Synthesis and optical characterization of Ba2La3(SiO4)2(PO4)O:Dy3+ yellow phosphors with abnormal thermal quenching

This research involved the synthesis of a series of single-phase oxyapatite-type phosphors, Ba 2 La 3 (SiO 4 ) 2 (PO 4 )O:Dy 3+ through a high-temperature solid-state reaction methodology. A comprehensive examination was undertaken to elucidate their crystallographic structure, phase homogeneity, morphological features, photoluminescence (PL) properties, and thermal stability. Phase purity was meticulously assessed via X-ray diffraction (XRD) analysis, confirming the hexagonal crystal system alignment with space group P 6 3 / m (No.176) for the Ba 2 La 3 (SiO 4 ) 2 (PO 4 )O:Dy 3+ phosphors. Excitation at 349 nm revealed a triplet of distinguished emission peaks situated at wavelengths of 480 nm (attributed to the 4 F 9/2 - 6 H 15/2 transition), 572 nm (corresponding to 4 F 9/2 - 6 H 13/2 ), and 664 nm (stemming from 4 F 9/2 - 6 H 11/2 transitions). The investigation pinpointed a 0.05 mol concentration of Dy 3+ as the optimum doping level within the Ba 2 La 3 (SiO 4 ) 2 (PO 4 )O matrix for maximized luminescence. Of note, these phosphors exhibit an abnormal thermal quenching behavior alongside a substantial activation energy barrier E a  = 0.37 eV, underscoring their robustness at elevated temperatures. The exhaustive findings from this study for advocating the application of these phosphors in light-emitting devices.