Luminescent and Scintillation Properties of LiLu(PO ₃ ) ₄ : Pr ³⁺ Nanophosphor

Background: Recent advancements in luminescent materials have drawn significant interest due to their wide-ranging applications in radiation detection, lighting, and display technologies. Praseodymium-doped phosphates, in particular, have shown promise because of their unique luminescent and scintillation properties. Objective: This study aims to synthesize, characterize, and evaluate the luminescent and scintillation properties of praseodymium-doped polyphosphate LiLu(PO3)4, focusing on the potential applications of these materials. Methods: LiLu(PO3)4:Pr3+ microcrystals were synthesized using the flux method, while nanocrystals were produced via the coprecipitation technique. The synthesized polyphosphates were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. Results: LiLu(PO3)4:Pr3+ crystals were found to crystallize in the monoclinic C2/c space group with specific lattice parameters. The structural analysis revealed that the basic units are helical ribbons of (PO3)n formed by corner-sharing PO4 tetrahedra, with LuO8 dodecahedra and LiO4 tetrahedra forming linear chains. The incorporation of praseodymium ions resulted in the observation of both ultraviolet and visible luminescence under X-ray and laser excitations. UV emission, originating from 4f-5d → 4f2 transitions, exhibited a very fast lifetime (τ4f-5d = 3 ns), while visible emission from transitions within the Pr3+ 4f2 ground configuration showed a short decay time of approximately 100 ns. Conclusion: The scintillation properties of LiLu(PO3)4:Pr3+ demonstrated promising results, indicating their potential for various high-performance applications, including solid-state lighting, bioimaging, and radiation detection.