Non‐volatile Sliding Ferroelectric Memory Effect in Ultrathin γ‐InSe

ABSTRACT Ferroelectrics exhibit field‐tunable non‐volatile polarization, making them essential for modern electronic devices, including memories and sensors. Conventional ferroelectric transistors typically suffer from limited memory windows and poor fatigue resistance due to ionic defect migration during polarization switching. In contrast, sliding ferroelectrics utilize interlayer sliding as a polarization‐switching mechanism, providing reduced switching barriers and enhanced fatigue endurance. Here, we demonstrate room‐temperature sliding ferroelectricity in γ‐InSe and develop a 2D sliding ferroelectric field‐effect transistor that achieves a memory window of 6.8 V, conductance modulation exceeding 10 4 , retention times beyond 10 years, and endurance surpassing 10 3 switching cycles. The device showed an ideality factor (α) as high as 0.97, approaching the theoretical limit. Furthermore, a ferroelectric tunnel junction constructed by an ultrathin (4.8 nm) γ‐InSe layer exhibits reversible switching between high‐resistance and low‐resistance states, achieving a tunnelling electroresistance (TER) ratio of ∼10 5 at room temperature. The high‐resistance state resistance decreases with temperature, while the TER ratio exceeds 10 6 at low temperatures, suggesting a thermally activated tunnelling mechanism alongside direct tunnelling under positive polarization. These findings highlight the potential of sliding ferroelectrics as robust candidates for next‐generation rewritable, fatigue‐resistant non‐volatile memory technologies.