PbI₃⁻ ion abnormal migration in CH₃NH₃PbI_xCl_3-x ultralong single nanowire for resistive switching memories

Whether the resistive switching (RS) behavior can be triggered in macroscopic level or not is still decade-long controversy because the mobile ion migration is extremely limited in such level. To demonstrate this point, ultra-long hybrid organic-inorganic perovskite halide (HOIPH; CH₃NH₃PbI_xCl_3-x) single nanowire is deliberately synthesized by three-steps: heating, vacuuming, and exposing to air atmosphere. A typical bipolar RS behavior with resistance ON/OFF ratio of >10⁵ is observed in the HOIPH-based memristor. The MAPbI₃-type perovskite crystal, I⁻, PbI₃⁻ and MA⁺ surrounded by the transition phase crystal to form the ultra-long HOIPH nanowire is verified by the HR-TEM observation. The observed RS memory behavior is ascribed to the ion long-distance migration in the transition phase. The Joule heat-based sublimation leads to the HOIPH structure collapse and then causes the RS invalidation. We disclose a novel RS memory mechanism that involves the ion abnormal migration in transition phase CH₃NH₃PbI_xCl_3-x ultralong single nanowire. This work provides a deep comprehension on the HOIPH system in various nanoscale electronic devices.