Ferroelectricity in graphene nanoribbon devices enabled by collective water molecule dynamics

Water is omnipresent in nanoscale systems, yet its collective dynamics and
impact on emerging electronics remain poorly understood. Here, we investigate
the role of water molecule dynamics in the ferroelectric response of
graphene nanoribbon devices. Our findings demonstrate that the collective
dynamics of water molecules stabilize the ferroelectric effect. We find that a
minimum bi-layer thickness is required for the temperature stability of the
ferroelectric effect. In contrast, mono-layer ribbons show a 70% shrinkage of
the hysteresis window between 120 and 400 K. Using a combination of electrical
transport measurements and molecular dynamics simulations, we conclude
that water molecules bridging between graphene nanoribbon layers
stabilize the formation of water clusters via intermolecular Coulomb interactions,
driving a robust ferroelectric behavior and remnant polarization
observed at the device level. This work lays the foundations for exploiting
water dynamics in next-generation ferroelectric heterostructures, with direct
implications for neuromorphic computing and memory devices.