Oxadiazole-Functionalized Europium(III) β-Diketonate Complex for Efficient Red Electroluminescence

An oxadiazole-functionalized europium β-diketonate complex [(OXD−PyBM)Eu(DBM)3] was designed and synthesized. The double-layer device with the configuration of ITO/TPD (40 nm)/(OXD−PyBM)Eu(DBM)3 (50 nm)/LiF (1 nm)/Al (200 nm) emitted pure bright red light with an emission at 612 nm. An external quantum efficiency of 1.7% and luminance efficiency of 1.9 cd/A at the current density of 3 mA/cm2 were obtained and were significantly improved, in comparison with those of the europium complex without the electron-transporting moiety.