Scientists obtain graphene with high resistance to ozonation

October 31, 2016, National Research Nuclear University
Credit: National Research Nuclear University

A group of scientists from the National Research Nuclear University MEPhI (Russia) and a series of foreign universities have developed an industrial technology for the purification of graphene, which has higher stability under the influence of aggressive oxygen free radicals. This discovery is of the crucial importance for the development of nanoelectronics.

Graphene is crystalline carbon film with the thickness of one atom. Thanks to its unique characteristics (special electronic properties, high conductivity, transparency for light, an ability for mechanical stretching and others), is a promising material in high demand in nanoelectronics.

Manufacturing of various nanoelectronic devices involves applying a polymeric covering on graphene and then peeling it off. The remains of that coating "pollute" the graphene, lowering the mobility of charge carriers in it. Different treatment methods (thermal annealing, plasma stripping and chemical solvents) can remove the polymer residues, but they worsen the quality of the graphene. For example, ozone, which has high reactivity, is commonly used. However, under the influence of ozone, not only is polymeric residue destroyed, but defects appear in the graphene, which leads to the deterioration of its characteristics. Scientists from MEPhI have managed to obtain graphene with a very high stability to ozonation using high-temperature sublimation of (SiC). The obtained graphene maintains contact with the ozone for more than 10 minutes, while ordinary graphene loses its properties in only three or four minutes under such conditions. The results of the research have been published in the journal Carbon.

Scientists from Greece, France and Sweden contributed. With the help of computer modeling, the experts were able to determine the reasons that SiC-graphene increased stability under the impact of aggressive . The new graphene's abnormal stability turned out to be associated with the low roughness of on the SiC-substrate (epitaxy is a natural buildup of one crystalline material upon the surface of another).

"It was found that the usual 'rough' graphene is more vulnerable because of the presence of convex areas; these areas show high reactivity to the formation of epoxy groups, which destroy its integrity," said Konstantin Katin, Assistant Professor of the Department of Condensed Matter Physics at the MEPhI Institute of Nanotechnology in Electronics, Photonics, and Spintronics. "The results show that the technological process for the production of industrial graphene with improved characteristics can involve the nanofabrication of graphene on the basis of silicon carbide with its subsequent ozonation. Ozonation itself is an effective way of clearing graphene obtained in any way. The only limitation on the purification techniques has to do with the possible roughness of the graphene sheet—it should be practically perfectly smooth," said Mikhail Maslov, Assistant Professor of the Department of Condensed Matter Physics.

The scientists' discovery will become a basis for technologies to purify high-quality industrial graphene with stable electronic characteristics.

Explore further: New study shows nickel graphene can be tuned for optimal fracture strength

Related Stories

Low-cost and defect-free graphene

September 2, 2016

Graphene is one of the most promising new materials. However, researchers across the globe are still looking for a way to produce defect-free graphene at low costs. Chemists at Friedrich-Alexander-Universiät Erlangen-Nürnberg ...

Topographical approaches to measuring graphene thickness

September 28, 2012

(Phys.org)—Graphene has long shown potential for use in electronics, but difficulties in producing the material to a high enough quality has so far prevented the commercialisation of graphene-based devices.

Recommended for you

Nanoscale Lamb wave-driven motors in nonliquid environments

March 19, 2019

Light driven movement is challenging in nonliquid environments as micro-sized objects can experience strong dry adhesion to contact surfaces and resist movement. In a recent study, Jinsheng Lu and co-workers at the College ...

OSIRIS-REx reveals asteroid Bennu has big surprises

March 19, 2019

A NASA spacecraft that will return a sample of a near-Earth asteroid named Bennu to Earth in 2023 made the first-ever close-up observations of particle plumes erupting from an asteroid's surface. Bennu also revealed itself ...

The powerful meteor that no one saw (except satellites)

March 19, 2019

At precisely 11:48 am on December 18, 2018, a large space rock heading straight for Earth at a speed of 19 miles per second exploded into a vast ball of fire as it entered the atmosphere, 15.9 miles above the Bering Sea.

Levitating objects with light

March 19, 2019

Researchers at Caltech have designed a way to levitate and propel objects using only light, by creating specific nanoscale patterning on the objects' surfaces.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.