Metal-perovskite interfacial engineering for quasi-2D CsPbBr3-based memristor devices

Understanding the intricate interplay between electrode reactivity and interfacial chemistry is crucial for advancing halide perovskite memristors toward practical applications. Here, we systematically investigate how top electrode materials (Au, Ag, Cu, Al) influence the resistive switching behavior of quasi-2D CsPbBr3 devices through controlled interfacial engineering. By introducing a novel bilayer electrode architecture, we successfully decouple electrode surface oxidation effects from perovskite/electrode interfacial oxidation reactions for the first time. In situ XRD, photoluminescence spectroscopy, and interfacial XPS analysis reveal that voltage-driven bromide ion migration coupled with electrode-dependent reactions governs the switching mechanisms. Chemically inert Au electrodes show no switching due to insufficient interfacial reactivity, while highly reactive Al electrodes cause irreversible degradation through excessive chemical interactions. In contrast, moderately active Ag and Cu electrodes enable stable bipolar switching with dual negative differential resistance characteristics. The optimal performance emerges from balanced electrode reactivity that facilitates reversible interfacial redox reactions without structural degradation. These findings establish fundamental design principles linking electrode chemical activity to device functionality, providing a rational framework for engineering robust perovskite memristors with enhanced stability and performance for next-generation memory and neuromorphic computing applications.