To obtain the rule of influence of donor(D)-acceptor(A) structures attached into iridium complexes by a non-conjugated connection on the optoelectronic properties of their iridium complexes, a series of cyclometalated iridium(III) complexes with D-A structures containing carbazole and oxadiazole units were synthesized, and their optoelectronic properties were also investigated. The results show that these D-A based iridium complexes exhibited better thermal stability, more intense red-shifted UV absorption peak, higher emission quantum yield, as well as improved electrochemical and electroluminescence properties, compared with the classical di[2-(4 ,6 -diflurophenyl) pyridine-C²,N ](piconilic acid) iridium(III). Their maximum UV absorption and emission peaks located respectively at around 297 nm and 476 nm in dichloromethane, but the maximum emission peak shifted to (520±6) nm in their neat films. In these iridium complexes, (t-Bu-OXDdfppy)₂Ir(pic-Cz) presented a current efficiency of 2.5 cd/A in its doped polymer light-emitting devices, which is higher than that of the (dfppy)₂Ir(pic) doped device with the same device configuration.

Key words: cyclometalated iridium complex, donor-acceptor, synthesis, photoelectronic property, polymer light-emitting device