Chemical Physics Letters, Vol.441, No.4-6, 277-281, 2007
Highly efficient saturated red electrophosphorescence from isoquinoline-based iridium complex containing triphenylamino units in polymer light-emitting devices
To obtain highly efficient saturated red-emitting polymer light-emitting devices, the opto-physical and electrophosphorescent properties of a novel isoquinoline-based iridium complex containing triphenylamino units were investigated. The devices using this iridium complex as a dopant and a blend of poly(9,9-dioctylfluorene) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole as a host matrix displayed bright saturated red emission at 637 nm with Commission Internationale de I'Eclairage coordinate of (0.64,0.31). The maximum external quantum efficiency of 10.8% photos/electron and current efficiency of 4.6 cd/A at 1.7 mA/cm(2), and the peak brightness of 5453 cd/m(2) at 228 mA/cm(2) were obtained in the device at 2% dopant concentration. (c) 2007 Elsevier B.V. All rights reserved.