Crystal structure and luminescent properties of a novel high efficiency blue-orange emitting NaCa2LuSi2O7F2:Ce3+,Mn2+ phosphor for ultraviolet light-emitting diodes

Abstract

A series of NaCa₂LuSi₂O₇F₂:xCe³⁺,yMn²⁺ phosphors are firstly prepared by a high-temperature solid-state reaction technique. The Rietveld refinement analysis confirmed that the obtained phosphors have a pure crystalline phase with cuspidine-group structure. NaCa₂LuSi₂O₇F₂:xCe³⁺,yMn²⁺ phosphors can be efficiently excited by UV light and have two emission bands at about 410 and 600 nm. The luminescent properties of the singly-doped samples reveal that the Ce³⁺ ions occupy two different Lu³⁺ sites in the host lattice. We observed an efficient energy transfer from the Ce³⁺ to Mn²⁺ ions. The investigation revealed that the mechanism of the energy transfer was a resonant type via a nonradiative dipole–quadrupole interaction. The hues can be adjusted and white light can be obtained by tuning the concentration of Mn²⁺ ions in the codoped phosphors through the energy transfer from the Ce³⁺ to Mn²⁺ ions, hinting a promising application of NaCa₂LuSi₂O₇F₂:xCe³⁺,yMn²⁺ as a single-component phosphor that can produce white light from UV-based LEDs.