Enhanced yellow afterglow in Ca₂SnO₄:Dy³⁺ by co-doping Na⁺/K

A new yellow long afterglow luminescent material Ca₂SnO₄:Dy³⁺ was prepared by the solid state method at 1350 °C. The yellow LLP (long-lasting phosphorescent) material Ca₂SnO₄:Dy³⁺ was prepared by co-doping alkaline ions (K⁺ and Na⁺) and investigated using an X-ray diffractometer (XRD), photoluminescence spectrometer, afterglow meter and thermoluminescence spectrometer. The excitation and emission spectra showed an excitation peak at 350 nm and an emission peak at 573 nm. The optimized Dy³⁺ dopant concentration was found to be 1 mol%. For the improvement in the photoluminescence performance, we can co-dope it with alkaline ions (K⁺ and Na⁺), with the optimal concentration of the alkaline ions being 1 mol%. On the basis of the experimental results, we constructed a probable model for explaining the mechanism of LAG in detail.