Sub-Millisecond Visible-Light Gating of a Zinc Oxide Nanowire

Semiconductor nanowires are the building blocks of many nanoscale electrical and neuromorphic circuits. Here, we demonstrate a simple arrangement wherein an ethanol-adsorbed ZnO single nanowire, deposited between gold electrodes using dielectrophoresis exhibits significant change in resistance when activated by visible light. Here we have observed that the transition timescale between two stable ohmic states, one in the dark and the other in the illuminated regime in a single nanowire can occur in the submillisecond order, which is 7 orders of magnitude lower than our previously reported switching timescale in bulk ZnO thin films. A mathematical model of the light activated resistance switching mechanism is proposed based on the adsorption-desorption kinetics of oxygen molecules at the surface of the nanowires.