Electrophosphorescent Polyfluorenes Containing Osmium Complexes in the Conjugated Backbone

lectrophosphorescent copolymers have been synthesized by covalent bonding of a red-emitting osmium complex Os(bpftz), hich contains two 3-trifluoromethyl-5-(4-tert-butyl-2-pyridyl)triazolate (bpftz) cyclometalated ligands, into the backbone of a ipolar polyfluorene (PF) copolymer. Employing these copolymers, a highly efficient red polymer light-emitting diode has been ealised that has an external quantum efficiency of 18.0%, a maximum brightness of 38 000 cdm , and an emission centered at 18 nm. In addition, after incorporating appropriate amounts of green-emitting benzothiadiazole (BT) and the aforementioned s(bpftz) into the bipolar PF, an efficient white-light electroluminescent polymer is obtained that displays simultaneous blue, reen, and red emissions.