Highly Efficient Organic Blue‐and White‐Light‐Emitting Devices Having a Carrier‐ and Exciton‐Confining Structure for Reduced Efficiency Roll‐Off

Highly efficient blue and white OLEDs with reduced efficiency roll-off based on a carrier- and exciton-confining structure are developed. Record power efficiencies of 46 and 44 lm W−1 and an external quantum efficiency of 25% at the illumination-relevant luminance of 1000 cd m−2 are achieved for the blue and white OLEDs, respectively, without the use of any outcoupling techniques.