Tunable luminescence and efficient energy transfer of Na2BaMgP2O8:Eu2+, Tb3+ phosphor for white light-emitting diodes

Na2BaMgP2O8:Eu2+, Tb3+ phosphors were synthesized via a solid-state reaction method and their phase structures were carefully studied by powder X-ray diffraction (XRD) and detailed Rietveld refinement, respectively. Upon excitation with a wavelength at 365 nm, the as-obtained phosphors exhibited two characteristic emission bands ascribed to the allowed 4f–5d transition of Eu2+ ion and the 5D4−7FJ (J= 6, 5, 4, 3) transition of Tb3+ ion, respectively. The emission intensities and lifetime values of Eu2+ emission for Na2+yBa0.99−2yMgP2O8:0.01Eu2+, yTb3+ phosphors decreased with increasing the concentration of Tb3+ ion, which strongly verified that an effective energy transfer occurred from Eu2+ to Tb3+ in Na2BaMgP2O8 host.