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 Pr^{3+ 3}P₀ 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, Pr^{3+ 3}P₀ 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 C_DA 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.

The host structure and the synchrotron radiation VUV-UV luminescence properties of samples BaMg₂Si₂O₇ (BMSO):Ln (Ce³⁺, Eu²⁺) at different doping levels and different temperatures were investigated in detail. Three important aspects are studied to elucidate the luminescence properties of samples: (1) the vacuum referred binding energy (VRBE) scheme is constructed with the electron binding in the BMSO host bands and in the Ce³⁺ and Eu²⁺ impurity levels with the aim to explain the different thermal stabilities of Ce³⁺ and Eu²⁺ emissions; (2) the electron-vibrational interaction analysis on the narrow Eu²⁺ emission indicates a weak electron-phonon interaction in the current case; (3) by using three models (Inokuti-Hirayama, Yokota-Tanimoto, and Burshteǐn models) at different conditions, the energy transfer dynamics between Ce³⁺ and Eu²⁺ was analyzed. It reveals that the energy transfer from Ce³⁺ to Eu²⁺ via electric dipole-dipole (EDD) interaction is dominant while energy migration between Ce³⁺ is negligible. Finally, the X-ray excited luminescence spectra of samples BMSO:Ce³⁺/Eu²⁺ are collected to evaluate their possible scintillator applications.

A series of Ln-doped KSrPO₄ (Ln = Ce³⁺, Eu³⁺, Eu²⁺, Pr³⁺) phosphors are prepared through a high-temperature solid-state method. The KSrPO₄ compound is confirmed to possess a β-K₂SO₄ structure with the Pnma group by Rietveld refinement, and the temperature-dependent lattice parameters are investigated with the powder X-ray diffraction results at different temperatures. Ce³⁺ and Eu³⁺ ions are introduced to probe the crystal field strength (CFS) and the lanthanide site symmetry by using VUV-UV-vis spectroscopy. The temperature-dependent luminescence properties of KSrPO₄: Ce³⁺/Eu²⁺ exhibit an excellent thermal stability of Ce³⁺/Eu²⁺ luminescence. Based on the VUV-UV-vis spectra of Ce³⁺ and Eu³⁺ doped KSrPO₄, the vacuum referred binding energy (VRBE) scheme is constructed to understand the redox properties of Eu, the 5d energy levels of Pr³⁺ and the thermal quenching characteristics of Ce³⁺ and Eu²⁺ luminescence.

A series of Ce³⁺-doped (Ca,Sr)₂Al₂SiO₇ phosphors with different Ce³⁺ and Ca²⁺/Sr²⁺ concentrations were prepared by a high temperature solid-state reaction technique. To get insight into the structure-luminescence relationship, the impact of incorporation of Sr²⁺ on structure of (Ca,Sr)₂Al₂SiO₇ was first investigated via Rietveld refinement of high quality X-ray diffraction (XRD) data, and then the VUV-UV excitation and UV-vis emission spectra of (Ca,Sr)₂Al₂SiO₇:Ce³⁺ were collected at low temperature. The results reveal that the crystal structure evolution of (Ca,Sr)₂Al₂SiO₇:Ce³⁺ has influences on band gaps and Ce³⁺ luminescence properties including 4f-5d_i (i = 1-5) transition energies, radiative lifetime, emission intensity, quantum efficiency, and thermal stability. Moreover, the influence of Sr²⁺ content on the energy of Eu³⁺-O^2- charge-transfer states (CTS) in (Ca,Sr)₂Al₂SiO₇:Eu³⁺ was studied in order to construct vacuum referred binding energy (VRBE) schemes with the aim to further understand the luminescence properties of (Ca,Sr)₂Al₂SiO₇:Ce³⁺. Finally, X-ray excited luminescence (XEL) spectra were measured to evaluate the possibility of (Ca,Sr)₂Al₂SiO₇:Ce³⁺ as a scintillation material.