Mimicking synaptic plasticity and learning behaviours in solution processed SnO2 memristor

In this study, a transparent memristor with a configuration of Au/SnO2/FTO is fabricated by a simple solution process at low temperature and further utilized to mimic biological synapses. A series of significant synaptic functions, including nonlinear transmission characteristics, spike-rate-dependent plasticity (SRDP), short-term plasticity (STP) and long-term plasticity (LTP) are emulated. The transition from short-term to long-term plasticity is also investigated in the device by repeated stimulation. The nonlinear rectification characteristic in the current memristor is attributed to the Schottky barrier at the Au/SnO2 interface. By controlling the oxygen vacancy migration induced under electrical input, the barrier at the interface can be modified, giving rise to the different synaptic functions. These results suggest that the proposed Au/SnO2/FTO memristor in this study is a promising synaptic device for artificial neural network applications. (C) 2018 Elsevier B.V. All rights reserved.