Synthesis and photophysical characterization of orange-emitting iridium(III) complexes containing benzothiazole ligand

Two novel iridium(III) (Ir(III)) complexes (dmabt)2Ir(acac) and (dpabt)2Ir(acac)(dmabt, 4-N,N-dimethylbenzenamineyl-2-benzo[d]thiazole; dpabt, 4-N,N-diphenylbenzenamineyl-2-benzo[d]thiazole; acac, acetylacetone) were synthesized and structurally characterized by NMR and mass spectrometry. The organic light-emitting diodes based on these complexes with the structure of ITO/m-MTDATA (10 nm)/NPB (20 nm)/CBP: Ir-complex (X%, 30 nm)/BCP (10 nm)/Alq3 (30 nm)/LiF (1 nm)/Al (100 nm) were fabricated. The device based on (dmabt)2Ir(acac) exhibited a maximum efficiency of 19.5 cd/A, a luminance of 15802 cd/cm2; and the device based on (dpabt)2Ir(acac) showed a maximum efficiency of 14.8 cd/A, a luminance of 11334 cd/cm2. Both devices displayed orange emissions and the corresponding Commission International de L’Eclairage (CIE) coordinates (1931) were (0.517, 0.481) and (0.557, 0.443), respectively.