Luminescence and Energy Transfer between Ce³⁺ and Pr³⁺ in BaY₂Si₃O₁₀ under VUV–vis and X‑ray Excitation

A detailed investigation on photoluminescence properties and energy transfer (ET) dynamics of Ce³⁺, Pr³⁺-doped BaY₂Si₃O₁₀ is provided along with the potential X-ray excited luminescence application. The luminescence properties of Pr³⁺ are studied in VUV–UV–vis spectral range at low temperature, and the spectral profiles of Pr³⁺ ³P₀ and ¹D₂ emission lines are determined using time-resolved emission spectra. Upon 230 nm excitation, the electron population from Pr³⁺ 4f5d state to its 4f² excited state is discussed in detail. As Pr³⁺ concentration rises, Pr³⁺ ³P₀ and ¹D₂ luminescence possess different concentration-related properties. The incorporation of Ce³⁺ in the codoped sample produces the strong Ce³⁺ luminescence under 230 nm excitation, which is the combined result of Pr³⁺ 4f5d → Ce³⁺ 5d ET and Ce³⁺ intrinsic excitation. On the other hand, the increasingly strong ET of Ce³⁺ 5d → Pr³⁺ 4f² results in the decrease of Ce³⁺ emission intensity and the gradual deviation of Ce³⁺ luminescence decay from the single exponential in the system. By employing the Inokuti–Hirayama model, the dipole–dipole interaction is confirmed as the predominant multipolar effect in controlling this ET process, and the value of <i>C</i>_<i>DA</i> is determined to be 9.97 × 10^–47 m⁶·s^–1. Finally, the relatively low scintillation light yield of Ce³⁺-doped BaY₂Si₃O₁₀ material impedes its application potential in the scintillator field, and the cosubstitution of Pr³⁺ results in the observable decline of scintillation performance