Fluorescent, multifunctional anti-counterfeiting, fast response electrophoretic display based on TiO/CsPbBr composite particles.

Traditional optical anti-counterfeiting (AC) is achieved by static printed images, which makes them susceptible to lower levels of security and easier replication. Therefore, it is essential to develop AC device with dynamic modulation for higher security. Electrophoretic display (EPD) has the advantages of low power consumption, high ambient contrast ratio, and capability of showing dynamic images which is suitable for dynamic AC applications. Herein, we prepared a dynamical AC device based on a fluorescent EPD, and achieving the image switch between black, white, and green fluorescence states under the dual-mode driving (electronic field and UV light). We loaded perovskite quantum dots (CsPbBr) onto the TiO particles and further prepared fluorescent electrophoretic particles TiO/CsPbBr-3-PLMA (TiO/CPB-3) by grafting and polymerizing method. In addition, we fabricated the AC devices based on the fluorescent EPD, which exhibits the multifunctional AC, where the fluorescent EPD has a fast response time of 350 ms, a high contrast ratio of 17, and bright green fluorescence. This prototype demonstrates a new way for future dynamic AC and identification.