Enhanced luminescence properties and energy transfer in Ce3+ and Tb3+ co-doped NaCaBO3 phosphor

A series of color-tunable NaCaBO3: Ce3+, Tb3+ phosphors have been synthesized on the basis of efficient Ce3+→Tb3+ energy transfer. The photoluminescence emission and excitation spectra, the lifetime, and the effect of Tb3+ concentration are investigated in detail. The enhanced photoluminescence of Tb3+ with sharp emission lines could be obtained by the broad excitation band from the allowed 4f-5d absorption of Ce3+ ions. The intensity ratio of blue emission from Ce3+ and green emission from Tb3+ can be tuned by adjusting their concentrations. The energy transfer from Ce3+ to Tb3+ in NaCaBO3 was found to be an electric dipole-quadrupole interaction.