Enhancing the memristive effects in SnO2 nanowire networks

We present a study of SnO2 nanowire network acting as a resistive memory device. Charge transport features in these devices were controlled by modulating the behavior of the energy barriers of nanowire-nanowire interfaces and the Schottky barrier under the electrodes. Both barriers were found to be affected by the distribution and availability of charges along the nanowires mesh and in the surrounding atmosphere. The consequent memristive effect was dependent of the environment conditions but also controllable by managing the availability of charges for the transport properties. Using a polymeric barrier layer to avoid the direct contact of nanowires with the surrounding atmosphere proved to be an effective method to obtain reliable/better results after many memristive cycles. This simple procedure of polymeric coating offers some benefits such a more stable gain and a ON/OFF ratio improvement (from 1.55 to 3.60). Furthermore, coated devices showed potential features for use in synaptic learning applications.