Preparation and Luminescence Properties of the New Long Phosphorescent Phosphors Ba1-x Cax Al2O4 ： Eu^2＋ , Dy^3

New long phosphorescent phosphors Ba1-x CaxAl2O4:Eu^2+, Dy^3+ with tunable color emission were prepared and studied. The emission spectra show that the tuning range of the color emission of the phosphors is between 498 and 440 nm, which is dependent on x, under the excitation of UV. The wavelength of the afterglow increases with the increasing of x until x equals 0.6. The XRD patterns show that the single phase limit in the phosphors is below x value of 0.4.The Thermolumineseence spectra were measured to investigate the traps created by the doping of Dy^3+ .