Doping Mn²⁺in hybrid Ruddlesden-Popper phase of layered double perovskite (BA)₄AgBiBr₈

The layered hybrid double perovskites emerged as excellent semiconductor materials owing to their environment compatibility and stability. However, these materials are weakly luminescent, and their photoluminescence (PL) properties can be modulated via doping. While Mn²⁺doping in perovskites is well known, but to the best of our knowledge the doping of Mn²⁺in layered double perovskites (LDPs) is yet to be explored. Herein, for the first time, we demonstrate the doping of Mn²⁺in hybrid inorganic-organic two-dimensional (2D) LDPs, (BA)₄AgBiBr₈(BA = n-butyl amine) via a simple solid-state mechanochemical route. The powder x-ray diffraction pattern, and electron paramagnetic resonance analysis confirm the successful incorporation of Mn²⁺ions inside (BA)₄AgBiBr₈lattice. The Mn²⁺doped 2D LDP shows energy transfer from host excitons to d-electrons of Mn²⁺ions, which results in red-shifted broad Mn²⁺emission band centered at 625 nm, attributed to thespin-forbidden⁴T₁to⁶A₁internal transition. This work opens up new possibilities to dope metal ions in 2D LDPs to tune the optical as well as magnetic properties.