A Mechanism Of Effect Of Optical Excitation On Resistive Switching In Zro2(Y) Films With Au Nanoparticles

A mechanism of effect of optical excitation on resistive switching of dielectric films with embedded metal nanoparticles (MNPs) has been proposed. The mechanism is related to a charging of the MNPs due to internal photoemission of electrons from the MNPs, which results in an increasing of the electric field strength at the MNP surfaces that, in turn, promotes the rupture and restoring of the conductive filaments in the dielectric film. The increasing of the electric filed strength due to the MNP charging as a function of the MNP sizes and positions inside the dielectric films was evaluated using a simple model taking into account the mirror charges on the conductive electrodes of a memristor stack. The single electron charging was found to be essential at small MNP radii (similar to 1 nm). The proposed mechanism was confirmed experimentally by studying the photoexcitation-induced charging of Au MNPs (with average radius 1.6-1.8 nm) embedded into a 10 nm thick ZrO2(Y) film by Kelvin probe force microscopy.