All-In-One Optoelectronic Neuristor Based on Full-vdW Two-Terminal Ferroelectric p-n Heterojunction

Photoelectric synaptic devices with optical sensing capability are of great importance in simulating human vision systems. Especially realizing all-in-one vision neuristor on silicon based new materials and principles is being pursued. 2D van der Waals (vdW) materials have the unique advantage of arbitrary stacking on demand. Herein, a full-vdW two-terminal 2D ferroelectric & alpha;-In2Se3/SnSe p-n heterojunction is proposed to construct an optoelectronic neuristor to simulate visual synaptic functions. Implementation of these simulations is attributed to the co-modulation of the electrical polarization reconfigurable built-in electric field caused by p-n junction and photo-inducing ferroelectric polarization switching. These functions include ultra-high paired-pulse facilitation index (457%), short synaptic plasticity, long synaptic plasticity, and retina-like optical adaptations. The high PPF is crucial for high-precision decoding and processing of visual information. Meanwhile, the classical Pavlovian conditioned reflexes associated with associative learning are also emulated showing the ability of the device to handle complex electrical and optical inputs. This study demonstrates that two-terminal ferroelectric p-n heterojunctions have great potential in high-precision multifunctional optoelectronic visual synaptic devices.