Robust resistive switching in solution-processed copper bromide binary metal halide system

Abstract

Resistive switching devices utilizing metal halide materials hold great promise for flexible resistive randomaccess memory (RRAM) due to their low fabrication costs and low processing temperatures. However, the commercialization of these materials is hindered by issues related to phase instability and stoichiometric complexity. In this study, we demonstrate a binary metal halide-based resistive switching memory using copper bromide (CuBr) as the active component and that showed remarkable stability and reliability. The Au/CuBr/Au memristor exhibited a stable on/off ratio of 5 x 10 1 during low-voltage operation between 1.4 V to -1.6 V, a significant achievement for data storage devices. Detailed analysis using X-ray photoemission spectroscopy (XPS) provided insights into the chemical states and electronic structures of the CuBr layer, revealing that the resistive switching mechanism is driven by the formation of a metallic copper ion-based conductive filament (CF). This CF formation explains the area-dependent resistances and temperature-dependent resistances and is further supported by impedance spectroscopy. The devices also displayed exceptional switching stability, maintaining data integrity for more than 300 days at room temperature under ambient conditions. The device also exhibited impressive endurance, withstanding more than 1.2 x 104 cycles, highlighting its potential for long-term operational stability. Additionally, the air stability of the CuBr memristors and their low-temperature solution processing make them suitable for practical memory applications. In conclusion, this research provides a robust solution to the challenges faced by halide perovskite-based memristors, offering a highly stable, ambientcondition-resistant, and low-cost memory device. The work lays the foundation for next-generation memory devices that are both durable and environmentally adaptable, contributing significantly to the advancement of memory storage technologies.