The crystal structure, energy transfer and tunable luminescence properties of NaLaMgWO6:Tm3+, Eu3+ phosphors

A series of NaLaMgWO6:Tm3+, Eu3+ phosphors with color-tunable emission were successfully synthesized by the solid-state reaction method. The crystal structure, luminescence characteristics and energy transfer of NaLaMgWO6:Tm3+, Eu3+ phosphors have been studied. It is observed that Tm3+ singly doped phosphors exhibit intense blue emission at 484 nm, and Eu3+ singly doped phosphors emit red light at 621 nm. The phosphors co-doped with Tm3+, Eu3+ exhibit fluorescence spectra composed by the characteristic emission peaks of Tm3+ ions and Eu3+ ions. A tunable emission color from blue to red can be obtained by adjusting the ratio of the doping concentration of Tm3+/Eu3+, indicating a significant energy transfer from Tm3+ to Eu3+. The energy transfer mechanism between Tm3+→Eu3+ in the NaLaMgWO6:Tm3+, Eu3+ phosphors is proved to be a quadrupole-quadrupole interaction. These results show that NaLaMgWO6:Tm3+, Eu3+ phosphors may have a potential application in white light emitting diodes.