About carrier's self-trapping and dynamical Rashba splitting in the two-dimensional hybrid perovskite (BA) 2 (MA) 2 Pb 3 I 10

Time-and Angle-Resolved Photoelectron Spectroscopy is employed to monitor photoexcited electrons in the two-dimensional (BA)2(MA)2Pb3I10. ARPES intensity maps are in good agreement with ab-initio calculations of the band structure. The effective mass is -0.18 ± 0.02me and 0.12 ± 0.02me for holes and electrons, respectively. In the photoexcited state, spin-orbit splitting of the conduction band cannot be resolved. This sets the upper bound of photoinduced Rashba coupling to αC < 2.5 eV Å. The correlated electron-hole plasma evolves in Wannier excitons with Bohr radius of 2.5 nm, while no sign of self-trapping in small polarons is found within the investigated time window of up to 120 ps following photoexcitation.