Efficient Solution-Processed Nondoped Deep-Blue Organic Light-Emitting Diodes Based on Fluorene-Bridged Anthracene Derivatives Appended with Charge Transport Moieties

A series of fluorene-bridged anthracene derivatives appended with different charge transport moieties were synthesized, and their thermal, photophysical, and electrochemical properties were investigated. By the introduction of fluorene between two anthracene units as well as peripheral functional aryl substituents, the sophisticated compounds show a decreased tendency to crystallize and have high glass transition temperatures ranging from 165 to 229 °C. The theoretical calculations reveal that the four self-hosted blue emitters possess noncoplanar structure to suppress the intermolecular interaction in films. Solution-processed small-molecular organic light-emitting diodes featuring 1 as the emitter achieve a maximum current efficiency of 2.0 cd A –1 with Commisssion Internationale de L’Eclairage (CIE) coordinates of (0.15, 0.13), which are very close to the National Television Standards Committee’s blue standard. A facile strategy to design solution-processable highly emissive anthracene derivatives for nondoped deep-blue electroluminescence by incorporating π-conjugated bridge and bipolar charge transport periphery is demonstrated.