Advanced Luminescent Material for Multikey Static and Dynamic Anticounterfeiting and Information Encryption

Current static luminescent anticounterfeiting techniques exhibit limited security efficacy, highlighting an urgent demand for more advanced anticounterfeiting technologies. In this study, we present a persistent luminescent material, Zn<inf>2.95</inf>Ga<inf>2</inf>SnO<inf>8</inf>:Cr³⁺/Ho³⁺/Yb³⁺, which additionally demonstrates upconversion (UC) emission capabilities. The multifaceted emission characteristics of this material were utilized to create a high-concealment information encryption-decryption label. Our investigation indicates that the persistent luminescence (PersL) is attributable to the presence of suitably positioned traps within the phosphor matrix. Importantly, the phosphor also exhibits near-infrared (NIR) excited PersL, resulting from energy transfer processes between Ho³⁺and Cr³⁺ions. We successfully showcased the potential for dynamic anticounterfeiting and dual-mode information encryption-decryption by integrating this versatile material into anticounterfeiting patterns. The capacity to excite these phosphors using cost-effective UVA flashlights, combined with the visibility of their emissions to the naked eye and standard smartphone cameras, underscores their viability for large-scale applications in anticounterfeiting and secure information technologies.