Stepwise intercalation of silicon and oxygen, allows the synthesis of a SiO2 film below a graphene layer epitaxially grown on Ru(0001). We used photoemission spectroscopy to follow the reaction steps, which lead to a graphene layer electrically insulated from the substrate, as demonstrated by surface resistance data.
S. Lizzit et al., Nano Lett. 12, 4503 (2012).
The transport properties of high-quality and large-area epitaxial graphene grown on metal surface cannot be fully exploited because the electrical conduction is dominated by the substrate. In this study we succeded in insulating epitaxial graphene on Ru(0001) by a stepwise intercalation of silicon and oxygen, and the eventual formation of a SiO2 layer between the graphene and the metal. The reaction steps were followed by X-ray photoemission spectroscopy and the electrical insulation demonstrated by using a nanoscale multipoint probe technique. The described method can be employed for the insulation of graphene nanoribbons from their metal support, opening
many design options in graphene research and device fabrication.
Transfer-Free Electrical Insulation of Epitaxial Graphene from its Metal Substrate;
Silvano Lizzit, Rosanna Larciprete, Paolo Lacovig, Matteo Dalmiglio, Fabrizio Orlando, Alessandro Baraldi, Lauge Gammelgaard, Lucas Barreto, Marco Bianchi, Edward Perkins, and Philip Hofmann;
Nano Lett. 12, 4503 (2012).