Nano-scale single layer TiO2-based artificial synaptic device

Abstract

Synaptic nano-electronic devices for brain-inspired computing have become increasingly popular because of their biological neuron-like properties such as massive parallelism with lower power consumption. Metal oxide-based resistive switching memory devices for the implementation of synapses are of great interest due to their low cost, easy production and complementary metal-oxide semiconductors (CMOS) compatibility. This study presents a simple, single-layer nano-scale TiO2-based artificial synaptic device for neuromorphic applications. the structural properties of the proposed nano-scale TiO2-based device were confirmed via both X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX). the bipolar resistive switching behavior of the device is shown by gradual increases in the low resistance (SET) state and gradual decreases in the high resistance (RESET) state. the synaptic characteristics of the device were resolved by applying voltage pulses. the typical potentiation and depression functions were obtained. Conforming to spike time dependent plasticity (STDP) was also achieved using synaptic weight changes. Homogeneous synaptic behaviors were associated with oxygen vacancies in the TiO2 layer, while abrupt changes in synaptic behavior were ascribed to filamentary transitions resulting from impurities in the metal oxide layer.