Short-range structure and photoluminescent properties of the CaTiO3:Pr,La phosphor

Pr3+-doped CaTiO3 perovskite is a promising phosphor compound with the possibility of use in several technological applications. In this paper, we report the substitution of Ca2+ ions with La3+ ions in order to promote Ca vacancies to further enhance photoluminescence (PL). CaTiO3:Pr,La samples were prepared by the polymeric precursor method and their short- and long-range structure and photoluminescent properties were investigated in this paper. PL measurements show a narrow emission centered at 612 nm typical of the1D2 - 3H4 transition of Pr3+ ions. As the La content increases, the intensity of this peak is increased. This enhancement of PL curves for CaTiO3:Pr,La samples is associated with disorder in the CaTiO3 lattice caused by the La incorporation. This disorder as a function of the La content is shown by both X-ray absorption near edge structure (XANES) spectra at the Ti K-edge and Raman spectroscopy measurements. CaTiO3:Pr,La samples do not present PL with long term afterglow.