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

Abstract

Tunable blue-green-yellow emitting Sr₃YNa(PO₄)₃F (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 Å. 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.