By introducing 2-hydroxy-4-methoxy-benzophenone (UVA) and 1,10-phenanthroline (Phen) as the ligands, the ternary rare earth complex of Eu(UVA)₃Phen is synthesized, and it is characterized by elemental analysis, mass spectra (MS) and infrared (IR) and ultraviolet (UV) spectroscopy. Results show that the Eu(III) in complex emits strong red luminescence when it is excited by UV light, and it has higher sensitized luminescent efficiency and longer lifetime. The organic-inorganic thin film of complex Eu(UVA)₃Phen doped with nano-TiO₂is prepared, and the nano-TiO₂is used in the luminescence layer to change the luminescence property of Eu(UVA)₃Phen. It is found that there is an efficient energy transfer process between ligands and metal ions. Moreover, in an indium tin oxide (ITO)/poly(N-vinylcar-bazole) (PVK)/Eu(UVA)₃Phen/Al device, Eu³⁺can be excited by intramolecular ligand-to-metal energy transfer process. The main peak of emission at 613 nm is attributed to ⁵D₀→⁷F₂ transition of the Eu³⁺, and this process results in the enhanced red emission.