New blue phosphorescent iridium complexes for OLEDs

— A new class of ligands for complexation with Ir(III) has been developed. Tris-homoleptic complexes derived from these ligands have been found to exhibit highly efficient blue phosphorescence with photoluminescent quantum yields in solution at room temperature of >0.9. These complexes have been applied as the emissive materials in OLEDs to give devices with efficiencies of up to 26 cd/A and an E.Q.E. of 1 7.4% at 1 mA/cm2.