Core-Shell Structured Upconversion/Lead-Free Perovskite Nanoparticles for Anticounterfeiting Applications

In view of their excellent luminescence properties, nanocrystalline metal halide perovskites have diverse optoelectronic applications, including those related to anticounterfeiting. However, high-quality optical anticounterfeiting typically requires multiple encryptions relying on several optical modes to ensure information security. Herein, an efficient anticounterfeiting strategy based on dual optical encryption is realized by combining up- and downconversion luminescence in a nanocomposite with NaYF4 : Er3+,Yb3+ as core and a CsMnCl3 as shell. The emission color of this nanocomposite depends on the penetration depth of incident radiation and can be changed by varying the excitation source (980 nm laser or UV light) to produce different luminescent patterns. This feature allows one to effectively improve the anticounterfeiting index and fabricate professional anticounterfeiting materials.

Automated summary

This study demonstrates an efficient anticounterfeiting strategy based on dual optical encryption by combining up- and downconversion luminescence in a nanocomposite material. The emission color of the nanocomposite can be changed by varying the excitation source, allowing for different luminescent patterns to improve the anticounterfeiting index and fabricate professional anticounterfeiting materials.