Solution-processed blue and blue-green phosphorescent organic light-emitting devices using iridium(III) complexes based on 9-(6-(4-phenyl-1H-1,2,3-triazol-1-yl)hexyl)-9H–carbazole ligand

• Three Ir (III) complexes emitting a pure-blue and blue-green were synthesized.
• All of complexes show excellent solubilities in common organic solvents.
• The host-free and doped phosphorescent organic light-emitting devices (PhOLEDs) were fabricated by spin-coating technology.

We have designed and successfully synthesized a series of solution-processed iridium(III) complexes of (Czphtz)2Ir(NˆN) bearing main ligand of 9-(6-(4-phenyl-1H-1,2,3 -triazol-1-yl)hexyl)-9H-carbazole, namely (Czphtz)2Ir(tfmptz) (Ir1) (Czphtz)2Ir(pptz) (Ir2) and (Czphtz)2Ir(fpptz) (Ir3). The hole-transporting carbazole and electron-transporting 1, 2, 4-trizole moieties were introduced through hexyl to balance carrier transport. The solution-processed host-free and doped phosphorescent organic light-emitting devices (PhOLEDs) were fabricated. Here, in this paper, we will present the photophysical, electrochemical properties and performances in devices of three complexes. All of them exhibit excellent solubilities in common organic solvents. The pure-blue-light-emitting Ir1 with the maximum emission peak at 463 nm was attained by varying the structure of ancillary ligand and have the CIE coordinate of (0.19, 0.18) in host-free PhOLED. Our work shows that the rational structure modification of ancillary ligand is an effective approach to develop deep blue-light-emitting materials.

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