Artificial synaptic transistors based on Schottky barrier height modulation using reduced graphene oxides

Development of artificial synapses is essential for highly-efficient brain-inspired neuromorphic computing. To achieve the high-performance artificial synapses, gradual change in synaptic weight with linear and symmetric forms is required. Here, we propose artificial synapses, in which synaptic weight is changed gradually by use of gate bias to modulate the Schottky barrier height between reduced graphene oxide and oxide semiconductor. This approach enables linear and symmetric change in synaptic weight. Also, an ion gel is used as the gate electrolyte, which can reduce the gate voltage required for modulation of Schottky barrier height. The fabricated artificial synapses show essential synaptic functions such as excitatory postsynaptic current, paired-pulse facilitation, and potentiation/depression. These results demonstrate that the devices that exploit modulation of Schottky barrier height can be applied to artificial synapses in advanced neuromorphic computing. (c) 2020 Elsevier Ltd. All rights reserved.