Benzotriazole-containing donor-acceptor-acceptor type cyclometalated iridium(III) complex for solution-processed near-infrared polymer light emitting diodes

A novel near-infrared-emitting cyclometalated iridium(III) complex of (CH(3)OTPA-BTz-Iq)(2)Irpic containing benzotriazole unit with a donor-acceptor-acceptor (D-A-A) chromophore was synthesized and characterized. The optophysical, electrochemical and electroluminescent characteristics were primarily studied. A near-infrared emission peaked at 716 nm with a shoulder at 790 nm was exhibited in the (CH(3)OTPA-BTz-Iq)(2)Irpic dichloromethane solution at 298 K. In its optimized solution-processed polymer light-emitting diodes, a near-infrared electroluminescent emission peaked at 723 nm with a shoulder at 780 nm was observed with a maximum external quantum efficiency of 0.41% at 8.14 mA cm(-2). This work indicates that introducing appropriate D and A units to develop D-A-A structure is an efficient approach to construct near-infrared-emitting iridium(III) complex in the polymer light-emitting diodes with suppressive efficiency roll-off. (C) 2016 Elsevier Ltd. All rights reserved.