High-throughput solution processing of large-scale graphene

Abstract

The electronic properties of graphene, such as high charge carrier concentrations and mobilities, make it a promising candidate for next-generation nanoelectronic devices. In particular, electrons and holes can undergo ballistic transport on the sub-micrometre scale in graphene and do not suffer from the scale limitations of current MOSFET technologies. However, it is still difficult to produce single-layer samples of graphene and bulk processing has not yet been achieved, despite strenuous efforts to develop a scalable production method. Here, we report a versatile solution-based process for the large-scale production of single-layer chemically converted graphene over the entire area of a silicon/SiO(2) wafer. By dispersing graphite oxide paper in pure hydrazine we were able to remove oxygen functionalities and restore the planar geometry of the single sheets. The chemically converted graphene sheets that were produced have the largest area reported to date (up to 20 x 40 microm), making them far easier to process. Field-effect devices have been fabricated by conventional photolithography, displaying currents that are three orders of magnitude higher than previously reported for chemically produced graphene. The size of these sheets enables a wide range of characterization techniques, including optical microscopy, scanning electron microscopy and atomic force microscopy, to be performed on the same specimen.

A low-temperature method to produce highly reduced graphene oxide

“…16), and aluminium powder 17 , have been used to reduce GO to produce RGO in the solution phase. The reduction of GO by pure hydrazine in the solution phase is particularly interesting because it can produce RGO of relative high quality with relatively small oxygen content 18 . Direct reduction of GO film has also been reported by exposure to hydrazine vapour and/or annealing at high temperature [19][20][21][22] .…”

Probing top-gated field effect transistor of reduced graphene oxide monolayer made by dielectrophoresis

“…Graphene can be prepared by various methods such as micro-mechanical cleavage [2], chemical vapor deposition [8], thermal annealing of SiC [9] and arc discharge method [10]. In recent years chemical methods [11,12] of preparing graphene with some functional oxide groups, referred to as reduced graphene oxide (RGO), are getting attention to get high yield of single and a few layer graphene flakes which can be deposited on desirable substrates to make large area conducting coatings and to fabricate devices and sensors.…”

Practical Chemical Sensors from Chemically Derived Graphene

“…The effectiveness of this reduction step appears to have a large affect on the quality of the resulting graphene, and most recently, it has been shown that liquid anhydrous hydrazine is a very effective reducing agent and solvent for dispersion of large, high quality graphene flakes. 7 This has opened the door to a wide range of possible applications, one of which is for chemical sensors.…”