Self-Activated Cubic Magnesium Stannate Afterglow Phosphors With Widely Distributed Traps for Dynamic Information...

Through performance regulation of long afterglow luminescent materials (color, decay time of afterglow, and regulation of excitation mode), the multifunctional applications in bio-labeling and information encryption fields have been extensively developed. At present, a common approach is to regulate the afterglow performance by adjusting the trap concentration, but the effect is limited. Therefore, regulating the trap distribution of long afterglow luminescent materials is considered an effective means of controlling its performance. Herein, a series of Mg_2-xZn_xSnO₄ (x = 0, 0.25, 0.5, 0.75, and 1) powder samples were prepared. As can be seen from the afterglow decay spectra, materials exhibited cyan photoluminescence under the excitation wavelength of 254 nm. Meanwhile, in the process of trap regulation, we controlled the distribution of traps by adjusting the doping concentration of Zn²⁺, thus obtaining trap adjustable materials. The proportion of shallow traps gradually enhances with the increase of the concentration of Zn²⁺. Lastly, only shallow traps remain in Mg_1.25Zn_0.75SnO₄ and MgZnSnO₄ samples. In order to demonstrate the feasibility of phosphors for anti-counterfeiting, we create two optical devices. The dynamic information encryption of numbers and patterns was achieved. This dynamic luminescence phosphor shows important potential in anti-counterfeiting and information encryption.