High-efficiency saturated red emission from binuclear cyclo-metalated platinum complex containing 5-（4-octyloxyphenyl）-1,3,4-oxadiazole-2-thiol ancillary ligand in PLEDs

A novel red-emitting binuclear platinum complex （dfppy）zPtz（C~OXT）z was synthesized and characterized, in which dfppy represents 2-（4＇,6＇-difluorophenyl）pyridinato unit and CsOXT is abbreviated for 5-（4-octyloxyphenyl）-1,3,4-oxadiazole-2-thiol as a bridging ancillary ligand. Its photophysical, electrochemical and electroluminescent characteristics were primarily studied. The made single-emissive-layer （SEL） polymer light-emitting devices using （dfppy）2Ptz（CsOXT）2 as emitter exhibited a satu- rated red emission peaked at 620 nm. The best device performances were obtained in the device at 8 wt% dopant concentration, with a maximum external quantum efficiency of 8.4%, a current efficiency of 4.2 cd/A and brightness of 3228 cd/m~. This work provides an effective approach to obtain high-efficiency red emission through construction of new binuclear platinum complex and its doped SEL devices.