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As a new generation of core components for neuromorphic computing, optoelectronic synaptic devices have the advantages of high bandwidth and less energy consumption. They can combine the functions of visual sensing, signal processing, and memory in one device. Herein, an all‐solid‐state optoelectronic synaptic transistor using indium gallium zinc oxide (IGZO) as the channel and lanthanum fluoride (LaF3) as the gate dielectric is designed and fabricated. Its synaptic plasticity induced by electric and optical stimuli is investigated. LaF3 is a solid superionic conductor with plenty of mobile fluoride ions, which can be used to achieve a high on/off ratio of more than 105 and a low subthreshold swing less than 150 mV dec−1 in this novel synaptic transistor. Due to the ion‐trapping effect at the interface, synaptic plasticity can be achieved upon electrical stimulation. Synaptic plasticity by light pulse stimuli can also be accomplished with the assistance of the persistent photoconductivity effect in IGZO channel. Furthermore, it is found that the synaptic plasticity induced by light stimuli can be modulated by gate voltage. These results provide a new way to control synaptic function and extend the function of optoelectronic synaptic devices. [ABSTRACT FROM AUTHOR]

Flexible synaptic devices that emulate biological synapses are the key to developing wearable intelligent equipment. However, there are still challenges to achieving multiple synaptic functions in flexible synaptic devices and realizing large‐scale production of synaptic devices. Herein, a flexible synaptic transistor on polyimide substrate is designed and fabricated using a solid‐state electrolyte gate and a VO2 Mott insulator thin film channel. Four orders conductance modulation is obtained in the VO2 thin film channel across the metal‐insulator transition. Several essential synaptic behaviors, including potentiation, depression, and short‐term/long‐term plasticity, are successfully demonstrated in this flexible synaptic device. More importantly, this synaptic transistor exhibits high cycling stability and good tolerance to bending deformation. A simulated artificial neural network built from this synaptic device achieves high recognition accuracy of 98% in the flat state and 92% in the bending state. In addition, this flexible device is fabricated on polyimide substrate by magnetron sputtering method, which has low cost and is compatible with modern semiconductor technology. This work can pave the way for large‐scale production of flexible synaptic Mott transistor devices. [ABSTRACT FROM AUTHOR]