Fig. 4: Spatio-temporal quasi-particle carrier evolution.
From: Nanoscale heterogeneity of ultrafast many-body carrier dynamics in triple cation perovskites
a Instantaneous relaxation rate images derived from the set of spatio-temporal images of Fig. 2c via bi-exponential fitting. b Corresponding temporal evolution of polaron effective stabilization energy Ep and polaron delocalization radius R, or Drude scattering time τD, based on the relationship derived in Fig. 3e, f. c Increase of R(T) (polaron absorption model) or τD (Drude scattering time) at two selected sample locations indicated in panel b, showing the spatial heterogeneity in the dynamic evolution of polaron size or carrier mobility. d Cartoon indicating the spatially non-uniform electron-lattice coupling as a potential underlying mechanism for heterogeneous carrier relaxation dynamics, which in turn results in the heterogeneity in carrier recombination and relaxation. Larger polarons associated with longer lifetime promote charge separation whereas smaller polarons with shorter lifetime are more susceptible to carrier recombination.
