Enhancement of the red emission in CaTiO3:Pr3+ by addition of rare earth oxides

Enhancement of the 1D2–3H4 red emission of CaTiO3:Pr3+ with addition of rare earth oxides Ln2O3 (Ln = Lu, La, Gd) is reported. Ca2+ and Ti4+ in CaTiO3 can be substituted by Ln3+ ions as donors and acceptors, respectively. Ca2+ and Ti4+ vacancies, as quenching centers in the host, are effectively suppressed by the self-compensation, leading to the increase of lifetimes and then the emission efficiency of 1D2. The red fluorescence intensity for CaTiO3:Pr3+ phosphor co-doped with 5 mol% Lu2O3 is nearly 3 times greater than that of the Lu-free samples.