Photoluminescence properties of color-tunable novel Na2Ca4(PO4)2SiO4:Ce3+, Tb3+ near ultraviolet convertible phosphors

• A novel color tunable phosphor Na2Ca4(PO4)2SiO4:Ce3+, Tb3+ is synthesized by a solid state process.
• The energy transfer mechanisms of Ce3+–Ce3+ and Ce3+–Tb3+ in Na2Ca4(PO4)2SiO4 are investigated by fluorescence decay time.
• The Na2Ca4(PO4)2SiO4:Ce3+, Tb3+ phosphor presents high thermal stability.

A series of Ce3+ and Tb3+ doped color-tunable novel phosphors with both phosphate and silicate hosts, Na2Ca4(PO4)2SiO4, were synthesized by a solid-state process for the first time as far as we know. The photoluminescence properties, energy transfer (ET) among rare earth ions and temperature quenching effect were investigated. Dipole–dipole and dipole–quadrupole interactions were proved to be responsible for ET mechanisms of Ce3+–Ce3+ and Ce3+–Tb3+ in Na2Ca4(PO4)2SiO4, respectively. Furthermore, the emitting color of phosphors can be tuned from blue to green by increasing the dopant concentrations of Tb3+ ions. Finally, temperature-quenching measurement revealed that the as-synthesized phosphor had good thermal characteristics, which indicates that the phosphor can be served as a key material for phosphor-converted white LEDs.