Fig. 3: Transient broadband infrared absorption spectroscopy.
From: Nanoscale heterogeneity of ultrafast many-body carrier dynamics in triple cation perovskites
a Transient absorption relaxation ΔA(T) for variable carrier density (solid lines), with global fit to recombination model (Eq. (1), dashed). b Calculated carrier relaxation rate as function of injected carrier density based on fit parameter from A, with many-body regime for densities above 1019 cm−3. c Transient absorption spectra \({{\Delta }}A(\overline{\nu })\) at different pump-probe delays T for an injected carrier density of 1.7 × 1019 cm−3. Bold line - transient absorption spectra, thin line - fitting with polaron absorption model in Eq. (2). Inset: evolution of line shape based on normalized spectra. d Effective polaron stabilization energy and size evolution derived from fits of spectra in C and polaron absorption in Eq. (2). See main text Eqs. (2) and (3) and associated discussion for the details of these parameters. e Anti-correlation between instantaneous decay rate constant k and effective stabilization energy Ep and size R. f Corresponding anti-correlation between k and Drude scattering time τD extracted from Drude lineshape fitting of the data in panel c.
