Simultaneous achievement of sensitivity enhancement and dual-mode luminescence through co-doping Eu3+ in Ca2MgWO6:Er3+/Yb3+ phosphor

Demands for temperature probe technologies and information security have driven the development of luminescent materials doped with lanthanide ions (Ln3+) because of their distinctive optical properties. Nevertheless, the problems of poor temperature sensing performance and single-mode luminescence restrict most materials' applications in the fields of temperature sensing and optical anti-counterfeiting. Herein, we have effectively achieved the enhancement of the temperature sensing sensitivity factor and the multi-mode anti-counterfeiting at the same time by co-doping Eu3+ in the up-conversion Ca2MgWO6:Er3+/Yb3+ material. The maximum absolute sensitivity based on the 2H11/2/4S3/2 couples of Er3+ increased from 81.83 x 10-4 K-1 at 423 K to 88.12 x 10-4 K-1 at 398 K, which was attributed to the energy transfer between Er3+ and Eu3+ which increases the fluorescence intensity ratio values. Utilizing the down-conversion luminescence characteristics of Eu3+ ion, phosphors exhibited color tunability under 980 nm and 365 nm excitations to achieve dual-mode anti-counterfeiting function. Meanwhile, the fluorescent anti-counterfeiting pattern prepared by screen printing technology helped materials towards emerging anti-counterfeiting applications. Therefore, the novel phosphors have potential applications in noncontact temperature sensing and optical anti-counterfeiting security fields.