Figure 4.

Charge-carrier mobility changes indicative of excited-state localization. (a) Temperature dependence of the localization rate (k_loc, blue crosses) within the two-state mobility model for Cs₂AgBiBr₆. The red dashed line indicates the mean value, with its uncertainty represented by the red shaded area. (b) Temperature dependence of the effective charge-carrier mobilities associated with the delocalized (μ_deloc, green) and localized (μ_loc, blue) states. Power-law fits are plotted as solid lines in the corresponding colors, with their exponents (p) displayed alongside. The data points for μ_deloc at the lowest two temperatures were not included in the fit as the power-law model becomes unphysical in this region, indicated by the dashed green line. The mobilities are “effective” since the photon-to-charge branching ratio, ϕ, is not necessarily 1.