Smart tri-mode imaging material for on-demand visual encryption and dynamic displays

Abstract

This study demonstrates the synergistic integration of X-ray-induced radioluminescence (RL), persistent luminescence (PersL) and radio-photoluminescence (RPL) in a single material system, which provides innovative multimodal applications for radiometric information sensing, storage and reading, anti-counterfeiting and imaging. A novel radiation-sensing material, BaMgP₂O₇:Sm, was prepared using a high temperature solid state method. Under X-ray irradiation, the pale pink phosphor shows distinct luminescence from defects. Under 365 nm ultraviolet (UV) light (bright-field), it emits bright red light, confirming trivalent samarium (Sm³⁺) reduction to divalent samarium (Sm²⁺). In dark-field, orange fluorescence appears, indicating defect-mediated charge storage and slow release. Notably, the material enables single-irradiation multiple imaging, effectively overcoming the limitation of conventional materials that only allow single imaging per irradiation event, thereby greatly enhancing information utilization and imaging flexibility. Moreover, the flexible film based on polydimethylsiloxane (BaMgP₂O₇:Sm@PDMS) demonstrates remarkable tri-mode X-ray detection and imaging capabilities, it has a high spatial resolution of 14.4 lp mm⁻¹, integrating real-time readout, delayed readout, and long-term information storage. BaMgP₂O₇:Sm enables dynamic anti-counterfeiting via time-dependent luminescence and precise radiation dose monitoring through X-ray responsive emission, these features make it a promising multifunctional material.