Solid-state electrolyte gated synaptic transistor based on SrFeO2.5 film channel

Abstract

In the past few years, synaptic device has become a hot topic in material science because of the urgent demand of neuromorphic computing. Ionic liquids gated three-terminal synaptic transistors have drawn extensive attention due to their outstanding energy efficiency, linearity, and symmetry. However, utilization of liquid electrolyte is not appropriate for the requirement of the practical application. Herein, a novel three-terminal synaptic transistor is designed and constructed using a solid-state electrolyte gate and a brownmillerite SrFeO2.5 thin film channel. Topotactic phase transformation can be induced between insulative brownmillerite SrFeO2.5 and conductive perovskite SrFeO3−δ. Nonvolatile conductance switching of the SrFeOx film can be realized by inserting and extracting of oxygen ions with electrolyte gating. The essential synaptic learning functions including excitatory postsynaptic current, and short-term/long-term plasticity, are successfully mimicked in the three-terminal synaptic transistor. This synapse device achieves a large scale adjusted range and multistable plasticity, demonstrating a new way to achieve key component of upcoming neuromorphic circuitry.