CUTTING OF GRAPHENE BY METALLIC NANOPARTICLES
Irene Calizo, Guangjun Cheng, Angela R. Hight Walker
Future nano-electronic graphene device fabrication will require the advanced development of various techniques to create graphene configurations of different shapes and sizes. Nanoparticle etching has emerged as a possible route to cut graphene. In this work we characterized the cutting of graphene and graphene layers by Cu nanoparticles and Fe nanoparticles using scanning electron microscopy (SEM), optical microscopy, atomic force microscopy (AFM), and Raman microscopy. Metallic thin films were deposited onto mechanically exfoliated graphene flakes on Si/SiO2 substrates by a magnetron sputtering technique. When these thin films were annealed in a forming gas environment, nanoparticles were produced due to the dewetting of the thin film. Cutting occurs by a catalytic hydrogenation of carbon where molecular H2 is dissociated on the nanoparticle surface then interacts with carbon at the graphene-nanoparticle interfaces to form CH4. SEM images reveal different morphology of Cu and Fe nanoparticles due to their surface wettability with the graphene. Raman spectroscopy provides insight into the amount of defects and disorder introduced after the cutting process.