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

A novel red-emitting binuclear platinum complex (dfppy)₂Pt₂(C₈OXT)₂ was synthesized and characterized, in which dfppy represents 2-(4′,6′-difluorophenyl)pyridinato unit and C₈OXT 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)₂Pt₂(C₈OXT)₂ as emitter exhibited a saturated 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/m². This work provides an effective approach to obtain high-efficiency red emission through construction of new binuclear platinum complex and its doped SEL devices.