Rare earth halide double perovskites for high-performance resistive random access memory

Resistive random-access memories (ReRAMs) are considered as promising candidates for novel information storage techniques owing to their fast operation speed, simple structure and high integration density. Halide perovskites, with fast ion migration and facile fabrication, have been widely investigated as active layers for nonvolatile ReRAM devices. However, the ambient instability and toxicity of lead halide perovskites limit their further commercial application. In this work, for the first time, we report the ReRAM devices based on environmentally friendly and air-stable lead-free double perovskite Cs₂AgEuBr₆. We used a facile solution process method and vacuum sublimation to obtain Cs₂AgEuBr₆ crystals and fabricated a memory device based on high quality Cs₂AgEuBr₆ films. The memory device of the Au/Cs₂AgEuBr₆/ITO structure was designed in a cross-bar array architecture with the aim of simple operation and high integration. The resistive memory devices exhibited robust and reproducible bipolar switching behavior with a large ON/OFF ratio up to 10⁴ and long retention time of 12 000 s. This study will inspire the further design of nonvolatile memory devices and other electronics using the novel lead-free halide perovskite.