Stable Bipolar Resistive Switching in Lead-Free Cs₂AgBiBr₆ Memristors for Neuromorphic Computing

The lead-free double-perovskite Cs₂AgBiBr₆, which combines nontoxicity with superior stability, has been highlighted as an ecofriendly alternative to lead-halide perovskites in photoelectric devices by recent advancements. Herein, Cs₂AgBiBr₆ films were successfully synthesized on a fluorine-doped tin oxide (FTO) glass substrate via a spin-coating method in a dry-air glovebox (relative humidity (RH) less than 20%), eliminating the need for antisolvent dripping or inert gas protection. The films exhibited a uniform morphology, with root-mean-square (RMS) and average (R _a) roughness values of 15.4 and 11.9 nm, respectively. The fabricated Cs₂AgBiBr₆-based memristors demonstrated stable, repeatable bipolar resistive switching behavior with low operating voltages (+0.4 V, -0.3 V), an on/off ratio of 479, an endurance of 1000 cycles, and a retention time of 10⁴ s. Remarkably, the resistance ratio between the high-resistance state (HRS) and low-resistance state (LRS) remained stable at approximately 441 even after 30 days of ambient storage. Furthermore, the memristor mimicked biological synaptic functions, achieving an accuracy of 91.39% in machine learning simulations. These findings highlight the viability of using Cs₂AgBiBr₆ in both memory and computational applications, thus offering a promising pathway for developing sustainable and efficient memristor-based systems for use in neuromorphic computing and information storage.