Enhanced resistive switching uniformity in HfO2/TiO2 NWA memristor for synaptic simulation

In this article, we fabricated a memristive device with a Cu/HfO2/TiO2 nanowire array (NWA)/FTO structure through a hydrothermal method and atomic layer deposition. The devices exhibit good resistive switching properties, including low set voltages (∼1 V), good retention (>104 s), and multilevel storage. Compared with the Cu/TiO2 NWA/FTO device, Cu/HfO2/TiO2 NWA/FTO devices exhibit better uniformity, which could be due to the difference between the dielectric constants of TiO2 and HfO2. Under the application of consecutive voltage pulses, some synaptic functions were mimicked, including long-term potentiation/depression, paired-pulse facilitation, and spike timing dependent plasticity.