SnS‐Facilitated ZnAlSnO‐Based Fully Optically Modulated Artificial Synaptic Device for Image Processing

Abstract Optical synapses offer a promising solution to the high energy consumption of von Neumann architectures. Despite significant research, existing photoconductivity modulation methods are typically unidirectional, and inhibitory behavior still depends on electrical stimulation. To address this, a two‐terminal planar fully optically modulated synapse device based on a ZnAlSnO/SnS heterostructure, demonstrating bidirectional optical response is presented. This device exhibits an excitatory postsynaptic current (EPSC) when exposed to 370 nm UV light and generates an inhibitory postsynaptic current (IPSC) under 630 nm red light. Continuous potentiation and depression stimuli reveals the stability of fully optically modulated artificial synapses. Leveraging its fully optically modulated conductance, a three‐layer artificial neural network is implemented for handwritten digit and clothing recognition, achieving accuracies of 91.12% and 78.22%, respectively. Additionally, based on its unique electrical response to UV light pulse, the development process of the Polaroid camera is well simulated. This work not only enriches the content of optical synapses, but also contributes to advancements in artificial intelligence, brain‐like computing, and image‐processing technologies.