In situ etching of graphene by nonmetallic SiO_x nanoparticles

This paper introduced a general method of etching suspended graphene by nonmetallic SiO_x nanoparticles (SiO_x NPs) in graphene synthesis. Effects of etching time, concentration of silica gel and type of graphene on the etching mode of graphene have been systematically considered with using as-grown graphene film on a silica gel coating copper as model system. Nonmetallic SiO_x NPs acted as etchant plays important role in the in situ etching process during the fabrication of graphene. The etched multilayer graphene pattern can be modulated from large area films to a rectangle pattern by varying the Si concentration and etching time, while single layer graphene pattern alters little. The morphology and critical structure of SiO_x etched graphene were characterized by Raman spectra, transmission electron microscopy, scanning electron microscope and X-ray photoelectron spectrum. The process and mechanism described here open the way for tailoring graphene via nanoparticles instead of metal, which show significant influence of the electrical properties of graphene.