Ultrafast Switching and High-Endurance Nonvolatile Memory Using Ferroelectric Janus Monolayers

The discovery of two-dimensional semiconducting ferroelectric (SFe) materials marks a pivotal step toward the commercialization of ferroelectric random-access memory. Despite their potential as ideal platforms for ultrafast switching and ultralow power consumption, SFe monolayers remain unexplored. Here, we demonstrate an SFe field-effect transistor based on monolayer Janus MoSeS, integrated with a ZrO ₂ high-κ (κ denotes dielectric constant) gate dielectric. The inherent non-centrosymmetry of the Janus structure leads to gate-switchable spontaneous out-of-plane polarity. The device exhibits counterclockwise memory windows of ~5 V, an on/off ratio exceeding 10 ⁷ at zero gate bias, and an extrapolated retention time of up to 10 years. It also achieves fatigue-free endurance over 4 million cycles and ultrafast responses to 36 ns voltage spikes, resulting in ultralow power consumption of 120/98 fJ per program/erase cycle. These findings establish Janus monolayers as promising candidates for next-generation nonvolatile memory and neuromorphic computing applications.