Luminescence and Energy Transfer between Ce and Pr in BaYSiO under VUV-vis and X-ray Excitation.

A detailed investigation on photoluminescence properties and energy transfer (ET) dynamics of Ce, Pr-doped BaYSiO is provided along with the potential X-ray excited luminescence application. The luminescence properties of Pr are studied in VUV-UV-vis spectral range at low temperature, and the spectral profiles of PrP and D emission lines are determined using time-resolved emission spectra. Upon 230 nm excitation, the electron population from Pr 4f5d state to its 4f excited state is discussed in detail. As Pr concentration rises, PrP and D luminescence possess different concentration-related properties. The incorporation of Ce in the codoped sample produces the strong Ce luminescence under 230 nm excitation, which is the combined result of Pr 4f5d → Ce 5d ET and Ce intrinsic excitation. On the other hand, the increasingly strong ET of Ce 5d → Pr 4f results in the decrease of Ce emission intensity and the gradual deviation of Ce 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 C is determined to be 9.97 × 10 m·s. Finally, the relatively low scintillation light yield of Ce-doped BaYSiO material impedes its application potential in the scintillator field, and the cosubstitution of Pr results in the observable decline of scintillation performance.