Cr3+/Er3+ co-doped LaAlO3 perovskite phosphor: a near-infrared persistent luminescence probe covering the first and third biological windows

We have developed a novel persistent phosphor of LaAlO₃ perovskite doped with Er³⁺, Cr³⁺ and Sm³⁺ (LAO:Er–Cr–Sm), which exhibits long persistent luminescence (PersL) at 1553 nm due to the Er³⁺:⁴I_13/2 → ⁴I_15/2 transition as well as at 734 nm due to the Cr³⁺:²E(²G) → ⁴A₂(⁴F) transition.