Laser-Controlled Information Releasing and Hiding Based on Perovskite Phosphors

Laser-active interference with high confidentiality and convenience opens up a cutting-edge path for releasing and hiding key targets; however, its development still faces enormous challenges owing to the difficulty of concealing objects. Herein, a novel conceptual design for laser-controlled information release and hiding (LIRH) is proposed and successfully realized. Cs₂NaInCl₆:Er³⁺, Yb³⁺ (CNIC:Er, Yb) perovskite microcrystal is adopted as a carrier for LIRH implementation, exhibiting excellent up-conversion (UC) emission under NIR (980 and 1530 nm) irradiation due to its ultralow phonon energy. The fluorescence intensity crossover and outstanding photon output capacity are revealed in comparison with Er³⁺/Yb³⁺ codoped and Er³⁺ single-doped CNIC phosphors under different laser sources, and the obvious difference in quantum yields (QY) under 980 and 1530 nm excitation provides theoretical possibility for LIRH. More importantly, the obtained LIRH features high stability at temperatures up to 413 K, showing good adaptability in various potential scenarios. Moreover, CNIC:Er, Yb is further combined with polyacrylonitrile (PAN) polymer to form fluorescent fibers with exceptional crystal stability and composite flexibility, thus making the LIRH code a reality based on perovskite composite phosphors. The laser-active invisibility offers an innovative idea for LIRH, further extending the application of LIRH in the field of information encryption, which has promising prospects in information safety, advanced anticounterfeiting, and smart responsive materials.