Fig. 6. (A and B) Time-resolved transient absorption spectra recorded following 400 nm laser pulse excitation (32 μJ cm−2) of 2D mixed halide perovskite films with (A) BA and (B) PDMA. (C) Normalized bleach recovery profiles of 2D mixed halide perovskites with BA, BDA, and PDMA before 405 nm diode laser irradiation. (D) Time-resolved transient absorption spectra of 2D mixed halide perovskite films with BA after 405 nm laser diode excitation (25 mW cm−2) for 10 min. (E) Bleach recovery profile at the I-rich domain peak (around 505 nm) recorded before (black) and after photoirradiation (blue) of 2D mixed halide perovskites with BA ligands. The inset of (E) shows the magnified kinetics at an earlier time scale of 0–5 ps. (F) Energy diagram of phase segregation and corresponding e–h transfer across the halide phases.
