Photoluminescence properties of Dy3+/Pr3+co-doped NaLaMgWO6 double perovskite phosphors for solid-state lighting

Dy3+ and Pr3+ ions activated NaLaMgWO6 double perovskite phosphors were prepared by a traditional high- temperature solid-state reaction. The crystal structure, chemical composition, and optical properties were investigated in detail. The efficient energy transfer from Dy3+ to Pr3+ significantly improves the Pr3+ emission in NaLaMgWO6: Dy3+, Pr3+ phosphors, and the color tunable single-phase phosphor can be achieved by changing the ratio of the Dy3+/Pr3+ ions. More importantly, Li + ions were doped into the Na sites of the NaLaMgWO6: Dy3+, Pr3+ phosphors, which induced the tilt of [MgO6]10- and [WO6]6- octahedron. This octahedral distortion changes the crystal symmetry, crystal field strength and electronic structure of the phosphors, leading to the improvement of the luminous performance of the NaLaMgWO6: Dy3+, Pr3+ phosphors. These results indicate that color tunable single-phase Na1-xLixLaMgWO6: Dy3+, Pr3+ phosphors could be a potential phosphor for LED applications.