Improved photoluminescence and afterglow in CaTiO_3:Pr ~3 with addition of nanosized SiO_2

摘要

Enhancement of the ~1D_2~3H_4 red emission in CaTiO_3:Pr~3 with addition of nanosized SiO _2 fabricated by a solid state reaction method is reported. The dynamical processes for the improvement of red emission were systematically investigated using photoluminescence (PL) and PL excitation spectra, and diffused reflectance spectra as well as time decay patterns of PL and persistent afterglow. Higher efficiency of energy transfer from CaTiO_3 host to the activator Pr~3 due to the improvement of crystallinity by SiO _2 addition was discussed in comparison with that of the SiO _2 free sample. The enhancement of persistent afterglow after the cessation of excitation in SiO_2 added CaTiO_3:Pr ~3 was also analyzed by theoretically fitted results.