Controlling the macroscopic electrical properties of reduced graphene oxide by nanoscale writing of electronic channels

TL;DR

This paper demonstrates a nanoscale writing technique to control the electrical properties of reduced graphene oxide, enabling tunable electronic channels with complex transport behaviors for potential all-carbon electronic applications.

Contribution

It introduces a scanning probe tip method for precise nanoscale reduction of graphene oxide, allowing tunable bandgap and controlled electronic properties in fabricated devices.

Findings

Nanoscale reduction creates conducting graphitic regions on GO.

Transport mechanisms vary between tunneling, hopping, and activation.

Surface potentiometry reveals phase-separated electronic domains.

Abstract

The allure of all carbon electronics stems from the spread in physical properties, across all its allotropes. The scheme also harbours unique challenges, like tunability of band-gap, variability of doping and defect control. Here, we explore the technique of scanning probe tip induced nanoscale reduction of graphene oxide (GO), which nucleates conducting, sp2 rich graphitic regions on the insulating GO background. Flexibility of direct writing is supplemented with control over degree of reduction and tunability of bandgap, through macroscopic control parameters. The fabricated reduced - GO channels and ensuing devices are investigated via spectroscopic, and temperature and bias dependent electrical transport and correlated with spatially resolved electronic properties, using surface potentiometry. Presence of carrier localization effects, induced by the phase-separated sp2/sp3 domains, and large local electric field fluctuations are reflected in the non-linear transport across the channels. Together the results indicate a complex transport phenomena which may be variously dominated by tunnelling, variable range hopping or activated depending on the electronic state of the material.