Multilevel Programming and Light-Assisted Resistive Switching in a Halide-Tunable All-Inorganic Perovskite Cube for Flexible Memory Devices

All-inorganic halide perovskites CsPbX3 (X = Cl, Br or I) have transpired to be utilized in several optoelectronic devices owing to their multifaceted optical and electrical features and superior thermal stability as compared to other organic–inorganic hybrid perovskites. Herein, a bipolar resistive switching (RS) characteristic of the CsPbX3 cube in Al/CsPbClxBr3–x (x = 3, 1.5, 0)/ITO/PET configuration is reported with a low operating voltage. Among all the fabricated memory devices, the CsPbBr3-based system presents the most pronounced RS characteristics such as no initial forming process, reproducibility, uniform switching, and long retention time with a high on/off ratio. By a subtle control over current compliance and stopping voltage, the multilevel data storage capabilities are also observed in flexible memory devices. Owing to the increasing demand of flexible electronics, current–voltage characteristics are further carried out under different bending diameters to access the mechanical stability and electrical reliability of the perovskite-based memory device. No discernible difference is observed in the low-resistance state and high-resistance state current under flat and bending conditions. Additionally, as fabricated devices show an enhanced RS effect where the resistance can be controlled both by electrical field and light illumination, this study also explores the data encoding process by using certain light irradiance during the SET process. The registered RS behavior is elucidated with a model of the creation and annihilation of a conductive multifilament that originated from the migration of halide ions and their corresponding vacancies in halide perovskite layers. This study will pave the way for the utilization of inorganic-halide perovskites with different nanoforms in low-power consumption nonvolatile memory of future wearable electronic gadgets.