  Ferroelectric materials with switchable electric polarization hold great
promise for a plethora of emergent applications, such as post-Moore's law
nanoelectronics, beyond-Boltzmann transistors, non-volatile memories, and
above-bandgap photovoltaic devices. Recent advances have uncovered an exotic
sliding ferroelectric mechanism, which endows to design atomically thin
ferroelectrics from non-ferroelectric parent monolayers. Although notable
progress has been witnessed in understanding its fundamental properties,
functional devices based on sliding ferroelectrics, the key touchstone toward
applications, remain elusive. Here, we demonstrate the rewritable, non-volatile
memory devices at room-temperature utilizing a two-dimensional (2D) sliding
ferroelectric semiconductor of rhombohedral-stacked bilayer molybdenum
disulfide. The 2D sliding ferroelectric memories (SFeMs) show superior
performances with a large memory window of >8V, a high conductance ratio of
above 106, a long retention time of >10 years, and a programming endurance
greater than 104 cycles. Remarkably, flexible SFeMs are achieved with
state-of-the-art performances competitive to their rigid counterparts and
maintain their performances post bending over 103 cycles. Furthermore,
synapse-specific Hebbian forms of plasticity and image recognition with a high
accuracy of 97.81% are demonstrated based on flexible SFeMs. Our work
demonstrates the sliding ferroelectric memories and synaptic plasticity on both
rigid and flexible substrates, highlighting the great potential of sliding
ferroelectrics for emerging technological applications in brain-inspired
in-memory computing, edge intelligence and energy-efficient wearable
electronics.
