Efficient green-phosphorescent light-emitting diodes based on polymeric binary-host systems

► We fabricate the green PLEDs based on emission from Ir-complex doped into a polymeric binary host. ► Balanced transport of the holes and the electrons is realized using a conjugated polymer as the assisting host. ► Recombination zone is confined in the emissive layer by controlling the ratio of major host to assisting host.