Study of the Effect of Optical Illumination on Resistive Switching in ZrO2(Y) Films with Au Nanoparticles by Tunneling Atomic Force Microscopy

Abstract

The effect of optical illumination on the resistive switching in ultrathin (~4 nm) ZrO₂(Y) films with embedded single-layer Au nanoparticle arrays 2–3 nm in size is studied via tunneling atomic force microscopy. The ZrO₂(Y) films with Au nanoparticles are grown by layerwise magnetron deposition onto glass substrates with a conductive indium-tin-oxide sublayer, followed by annealing at 450°C. An increase in hysteresis due to bipolar resistive switching in the ZrO₂(Y) films is observed on the cyclic current–voltage curves of the microscope probe-to-sample contact. The effect is found to manifest itself in a dense Au nanoparticle array (~660 nm) when the contact area is photoexcited through a transparent substrate exposed to the radiation of a semiconductor laser at the plasmon-resonance wavelength. The effect is attributed to the photon-assisted field emission of electrons from Au nanoparticles to the conduction band of ZrO₂(Y) in a strong electric field between the microscope probe and the indium-tin-oxide substrate under plasmon-resonance conditions.