Strong broad green UV-excited photoluminescence in rare earth (RE = Ce, Eu, Dy, Er, Yb) doped barium zirconate

The wet synthesis hydrothermal method at 100 degrees C was used to elaborate barium zirconate (BaZrO3) unpurified with 0.5 mol% of different rare earth ions (RE = Yb, Er, Dy, Eu, Ce). Morphological, structural and UV-photoluminescence properties depend on the substituted rare earth ionic radii. While the crystalline structure of RE doped BaZrO3 remains as a cubic perovskite for all substituted RE ions, its band gap changes between 4.65 and 4.93 eV. Under 267 nm excitation the intrinsic green photoluminescence of the as synthesized BaZrO3: RE samples is considerably improved by the substitution on RE ions. For 1000 degrees C annealed samples, under 267 nm, the photoluminescence is dominated by the intrinsic BZO emission. It is interesting to notice that Dy3+. Er3+ and Yb3+ doped samples present whitish emissions that might be useful for white light generation under 267 nm excitation. CIE color coordinates are reported for all samples. (C) 2011 Elsevier B.V. All rights reserved.