Structure and Luminescence Characteristics of Eu3+-Activated Trigonal Layered Perovskite Ba2La2ZnW2O12

Eu3+-doped tungstate Ba2La2ZnW2O12 phosphors with perovskite-structure were prepared by the high temperature solidstate reaction. The X-ray powder diffraction (XRD) patterns and structure refinements indicate that the phosphors crystalized in the trigonal layer-perovskite. The luminescence properties of the phosphors were investigated such as photoluminescence (PL) excitation and emission spectra, decay lifetimes, and color coordinates. It was found that the pure host shows self-activated emission excited by the UV light. Moreover, Ba2La2ZnW2O12 also shows scintillation characteristics under the X-ray irradiation. The near-UV and blue light can efficiently excite Eu3+-doped Ba2La2ZnW2O12 phosphors inducing the strong orange-red luminescence. The optimal Eu3+ doping concentration in this host is 40 mol%. The luminescence spectra and the luminescence color of the phosphors strongly depend on the doping levels and excitation wavelength. The different luminescence features were discussed on the base of crystal structure. Eu3+ ions have two possible substitutions on A or B sites in this trigonal layered perovskite. The phosphor could act as a candidate for the potential application in near-UV excited white-LEDs lighting.