a, PCE extracted from continuous MPP tracking (red curve) versus periodic J–V scans collected from forward to reverse bias (black circles) for the same PSC. b, Normalized PCE of PSC subjected to repeated 12 h light on–off cycles at 25 °C and 10% RH. c, PCE evolution of PSCs exposed to continuous (blue curve) or cycled (6/6 h, red curves) illumination by white-light-emitting diodes. d, Normalized PCE changes of PSCs exposed to different forward bias in the dark. e, Light J–V curves for a fresh PSC, after 1 min at −20 mA cm–2 and after recovering for over 3 h of MPP tracking. Panel a was adapted with permission from ref. 8, Elsevier; panel b was adapted with permission from ref. 82, Elsevier; panel c was adapted with permission from ref. 4, Springer Nature Ltd; panel d was adapted with permission from ref. 26, the American Chemical Society; panel e was adapted with permission ref. 88, John Wiley and Sons.