Neutron-Induced Defect-Driven Degradation of Ferroelectric Memory and Neuromorphic Synapses in α-In2Se3 FeS-FETs

Reliable ferroelectric semiconductor devices are essential for memory and neuromorphic technologies; however, neutron-induced degradation pathways remain unclear. Here, we establish an integrated experimental framework, linking defect characterization with device-level electrical and synaptic evaluations to investigate neutron irradiation effects on α-In2Se3 ferroelectric semiconductor field-effect transistors (FeS-FETs). After neutron irradiation, energy-dispersive spectroscopy (EDS) reveals irradiation-induced compositional changes, while electrical analysis indicates an increased acceptor-like trap density (DA(E)). These defect-related trap states disrupt polarization-dependent charge transport, leading to a substantial drain current reduction (∼88.95%), and degrade the memory-window-to-sweep-range ratio (MW/SR) (∼48.20%) and endurance characteristics. Synaptic functionality is also impaired, with increased nonlinearity and reduced dynamic range, which propagate to array-level synaptic weight uncertainty and degrade neural network inference accuracy. Overall, our results suggest that defect-related trap states are a key contributor to neutron-induced degradation in α-In2Se3 FeS-FETs. By clarifying this degradation pathway, this work provides insight into defect-related degradation mechanisms that may guide the future design of radiation-resilient ferroelectric memory and neuromorphic electronics.