Fabrication of flexible memristors using PMMA-rGO/Au nanocomposite thin films with improved stability and retention time

Abstract

Flexible memristor devices with high retention capability and enhanced stability are fabricated using a cost-effective, low-temperature spin coating technique. The active switching layer of the device, composed of polymethyl methacrylate embedded reduced graphene oxide (rGO)/Au nanoparticle (NPs) heterostructure thin films, is sandwiched between an ITO-coated conducting PET substrate as the bottom electrode and thermally deposited aluminum top electrodes. Compared to the reference GO/PMMA device, this device exhibited remarkable enhancement in overall electrical performance. The operating voltages are limited to +1.4 V/−2.15 V, representative of the low power consumption of the device. The device also exhibited excellent endurance, maintaining stable operation for over 75 consecutive switching cycles and a high retention time of ∼2 × 10⁴ s. The excellent stability of the device is attributed to the incorporation of Au nanoparticles within the graphene nanosheets, which improved the structural stability of the heterostructures by preventing the restacking of the nanosheets. Additionally, Au nanoparticles introduced localized electronic states, acting as active sites for charge storage and improving the overall conductivity. The nanoscale interactions between Au NP and graphene nanosheets reduced the energy barriers and contributed to improved charge mobility. Flexibility studies established a critical bending radius of 6 mm, and the device exhibited stable switching operation even after 1000 continuous bending cycles, establishing it as an excellent memory candidate for low-power flexible and portable electronics.