Magnetic Field Induced Circular Polarization of Photoluminescence from Manganese Doped Perovskites

Abstract 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 BA₂Pb_0.8Mn_0.2Br₄ （BA = butylamine）, where exciton and Mn²⁺ 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 Mn²⁺ emission under ±1.6 T. Structural analyses confirm the substitution of Pb²⁺ with Mn²⁺ in the perovskite lattice, while magnetic measurements reveal the paramagnetic nature of BA₂Pb_0.8Mn_0.2Br₄, originating from the high‐spin configuration of Mn²⁺. Zeeman splitting for both the ground state and excited state is considered for Mn²⁺, generating CPL signals opposite to those of exciton emission. This observation is further validated in Mn²⁺‐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.