A series of Ce3+- and Ce3+/Tb3+-activated Ba10(PO4)6F2 phosphors with apatite structure have been synthesized via high temperature solid-state reaction. X-ray diffraction (XRD), scanning electron microscopy (SEM), the photoluminenscence excitation (PLE) spectra and photoluminescence (PL) spectra were used to characterize samples. The results revealed that the fluorapatite structured Ba10(PO4)6F2∶Ce3+,Tb3+ phosphor particles with irregular morphology have been obtained. The relative intensities of PL spectra of Ba10-x(PO4)6F2:xCe3+ phosphors increased with increasing x values, and reached the maximum at x=0.09. The as-prepared phosphors Ba10(PO4)6F2∶Ce3+,Tb3+ phosphors exhibited broad excitation band ranging from 240 to 330 nm. The emission spectra of Ba10(PO4)6F2∶Ce3+,Tb3+ phosphor showed the violet-emitting band centered at 335 and 358 nm and green light-emitting band centered at 542 nm, which originate from the 5d→4f transitions of Ce3+ and 4f→4f transitions of Tb3+, respectively. The spectral characteristics showed that the energy transfer occurs from Ce3+ to Tb3+ in Ba10(PO4)6F2∶Ce3+,Tb3+ phosphors, and the energy transfer efficiency between Ce3+ and Tb3+ could reach up to 60%. The critical distance of Ce3+ and Tb3+ was calculated to be 0.79 nm, and the mechanism of energy transfer from Ce3+ to Tb3+ is dipole-dipole interaction. In addition, the energy transfer behavior and luminescence process were discussed in detail. By adjusting the concentration of Tb3+, the relationship between chromatic coordinate and the doping concentration of Tb3+ was studied. The Ba10(PO4)6F2∶Ce3+,Tb3+ phosphors emission color could adjust from blue to green, and the chromatic coordinate tuned from (0.149 4, 0.045 1) to (0.280 1, 0.585 3) with increasing the concentration of Tb3+ from 0 to 0.52.
Chinese Journal of Inorganic Chemistry
high-temperature solid-state reaction
Ce3+/Tb3+- activated phosphor