Researchers from Oxford University have found a new way of growing defect-free graphene using chemical vapor deposition (CVD). Defects weaken the material and prevent electronics from flowing freely through it, and this method could pave the way toward large-scale graphene production.
The researchers say that the random graphene flakes which are formed during the CVD process can be lined up by manipulating the alignment of carbon atoms on a relatively cheap copper foil. In fact the atomic structure of the copper surface acts as a ‘guide’ that controls the orientation of the carbon atoms growing on top of them. By combining the control of the copper foil and the pressure applied during growth, makes it possible to control the thickness of these domains, the geometry of their edges and the grain boundaries where they meet.
The research published in ACS Nano, reveals how these graphene flakes, known as ‘domains’, can be lined up by manipulating the alignment of carbon atoms on a relatively cheap copper foil – the atomic structure of the copper surface acts as a ‘guide’ that controls the orientation of the carbon atoms growing on top of them.
“Current methods of growing flakes of graphene often suffer from graphene domains not lining up,” said Professor Nicole Grobert of Oxford University’s Department of Materials who led the work. “Our discovery shows that it is possible to produce large sheets of graphene where these flakes, called ‘domains’, are well-aligned, which will create a neater, stronger, and more ‘electron-friendly’ material.”
The Oxford-led team, which includes researchers from the universities Forschungszentrum Juelich and Renishaw, Germany, and the University of Ioannina, Greece, has shown that it is also possible using the new technique to selectively grow bilayer domains of graphene – a double layer of closely packed carbon atoms – which are of particular interest for their unusual electrical properties.