Fig. 3
Surface potential evolution of perovskite solar cells at the nanoscale;22 a topography and b dark-KPFM measurements on a representative area. A sequence of fast-KPFM measurements were acquired on the region highlighted by the white dashed square in a, b: c dark-KPFM, d illuminated-KPFM, e–h dark-KPFM scans as a function of time, and i histograms of voltage distribution as a function of time showing reversible dynamics upon a sequence of dark scans. (Reprinted with permission from ref. 22 Copyright 2017 American Chemical Society)
