Photoluminescence properties of Pr doped and Tb-Mg codoped CaSnO3 with perovskite structure

In the survey of photoluminescence properties of rare-earth doped alkaline-earth stannates, CaSnO3 was found to show intense white luminescence by Pr doping and green luminescence by Tb-Mg codoping. Pr doped CaSnO3 showed not only a red emission line originating from the f-f transition from D-1(2) to H-3(4) state, which is observed in Pr doped CaTiO3 or SrTiO3, but also an intense blue-green line assignable to the f-f transition from P-3(0) to H-3(4) state in Pr3+ ions. Because of the mixture of the red and blue-green luminescence, the Pr doped CaSnO3 was seen in white under uv excitation. Tb-Mg codoped CaSnO3 showed a sharp green emission line derived from the f-f transition of from D-5(4) to F-7(5) state in Tb3+ ions along with other small emission lines. Tb-Mg codoping effectively enhanced the green luminescence of Tb3+ ions probably due to the local lattice distortion around Tb ions induced by the small Mg ions at Ca sites. The photoluminescence properties of Pr doped and Tb-Mg codoped ASnO(3) (A = Sr, Ba) and CaMO3 (M = Ti, Zr) with perovskite structures were also examined and compared to understand the luminescence mechanisms in these materials. (C) 2007 Elsevier B.V. All rights reserved.