Exciton diamagnetic shifts and spin dynamics in lead halide perovskites under high magnetic fields

Semiconductor lead halide perovskites have attracted significant attention for various applications. Understanding the impact of material composition on optical properties is essential for optimizing device performance. Here, we performed magneto-optical spectroscopy on high-quality bulk CsPbBr3, MAPbBr3, and MAPbI3 single crystals under magnetic fields of up to 30 T. The results revealed distinctive excitonic responses to the magnetic field, with bromide-based perovskites exhibiting modest diamagnetic shifts, while MAPbI3 showed a more pronounced response, even including an emission peak with a negative diamagnetic coefficient. Analysis of the magnetic-field induced photoluminescence circular polarization revealed slow exciton spin dynamics, with comparable spin relaxation and radiative recombination times across all perovskites. Our insights enhance the understanding of the complex interactions between cationic and anionic influences, offering pathways for innovations in photovoltaics, optoelectronics, and quantum optics.