Dependence of luminescence properties of CaTiO3:Pr3 + on different TiO2 polymorphs

CaTiO3 is widely used in the ceramic industry, and when it is doped with Pr3 + it glows with a single red emission at a wavelength of 613 nm upon ultraviolet or electron beam irradiation. The red emission is attributed to the 1D2 → 3H4 radiative transition of Pr3 +. The compound was prepared by using either rutile or anatase polymorphs of TiO2 to investigate their effects on the luminescence properties. X-ray diffraction patterns of CaTiO3:Pr3 + phosphor prepared with rutile polymorph show that the phosphor was successfully synthesized without any additional phases, whereas the patterns for the phosphor prepared with anatase polymorph show unreacted TiO2 phases. The unreacted phases resulted in lowered luminescence intensity of the phosphor prepared with the anatase TiO2. The cathodoluminescence stability of the phosphor was also investigated by exposing it to a prolonged electron beam irradiation. The persistent emission lifetimes increased with an increase in the synthesis temperature, with that of the anatase polymorph lasting longer. The energy distribution of the electron trapping centers was also determined.