Magnetic-field-induced energy bandgap reduction of a perovskite by spin-orbit coupling via a low strength magnet
Broad impact may be anticipated when an energy bandgap is varied substantially by a small change of the physical environment. Such possibility has now been discovered by the example of perovskite structure of KMnF3 in this paper, where the photoluminescence, X-ray diffraction, scanning electron microscope and conductivity measurements were conducted, and the bandgap reduced up to 20% when a small magnet was placed beneath the substrate. It was also found that the electrical conductivity increased in the meantime by more than 15 folds under the 0.6 Tesla field strength. Such enhancement in the perovskite bandgap and transport properties were also observed by us in other structures, such as CH3NH3PbI3 and CsPbBr3.