A terbium (III) complex with triphenylamine-functionalized ligand for organic electroluminescent device

摘要

A novel ligand, 4-diphenylamino-benzoic acid (HDPAB), and the corresponding Tb (III) complex, Tb (DPAB)3 which can be dissolved easily in organic solvents were synthesized and characterized. Organic electroluminescent (EL) device with a structure of indium tin oxide (ITO)/poly(N-vinylcarbazole) (PVK): Tb (DPAB)3 (50 wt , 80 nm)/1,3,5-tris-(N-phenylbenzimidazol-2-yl)benzene (TPBI)(30 nm)/tri(8-hydroxyquinoline)aluminum(AlQ)(20 nm)/LiF(1 nm)/Al (150 nm) in which Tb (DPAB)3 acted as an emitter were fabricated. The maximum luminance of 230 cd m(-2) at 20 V and the maximum efficiency of 0.62 cd A(-1) were obtained due to the introduction of hole-transporting group, representing the best result to date among Tb (III) carboxylate complexes based EL devices. These results indicate that modifications of rare earth complexes are a promising way to improve the properties of EL devices. (c) 2007 Elsevier B.V. All rights reserved.