Preparation, luminescence properties, and energy transfer of color-tunable whitlockite-type Ca₈MgBi(PO₄)₇:Ce³⁺, Tb³⁺ phosphors

A series of Ca8MgBi(PO4)(7):Ce3+, Tb3+ phosphors with whitlockite-type structure and adjustable color were prepared by the high- temperature solid- phase method. The phase composition, microstructure, and luminescence properties were studied by X-ray powder diffraction (XRD), scanning electron microscope (SEM), and fluorescence spectroscopy. X- ray diffraction results confirmed doping a small amount of Ce3+ and Tb3+ did not change the crystal structure of the matrix. The energy transfer between Ce3+-Tb3+ was confirmed by the fluorescence spectrum and fluorescence lifetime curve. The energy transfer mechanism was quadrupole- quadrupole interaction, and the energy transfer efficiency could reach 81%. The emission color of the series Ca8MgBi(PO4)(7):0.08Ce(3+), yTb(3+) phosphors can be adjusted from blue light to green light by changing the doping concentrations of Tb3+, realizing the controllable emission color change.