Effects of Halide Composition on Endurance and Retention Performance in Double Perovskite Resistive Switching Memory

Due to their low operating voltage, high on/off ratio, and tunable band gap, Cs₂AgBiBr_6-xCl_x halide double perovskites (DPs) are being considered as promising materials for lead-free resistive switching (RS) memory devices. However, while the performance of conventional halide DP-based RS memory devices can be significantly improved by changing composition of halide materials, the mechanisms behind materials composition and its effects on performance are often insufficiently understood. This study reports on the effects of halide composition in DP-based RS memory devices. The Cs₂AgBiBr₄Cl₂ device demonstrates enhanced properties, with an endurance of 6500 cycles at room temperature and a retention of 10000 s at 100 °C. The thermal ion activation energy and time-of-flight secondary-ion-mass spectrometry revealed that the halide DP-based RS memory devices operate via an electrochemical metallization mechanism due to the migration of Cu ions. Additionally, studies on cohesive energies through first-principles simulations and thermal stability via thermogravimetric analysis demonstrate that the improved stability of halide DPs effectively increases the formation voltage by retarding Cu ion migration, thereby leading to enhanced endurance and retention properties. This report proposes a relationship between the change in halide composition and endurance and retention properties of lead-free DP-based RS memory devices.