Bifunctional Star‐Burst Amorphous Molecular Materials for OLEDs: Achieving Highly Efficient Solid‐State Luminescence and Carrier Transport Induced by Spontaneous Molecular Orientation

Bifunctional star-burst amorphous molecular materials displaying both efficient solid-state luminescence and high hole-transport properties are developed in this study. A high external electroluminescence quantum efficiency up to 5.9% is attained in OLEDs employing the developed amorphous materials. It is revealed that the spontaneous horizontal orientation of these light-emitting molecules in their molecular-condensed states leads to a remarkable enhancement of the electroluminescence efficiencies and carrier-transport properties.