Color-tunable luminescence and energy transfer properties of Ba₃Y_1-xM_x(PO₄)₃ (M= Dy, Tm) phosphor with UV light excitation

A series of powder samples Ba₃Y_1-x-y(PO₄)₃:xTm³⁺-yDy³⁺ were synthesized by a standard solid state reaction. The structure of the compound was confirmed by XRD technique. The concentration quenching of Ba₃Y_1-x-y(PO₄)₃:xTm³⁺ was investigated in detail. The photoluminescence emission and decay measurements of Ba₃Y_1-x-y(PO₄)₃:xTm³⁺-yDy³⁺ revealed the energy transfer from Tm³⁺ to Dy³⁺ ions under 359 nm excitation. The energy transfer mechanism from Tm³⁺ to Dy³⁺ in Ba₃Y_1-x-y(PO₄)₃:xTm³⁺-yDy³⁺ phosphors was confirmed. The emitting colors could be tuned form blue to white and then to yellow through adjusting the concentration of Tm³⁺/Dy³⁺ ions. Under 353 nm excitation, the corresponding color coordinates of the Ba₃Y_0.93(PO₄)₃:0.03Tm³⁺−0.04Dy³⁺ phosphors is very close to the stand white color chromaticity coordinates (x=0.33, y=0.33).