Multimodal and Multicolor Anti-counterfeiting Realized in CaCd 2 Ga 2 Ge 3 O 12 with a Single Activator of Mn 2 .

The continuously growing significance of information security and authentication has put forward many new requirements and challenges for modern luminescent materials and anti-counterfeiting technologies. Recently, luminescent materials have attracted much attention in this field owing to their legibility, repeatability, multicolor, and multiple stimuli-responsive nature. In this work, the efficient multicolor and multimodal luminescence material CaCd 2 Ga 2 Ge 3 O 12 :Mn 2+ was successfully designed and synthesized using the strategy of single-doped Mn 2+ in a single matrix. Also, we combined the morphology, crystal structure, energy band calculation, luminescence properties, and trap analysis to study the optical data storage capacity of CaCd 2 Ga 2 Ge 3 O 12 :Mn 2+ . Interestingly, in the presence of the 254 nm UV lamp, the sample can exhibit a tunable emission color from bule to cyan to yellow by increasing the dopant concentration of Mn 2+ . Also, under the afterglow and thermoluminescence luminescence modes, it presented strong yellow emission centered at 558 nm. Based on the advantage of multiple tunable luminescence, samples were made into anti-counterfeiting ink and were used to print four optical devices through the screen printing technology. The results show that the material has excellent multicolor anti-counterfeiting properties under the three luminescence modes, which has contributed to the development of many kinds of luminescent anti-counterfeiting materials for security purposes.