Change of optical responses of Au nanoparticles induced by high-energy Si ion-irradiations

Au nanoparticles onto a silica-glass (SiO2) surface have been formed due to thermal dewetting of Au thin films. Subsequently, high energy Si ion-irradiations on the pristine Au nanoparticles result systematic redshifts of optical responses and concomitant broadening of the optical absorption peaks with the increase of ion doses. Essentially, these phenomena have been explained in the light of ion-beam mixing and transient molten-state diffusion process of Au atoms in the underneath SiO2 substrate. Analysis of high resolution electron microscopy and Rutherford backscattering data have corroborated the ion-beam induced mixing of Au atoms with the silica glass. Copyright © 2017 VBRI Press.