Improved Performance of CH₃NH₃PbI_3–xCl_x Resistive Switching Memory by Assembling 2D/3D Perovskite Heterostructures

The rapidly growing demand for fast information storage and processing has driven the development of resistive random access memories (RRAMs). Recently, RRAMs based on organometal halide perovskite materials have been reported to have promising memory properties, which are essential for next-generation memory devices. In this study, a hybrid two-dimensional/three-dimensional (2D/3D) perovskite heterostructure has been created by depositing n-butylammonium iodide on top of the CH₃NH₃PbI_3–xCl_x (MAPbI_3–xCl_x) surface. The perovskite film is fabricated by a facile one-step spin-coating method with room-temperature molten salt methylammonium acetate in the air. Resistive switching memory devices with a 2D/3D perovskite heterostructure exhibit a significantly improved switching window (ON/OFF ratio over 10³) with a lower operation voltage compared with their 3D counterparts. The 2D/3D perovskite heterostructure is advantageous for fabricating uniform-crystalline-grain, highly compact structures and can passivate defect states for the MAPbI_3–xCl_x film and the interface, which results in improved memory properties. These results provide a new perspective for developing high-performance perovskite-based memory devices.