A new path to design near-infrared persistent luminescence materials using Yb3+-doped rare earth oxysulfides

Abstract RE 2 O 2 S:Yb 3+ and RE 2 O 2 S:Yb 3+ ,Ti,Mg 2+ near-infrared persistent luminescence materials (RE 3+ : La, Gd, Y) were designed based on the efficient red-emitting RE 2 O 2 S:Eu 3+ ,Ti,Mg 2+ , due to the similar ground state level positions between Eu 3+ and Yb 3+ . The Y 2 O 2 S:Yb 3+ ,Ti,Mg 2+ showed the longest near-infrared (~983 nm) persistent luminescence time (~1 h) when excited at the charge transfer transition, demonstrating that Ti,Mg 2+ co-doping enhances the persistent luminescence only for the Y 2 O 2 S host. The unprecedented relationship between Eu 3+ and Yb 3+ persistent luminescence opens a new path in the systematic design of efficient Yb 3+ -activated persistent luminescence materials e.g. Y 2 O 2 S:Yb 3+ ,Ti,Mg 2+ , which present potential for photonic applications such as bioimaging probes.