Visible-light-driven photoelectric synaptic transistors based on Ga2O3/IGZO heterostructure for neuromorphic computing

Photoelectric synaptic transistors (PSTs) based on metal-oxide semiconductors are endowed with advantages such as stability and scalability. However, they encounter difficulties in the modulation under visible light. In this study, a visible-light-driven PST was proposed, in which the indium gallium zinc oxide was employed as the channel and gallium oxide was utilized as the modification layer. All layers of the PST were fabricated using the solution-processed method. The PST device exhibits persistent photoconductivity under illumination at a wavelength of 532 nm, which enables the synaptic plasticity behaviors such as excitatory postsynaptic current, paired-pulse facilitation, and the transition from short-term memory to long-term memory. Moreover, the role of the Ga₂O₃ modification layer was investigated, and the formation of oxygen vacancies is effectively enhanced due to the modification layer. Both the short-term and long-term plasticity of the PST are significantly enhanced, and its cyclic stability is also ensured. An artificial neural network was constructed based on the long-term plasticity of the PST, and 93.1% accuracy is achieved in image recognition tasks. The development of oxide-based PSTs is promoted, and its broad potential in artificial vision technologies is highlighted.