Magnetoabsorption of the lowest exciton in perovskite-type compound (CH3NH3)PbI3

Magnetoabsorption spectra of (CH3NH3)PbI3 are investigated in the Faraday configuration up to 40 T at 4.2 K. The compound consists of three-dimensional networks of corner-sharing octahedra [PbI6]4−. The Zeeman splitting and the diamagnetic shift are observed, and the effective g-factor and the diamagnetic coefficient are 1.2 ± 0.1 and (2.7 ± 0.1) × 10−6eV/T2, respectively. From the diamagnetic shift, the Bohr radius, the binding energy and the reduced mass of the exciton are estimated to be 28 Å, 37 meV and 0.12m0, respectively. The exciton in (CH3NH3)PbI3 is one of typical Wannier-type excitons with large radius, which is in contrast with the exciton in (C10H21NH3)2PbI4, consisting of two-dimensional networks of [PbI6]4−.