Synthesis and tunable luminescence of RbCaGd(PO4)2:Ce3+, Mn2+ phosphors

•Phosphors RbCaGd(PO4)2:Ce3+, Mn2+ were synthesized for the first time.•Structural and luminescent properties of as-synthesized phosphors were investigated.•The efficient energy transfer from the Ce3+ to Mn2+ ions was achieved.•With tuning the ratio of Ce3+ to Mn2+, the color change from blue to yellow.

RbCaGd(PO4)2 doped with Ce3+, Mn2+ was synthesized by the sol-gel method. The crystal structure and crystallographic location of Ce3+ in RbCaGd(PO4)2 were identified by Rietveld refinement. Powder X-ray diffraction (XRD) revealed that the structure of RbCaGd(PO4)2:Ce3+ compounds is hexagonal structure which is similar to that of hexagonal LnPO4 with the lattice constant of a = b = 7.005(57) Å, c = 6.352(05) Å, and V (cell volume) = 269.980 Å3. The photoluminescence behavior and emission mechanism were studied systematically by doping activators in the RbCaGd(PO4)2 host. The Mn2+ incorporated RbCaGd(PO4)2:Ce3+, Mn2+ compounds exhibited blue emission from the parity- and spin-allowed f-d transition of Ce3+ and orange-to-red emission from the forbidden 4T1 → 6A1 transition of Mn2+. The emission chromaticity coordinates of RbCaGd(PO4)2:0.10Ce3+, xMn2+ (x = 0.16, 0.25) are close to the white region due to an energy transfer process and the energy transfer mechanism from Ce3+ to Mn2+ in the RbCaGd(PO4)2 host was dominated by dipole-dipole interactions.

Graphical abstractIn this letter, a novel double-phosphate phosphor, RbCaGd(PO4)2:Ce3+, Mn2+ was prepared by the sol-gel method. The crystal structure was determined in the first time based on Rietveld refinements. Based on the experimental results and the theoretical calculation, it is identified that the dipole-dipole interaction plays a major role in the mechanism of energy transfer from Ce3+ to Mn2+ in this phosphor. Tunable luminescence can be accomplished from the RbCaGd(PO4)2:Ce3+, Mn2+ phosphors by adjusting the contents of Mn2+ and the emission can be varied from blue (0.1701, 0.0294) to yellow (0.3766, 0.4209).Figure optionsDownload full-size imageDownload high-quality image (178 K)Download as PowerPoint slide