Magnetic optical rotary dispersion and magnetic circular dichroism in methylammonium lead halide perovskites

Abstract Large magnetic optical rotary dispersion (Faraday rotation) has been demonstrated recently in methylammonium lead bromide. Here, we investigate the prospect of extending active spectral range by altering halogen. We also origins large Faraday rotation these diamagnetic materials using circular dichroism (MCD) spectroscopy and Kramers–Kronig relations. find that, while MAPbCl 3 (MA = methylammonium) single crystals exhibit a Verdet constant blue, no appreciable is observed red/near infra‐red for MAPbI crystals. However, all film samples, clear evidence MCD resulting from Zeeman splitting highly resonant 1s exciton state. Our calculations based on data matches well with our experimental MAPbBr , some deviation magnitude—demonstrating excitonic nature materials. predict significant contrary to results, indicating potential discrepancy between properties thin crystal.