Separation of large graphene oxide and Its electrical property

Abstract

Fabricating graphene oxide and reduction of it offers new routes for creation of carbon-based electronics. However, high edge resistance of reduced graphene oxide is a huge barrier for electrical application. Here, we introduce that large graphene oxide flake can be selectively separated from as-made solution by its liquid crystal property. Large graphene oxide solution overcome its limitation on fabrication and was easily spin-casted by using electrostatic interaction with amine group of self-assembled monolayer. After nitrogen doping with hydrazine and ammonia gas, N-doped reduced large graphene oxide film shows much lower sheet resistance ($~300 \Omega /sq$ at 80% transmittance.) than N-doped reduced graphene oxide. Furthermore, separation of small flakes did not affect to the sheet resistance because large flakes dominates whole sheet resistance of the film.