Bioinspired Fully Optical Modulated Artificial Visual Synapse with Outstanding Memory Retention Based on Hollow Multishelled Structure

Achieving memory retention and intelligent perceptual function stand as the paramount objectives and great challenges in achieving neuromorphic perceptual synaptic devices. Inspired by the human visual system, herein, the two-terminal artificial visual synapse is designed with a porphyrin-modified ZnO hollow multishelled structure (porphyrin/ZnO HoMS) demonstrating light-induced plasticity for full spectrum recognition. Meanwhile, the artificial synaptic device enables the realization of “learning-experience” behavior, which relies on the photocarrier trapping characteristics of oxygen vacancies in ZnO and the multiple carrier release paths within HoMS. By the learning process, carriers can be temporarily trapped and enriched on shells rich with oxygen vacancies to achieve memory retention of light recognition. The long-term retention time exceeds 10 000 s, which markedly surpasses most existing photonic synaptic devices, demonstrating the excellent memory capability of these devices. Moreover, the synaptic array successfully simulates the visual system to dynamic response and real-time detection of color and shape. The HoMS platform offers a novel and efficient approach to emulate the neural-like functions of the rapid response and memory retention to external signals in artificial interactive devices.