a fluorine functionalized 1,10-phenanthroline ligand, 3-ethyl-2-(2-fluorophenyl) imidazo[4,5-f]1,10-phenanthroline(EFPIP) and the corresponding red-emitting Eu(ΙΙΙ) complex Eu(DBM)3(EFPIP) (DBM = dibenzoylmethanate) was synthesized and the photophysical properties and electroluminescent(EL) performances were researched. When Eu(DBM)3(EFPIP) was used as emitting material in organic devices, the maximum efficiency and luminance of red emission achieved from the EL device with the configuration of ITO/m-MTDATA (30 nm)/NPB (20 nm)/ x wt% Eu(DBM)3(EFPIP) doped in CBP (30 nm)/Bphen (20 nm)/Alq3 (20 nm)/LiF (0.8 nm)/Al were 3.6 cd/A and 563 cd/m2, respectively. Compared with the previously reported devices based on methyl or chlorine substitute Eu(ΙΙΙ) complexes, the EL performances of the device using Eu(DBM)3(EFPIP) as an emitter was significantly enhanced due to the introduction of fluorine.
Luminescent Properties of Europium Complex Enhanced by Replacement of Water Molecules by 2,2'-Bipyridine