Novel Tetradentate Platinum(Ⅱ) Complexes and Their Use in Blue Phosphorescent Organic Light-Emitting Diodes

摘要

Although the remarkable growth of the organic light-emitting diode (OLED)industry has occurred via continuous, extensive efforts toward the utilizationof various organometallic luminophores as phosphorescent emitters, thedevelopment of blue phosphorescent emitters with improved efficiencies andhigh electrochemical stabilities is essential. To this end, herein the preparationof two novel tetradentate Pt(Ⅱ) complexes, Pt1 and Pt2, and their applicationas blue phosphorescent emitters in OLED devices is described. Bothcomplexes exhibit intense bluish emission in the solution and solid states.In addition, these complexes display very high phosphorescent quantumefficiencies (>89) with host materials and thermal stabilities (>390℃).Multilayer phosphorescent OLEDs containing Pt1 or Pt2 as emitters withmCBP/CNmCBP-CN mixed-host systems are fabricated. The devices exhibitoutstanding performances, including high current, power, external efficiencies,and potential device lifetime in addition to sky-blue (Pt1) or blue (Pt2)electroluminescence. These results clearly suggest that these tetradentatePt(II) dopants are promising candidates as highly efficient, stable blue phosphorescentemitters in OLEDs.