Mesophase silica thin film doped with in-situ formed ternary Eu complex was synthesized by adding ligands (DBM = dibenzoylmethane, phen = 1,10-phenanthroline), Eu ions (EUCl3 center dot 6H20), and Pluronic P123 triblock copolymer into hydrolyzed tetramethoxysilane (TMOS). The structure of this inorganic/organic film was characterized as a 2d-hexagonal structure by X-ray diffraction (XRD) and TEM analysis. The excitation spectra (lambda(em) = 612 nm) and emission spectra (A,,, = 325 nm) indicated that the ternary complex, Eu-DBM-phen, was formed in-situ during the formation of the film. The mesophase silica thin film doped with the in-situ formed Eu complex showed a higher quantum efficiency compared to a pure Eu(DBM)(3)phen complex and a mesophase silica thin film doped with in-situ formed binary Eu-phen complex. (c) 2007 Elsevier B.V. All rights reserved.