Filamentary Gate‐Controlled CNT‐Based Optoelectronic Synaptic Devices for Light‐Driven Neuromorphic Memory

Abstract Neuromorphic systems aim to replicate the brain's ability to process information with high efficiency and low energy consumption. Optoelectronic synaptic devices, which leverage light stimuli for signal processing and memory operations, have emerged as promising components for artificial visual perception. However, conventional gate control based on field‐effect mechanisms is limited in modulation depth and energy efficiency. Here, a three‐terminal carbon nanotube based optoelectronic synaptic device is presented that employs a filamentary gate modulation scheme via conductive filaments (CFs) formed in a SiO ₂ layer. The device, which is fabricated using a scalable spin‐coating method, exhibits key synaptic functions including excitatory postsynaptic current potentiation, paired‐pulse facilitation, and long‐term retention. Unlike traditional field‐effect transistors, gate voltage in this system modulates carrier dynamics by injecting or extracting charges through CFs, enabling precise and energy‐efficient control of photo‐excited currents. The device operates reliably across a 3 × 3 visual array, supporting high‐fidelity image encoding and memory decay behaviors. This filament‐assisted gating strategy provides a new pathway for optoelectronic synapse engineering, combining low‐power operation with robust memory functionality and opening a new direction for scalable neuromorphic vision hardware.