fig2

Figure 2. TAS of pristine PVK film under 660 nm excitation. (A-C) 2D pseudo-color plots of TAS at pump fluences of 4.5 µJ/cm² (A), 22.7 µJ/cm² (B), and 59.1 µJ/cm² (C); (D-F) Corresponding DAS extracted from global fitting of the data in (A-C), revealing the characteristic fast and slow decay components at each fluence. TAS: Transient absorption spectroscopy; PVK: pristine perovskite; DAS: decay-associated spectra.