A Floating‐Gate‐Like Transistor Based on InSe vdW Heterostructure with High‐Performance Synaptic Characteristics

With the arrival of the “von Neumann bottleneck,” neuromorphic systems are receiving a lot of attention from scholars as an innovative technology by mimicking the massive parallelism and low‐power operation of the human brain. Herein, a floating‐gate‐like device constructed by the InSe/hBN/O 2 ‐hBN van der Waals heterostructure, where the defective O 2 ‐hBN plays the central role to trap charges, is proposed. This well‐designed device is proved to realize the synaptic functions under UV laser irradiation, such as short‐term plasticity (STP), long‐term plasticity (LTP), paired‐pulse facilitation (PPF), and long‐term potentiation/long‐term depression (LTP/LTD). Especially, the synaptic weight of excitatory postsynaptic current (EPSC) reaches as high as 10 4 %, it reaches the highest standard of this kind of device in recent years, and remains above 300% synaptic weight after 200 s, thus successfully imitating the LTP in biological synapses. The key factors of LTP/LTD curves are overall excellent and can be optimized with input pulses: nonlinearity value can reach 3.32/2.35, and G max / G min above 10 is achieved. The InSe floating‐gate‐like device with O 2 ‐hBN layer provides an alternative for better and more practical synaptic performances in the field of neuromorphic architectures based on 2D materials.