Lead-free all-inorganic halide perovskites for resistive switching memory: Mechanisms and emerging applications

Halide perovskites (HPs) have been recognized as promising materials for next-generation non-volatile memories, particularly resistive random-access memory (ReRAM). However, conventional Pb-based HPs suffer from environmental instability and poor long-term reliability, primarily due to degradation under moisture, oxygen, and thermal stress. Lead-free all-inorganic HPs have emerged as novel materials that can simultaneously ensure environmental sustainability and thermal stability. This review provides a comprehensive overview of lead-free all-inorganic HPs in terms of performance and potential application for ReRAM devices. Emphasis is placed on their prospects in flexible electronics and neuromorphic systems. Finally, we summarize key challenges for commercialization and outline future research directions, including strategies based on compositional and interfacial engineering.