Exploring Ferroelectric Switching in α-In₂Se₃ for Neuromorphic Computing

Recently, 2D ferroelectrics have attracted extensive interest as a competitive platform for implementing future generation functional electronics, including digital memory and brain-inspired computing circuits. Fulfilling their potential requires achieving the interplay between ferroelectricity and electronic characteristics on the device operation level, which is currently lacking since most studies are focused on the verification of ferroelectricity from different 2D materials. Here, by leveraging the ferroelectricity and semiconducting properties of α-In₂Se₃, ferroelectric semiconductor field-effect transistors (FeSFETs) are fabricated and their potential as artificial synapses is demonstrated. Multiple conductance states can be induced in α-In₂Se₃-based FeSFETs by controlling the out-of-plane polarization, which enables the device to faithfully mimic biosynaptic behaviors. In comparison with charge-trapping-based three-terminal synaptic devices, the electronic synapses based on α-In₂Se₃ have the advantages of good controllability, fast learning, and easy integration of gate dielectric, rendering them promising for neuromorphic computing. In addition, an abnormal resistive switching phenomenon in α-In₂Se₃ is reported when operated in the in-plane ferroelectric switching mode. The findings pave the way forward for α-In₂Se₃-based FeSFETs for developing neuromorphic devices in brain-inspired intelligent systems.