Electrode-dependent memristive mechanism of two-dimensional EA4Pb3Br10 perovskite memristors

Halide perovskite memristors have become promising candidates for neuromorphic computing due to their intrinsic ion migration, tunable optoelectronic properties, and simple solution processing. Herein, we construct two-dimensional EA4Pb3Br10 perovskite memristors and evaluate the electrode effect of Au, and Ag electrodes with and without PMMA buffer layer on the resistive switching (RS) characteristics. The device with an active Ag electrode exhibits nonvolatile RS behavior, originating from the formation and rupture of Ag conductive filaments. In contrast, the inert-Au-electrode device shows volatile unipolar memristive characteristics assisted by halogen vacancies, while the insertion of a PMMA buffer layer under Ag electrode degrades memristive performance. Through experiment and first-principle calculation, we confirm that the chemical reaction between Ag and Br− in the perovskite and the Ag+ ion migration are the mechanisms underlying the RS. Moreover, the Ag electrode devices possesses reasonable endurance, continuously tunable conductance states, and synaptic characteristics, such as long-term potentiation/depression and paired-pulse facilitation. When integrated into an artificial neural network for image recognition simulation, the device achieves a high recognition accuracy of 95%. This work elucidates the electrode-dependent RS mechanism in halide perovskite memristors, offering critical insights into interfacial ion migration and electrochemical dynamics.