Multiple Anti-Counterfeiting and optical storage of reversible dual-mode luminescence modification in photochromic CaWO4: Yb3+, Er3+, Bi3+ phosphor

[Display omitted] •Double-light induced reversible photochromism was realized in CaWO4: Yb3+, Er3+, Bi3+ phosphor.•Dual-mode luminescence modification was observed.•Multiple anti-counterfeiting can be obtained based on the photochromism and luminescence modification.•Dual-mode optical storage can be realized upon the UV and near infrared light excitation. Luminescence modification of rare earth ions doped phosphors based on photochromism is beneficial to expand their practical applications. Here, Bi3+ co-doping CaWO4: Yb3+, Er3+ phosphor is prepared. Color of CaWO4: Yb3+, Er3+, Bi3+ phosphor turn black grey upon the 254 nm ultraviolet light irradiation due to Bi3+ co-doping induced formation of the defects. Black grey CaWO4: Yb3+, Er3+, Bi3+ phosphor can recover their color to the primitive state under the stimulation of 473 or 532 nm lasers, exhibiting the double-light induced reversible photochromism. Dual-mode upconversion and downshift luminescence of CaWO4: Yb3+, Er3+, Bi3+ phosphor is reversibly modified based on its photochromism property. Potential applications of CaWO4: Yb3+, Er3+, Bi3+ phosphor are explored. The CaWO4: Yb3+, Er3+, Bi3+ phosphor is formulated into the inks, printed on the flexible substrate by the screen-printing technology. The luminescence color of printed various patterns can be changed based on the dual-mode luminescence modification, which demonstrate that the CaWO4: Yb3+, Er3+, Bi3+ phosphor ink is an ideal multiple anti-counterfeiting agent. The optical information recorded on the binary photochromic dot arrays of CaWO4: Yb3+, Er3+, Bi3+ sheet could be read upon the UV and near infrared light excitation, exhibiting the potential application of CaWO4: Yb3+, Er3+, Bi3+ phosphor as optical data storage medium.