Infrared-Triggered Retinomorphic Artificial Synapse Electronic Device Containing Multi-Dimensional van der Waals Heterojunctions.

Biological systems excel in image recognition with low power and fast responses. Inspired by the human eye, researchers have developed solid-state artificial visual systems. In this study, a retinomorphic artificial synapse device based on a tungsten diselenide (WSe2)/indium arsenide quantum dot (InAs QD) heterostructure is developed. This device exhibits enhanced short-wavelength infrared (SWIR) responsivity at 1060 nm, which is a synaptic behavior analogous to the human retina. The WSe2/InAs QD improves charge transport and photon absorption through the quantum confinement effects of InAs QDs, facilitating efficient SWIR detection. The heterojunction enables effective electron-hole pair separation, enhancing the photodetector performance. The device adapts to SWIR signal pulses like the human eye to light flicker. The WSe₂/InAs QD device demonstrates significantly higher responsivity and a superior ability to emulate a wide range of synaptic properties compared to previously reported Si-based and 2D material/QD-based devices. An artificial neural network trained on the Fashion MNIST dataset achieved over 85% accuracy, which is higher than previous reports. This showcases the potential of retina-inspired SWIR optoelectronic devices for compact, efficient machine vision and in-sensor computing. This study underscores the potential of integrating QDs with 2D materials to create advanced photodetectors that mimic biological sensory functions.