MAGNETOOPTICAL EFFECTS OF EXCITONS IN (C10H21NH3)2PBI4 UNDER HIGH MAGNETIC-FIELDS UP TO 40-T

Magneto-absorption spectra have been measured over the lowest-energy exciton region of (C10H21NH3)2PbI4, a layered perovskite-type material, under high magnetic fields up to 40 T at 4.2 K. The magnetic field is applied perpendicular and parallel to the layer planes. An obvious splitting and a shift of the exciton lines are observed in the perpendicular-field configuration, whereas no change is detected up to 40 T in the parallel-field configuration. This characteristic phenomenon probably occurs as the result of strong two-dimensional confinement caused by the existence, in this material, of large steps of the band gap and the dielectric constant in combination with a very thin potential-well layer.