Luminescence and Location of Gd3+ or Tb3+ Ions in Perovskite-Type LaScO3

The luminescence properties of Gd3+ or Tb3+ ions at La and Sc sites were investigated in LaScO3 with a distorted perovskite-type structure (ABO3). Although the luminescence of lanthanide ions located at B sites is not common and has not been examined in detail, Gd3+ or Tb3+ luminescence from B sites and A sites is clearly observed in Gd3+- or Tb3+-doped LaScO3. The differences in the luminescence characteristics concern peak positions, peak shapes, and decay time, which are all influenced by the crystal field and the site symmetry. The UV luminescence of Gd3+ at B sites shows a red shift compared to Gd3+ at A sites, and the green luminescence of Tb3+ at B sites contrasts with the blue-violet and green luminescence of Tb3+ at A sites. The decay time of the luminescence from B sites is systematically longer than that from A sites in both the Gd3+ and Tb3+ cases.