Enhancement of red fluorescence and afterglow in CaTiO3: Pr3+ by addition of LU2O3

CaTiO3:Pr3+ with addition Lu2O3 are synthesized by conventional solid-state reaction methods. It is found that the addition of Lu leads to the enhancement of red fluorescence and phosphorescence at 615 nm originating from D-1(2)-> H-3(4) transition of Pr3+ following the increase of the lifetime for the D-1(2) state. As a result, it is indicated that the non-radiative centers for the D-1(2) state are suppressed by the addition of Lu ions. The persistent time of the afterglow is observed to increase from less than 15 min to over 2 h after the addition of 5 mol% Lu2O3. A tentative mechanism of the Lu-addition effect on the optical properties is discussed. (c) 2006 Elsevier B.V. All rights reserved.