Tunable luminescence and energy transfer properties of Ca-5(PO4)(2)SiO4:Ce3+/Tb3+/Mn2+ phosphors

A series of single-composition phosphors Ca-5(PO4)(2)SiO4:Ce3+, Tb3+, Mn2+ have been prepared via a high-temperature solid-state reaction process. The Ce3+ emission at different lattice sites has been identified and discussed. The energy transfer from Ce3+ to Tb3+ and Mn2+ ions has been validated. The emissive colors of Ca-5(PO4)(2)SiO4:Ce3+, Tb3+/Mn2+ samples can be adjusted from blue to green and from blue to red-orange by the energy transfer of Ce3+ -> Tb3+ and Ce3+ -> Mn2+, respectively. More importantly, white emission has been obtained through adjusting the relative concentrations of Ce3+, Tb3+ and Mn2+ ions in the Ca-5(PO4)(2)SiO4 host under UV and low-voltage electron beam excitation, respectively. Additionally, the temperature-dependent photoluminescence and the degradation behaviors of cathodoluminescence under continuous electron bombardment for as-prepared phosphors have been investigated in detail. The results reveal that the Ca-5(PO4)(2)SiO4 host is stable enough to protect the photoluminescence and cathodoluminescence properties of Ce3+, Tb3+ and Mn2+ ions from being affected. Tunable luminescence and the stable structure suggest that Ca-5(PO4)(2)SiO4:Ce3+/Tb3+/Mn2+ phosphors have great potential in the application in WLEDs and FEDs.