Effects of Halide\nComposition on Endurance and Retention\nPerformance in Double Perovskite Resistive Switching Memory

Due to their low operating voltage, high on/off ratio,\nand tunable\nband gap, Cs<sub>2</sub>AgBiBr<sub>6–<i>x</i></sub>Cl<sub><i>x</i></sub> halide double perovskites (DPs) are\nbeing considered as promising materials for lead-free resistive switching\n(RS) memory devices. However, while the performance of conventional\nhalide DP-based RS memory devices can be significantly improved by\nchanging composition of halide materials, the mechanisms behind materials\ncomposition and its effects on performance are often insufficiently\nunderstood. This study reports on the effects of halide composition\nin DP-based RS memory devices. The Cs<sub>2</sub>AgBiBr<sub>4</sub>Cl<sub>2</sub> device demonstrates enhanced properties, with an endurance\nof 6500 cycles at room temperature and a retention of 10000 s at 100\n°C. The thermal ion activation energy and time-of-flight secondary-ion-mass\nspectrometry revealed that the halide DP-based RS memory devices operate\nvia an electrochemical metallization mechanism due to the migration\nof Cu ions. Additionally, studies on cohesive energies through first-principles\nsimulations and thermal stability via thermogravimetric analysis demonstrate\nthat the improved stability of halide DPs effectively increases the\nformation voltage by retarding Cu ion migration, thereby leading to\n enhanced endurance and retention properties. This report proposes\na relationship between the change in halide composition and endurance\nand retention properties of lead-free DP-based RS memory devices.