22 July 2005

Single-Atom-Thick Materials Almost Ready For Prime Time

by Kate Melville

British and Russian scientists led by Professor Andre Geim at the University of Manchester believe they have uncovered a whole family of previously unknown materials that are only one atom thick. The new research, published in the Proceedings of the National Academy of Sciences, follows on from the team's earlier work on the material graphene.

The new two-dimensional atomic crystals have been created by extracting individual atomic planes from conventional bulk crystals using a technique called 'micromechanical cleavage'. Not only are they ultra-thin, but they can also be tailored for different applications. Depending on the parent crystal, the one-atom-thick slices can be metals, semiconductors, insulators or magnets. It was previously thought that such thin materials could not exist, but the researchers have demonstrated that they are not only possible, but also fairly easy to make.

"This discovery opens up practically infinite possibilities for applications which people haven't even thought of yet. These materials are lightweight, strong and flexible, and there is a huge choice of them. Like polymers, whose pervasiveness changed our everyday life forever, one-atom-thick materials could be used in a myriad of routine applications from clothing to computers," said Geim.

Importantly, the researchers said that the atomically thin sheets they extracted were not only stable under ambient conditions, but also exhibited extremely high crystal quality, which gives them their unique properties. "Probably the most important part is that our discovery is not limited to just one or two new materials. It is a whole class of new materials, thousands of them. And they have a variety of properties, allowing one to choose a material most appropriate for a particular application," said co-researcher Dr Kostya Novoselov.

The researchers noted that some of the applications were probably decades away, but they expected to see ultra-fast transistors, micromechanical devices and nano-sensors based on one-atom-thick crystals already in a few years time. "We have now demonstrated the existence of 2D atomic crystals and believe that, once investigated and understood, it will be possible for them to be grown in large sizes required for industrial applications," the researchers concluded.