Reset Voltage-Dependent Multilevel Resistive Switching Behavior in CsPbBi I Perovskite-Based Memory Device.

All-inorganic CsPbBi I perovskite film was successfully fabricated by incorporating Bi in CsPbI to stabilize the cubic lattice. Furthermore, the perovskite film was applied to manufacture a simple Ag/CsPbBi I/indium tin oxide (ITO) memory device with a bipolar resistive switching behavior. Nonvolatile, reliable, and reproducible switching properties are demonstrated through retention and endurance test under fully open-air conditions. The memory device also presents highly uniform and long-term stable characteristics. Importantly, by modulating the reset stop voltages, multilevel high-resistance states are observed for the first time in lead halide perovskite memory device. The resistive switching behavior is proposed to explain the formation and partial rupture of conductive multifilament that are dominated by the migration of iodine ions and their corresponding vacancies in perovskite film. This study suggests Ag/CsPbBi I/ITO device potential application for multilevel data storage in a nonvolatile memory device.