Preparation and Luminescence Properties of Long-persistent Phosphor Ba5 SiO4 Cl6:Eu2+,Ln3+
Ba5SiO4Cl6∶Eu2+,Ln3+blue long-persistent phosphors were synthesized by high-temperature solid-state method and their structure and luminescence properties were characterized by means of X-ray diffraction,excita-tion and emission spectroscopy,afterglow decay curves,afterglow spectroscopy and thermoluminescence.The re-sults showed that under the excitation of UV light at 347 nm,both Eu2+single-doped and Eu2+,Ln3+co-doped phos-phors emit bright blue light,and the emission spectra showed that they have two obvious peaks located at 440 nm and 500 nm,which belong to the characteristic emission of Eu2+at different lattice positions(4f 65d1-4f 7).The in-corporation of Ln3+introduced hybrid energy levels within the bandgap,resulting in traps of varying depths,which enhanced the afterglow performance of the material to different extents.Among them,the Ba5SiO4Cl6∶Eu2+,Ho3+samples showed the best performance with an afterglow time of more than 12 h.The Ba5SiO4Cl6∶Eu2+,Er3+samples showed a 12-fold increase in the initial brightness compared to the singly doped samples.The doping of Dy3+effec-tively increased the concentration of the deep traps(T2)in the sample,which was expected to be used for optical data storage.
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