Color-tunable emission and energy transfer in NaCaPO4: Tb3+/Mn2+ phosphors

Mn2+/Tb3+ single-doped and codoped NaCaPO4 phosphors were prepared by a high-temperature solid-state reaction method. Under ultraviolet irradiation, the NaCaPO4: Tb3+, Mn2+ samples exhibit the typical green emission band of the Tb3+, as well as an red emission bands of the Mn2+. The red emission bands of the Mn2+ were attributed to the energy transfer from the Tb3+ to Mn2+, which has been justified through the luminescence spectra. The luminescence colors of NaCaPO4: Tb3+, Mn2+ phosphors can be easily tuned by changing the concentration of Mn2+. These results suggest that these phosphors can be explored for near ultraviolet LED.