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.