Photoluminescence of Praseodymium-Doped Srn+1TinO3n+1 (n=1, 2, ?)

Perovskite-related compounds, Srn+1TinO3n+1: Pr3+ (n=1, 2, ∞), were prepared by a Pechini-type polymerizable complex method using a citric metal complex and their photoluminescence properties were investigated. The photoluminescence spectra of these compounds show distinct peaks at approximately 490 nm and/or 610 nm, which correspond to the intra-4f transitions from the excited state 3P0 to the ground state 3H4, 1D2 to 3H4 of Pr3+, respectively. The excitation process is consistent with the transition between the valence band and the conduction band in host materials. The most intense red emission was observed for the compound with n=2 (Sr3Ti2O7: Pr3+), following by the compounds, n=1 and n=∞. The differences in luminescent properties among the compounds originate from the structural dependence of the energy transfer from the host to the activator Pr3+, and the site symmetry of Pr3+.