Low-Voltage Synaptic Transistors Based on PrOx/ZrO2 Bilayer Dielectric for Neuromorphic Computing

The stimulation of synaptic behavior through artificial synaptic devices is considered as the first step toward hardware implementation of neuromorphic computing systems. However, synaptic transistors based on solid-state oxides are currently underexploited. In this article, In2O3 synaptic transistors based on PrOx/ZrO2 bilayer dielectric fabricated by spin coating were proposed, and the synaptic functions were realized by using the trapping and detrapping of the charges at the trap centers in PrOx. By modulating the presynaptic spiking, synaptic behaviors, including excitatory/inhibitory postsynaptic currents, the transition from short-term plasticity to long-term plasticity, paired-pulse facilitation (PPF), and high-pass filtering characteristics, were simulated. Furthermore, the potentiation/depression of the conductance was demonstrated at low operating voltages (−2/0.5 V) and exhibited high stability. Finally, the high recognition accuracy (91.8%) of the synaptic transistors was achieved by the MNIST dataset handwritten digits training. This study provides an effective strategy for the design of solid-state oxide synaptic transistors.