Lead-free CsCu2Br3 perovskite for multilevel resistive switching memory

Organic–inorganic metal halide perovskites have recently attracted enormous interest in the field of resistive switching memories owing to their unique electrical properties. Unfortunately, two challenges, the inadequate long-term stability and the toxicity of lead, largely hinder their further practical application. Herein, a 1D all-inorganic lead-free CsCu2Br3 perovskite is proposed for resistive switching devices to resolve these issues. The CsCu2Br3-based resistive switching devices exhibit typical bipolar resistive switching behavior with low set voltage, high on/off ratio (103), stable retention properties (>2 × 104 s), and endurance (200 cycles) in air. The unencapsulated CsCu2Br3-based device still maintains resistive switching characteristics while stored in ambient environment for over 2 months. Moreover, four on-state multilevel information storage behavior has been observed by regulating the value of compliance current during set process. The resistive switching behavior is dominated by the formation and fracture of conductive filaments, which are induced by the movement of Br− ions under electrical bias. This work offers the opportunity and strategy for the design of air-stable and environment-friendly metal halide perovskite-based memory devices.