Low energy Ag ion irradiation-induced surface modification studies of Au-graphene oxide nanocomposite thin films

The surface modifications of graphene oxide (GO) based thin films have attracted considerable attention owing to the tuning of properties leading to several applications. Being a clean and impurity-free method, ion irradiation may prove superior to conventional methods in modifying the properties; however, the damage induced by the beam needs to be investigated. The present work investigates the surface modifications in the Au-graphene oxide thin films by 220 keV Ag ion irradiation at different ion fluence 3 x 1014, 1 x 1015, 3 x 1015, and 1 x 1016 ions/cm2. The Raman and X-ray Spectroscopy (XPS) show the transformation of GO matrix of Au-GO thin films into amorphous carbon at higher fluence, whereas the scanning electron microscopy and atomic force microscopy, show segregation of the Au thin layer into island type structures over the GO layer at high fluence; this is caused by the local heating produced due to ion irradiation. The XPS and X-ray diffraction results confirm the redistribution of the thin Au layer with Ag ion irradiation. The UV- visible spectroscopy show a slight blue shift in the surface plasmon peak of Au caused by the amorphization of GO matrix due to the beam irradiation. These thin ion beam-modified nanocomposites thin films may find various applications in surface-enhanced spectroscopy, optical filters, plasmonic devices, etc.