Silver Iodide Induced Resistive Switching in CsPbI₃ Perovskite‐Based Memory Device

Abstract

Abstract Lead halide perovskites‐based memory devices have attracted considerable interest due to their unique current–voltage ( I–V ) hysteresis. Herein, all‐inorganic CsPbI 3 perovskite film surviving 30 d of air storage is prepared by using a poly‐vinylpyrrolidone‐assisted passivation method under fully open‐air condition. Afterwards, a memory device with a sandwich structure of Ag/CsPbI 3 /indium tin oxide is manufactured. From I–V characteristics of pristine device, a spontaneous reaction between the active Ag electrode and I − ions under air exposure is suggested. Furthermore, complete degradation of Ag electrode and formation of AgI x are verified, which also accompanies with generation of more iodine vacancies (V I ) in perovskite film. The memory device with AgI x layer shows a bipolar resistive switching behavior, ultrahigh ON/OFF ratio (above 10 6 ), nonvolatile, reliable, and reproducible switching performance. Cell area and temperature dependent characteristics propose that the resistive switching is dominated by V I filament in low‐resistance state and thermally assisted hopping in high‐resistance state. This study provides a new insight to understand switching behavior from the way of electrode degradation and metal iodide formation in lead iodide perovskites‐based memory devices and also suggests a potential application for AgI x ‐induced resistive switching in CsPbI 3 ‐based memory device.