By stacking multiple colours of organic light-emitting diodes (OLEDs) together, researchers have fabricated a device that generates white light directly with 1000 cd/m2 brightness and 35 lm/W power efficiency. The devices have demonstrated 100,000 hour lifetimes in testing
OLEDs have not yet entered the lighting market, but that will probably change soon. Already most of the big players in the field are preparing for OLEDs to become ‘the next big thing.’ However, several critical problems need to be solved before widespread use for lighting becomes feasible. Specifically, the lifetimes, power efficiencies, reliability, and cost-effectiveness of white OLEDs must be able to compete with existing lighting technologies.
There are many different approaches to generating white light with OLEDs..
In contrast to inorganic LEDs, light of different colours can be generated inside an OLED by mixing different organic emitter molecules in the emission zone