Unexpected Anisotropy of the Electron and Hole Landé g-Factors in Perovskite CH(3)NH(3)PbI(3) Polycrystalline Films

In this work, we studied, at low temperature, the coherent evolution of the localized electron and hole spins in a polycrystalline film of CH(3)NH(3)PbI(3) (MAPI) by using a picosecond-photo-induced Faraday rotation technique in an oblique magnetic field. We observed an unexpected anisotropy for the electron and hole spin. We determined the electron and hole Landé factors when the magnetic field was applied in the plane of the film and perpendicular to the exciting light, denoted as transverse [Formula: see text] factors, and when the magnetic field was applied perpendicular to the film and parallel to the exciting light, denoted as parallel [Formula: see text] factors. We obtained [Formula: see text] , [Formula: see text] for the electron and [Formula: see text] , [Formula: see text] for the hole. Possible origins of this anisotropy are discussed herein.