Lanthanide doped BaTiO3-SrTiO3 solid-solution phosphors: Structure, optical spectroscopy and upconverted temperature sensing behavior

Lanthanide doped Ba(1-x)SrxTiO(3) (x - 0-1) solid-solution phosphors were successfully prepared by a conventional solid-state reaction. Using Eu3+ dopants as the structural probe, the variation of D-5(0) -> F-7(2)/D-5(0) -> F-7(1) emission intensity ratio with increase of Eu3+ content and the excitation-wavelength- dependent luminescence in the Ba(1-x)SrxTiO(3) sample were demonstrated to be originated from the different emission behaviors of Eu3+ in Ba2+/Sr2+ site and Ti4+ site. Furthermore, upconversion luminescence for the Yb3+/Er3+ co-doped Ba1-xSrxTiO3 samples were investigated, and it was found that the emission intensity of Yb3+/Er3+: Ba0.5Sr0.5TiO3 phosphor was about 5 and 2 times as high as those of Yb3+/Er3+: BaTiO3 and Yb3+/Er3+: SrTiO3 ones. Using the investigated Yb3+/Er3+: Ba0.5Sr0.5TiO3 solid-solution as the optical thermometric medium, the temperature sensitivity was determined to be 0.76% K-1 at the temperature of 610 K based on the temperature-dependent fluorescence intensity ratio of the thermally coupled H-2(11/ 2) and S-4(3/2) emitting-states of Er3+. (C) 2016 Elsevier B.V. All rights reserved.