Enhanced resistive switching performance via air-stable FA3Sb2I9 thin films for flexible and multilevel memory applications

Organic–inorganic hybrid perovskites show promise for resistive random-access memory, especially antimony-based types due to their excellent optoelectronic properties and low toxicity. Herein, FA3Sb2I9 crystals were synthesized via the anti-solvent method and used to fabricate a memristor with the structure Ag/PMMA/FA3Sb2I9/ITO. The device demonstrates a low operating voltage, excellent endurance (>500 cycles), a high ON/OFF ratio (103), and robust retention (>104 s). It maintained stable electrical performance after more than 1 month of storage under ambient conditions. Moreover, the device shows multilevel resistive switching (RS) and maintains performance after 1000 bending cycles and various bending angles, demonstrating excellent mechanical flexibility. Density functional theory calculations reveal that the high stability originates from the strong Sb–I bonds in FA3Sb2I9. Analysis of the I–V characteristics further suggests that the RS is governed by the synergistic effect of Ag+ migration and iodine vacancies. This study presents a strategy to enhance the stability and enable high-density storage applications of halide perovskite RS memory devices.