Photoluminescence enhancement of Ca3Sr3(PO4)4:Dy3+ white-emitting phosphors by Li+ and Na+ charge compensation

A series of Ca3Sr3(PO4)(4):Dy3+, M+ (M=Li and Na) white-emitting phosphors was prepared via a high-temperature solid-state reaction, where M+ was co-doped in Ca3Sr3(PO4)(4):Dy3+ as charge compensators for enhancing its luminescence. Effects of synthesis temperature and charge compensator M+ on the structure and luminescence properties of as-prepared phosphors were studied in detail. The results of X-ray diffraction indicate that the structures of Ca3Sr3(PO4)(4):Dy3+, M+ samples were in agreement with the standard Ca2Sr(PO4)(2) phase. Under excitation of 352nm, there are two apparent peaks at 484nm (blue) and 577nm (yellow) in the emission spectra of Ca3Sr3(PO4)(4):Dy3+, M+ samples, which corresponding to the (F9/2H15/2)-F-4-H-6 and (F9/2H13/2)-F-4-H-6 electron transitions of Dy3+ ions, respectively. Luminescence intensity and lifetime of Ca3Sr3(PO4)(4):Dy3+ can be significantly enhanced through adding a charge compensator M+, which suggest that Ca3Sr3(PO4)(4):Dy3+, M+ can be used as a single-phase white-emitting phosphor in the applications of white light-emitting diodes.