Lead‐Free Sb–Bi Perovskite‐Inspired Memristors: Compositional Control of Vacancy Migration for Neuromorphic Computing

Neuromorphic hardware demands device elements that integrate low‐voltage analog memory with neuron‐like dynamics, all integrated into a sustainable materials platform. Halide frameworks offer electronic–ionic coupling essential for brain‐inspired electronics, but lead‐halide perovskites suffer from toxicity and instability. Here, we report triple‐cation antimony–bismuth (Sb–Bi) A ₃ B ₂ I ₉ perovskite‐inspired memristors exhibiting synaptic plasticity and neuron‐like spiking within a two‐terminal stack. Devices demonstrate reproducible bipolar switching, state retention (≈10 ³ s), and >600 operating cycles. Millisecond pulse trains enable analog potentiation and paired‐pulse facilitation with bi‐exponential decay, while microsecond stimuli induce spiking and oscillatory responses. Bias‐dependent impedance spectroscopy confirms coupled ionic migration and trap‐assisted electronic transport. Integrated into a memristive neural network via hardware–software co‐design, Sb–Bi devices achieve 96.52% classification accuracy, comparable to software‐based network (96.67%). These findings position lead‐free PIMs as less‐toxic, solution‐processable building blocks for ion‐controlled neuromorphic electronics and motivate array‐level demonstrations with extended retention, endurance, and energy benchmarking.