Visible-SWIR Sensitive Artificial Retina for Vision Sensors

In this study, we proposed a light sensitive artificial Spike-Afferent Visual Optoelectronic Nerve (SAVON) circuit for retinomorphic applications. The proposed SAVON circuit is designed with serially connected $WS _{2} /$Ge heterostructure as photoresponsive cell (i.e. emulating the photoreceptors functionality) and ${MoS}_{2}$ based Threshold Switching (TS) device emulating as artificial memristive neuron. We experimentally measured the photoresponse (i.e. from 660 nm to 1540 nm wavelength range) characteristics of our Pulsed Laser Deposited (PLD $) WS _{2} {/Ge} -$heretrostructure. Our heterostructure exhibits $\ge 10$% responsivity improvement as compared to organic counterparts. The proposed SAVON circuit exhibits the light dependent frequency modulation property thus encoding the illumination into electrical spike pulses. We simulated a spiking network for full MNIST-based image classification application and observed the maximum train/ test accuracy of 96.09%/ 93.86%, respectively.