Abstract In this paper, silica-based transparent organic–inorganic hybrid materials were prepared via the sol–gel process. Tetraethoxysilane (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS) were used as the inorganic and organic precursors, respectively. The terbium complex, Tb(Tfacac) 3phen (Tfacac=1,1,1-trifluoroacetylacetone, phen=1, 10-phenanthroline) was successfully doped into organically modified silicate (ormosil) matrix derived from TEOS and GPTMS, and the luminescent properties of the resultant ormosil composite phosphors [ormosil/Tb(Tfacac) 3phen] were investigated compared with those of the Tb(Tfacac) 3phen incorporated into SiO 2 derived from TEOS (labeled as silica/Tb(Tfacac) 3phen). Both kinds of the materials show the characteristic green emission of Tb 3+ ion. The luminescence behavior of the resultant composite products was dependent on the matrix composition. The optimized lanthanide complex concentration in the ormosil/Tb(Tfacac) 3phen was increased compared with in silica/Tb(Tfacac) 3phen. Furthermore, the lifetime of Tb 3+ in Tb(Tfacac) 3phen, silica/Tb(Tfacac) 3phen and ormosil/Tb(Tfacac) 3phen follows the sequence: ormosil/Tb(Tfacac) 3phen>silica/Tb(Tfacac) 3phen>pure Tb(Tfacac) 3phen.