Engineering chlorine-doped Cs 2 AgBiBr 6− x Cl x double perovskite memristors with PVP interlayer for enhanced performance and neuromorphic computing

Abstract Lead-free perovskites, particularly the Cs 2 AgBiBr 6 double perovskite, have emerged as promising candidates for eco-friendly nonvolatile memory and neuromorphic computing, with halogen doping being an effective strategy to tailor its electronic properties for memristive applications. In this work, high-quality Cl-doped Cs 2 AgBiBr 6− x Cl x double perovskite films were fabricated via a one-step spin-coating method followed by low-pressure assisted treatment for high-performance memristors. Systematic investigation reveals that moderate Cl doping ( x = 0.5) can optimize the resistive switching performance by enlarging the memory window ( R HRS / R LRS ratio). Furthermore, a critical switching failure mechanism is identified to be caused by the electrochemical reaction between the Ag electrode and halide ions (Br − /Cl − ), which consumes the electrode and limits endurance to ∼100 cycles. By introducing a thin polyvinyl pyrrolidone (PVP) interlayer, this interfacial reaction is successfully suppressed, and the cycling stability can be significantly enhanced to over 1200 cycles. The optimized Ag/PVP/Cs 2 AgBiBr 5.5 Cl 0.5 /ITO memristor effectively emulates essential synaptic functions, including short-term and long-term plasticity, as well as bidirectional conductance modulation. Leveraging this, a fully connected neural network based on these devices achieved a recognition accuracy of 92.3% on the MNIST handwritten digit dataset. This work provides a co-design strategy combining halogen doping and interface engineering for developing reliable lead-free perovskite memristors, offering a viable pathway toward sustainable neuromorphic electronics.