Impact of anisotropy in spin-orbit coupling on the magneto-optical properties of bulk lead halide perovskites

Abstract

The renaissance of interest in halide perovskites, triggered by their unprecedented performance in optoelectronic applications, elicited worldwide efforts to uncover a variety of intriguing physical properties, with a particular interest in spin-orbit effects. The current work presents the first magneto-optical experimental evidence for anisotropic electron-hole interactions arising from bulk orthorhombic MAPbBr3. Magneto-photoluminescence spectra, monitored along with several different crystallographic directions, were dominated by dual exciton emission peaks, while each exhibited a highly nonlinear response to a magnetic field. Moreover, these plots depicted asymmetry from -B0 to +B0, with a strong dependence on the axis of observations. A theoretical model implementing anisotropy in the electron-hole interaction, Rashba effect, Landé g factors, and a lesser contribution from an Overhauser effect, corroborated the experimental results. These research discoveries expand the possible applications of excitons in halide perovskites toward optoelectronic and information devices.