Printed Optoelectronic Memories Using Gr/WS2 Nanostructured Composite Ink for Retina-Inspired Vision Persistent Synapses

Abstract

The rapid advancement of neuromorphic computing and machine vision drives the need for optoelectronic memories that mimic neural and visual systems, integrating optical sensing, data storage, and processing. Traditional fabrication methods are often complex, multistep processes that struggle to achieve lightweight, scalable, and flexible designs. This limitation highlights the need for alternative approaches like printing technologies to enable flexible optoelectronic memory development. Here, a novel approach is presented to print optoelectronic memories using graphene (Gr)/WS₂ nanostructured composite ink. This composite ink utilizes Gr nanosheets as conductive channels and defect sites in WS₂ as charge capture centers, forming local heterojunctions that enable efficient photoelectric storage. Two types of Gr/WS₂ composite inks are developed, tested, and compared with pure Gr ink. The findings reveal that the Gr/WS₂ nanocomposite ink with enhanced edge states exhibits superior memory performance. Devices print using this ink demonstrated the ability to store visual information in both single-pulse and multi-pulse modes, reflecting potential applications in retina-inspired visual persistence and neuromorphic computing. This work highlights the promise of printed 2D material-based optoelectronic memories for advancing scalable, low-cost, and flexible electronic devices.