(a) Schematic illustration of the MAPbI₃ memristor illuminated by broadband visible light. (b) Formation and inhibited growth of CF during light stressing and removal, respectively. (c) Inhibiting formation (left) and accelerating annihilation (right) of CFs under light illumination.^[50] Copyright (2018) American Chemical Society. (d) ToF-SIMS image of the iodide distribution in light-illuminated region. (e) Iodide distribution (right axis) in line scan area of the blue arrow in (d) and spatial profile of the illumination (blue line) (left axis).^[87] Copyright (2016) Springer Nature. (f) The formation of thinner oxygen vacancy filament and the interstitial oxygen ions released in the neighborhood of the filament with low compliance current level (CCL). (g) Disruption of filament by photo-excited interstitial oxygen ions migration to recombine with the filament vacancies. (h) Formation of the stronger filament at a higher CCL with fewer interstitial oxygen. (i) Partial disruption of filament due to limited supply of photo-excited migration of interstitial and lattice oxygen ions.^[89] Copyright (2015) AIP Publishing LLC.