Enhanced X-ray-induced luminescence and afterglow of NaLuF4:Gd3+/Tb3+ nanoparticles with Ca2+ doping

The synthesis of efficient nano-scintillators is of great significance for the development of X-ray imaging and other applications. Here, X-ray excited afterglow rare earth nanoparticles β-NaLuF4:Gd3+/Tb3+ are investigated. The X-ray-induced luminescence intensity and afterglow duration of NaLuF4:Gd3+/Tb3+ nanoparticles are effectively improved by Ca2+ doping. The optimal luminescence and afterglow performance are achieved when Ca2+ doping ratio reaches 10%. The change of crystal field symmetry is the main reason for the improvement of luminescence performance. According to the thermoluminescence curve, it is proved that Ca2+ doping increases the trap concentration and further enhances the afterglow. This study provides the research basis for the application of persistent luminescence materials in biomedical and other fields.