Achieving dynamic multicolor luminescence in ZnS:KBr,Mn2+ phosphor for anti-counterfeiting

A series of ZnS:KBr,x%Mn2+ (x = 0-0.25) phosphors with dynamic multicolor luminescence are obtained by simultaneously constructing strong host luminescence and heterochromatic doping emissive center in ZnS lattice. Under a fixed ultraviolet irradiation, the phosphors emit tunable colors ranging from cyan to yellow-orange with increasing x values gradually. Besides, those Mn2+-doped phosphor (x > 0) emits different colors under different UV excitations. After removal of the UV lamp, all ZnS:KBr,Mn2+ phosphors exhibit an orange afterglow that is different from its photoluminescence (PL) color. The dynamic PL and afterglow is associated with the interactions between two PL centers and traps in the material. Therefore, spatially and temporally resolved dynamic multicolor luminescence is realized by tuning doping concentration, excitation wavelength, and observation time, which features the ZnS:KBr,Mn2+ phosphors a great application potential in high-level secure anti-counterfeiting.

Automated summary

By simultaneously constructing strong host luminescence and heterochromatic doping emissive center in ZnS lattice, a series of ZnS:KBr,x%Mn2+ (x = 0-0.25) phosphors with dynamic multicolor luminescence were obtained. The dynamic multicolor luminescence, achieved by tuning doping concentration, excitation wavelength, and observation time, shows great application potential in high-level secure anti-counterfeiting. After removal of the UV lamp, the phosphors exhibit an orange afterglow in addition to their photoluminescence color.