Emission of Pr3+ from two sites in CaHfO3 perovskite

Pr-doped CaHfO3 is investigated. Luminescence of Pr from two sites was observed. About 85% of Pr ions occupy on Ca site (A site of perovskite ABO3) and 15% of Pr ions stay on Hf site (B site). Pr(A) shows an excitation band at 240 nm from the 4f5d state, and gives strong UV emission bands peaking at 294 and 337 nm. Emission at 490 nm from 3P0 is dominant. In contrast, Pr(B) shows 5d excitation band at 275 nm, and gives a weak and broad emission band near 390 nm. Emission from its 1D2 at 610 nm is stronger than the emission from 3P0 state (484 nm). Codoping with Na+, In3+, or Al3+ for the purpose of charge compensation could change distribution of Pr on both sites. Na+ tends to reduce, but In and Al tend to increase the population of Pr on Hf (B) site.