Blue-Green-Yellow Color-Tunable Luminescence of Ce3+-, Tb3+-, and Mn2+-Codoped Sr3YNa(PO4)3F via Efficient Energy Transfer

Tunable blue-green-yellow emitting Sr3YNa(PO4)(3)F (SYNPF):Ce3+,Tb3+,Mn2+ phosphors have been prepared via a high temperature solid-state reaction method. The structural and luminescent properties, energy transfer (ET) mechanism, and thermal quenching of the samples are investigated in detail. The ET from Ce3+ to Tb3+ and Mn2+ in SYNPF is identified as the interaction of the electric dipole-quadrupole with ET efficiencies of 81.6% and 69.3%, respectively. The critical distances for Ce3+/Tb3+ and Ce3+/Mn2+ are calculated through the spectral overlap method to be 9.54 and 10.92 A. Under UV excitation, high-efficiency tunable blue-green-yellow emissions from Ce3+ to Tb3+ and Mn2+ can be obtained. Moreover, white light can also be achieved by adjusting the stoichiometry of Ce3+ and Mn2+ properly in the SYNPF phosphor. In addition, the temperature-dependent luminescence spectra exhibit good thermal quenching behaviors for the as-prepared phosphors. The above results suggest that SYNPF:Ce3+,Tb3+,Mn2+ phosphors can act as color tunable emission phosphors for potential applications in WLEDs.