Using synchrotron radiation, a comparative VUV excitation study of YAG ceramics doped with Eu³⁺ and Cr³⁺ ions under VUV excitation (10.5–3.7 eV) at 9 K was conducted in this work. Both ceramics exhibit distinct excitation peaks in the VUV region, indicating high-energy transitions related to the internal electronic levels of the dopants and interband transitions within the YAG matrix. For YAG:Eu, the main excitation peaks at 6–7 eV correspond to transitions within the 4f-shell of Eu³⁺ and Eu³⁺-O²⁻ charge transfer states, showing weak dependence on the crystal field and high energy conversion efficiency. In contrast, YAG:Cr shows broad excitation bands due to transitions between levels influenced by strong crystal field interactions, resulting in lower luminescence efficiency. The study highlights the importance of crystal structure and dopant interactions in determining the spectral characteristics of YAG-based ceramics, offering potential for their application in advanced optoelectronic devices.

The results of the calculation of the energy band structure and luminescent research of CeF₃ crystals are presented. The existence of two 5d1 and 5d2 subbands of the conduction band genetically derived from 5d states of Ce³⁺ ions with different effective electron masses of 4.9 m_e and 0.9 m_e, respectively, is revealed. The large electron effective mass in the 5d1 subband facilitates the localization of electronic excitations forming the 4f-5d cerium Frenkel self-trapped excitons responsible for the CeF₃ luminescence. The structure of the excitation spectra of the exciton luminescence peaked at 290 nm, and the defect luminescence at 340 nm confirms the aforementioned calculated features of the conduction band of CeF₃ crystals. The peculiarities of the excitation spectra of the luminescence of CaF₂:Ce crystals dependent on the cerium concentration are considered with respect to the phase formation possibility of CeF₃.

The glass-ceramic materials studied in this work are designed using combinations of lithium vanadate borate glass matrices and lanthanum/rare earth (RE) vanadate nanoparticles. Three different techniques of sintering of the glass matrix and vanadate nanoparticles are investigated. The morphological characteristics and spectral properties of the glass-ceramic samples obtained by different techniques are investigated and analyzed in comparison with the properties of the original glass matrices and nanoparticles. The luminescence spectra of all glass-ceramic samples consist of a wideband glass matrix emission and the characteristic line emission of the RE ions that are incorporated into the glass matrices as nanoparticles. The RE luminescence of these glass-ceramics is promising for various optoelectronic applications.