Security Optical Memory Using Multi-Stimuli-Responsive UV Phosphors

In the quest for advanced memory systems that integrate high storage capacity with robust security, optical memory based on storage phosphors has emerged as a compelling solution. Here, a co-doped UV phosphor, LuAl₃B₄O₁₂:Bi³⁺,Gd³⁺, is presented for security optical memory applications. The phosphor can be effectively charged using UV mercury lamps, storing excitation energy in the form of trapped charges. Selective release of this energy as 312 nm UV emission is achievable through various stimuli, including heat, monochromatic light, and ambient lighting, enabling controllable data retrieval. The phosphor's broad energy distribution of multi-structure traps allows for multilevel readouts, facilitating high-density data storage. Additionally, it exhibits a daylight-stimulated UV readout and exceptional cyclability (>1000 cycles), ensuring reliable performance across various environments. These attributes position the phosphor as an excellent candidate for secure optical memory devices, where sensitive data can be securely stored and accessed only through specific stimuli, thereby enhancing protection against unauthorized access.