Synthesis of Green-Emitting (La,Gd)OBr:Tb(3+) Phosphors

Green-emitting phosphors based on lanthanum-gadolinium oxybromide were synthesized in a single phase form by the conventional solid state reaction method, and photoluminescence properties of them were characterized. The excitation peak wavelength of (La(1-x)Gd(x))OBr:Tb(3+) shifted to the shorter wavelength side with the increase in the crystal field around the Tb(3+) ions by doping Gd(3+) ions into the La(3+) site, and, as a result, the green emission intensity was successfully enhanced. The maximum emission intensity was obtained for (La(0.95)Gd(0.05))OBr:5%Tb(3+), where the relative emission intensity was 45% of that of a commercial green-emitting LaPO(4):Ce(3+),Tb(3+) phosphor.