Effect of the anion on the luminescence properties of Bi3+-doped X-mayenite (X=O, F, Cl) phosphors.

[Display omitted] • Bi3+-doped X-mayenite phosphors was synthesized via solid-state reaction method. • O-mayenite:Bi3+ exhibits a single blue emission band peaking at 452 nm. • F- and Cl-mayenite:Bi3+ phosphors show additonal ultraviolet emissions at 375 nm. • Emission color of Cl-mayenite:Bi3+ can be tuned by controlling the encaged anion. A series of Bi3+-doped X-mayenite (X = O, F, Cl) phosphors was synthesized via the conventional solid-state reaction method. Upon excitation at 325 nm, Bi3+-doped O-mayenite exhibits a single blue emission band peaking at 452 nm, which is assigned to the 3P 1 →1S 0 transitions of Bi3+ ions. For F-mayenite:Bi3+ and Cl-mayenite:Bi3+ phosphors, there is a new dominant ultraviolet emission centered at 375 nm and a weak blue emission. The luminescent dynamical process proves that two emission centers exist in F-mayenite:Bi3+ and Cl-mayenite:Bi3+. Our results confirm that the ultraviolet emission originates from the transitions of Bi3+ with Cl− or F− ions surrounded, and the blue emission corresponds to the transitions of Bi3+ with O2− ions surrounded. In addition, the emission color of Cl-mayenite:Bi3+ can be tuned both by controlling the encaged anions and Bi3+ content. We demonstrate that anion control is a new desirable strategy for photoluminescence tuning. [ABSTRACT FROM AUTHOR]