Photoluminescent properties of the terbium tris(acetylacetonate)tetrahydrated [Tb(acac)(3)(H2O)(4)], doped in the epoxy resin, in the solid state are reported. The polymeric Td(3+) system and the precursor terbium complex were characterized by elemental analysis, thermogravimetry, differential scanning calorimetry, and infrared and electronic spectroscopy. The excitation and emission spectra of the samples containing the Tb3+ complex doped diglycidyl epoxy resin were recorded at 298 and 77 K and exhibited the characteristic bands arising from the D-5(4) -->F-7(j) transitions (j = 6-0). The system shows an increase in the luminescence intensity with the increase in the Tb3+ complex in the 1, 5, and 10% concentrations due to the energy transfer from the polymer to the rare earth ion. On the other hand, the concentration quenching of luminescence of polymer doped with 15% of the Tb3+ complex was observed. The lifetime measurements (tau = 0.81, 0.80, 0.79, and 0.78 ms) decrease with the increase of Tb3+ -complex concentration (1, 5, 10, and 15%) doped in polymer. (C) 2004 Wiley Periodicals, Inc.