Color tunable emission and energy transfer of Ce3+ and Tb3+ co-doped novel La6Sr4(SiO4)6F2 phosphors with apatite structure

Single-phase LaGSr(4)(SiO4)(6)F-2: Ce3+, Tb3+ samples with apatite-like structure have been synthesized via solid-state reaction method. The phase structure, luminescence properties, lifetime, the PL thermal stability, as well as the fluorescence decay curves of the samples were investigated to characterize the resulting samples. Effective energy transfer occurs from Ce3+ to Tb3+ in La6Sr4(SiO4)(6)F-2, which shows more intense Blue-Green light under UV light excitation. In addition, a possible mechanism of the energy-transfer from Ce3+ to Tb3+ ion is also proposed. The critical distance R-c of Ce3+ to Tb3+ ions in La5Sr4(SiO4)(6)F-2 host was calculated to be 11.878 angstrom. All the results indicate that La6Sr4(SiO4)(6)F-2:Ce3+, Tb3+ phosphors have potential applications to be used as near UV-convertible phosphors for white light-emitting diodes. (C) 2015 Elsevier Ltd. All rights reserved.