Band-like transport in surface-functionalized highly solution-processable graphene nanosheets

Abstract

Substochiometric Graphite oxide (GO) nanosheets were surface-functionalized and purified to show excellent dispersity at the single-sheet level in organic solvents, sufficient for spin-coating and printing onto various substrates. It is found that the sheets are ca. 18-Å thick due to the combined thickness of the basal plane and the alkyl chains. No measurable dc conductance is obtained for anneal temperature below 180°C, which suggests the film conductivity less than 1×10-1 S cm-1. The sp 2 fraction of carbon atoms gives the fraction of carbons connected into the π-electron network responsible for the electronic and optical properties of the nanosheets. It is also found that mobile charge carriers are field-induced and confined on the most extended sections of these graphenites.