Synthesis, photoluminescence and electroluminescence of triphenylphosphine functionalized cyclometalated iridium(III) complexes

Abstract Three greenish-blue iridium (III) phosphorescent complexes with the molecular structure of [Ir(pppy) 2 (PPh 3 )L] (Hpppy = 2-(4-phenoxyphenyl)pyridine; L = Cl − , NCS − , NCO − ) were synthesized and characterized. Their photoluminescence spectra are significantly blue-shifted after introducing the strong-field ancillary ligand triphenylphosphine. These compounds exhibit emission peaks in the range of 474–479 nm in solutions at 298 K with quantum yields up to 0.33. The organic light-emitting diodes (OLEDs) were fabricated by thermal evaporation with complex 3 . The best OLED D3 was obtained with turn-on voltage of 4.3 V, maximum luminance of 11931 cd m −2 under 15.7 V, highest luminance efficiency ( η L ) as 16.6 cd A −1 , power efficiency ( η P ) as 12.2 lm W −1 and external quantum efficiency (EQE) as 5.6%.