Spectral and kinetic characteristics of trivalent praseodymium in LaF3-LiF and SrAl12O19

Recent data on cascade transitions in the 4f shell of the Pr³⁺ ion in various matrices are analyzed. Spectral and kinetic characteristics of LaF₃-LiF:Pr and SrAl₁₂O₁₉:Pr phosphors, which show photon cascade emission, were investigated. The emission intensities in the first (¹ S→¹ I ₆ transitions) and the second (transitions from the ³ P ₀ level to the ³ H and ³ F multiplets) cascade stages were measured and the temperature dependences of the intensities of the main emission lines and their kinetic characteristics were determined. The following parameters of SrAl₁₂O₁₉:Pr were found: the band gap width (7.5 eV), the energy gap between the ¹ S ₀, 4f and 5d levels (0.24 eV), and the characteristics of the 4f→5d band (6.0–7.5 eV) of the Pr³⁺ luminescence excitation. It is shown that the LaF₃-LiF:Pr compound has a number of specific features in comparison with other Pr³⁺-doped phosphors.