Small efficiency roll-off in electrophosphorescent devices based on a novel rhenium emitter

• 作 者: Xiao Li Dongyu Zhang Guoyong Xiao Haijun Chi Yan Dong Zhizhi Hu Wenlian Li
• 机 构: SchoolofChemicalEngineering,UniversityofScienceandTechnologyLiaoning,Anshan114051,People'sRepublico
• 出 处: 第12届全国发光学学术会议暨发光学相关产业研讨会
• 发表日期: 2010年11期

　　A novel rhenium complex, i.e., Re-APPP, (APPP, 2,3-acenaphtho[1,2-b]pyrazino [2,3-f][1,10]phenanthroline) was designed, synthesized and characterized by 1H NMR and Mass spectroscopy.The photophysical properties of this complex were studied.The emission bands centered at ca.326, 366 and 450nm of Re-APPP were attributed to the ligand-centered π →π* transition and the metal-to-ligand charge transfer dπ(Re)→π*(APPP) (1MLCT and 3MLCT) transition, respectively.The excited-state lifetime of Re-APPP with 1.2μs was also analyzed.The organic light-emitting diodes (OLEDs) using Re-APPP as a dopant emitter with the structures of ITO/m-MTDATA(10nm)/NPB(20nm)/CBP: X wt.% Re-APPP(30nm)/BCP(10nm)/Alq3(30nm) /LiF(1nm)/Al(100nm) were fabricated and a broad electroluminescent peak at 585nm was observed.Remarkably, the devices exhibited very small efficiency roll-off with only ca.50%, which was the best among the reported Re(Ⅰ) based devices.The possible reasons for such excellent performances were also investigated.