The promise of an organic light emitting diode (OLED) is that it will eventually become a super-efficient, low-cost light source to replace our archaic dependency on incandescent bulbs and those oh-so-yesterday LCD TVs, among other things. Ultimately, OLEDs were expected to possibly supplant the already efficient LEDs, too. That is, until a couple of Utah researchers revealed there could be some "complications." It seems we were half-right.
The issue lies with the theoretical efficiency ceiling assigned to OLEDs in a 2001 paper published in Nature. That paper suggested OLEDs would eventually be capable of converting 41 to 63% of electricity passed through them into light. The current ceiling for OLEDs is 25% efficiency, and that is where the most recent research out of Utah says it will probably stay.
In the end, all this talk of percentages and efficiency might be moot, especially considering OLEDs main purpose will be to replace LCD screens, not illuminate rooms or serve as the running lights on an Audi A5. OLEDs are also a superior light source for flexible materials, so there's that, too. They just won't be lighting up any kitchens or anything like that anytime soon.