Band gap excitation and luminescence of perovskites R_1/2Na_1/2TiO₃: Pr (R = La, Gd, Lu, and Y)

Abstract

Pr³⁺ doped perovskites R_1/2Na_1/2TiO₃: Pr (R=La, Gd, Lu, and Y) were synthesized, and their structures and luminescent propeties were elucidated. Red intense emission by band gap photo-excitaion was observed for all compounds. The wavelength of excitation peak decreased as the band absorption edge was blueshifted with a decrease of ionic radius of R. On the other hand, the wavelength of emission peaks increased with a decrease of ionic radius of R, which orginates from the increase in covalency between Pr and oxygen. The relationship between structure and emission properties is discussed.