Air-Stable Cesium Lead Iodide Perovskite for Ultra-Low Operating Voltage Resistive Switching

CsPbX₃ (X = halide, Cl, Br, or I) all-inorganic halide perovskites (IHPs) are regarded as promising functional materials because of their tunable optoelectronic characteristics and superior stability to organic–inorganic hybrid halide perovskites. Herein, nonvolatile resistive switching (RS) memory devices based on all-inorganic CsPbI₃ perovskite are reported. An air-stable CsPbI₃ perovskite film with a thickness of only 200 nm is successfully synthesized on a platinum-coated silicon substrate using low temperature all-solution process. The RS memory devices of Ag/polymethylmethacrylate (PMMA)/CsPbI₃/Pt/Ti/SiO₂/Si structure exhibit reproducible and reliable bipolar switching characteristics with an ultralow operating voltage (<+0.2 V), high on/off ratio (>10⁶), reversible RS by pulse voltage operation (pulse duration < 1 ms), and multilevel data storage. The mechanical flexibility of the CsPbI₃ perovskite RS memory device on a flexible substrate is also successfully confirmed. With analyzing the influence of phase transition in CsPbI₃ on RS characteristics, a mechanism involving conducting filaments formed by metal cation migration is proposed to explain the RS behavior of the memory device. This study will contribute to the understanding of the intrinsic characteristics of IHPs for low-voltage resistive switching and demonstrate the huge potential of them for use in low-power consumption nonvolatile memory devices on next-generation computing systems.