Dynamic anti-counterfeiting and information encryption of Sr3Y2Ge3O12: Tb3+, Er3+ phosphor via carriers filling and release processes

In this work, we have successfully synthesized SYGO: Tb3+ and SYGO: Tb3+, Er3+ phosphor with multi luminescent performances, including PL, LPL, ML, PSL and PSL-UC processes. Based on the time-dependent filling and release rate of carriers at shallow traps, the dynamic anti-counterfeiting technique is achieved by modulating the UV pre-irradiation time and the prolonged recorded time. [Display omitted] •The dynamic anti-counterfeiting materials with multi-dimensional luminescence modes (PL, LPL, PSL, ML and UC) are realized in the Tb3+ doped and Tb3+/Er3+ co-doped Sr3Y2Ge3O12 phosphors.•The carrier release rates of Sr3Y2Ge3O12:Tb3+ and comparison samples SrAl2O4: Eu2+, Dy3+ phosphors were studied by modulating the UV pre-irradiation time or switch-off time to achieve a diverse dynamic information encryption strategy.•Based on the PL, LPL, ML, PSL, and PSL-UC behaviors of the SYGO: Tb3+, Er3+ phosphor, the anti-counterfeiting dynamic model are successfully realized. Complex and high-security-level anti-counterfeiting strategies with multiple luminescent modes are extremely critical for meeting the requirement of constantly developing information storage and information security. In this work, Tb3+ ions doped Sr3Y2Ge3O12 (SYGO) and Tb3+/Er3+ co-doped SYGO phosphors are successfully fabricated and are unitized for anti-counterfeiting and information encoding under distinct stimuli sources. The green photoluminescence (PL), long persistent luminescence (LPL), mechano-luminescence (ML), and photo-stimulated luminescence (PSL) behaviors are respectively observed under the stimuli of ultraviolet (UV), thermal disturbance, stress, and 980 nm diode laser. Based on the time-dependence of the filling and releasing rate of the carriers from the shallow traps, the dynamic information encryption strategy is proposed by simply changing the UV pre-irradiation time or shut-off time. Moreover, a tunable color from green to red is realized by prolonging the 980 nm laser irradiation time, which is attributed to the elaborate cooperation of the PSL and upconversion (UC) behaviors. The anti-counterfeiting method based on SYGO: Tb3+ and SYGO: Tb3+, Er3+ phosphors herein possess an extremely high-security level with attractive performance for designing advanced anti-counterfeiting technology.