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.

An ultra high efficiency blue organic light-emitting device using wide-energy-gap electron-transport material containing 3,5-dipyridylphenyl moieties and blue phosphorescent emitter, FIrpic, was developed. The optimized device showed extremely high power efficiencies of 56 lm/W (53 cd/A) at 100 cd/m2 and 42 lm/W (46 cd/A) at 1000 cd/m2 without light outcoupling enhancement.

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