Crystal structure and photoluminescence properties of CaLaLiTeO6:Dy3+ phosphors for solid-state lighting

A series of CaLa1-xLiTeO6:xDy3+ phosphors were synthesized via a conventional solid-state reaction method, and the effects of different Dy3+ doping concentrations on the luminescence properties of the phosphors were studied. The excitation spectrum indicated that these synthesized phosphors had strong absorption bands in near-ultraviolet (n-UV) region in the range from 300 to 500 nm. There were two sharp emission peaks in the visible region, which were located at 483 nm, 574 nm, corresponding to transitions of 4F9/2→6H15/2 (magnetic dipole transition) and 4F9/2→6H13/2 (electric dipole transition), respectively. The phosphor CaLa0.95LiTeO6:0.05Dy3+ shows superior thermal stability. When the temperature rises to 425 K, the luminous intensity remains at 79% compared with the initial intensity of 300 K. These results demonstrate that the CaLa1-xLiTeO6:xDy3+ phosphors have great potential as a single-phase luminescence material for near-ultraviolet (n-UV) excitation.