Scientists from the independent Stanford Research Institute (SRI) have design a new efficient OLEDs using cavities - in fact the new OLEDs are five times as efficient as standard OLED (i.e. five times as much light per watt consumed). The green COLEDs (Cavity-OLEDs) achieved 80 lumens per watt, and the blue ones 30lumens per watt. 

They used Polymer-OLEDs provided by SDK, and the team says that they are ready to make white light (by mixing red, green and blue OLEDs), and estimate that products based on this new tech could arrive as soon as next year.