Luminescence Properties of Ca(Y0.915-xGdxAl0.025Eu0.06)BO4 Phosphors Under VUV Irradiation

The major phase of post-treated Ca(Y(0.915-x)Gd(x)Al(0.025)Eu(0.06))BO(4) (0 <= x <= 0.3) phosphors was solid solutions of the constituent oxides, which had an orthorhombic warwickite-like structure. The calculated crystallite size of the Ca(Y(0.915-x)Gd(x)Al(0.025)Eu(0.06))BO(4) phosphors was similar to 36 nm. The Gd additive significantly enhanced both the charge transfer (CT) transition of O(2-)-Eu3(divided by) and the absorption of the host materials, thereby resulting in an increase in emission intensity. The Ca(Y(0.715)Gd(0.2)Al(0.025)Eu(0.06))BO(4) phosphor showed the highest emission intensity at 593 nm, which was over five times as strong as that of a Gd-free Ca(Y(0.915)Al(0.025)Eu(0.06))BO(4) phosphor. The addition of Gd was desirable for improving the photoluminescent properties of red-emitting Ca(Y(0.915)Al(0.025)Eu(0.06))BO(4) phosphors.