Meng, Lingxue; Hao, Hongwei; Ma, Lan; Yue, Hangyu; Ye, Hang; Guo, Linhai; Huang, Zunkai; Tian, Li

APPLIED SURFACE SCIENCE

2025, ,

Meng, Lingxue; Hao, Hongwei; Ma, Lan; Yue, Hangyu; Ye, Hang; Guo, Linhai; Huang, Zunkai; Tian, Li

With the increasing computational demands faced by computing systems based on the von Neumann architecture, artificial synaptic devices that mimic the neural synapses of the human brain have emerged as a potential solution to this challenge. This study presents a photoelectric synaptic thin-film transistor (TFT) based on an ITO/IGZO composite active layer, aiming to enhance the device's responsiveness to visible light and synaptic plasticity. Compared to traditional single-layer devices, the ITO/IGZO bilayer structure exhibits significantly improved visible light response, particularly in the red and green light bands. X-ray photoelectron spectroscopy (XPS) analysis revealed an increase in oxygen vacancies and sub-bandgap states at the ITO/IGZO interface, which facilitates the generation of carriers excited by low-energy photons, thereby further enhancing the photoelectric performance. The photoelectric synaptic device demonstrates good short-term and long-term plasticity (STP and LTP) in mimicking synaptic plasticity and achieved an accuracy rate of 93% in the Modified National Institute of Standards and Technology (MNIST) handwritten digit recognition experiment. The results indicate that ITO/ IGZO TFTs not only enhance visible light response but also have the potential to simulate neural synaptic behavior, making them a promising component in neuromorphic computing and visual perception systems.