Layered hybrid metal halide perovskites, characterized by their distinctive quantum well structures and significant exciton binding energies, exhibit exceptional fluorescence properties, rendering them ideal candidates for high light yield scintillators. However, significant challenges remain in synthesizing layered metal halide perovskites with high photoluminescence quantum yields (PLQY), large Stokes shifts, and stable radioluminescence (RL). In this study, a stable Mn(II)-doped layered perovskite was successfully synthesized. Structural rigidity is largely enhanced by the unique carboxylic acid dimers, as a result reducing nonradiative recombination induced by the stretching vibration. Mn(II) doping into (HOOC