【Device Papers】Filamentary gate-controlled Ga₂O₃ synaptic device for in-sensing optoelectronic memory

      Researchers from the Tech University of Korea have published a dissertation titled "Filamentary gate-controlled Ga₂O₃ synaptic device for in-sensing optoelectronic memory" in Journal of Alloys and Compounds.

Abstract

      This study presents a three-terminal Pt/Ga₂O₃/Pt optoelectronic synaptic device that employs a conductive filament channel (CFC) for gate control, distinguishing it from conventional field-effect transistor (FET)-based devices. The amorphous Ga₂O₃ thin film facilitates the formation of an oxygen-vacancy-based CFC, dynamically modulating the excitatory post-synaptic current. Unlike FETs, this device enables direct control of synaptic behavior through CFC regulation rather than electrostatic gating, allowing for precise tuning of memory retention and decay. The results demonstrate that negative gate voltages enhance long-term memory (LTM) stability by promoting carrier accumulation in the CFC, whereas positive gate voltages accelerate forgetting by depleting carriers. Multi-level synaptic behavior is successfully realized through optical stimuli, supporting in-sensor computing and neuromorphic applications. Learning-experience simulations reveal that repeated training reduces the number of pulses required for memory formation, effectively mimicking biological synapses. Furthermore, paired-pulse facilitation measurements and a 3 × 3-pixel array simulation validate the device’s capability for optical information processing. By leveraging a CFC-based mechanism, this Ga₂O₃ optoelectronic synaptic device offers a low power operation and scalable approach for next-generation bio-inspired memory and artificial intelligence hardware, enabling highly efficient neuromorphic computing.

DOI：

https://doi.org/10.1016/j.jallcom.2025.182220