Core-shell mutual enhanced luminescence based on space isolation strategy for anti-counterfeiting applications

Abstract

Introducing multiple rare earth ions into the same matrix can achieve multi-band emission, but would significantly worsen the otherwise excellent properties of other ions due to the annihilation mechanism. Therefore, the innovative idea of core/shell mutual enhanced luminescence is proposed based on the dual-mode luminescence of YVO4:Er3+,Yb3+@YPO4:Eu3+ oxide-based nanoparticles. This strategy of space isolation can not only effectively inhibit the energy transfer between the activators (Er3+→Eu3+), but also significantly enhances the luminescence of Er3+ in the core due to the reduction of surface defects via the protection of the shell. At the same time, the high intensity luminescence of Eu3+ in the shell is sensitized by VO43− in the core, which realizes the purpose of mutually reinforcing luminescence of the core and shell. Compared with physical mixing materials, core/shell nanoparticles achieve efficient and stable dual-mode imaging, our work introduces a promising material in anti-counterfeiting field.