Luminescence Spectroscopy and Decay Kinetics of Pr³⁺ Ions in K₃LuSi₂O₇:Pr³⁺

Abstract—

The luminescent characteristics of K₃LuSi₂O₇:Pr³⁺ (1%), which is a promising optical material for the use as a scintillator, have been studied using a set of techniques. The luminescence spectra of K₃LuSi₂O₇:Pr³⁺ (1%) contain two bands in the UV-range with peaks at 284 and 330 nm, which correspond intraconfigurational 5d → 4f transitions in the Pr³⁺ ions. The radiation in the visible and near IR range (480–850 nm) has been represented by the intraconfigurational 4f → 4f transitions. The kinetics of 5d → 4f-luminescence contains a build-up stage (τ_rise ∼ 7–12 ns), nonexponential decay stage (τ_1/2 ∼ 60 ns), and a slow component of the μs-range when excited by high-frequency (∼8 MHz) synchrotron radiation of the X-ray range. The fast component of the decay (τ = 54 ns) dominates in the decay kinetics of luminescence along with the build-up stage while the contribution of the μs decay component is less than 0.5% at the excitation by an pulse electron beam (5Hz). The excitation spectra of d–f- and f–f-photoluminescence in the ultraviolet and vacuum ultraviolet range that are measured using synchrotron radiation reveal features that are caused by both intracenter transitions and processes related to the energy transfer from the intrinsic electronic excitations to the impurity center.