Phosphoryl/Sulfonyl-Substituted Iridium Complexes as Blue Phosphorescent Emitters for Single-Layer Blue and White Organic Light-Emitting Diodes by Solution Process

Two new phosphoryl/sulfonyl-substituted iridium complexes, POFIrpic and SOFIrpic, have been designed and synthesized on the basis of the structural frame of sky-blue FIrpic. The introduction of phosphoryl/sulfonyl moieties into the 5′-position of phenyl ring makes the emission peak blue-shift to the 460 nm, simultaneously the compounds maintain high photoluminescence quantum yields (PLQYs) of about 50% in solution. Single-layer blue and white polymer organic light-emitting diodes by full solution-process were fabricated with the following configuration: ITO/PEDOT:PSS/PVK:OXD-7:dopants/CsF/Al. The blue device based on POFIrpic shows a maximum current efficiency of 11.1 cd A –1, a maximum external quantum efficiency of 7.1%, which are the highest ever reported for blue PhOLEDs by full solution process. The white device with POFIrpic as blue component reveals a maximum current efficiency of 25 cd A –1, a maximum external quantum efficiency of 15%, and a good CRI value of 82.