Synthetic and electroluminescent properties of two novel europium complexes with benzimidazole derivatives as second ligands

With two second ligands, 2-(2-pyridyl)benzimidazole (HPBM) and 1-ethyl-2-(2-pyridyl)benzimidazole (EPBM). two novel europium complexes, Eu(TTA)(3)HPBM and Eu(TTA)(3)EPBM (TTA, thenoyltrifluoroacetonato) were synthesized and applied to organic electroluminescent (EL) devices as the emitting materials. The devices of ITO/TPD/Eu(TTA)(3)HPBM (or Eu(TTA)(3)EPBM)/AlQ/Al were fabricated. The EL devices emit red light originating from these two europium complexes. The EL brightness of Eu(TTA)(3)EPBM is much higher than that of Eu(TTA)(3)HPBM. For Eu(TTA)(3)EPBM, a maximum luminance of 36.6 cd/m(2) was achieved at 21 V. (C) 2002 Elsevier Science B.V. All rights reserved.