| 초록 |
Improvement of the stability of blue phosphorescent dopant material is one of the key factor for real application of organic light-emitting diodes. In particular, imidazole ligand of Ir(III) complex tend to play an important role in the stability of blue phosphorescence. In addition, N-heterocyclic carbene (NHC) ligands, or Ir(C∧C)3 known for thermodynamically stable. We report a study of the synthesis and photophysical properties of cyclometalated iridium complexes, some of which emit in the blue part of the spectrum, with N-heterocyclic Imidazolyl-carbene ligand has a stronger trans influence than (C∧N) ligand and, thus, imparts a greater ligand field strength. Both m-Ir(dmfmi)3 and f-Ir(dmfmi)3 complexes display strong metal-to-ligand-charge-transfer absorption transitions in the UV (λ = 270-370 nm) and phosphorescene in the blue region (E0-0 = 455 nm, 467 nm) at room temperature. |
