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

Lead halide perovskites-based memory devices have attracted considerable interest due to their unique current-voltage (I-V) hysteresis. Herein, all-inorganic CsPbI3 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/CsPbI3/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 AgIx are verified, which also accompanies with generation of more iodine vacancies (V-I) in perovskite film. The memory device with AgIx 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 AgIx-induced resistive switching in CsPbI3-based memory device.