Plasma treated graphene oxide films: structural and electrical studies

Abstract

The exfoliation of oxygenated functional groups from 60 W hydrogen plasma treated graphene oxide films was investigated using X-ray diffractometric (XRD), Raman spectroscopic and atomic force microscopic techniques. The interlayer spacing of the graphene oxide sheets was found from the XRD pattern to decrease from 0.88 to 0.35 nm after plasma treatment. The reduced intensity ratio of the D and G peaks of the Raman spectra indicates a decrease in the crystallite size of the sp ² domains due to plasma treatment. Atomic force microscope showed the continuous morphology of the plasma treated film. The electrical properties of plasma treated samples spin-coated on silicon were studied using Van Der Pauw and non contacting microwave techniques. The sheet resistivity determined from Van der Pauw measurements was $1.62\,{\text{M}}\Omega /{\text{sq}}$, yielding the value of $3.1\,{\text{S}}\,{\text{m}}^{ - 1}$ for the bulk conductivity. The charge mobility of $3.8\,{\text{m}}^{2} \,{\text{V}}^{ - 1} \,{\text{s}}^{ - 1}$ has been determined from Hall measurement technique.