A Gate-Tunable Adaptive Optoelectronic Synapse with Broadband Response for Neuromorphic Vision.

Neuromorphic visual perception systems necessitate devices that integrate broadband spectral sensitivity with dynamic adaptation capabilities. However, current optoelectronic synapses often suffer from limited spectral coverage and insufficient electrically programmable adaptation functionalities. To overcome these limitations, we demonstrate a gate-tunable optoelectronic synapse utilizing a two-dimensional (2D) MoS2/GeSe van der Waals heterojunction. By leveraging the complementary absorption profiles of MoS2 and GeSe alongside the synergistic effects of the heterojunction, the device achieves a continuous broadband response ranging from the ultraviolet (295 nm) to the near-infrared (830 nm) regions. Furthermore, the device emulates diverse synaptic plasticities, replicating biological memory dynamics and emulating scotopic and photopic visual adaptation through gate-voltage modulation. Integration of the device into a neuromorphic visual system facilitates efficient image preprocessing and robust recognition. This work presents a potential strategy for developing high-performance, adaptive optoelectronic synapses for intelligent visual perception systems.