The effect of degree of reduction on the electrical properties of functionalized graphene sheets

Abstract

We study the effect of carbon to oxygen ratio (C/O) on the electrical resistance of functionalized graphene sheets prepared by thermal exfoliation and reduction of graphite oxide at various temperatures. Using a 2-probe technique in conjunction with Kelvin probe force microscopy, we observe a transition from high-resistance (>400 kΩ/sq) nonlinear current/voltage characteristics at low C/O to low-resistance (<10 kΩ/sq) linear behavior at high C/O, indicating a transition from hopping to diffusive electron transport. Simultaneously, the metal-graphene contacts change from high-resistance Schottky-type behavior to nearly non-invasive metal-metal contact characteristics.

Graphene prepared by thermal reduction–exfoliation of graphite oxide: Effect of raw graphite particle size on the properties of graphite oxide and graphene

“…For example, the oxygen to carbon element ratio (O/C) and the electrical conductivity of graphene can be tunable by the reduction-exfoliation time and temperature [24]. Other recent works have also reported the preparations of high quality graphene having less structural and topological defects at a lower reduction-exfoliation temperature under vacuum, or with the assistance of a reduction-exfoliation accelerating agent such as H2 or HCl, or with microwave or irradiation assistance [25][26][27].…”

Electrode Surface Composition of Dual-Intercalation, All-Graphite Batteries

“…Overall, as compared to core-shell particles, the stacked SFG flakes exhibited greater concentrations of surface functional groups. Their intrinsic structure, which featured more prevalent exposed edge planes (previously shown to be more unstable) [21], make it more susceptible to functionalization.…”

Artemisia herba-alba Asso eco-friendly reduced few-layered graphene oxide nanosheets: structural investigations and physical properties

“…Similar results were obtained by Jang et al (99) from fibers of rGO nanoribbons. This can be caused by the large scattering of the effective individual sheet resistance which is likely due to the combined effect of fluctuations in the degree of reduction of individual graphene sheets, variations in the sheet thickness (number of layers), and inaccuracies caused by non-negligible and varying contact resistance at the metal contact pads which cannot be excluded in a 2-probe measurement (100).…”