by having several different light emitting molecules in action at once, each sending out its own color that combines with the others to create an overall white light. It’s a technology that took years to perfect, as both semiconductor and chemistry-based advances made new colors possible–remember when all there were were red ones, dotting every VCR and TV set around?
Previous attempts to mix two different color light-emitting molecules were limited by energy leakages between the branches of the molecules, which often meant one color was brighter than the other, and the result was an off-white color–some of the LED bulbs in my bathroom shed a distinctly orange cast, and others a blue one, for example. But the new invention has just a single light-emitting unit in its chemical make-up, which gets around this problem. Instead it works by sometimes emitting blue light, and sometimes emitting white light. With millions of molecules making this switch at any one moment, the resulting light is white.
This means that LEDs using the new technology shed a much more natural light, which is a criticism often aimed at LED bulbs. The technology also has the potential to be cheaper, once the efficiency of the light production has been improved. And that pretty much guarantees that white LEDs will assume the role of home lighting and general area lighting, bringing the eco-benefit of increased efficiency over both incandescent bulbs and CFLs.