Magnetic Field Induced Circular Polarization of Photoluminescence from Manganese Doped Perovskites

Achieving simultaneous circularly polarized luminescence (CPL) with opposite handedness introduces additional complexity in CPL modulation, which is difficult, as it requires the generation of two excited states with distinct spin orientations. Here, dual magnetic circular polarization of luminescence (MCPL) is demonstrated in BA 2 Pb 0.8 Mn 0.2 Br 4 （BA = butylamine）, where exciton and Mn 2+ d‐d emissions exhibit CPL with opposite handedness under an external magnetic field, with g MCPL values of ‐5.2/5.7 × 10 −3 for exciton emission and 2.4/‐2.1 × 10 −3 for Mn 2+ emission under ±1.6 T. Structural analyses confirm the substitution of Pb 2+ with Mn 2+ in the perovskite lattice, while magnetic measurements reveal the paramagnetic nature of BA 2 Pb 0.8 Mn 0.2 Br 4 , originating from the high‐spin configuration of Mn 2+ . Zeeman splitting for both the ground state and excited state is considered for Mn 2+ , generating CPL signals opposite to those of exciton emission. This observation is further validated in Mn 2+ ‐doped perovskites with different organic cations and dimensions, providing a new approach for modulating multi‐peak CPL with opposite handedness for applications in spintronics, quantum information, and magneto‐optical technologies.