Bi‐Doped Perovskite for High‐Performance Magnetic‐Optical Applications

Abstract Perovskite magneto‐optical (MO) materials are widely studied for the preparation of nonreciprocal photonic devices. Specifically, cubic perovskite materials exhibit significant MO effects in the visible light band. It is found that heavy element bismuth (Bi)‐doped MAPbBr ₃ can enhance spin‐orbit coupling effects and generate defect energy levels. Essentially, this doping increases the probability of electronic transitions and alters the energy of electronic transitions, thereby enhancing the MO effect of perovskite. Here, the optimization approach is investigated for perovskite MO materials and prepare methylammonium lead bromide (MAPbBr ₃ ) films doped with varying concentrations of Bi ranging from 1–20% using the spray method. The experimental results of the Faraday rotation angle indicate that the 1% Bi‐doped MAPbBr ₃ film achieved a 61.3% performance improvement compared to the MO material terbium gallium garnet material at a wavelength of 650 nm. Such low‐cost, easy‐to‐prepare, and high‐quality perovskite films provide important insights for designing and fabricating high‐integration nonreciprocal photonic devices.