Synaptic mechanisms of four W/WO x /ITO memristors with different WO x structures

Abstract

Memristor has been an important synaptic device for neuromorphological calculation, but its general model has not been established even though several mechanisms have been accepted widely. Fundamentally, the diversity of mechanisms lies in a wide range of materials that can be used in memristors. Obviously, the top/bottom electrodes and dielectric materials affect the properties/mechanisms of synapses. Hence, we fabricated four different W/WO x /ITO memristors among which the WO x -based layers have different structures due to the different deposition methods employed, i.e. hot wire chemical vapor deposition and magnetron sputtering. Surprisingly, a small change in WO x structure leads to significant differences of synaptic characteristics and mechanisms. By comparing the four W/WO x /ITO memristors, the diversity of mechanisms for memristor synapses is revealed and demonstrated deeply.