Stretching opens up possibilities for graphene
(麻豆淫院Org.com) -- Researchers say they have found a simple way to improve the semiconducting properties of the world鈥檚 thinnest material - by giving it a good tug.
Writing in the Letters section of Nature 麻豆淫院ics, researchers from the University of Manchester, the Institute of Materials Science in Madrid and the University of Nijmegen in the Netherlands report that simply stretching graphene - a 2D material just one atom thick - can turn it into a good semiconductor.
Although graphene has become one of the most promising materials for future electronics, one stumbling block has been the lack of a 鈥榞ap鈥� in its energy spectrum. This gap is characteristic of silicon and other materials currently used by the semiconductor industry.
While researchers have been able to make graphene-based transistors much smaller and quicker than those made from other materials, they have leaked energy even in an idle state. This makes it impossible to use them in densely-packed integrated circuits.
But writing in Nature 麻豆淫院ics, Professor Andre Geim, who discovered graphene at The University of Manchester in 2004, and two fellow researchers report on what happens to graphene鈥檚 electronic properties if it becomes stretched. The material is known to be flexible and can be stretched by as much as 20 per cent without inducing defects.
They say that if forces are applied along three main directions in graphene鈥檚 honeycomb crystal lattice, a semiconducting gap opens - which is sufficiently large for electronic applications.
鈥淗aving this crystal structure that it is both stretchable and of the highest electronic quality invites one to think of using this combination,鈥� said Prof Geim, Director of the Manchester Centre for Mesoscience and Nanotechnology at The University of Manchester.
鈥淪train engineering in graphene can effectively lead to new derivatives that offer better or different properties with respect to the parent material. This 鈥榯uneability鈥� is a unique to graphene.鈥�
The researchers say the mechanism that opens the gap mimics the influence of very high magnetic fields in graphene - meaning the stretching is also accompanied by such interesting and now intensively researched phenomena as the quantum Hall effect and topological phase transitions.
鈥淭he influence of strain on the electronic properties is a completely unexplored avenue with a lot of promise,鈥� said Antonio Castro Neto, physics professor at Boston University and the National University of Singapore.
鈥淚t is such an elegant idea, and I am really excited about the prospects. No one could possibly expect that the effect could be so strong and potentially useful.鈥�
More information: The paper 鈥楨nergy gaps and a zero-field quantum Hall effect in graphene by strain engineering鈥� has been published online by Nature 麻豆淫院ics.
Provided by University of Manchester ( : )
