A strategy for developing deep-UV phosphor: Sr3AlO4F: Tb3+/Sm3+

A series of Sr3AlO4F:A (A = Tb3+, Sm3+) phosphors were prepared by solid-state reaction process. The optical properties of Tb3+ and Sm3+ single-doped or co-doped Sr3AlO4F phosphors were researched by means of X-ray diffraction and photoluminescence spectra. Under the excitation of 250-400 nm, all samples exhibited their characteristic emissions of Sr3AlO4F:Tb3+ (D-5(3) -> F-7(5), blue and D-5(4) -> F-7(5), green), Sr3AlO4F:Sm3+ ((4)G(5/2) -> H-6(7/2), red). The concentration dependent luminescence intensity of Sr3AlO4F:A (A = Tb3+, Sm3+) phosphors have been investigated in detail. Besides, the energy transfer from Tb3+ to Sm3+ ion has been researched in the Sr3AlO4F host, and the energy transfer mechanism was demonstrated to be a resonant type, through a dipole-quadrupole mechanism on the basis of experimental and theoretical analysis. In addition, white/tunable light can be prepared by changed the doping concentration of Sm3+ from 0.03 to 0.12 mol in Sr3AlO4F:0.5 % Tb3+ under excitation of deep-UV. It is the first time to produce white light emission through Tb3+ and Sm3+ co-doped Sr3AlO4F phosphor.