Large Resistive Switching and Artificial Synaptic Behaviors in Layered Cs3Sb2I9 Lead-Free Perovskite Memory Devices

Organometal halide perovskites have recently attracted significant attention as switching materials for resistive random-access memory (ReRAM) applications. However, the susceptibility of conventional 3D hybrid halide perovskites to ambient condition has so far remained a deterrent. The promise of a lead-free and layered inorganic halide perovskite, Cs3Sb2I9, in designing efficient ReRAM and artificial synaptic devices is herein demonstrated. The memristive devices exhibit a reproducible bipolar resistive-switching with a large on/off ratio of approximate to 10(4), an excellent retention over 10(4) s, and a remarkable environmental sturdiness. As per available literature, the ratio is one of the highest in electroforming-free ReRAM devices based on halide perovskites. Moreover, owing to an intrinsic electronic-ionic coupling and a strong light-matter interaction in the perovskite, the ReRAM devices show promises toward realization of phototunable memories and artificial synaptic devices with capabilities of concurrent processing and learning. This work hence emphasizes the prospect of layered Cs3Sb2I9 perovskite thin-films toward designing of next-generation high-performance nonvolatile memory devices.