Fig. 2: Anomalous FePV switching behavior in CIPS.

a I-V characteristic of device under illumination after applying 3 V (−3 V) V_p, plotted by the red dots (blue dots). The black dots of I-V are measured in the dark condition. b Changing behaviors of photovoltaic current as V_p scans from 3 to −3 V and back to 3 V, with magnitude illustrated by a color map. c Extracted I_sc as a function of V_p from (b). d I-V characteristic of device under illumination after applying 11.4 V (−11.4 V) V_p, plotted by the red dots (blue dots). e Changing behaviors of photovoltaic current as V_p scans from 11.4 to −11.4 V and back to 11.4 V with a step of 0.6 V. f Extracted I_sc as a function of V_p from (e). g I_sc versus time of several typical polarization states in (f). h Retention characteristics of P_down (set by 11.4 V V_p, red line) and P_up (set by −11.4 V V_p, blue line) states. i Cycle-to-cycle measurement of I_sc at P_down and P_up states in (h).