Induced Aggregation of AIE‐Active Mono‐Cyclometalated Ir(III) Complex into Supramolecular Branched Wires for Light‐Emitting Diodes

Aggregation‐induced emission (AIE) is commonly observed in irregular bulk form. Herein, unique aggregation properties of an AIE‐active complex into branched supramolecular wires are reported for the first time. Mono‐cyclometalated Ir(III) complex shows in‐plane J‐aggregation at the air–water interface owing to the restriction of intramolecular vibration of bidentate phenylpyridinato and intramolecular rotations of monodentate triphenylphosphine ligands at air–water interface. As a consequence, a large enhancement of luminescence comparable to the solid state is obtained from the monolayers of supramolecular wires. This unique feature is utilized for the fabrication of light‐emitting diodes with low threshold voltage using supramolecular wires as active layer. This study opens up the need of ordered assembly of AIE complexes to achieve optimal luminescence characteristics.