Oxide Passivation of Halide Perovskite Resistive Memory Device: A Strategy for Overcoming Endurance Problem.

Owing to a low operation voltage, high on/off ratio, and tunable band gap, halide perovskites (HPs) are being conceived as an alternative to oxide or chalcogenide materials in resistive-switching (RS) memory devices. However, the HP-based RS memory devices face problems such as short endurance, low retention, and device stability. Herein, the oxide-passivated HP devices were fabricated by hybridizing the oxide sol-gel and halide adduct methods. The silicon oxide (SiO2)-passivation enhanced the device properties with an endurance of 6000 cycles and retention of 1.8 × 104 s. The study of activation energy using ionic conductivity and time-of-flight secondary-ion mass spectroscopy demonstrated that the migration path of the Ag ions is well-controlled by the SiO2 passivation layer. Various oxides were used as passivation materials. Especially, the zirconium oxide-passivated devices exhibit excellent properties with an endurance of 57 000 cycles and retention of 7.8 × 104 s. The high cohesive energy of oxides effectively increased the formation voltage by retarding the Ag-ion migration, leading to the improved endurance properties of the devices. This paper proposes a strategy for significantly improving the low endurance property of HP-based RS memory devices using the oxide passivation technology.