Stable Ultrathin Perovskite/Polyvinylidene Fluoride Composite Films for Imperceptible Multi-Color Fluorescent Anti-Counterfeiting Labels

As an essential part of information security in the Internet of Things (IoT), fluorescent labels possess a principal portion of anti-counterfeiting due to its easy fabrication, low cost, and high yield. Here an ultrathin, stable, and patterned multi-color fluorescent label with perovskite/polyvinylidene fluoride composite film is presented, which registers a resolution of 56.4 dpi and almost maintains its original fluorescent intensity after being immersed in water for 120 h. The variable color of fluorescent labels will improve the anti-counterfeiting dimensions for the information security due to precise halogen constitutions. The imperceptible fluorescent labels are typically with a thickness of 1.2 um and a weight of 1.2 mg. They can be conformally adhered on the arbitrary curved substrate as the intelligent multi-color fluorescent anti-counterfeiting labels for IoT applications.