Ultralow operation voltages of a transparent memristor based on bilayer ITO

Traditional memristors based on metal/insulator/metal sandwich structures generally require the operation voltages of several volts to switch the device between different resistance states. In this work, we report the ultralow set and reset voltages of 14 mV and 0.3 V in a simple bilayer device, respectively, which is composed of the widely used indium tin oxide (ITO) solely. Such low operation voltages might be ascribed to the synergistic effect of the loose porous structure in the upper ITO layer deposited by electron beam evaporation, the amorphous interface between two ITO layers, and the formation of an oxygen concentration gradient triggered by an initiation process. Based on the superior resistive switching properties of this kind bilayer device, synaptic functions and image memorization are achieved by applying ultralow electrical stimulus. The prototype device not only paves the way for simplifying the device structure and the fabrication process but also offers possibilities to develop transparent multifunctional devices with low power consumption.