Structure and tunable blue-white-red luminescence of Eu2+/Eu3+-doped Na5Al(PO4)2F2 single-phase phosphor

Abstract Eu 2+ /Eu 3+ -doped fluorophosphate Na 5 Al(PO 4 ) 2 F 2 was synthesized by the high-temperature solid-state reaction. The structural XRD refinement was used to investigate the phase formation and structure. The photoluminescence (PL) excitation and emission spectra were measured. The host accommodates two kinds of Eu-centers in the lattices, i.e., Eu 3+ and Eu 2+ , which were confirmed by the emission spectra and decay curves. Under the excitation of UV and near-UV light, the broad emission peaked at 420 nm and 530 nm from the 4 f 6 5 d –4 f 7  transition of Eu 2+  and narrow peaks at 592 nm, 615 nm from the 4 f –4 f  transitions of Eu 3+  ions were detected. The luminescence color could shift from blue to white and red by mixing the luminescence from the coexistence of Eu 2+ /Eu 3+  ions in the single-phase phosphor.