Cationic Effects on Photo- and X-ray Radioluminescence of K 3 RE(PO 4 ) 2 :Ce 3+ /Pr 3+ (RE = La, Gd, and Y) Phosphors toward X-ray Detection

• Published in: Inorganic chemistry 2023-04, Vol.62 (15), p.6181-6188
• Main Authors: Ou, Yiyi, Zhou, Weijie, Dorenbos, Pieter, Liang, Hongbin
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.3c00566

Cationic tuning for lanthanide (Ce /Pr )-activated inorganic phosphors with stable, efficient, and fast-decay 5d-4f emissions has emerged as an important strategy toward the continuing pursuit of superior scintillators. The in-depth understanding of the cationic effects on photo- and radioluminescence of lanthanides Ce and Pr centers is requisite for the rational cationic tuning. Here, we perform a systematic study on the structure and photo- and X-ray radioluminescence properties of K RE(PO ) :Ce /Pr (RE = La, Gd, and Y) phosphors to elucidate the underlying cationic effects on their 4f-5d luminescence. By using the Rietveld refinements, low-temperature synchrotron-radiation vacuum ultraviolet-ultraviolet spectra, vibronic coupling analyses, and vacuum-referred binding energy schemes, the origins of lattice parameter evolutions, 5d excitation energies, 5d emission energies, and Stokes shifts as well as good emission thermal stabilities of K RE(PO ) :Ce systems are revealed. In addition, the correlations of Pr luminescence to Ce in the same sites are also discussed. Finally, the X-ray excited luminescence manifests that the K Gd(PO ) :1%Ce sample possesses a light yield of ∼10,217 photons/MeV, indicating its potentiality toward X-ray detection application. These results deepen the understanding of cationic effects on Ce and Pr 4f-5d luminescence and inspire the inorganic scintillator development.