Color tunable (Ba,Ca)ScO2F: Eu2+, Bi3+, K+ perovskite with dependence of excitation wavelength for advanced anti-counterfeiting application

Fluorescent materials are widely used for anti-counterfeiting of information security and commodities. However, the increasing requirements for fluorescent anti-counterfeiting technology urgently require the development of novel fluorescent materials with multicolor fluorescence, single component, and excellent stability. Herein, a color tunable Ba 0·94 Ca 0.06 ScO 2 F: Eu 2+ , Bi 3+ , K + perovskite with dependence of excitation wavelength for high-level anti-counterfeiting is reported. The fluorescence spectra of Ba 0·94 Ca 0.06 ScO 2 F: Eu 2+ , Bi 3+ , K + perovskite show the tunable emission band with the peak between 479 and 509 nm. It is worth noting that the peak intensity ratio at 479 and 509 nm changes with the dependence of the excitation wavelength. Meanwhile, the snowflake pattern is designed to demonstrate the potential applications in anti-counterfeiting, which obviously shows four different color patterns under the sunlight, 320 360, and 415 nm excitation, respectively.