Hydrogen May be Key to Growth of High-Quality Graphene
A new approach to growing graphene greatly reduces problems that have plagued researchers in the past and clears a path to the crystalline form of graphite's use in sophisticated electronic devices of tomorrow.
Findings of researchers at the Department of Energy's Oak Ridge National Laboratory demonstrate that hydrogen rather than carbon dictates the graphene grain shape and size, according to a team led by ORNL's Ivan Vlassiouk, a Eugene Wigner Fellow, and Sergei Smirnov, a professor of chemistry at New Mexico State University. This research is published in ACS Nano.
"Hydrogen not only initiates the graphene growth, but controls the graphene shape and size," Vlassiouk said. "In our paper, we have described a method to grow well-defined graphene grains that have perfect hexagonal shapes pointing to the faultless single crystal structure."
In the past two years, graphene growth has involved the decomposition of carbon-containing gases such as methane on a copper foil under high temperatures, the so-called chemical vapor deposition method. Little was known about the exact process, but researchers knew they would have to gain a better understanding of the growth mechanism before they could produce high-quality graphene films.
Until now, grown graphene films have consisted of irregular- shaped graphene grains of different sizes, which were usually not single crystals.
"We have shown that, surprisingly, it is not only the carbon source and the substrate that dictate the growth rate, the shape and size of the graphene grain," Vlassiouk said. "We found that hydrogen, which was thought to play a rather passive role, is crucial for graphene growth as well. It contributes to both the activation of adsorbed molecules that initiate the growth of graphene and to the elimination of weak bonds at the grain edges that control the quality of the graphene."
Using their new recipe, Vlassiouk and colleagues have created a way to reliably synthesize graphene on a large scale. The fact that their technique allows them to control grain size and boundaries may result in improved functionality of the material in transistors, semiconductors and potentially hundreds of electronic devices.
Implications of this research are significant, according to Vlassiouk, who said, "Our findings are crucial for developing a method for growing ultra-large-scale single domain graphene that will constitute a major breakthrough toward graphene implementation in real-world devices."
Previous Story: Bacteria Use Grappling Hooks to Slingshot on Surfaces
Next Story: Quantum Dots Degrade in Soil Releasing Their Toxic Guts
The Institute of Nanotechnology puts significant effort into ensuring that the information provided on its news pages is accurate and up-to-date. However, we cannot guarantee absolute accuracy. Consequently, the Institute of Nanotechnology disclaims any and all responsibility for inaccuracy, omission or any kind of deficiency in relation to the news items and articles hosted herein.
- 25 November 2013Nanomedical Device and Systems Design: Challenges, Possibilities, Visions
- 01 November 2013NanoSafety Cluster Launches its first newsletter
- 14 October 2013Developing EU–Latin America Nanotech Cooperation - the NMP–DeLA project kicks off
- 24 September 2013Should We Use Nanotechnology to Feed Ourselves?
- 18 September 2013UCLA researchers' smartphone 'microscope' can detect a single virus, nanoparticles
- View All