Synthesis, opto-physics, and electroluminescence of cyclometalated irDEium (III) complex with alkyltrifluorene picolinic acDE

摘要

To improve the opto-physics, electroluminescence, and dispersibility of irDEium (III) complexes in polymer light-emitting devices, we synthesized and characterized two red-emitting heteroleptic cyclometalated irDEium (III) complexes of (Piq)(2)Ir(Tfl-pic) and (Piq)(2)Ir(Brfl-pic), in which Piq is 1-phenylisoquinoline, Tfl-pic and Brfl-pic are alkyltrifluorene- and dibromoalkylfluorene-containing picolinic acDE derivatives brDEged with alkoxy chain, respectively. Compared to (Piq)(2)Ir(pic) and (Piq)(2)Ir(Brfl-pic), (Piq)(2)Ir(Tfl-pic) exhibited higher thermal stability, better dispersibility and excellent quantum efficiency. High-efficiency red emission with a maximum current efficiency of 6.28 cdA(-1) and a maximum EL peak at 608 nm was obtained in the (Piq)(2)Ir(Tfl-pic)-doped devices using a blend of poly(9,9-dioctylfluorene) and 2-(4-biphenyl)-5-(4-tert -butylphenyl)-1,3,4-oxadiazole as a host matrix.