Extended Data Fig. 9: TR-PEEM data from a Cs0.05FA0.78MA0.17Pb(I0.83Br0.17)3 thin film sample.
From: Performance-limiting nanoscale trap clusters at grain junctions in halide perovskites
a, Percentage change in the PEEM intensity (4.65-eV probe) after pump excitation (1.55 eV), averaged over all trap sites in the ~10 × 10 μm2 field of view. Here, the pump fluence is ~100 μJ cm−2 per pulse, due to the low absorption at this photon energy. The grey line is a fit to a double exponential, yielding the amplitudes and time constants A1 = 2.0 ± 0.3, A2 = 4.2 ± 0.4, τ1 = 1.3 ± 0.5 ps and τ2 = 300 ± 80 ps, where the error is the standard error of the fit . b, Zoom-in of the signal at shorter time delays, where the fast component of the signal can be more easily seen. c, PEEM image of a cluster of trap sites. d, TR-PEEM difference images of c at several pump-probe time delays.
