Entirely new form of carbon follows the lead of graphene
Researchers in Europe have developed an entirely new form of carbon, one that bears similarities to the wonder material graphene but with some useful differences. The incredibly thin sheets of material offer some electrical properties that other forms of carbon do not, which could open up new possibilities around electronics and advanced lithium batteries.
Graphene has generated a lot of hype in material science circles due to its incredible strength, flexibility, thinness and lightness, along with its ability to act as an excellent conductor of heat and electricity. As a two-dimensional sheet of carbon, it owes these characteristics to its unique arrangement of atoms that are organized in a honeycomb pattern, and scientists have suspected that alternative arrangements could give other two-dimensional forms of carbon their own unique qualities.
While these carbon materials have been theorized, none have yet materialized, but scientists at University of Marburg in Germany and Aalto University in Finland have now made a big breakthrough. The work begins with carbon-containing molecules that are placed on a very smooth gold surface, where they form two mirroring types of chains, like left and right hands. Unlike graphene, where different chains bind together, only chains of the same type bind together to form not just honeycomb patterns, but squares and octagons, as well. They've dubbed this new material biphenylene.
"The new idea is to use molecular precursors that are tweaked to yield biphenylene instead of graphene," explains Linghao Yan, who carried out the high-resolution microscopy experiments at Aalto University.
Confirming the structure of the new material using high-resolution scanning probe microscopy, the team found that its electronic properties differed greatly from graphene. For example, narrow strips of the material measuring 21 atoms wide behaved like metal, whereas graphene strips of the same size behave as semiconductors.
"These stripes could be used as conducting wires in future carbon-based electronic devices," says professor Michael Gottfried, at University of Marburg, who leads the team.
The scientists are now working to produce larger sheets of the new material, which they'll use to further investigate its characteristics and potential.
"This novel carbon network may also serve as a superior anode material in lithium-ion batteries, with a larger lithium storage capacity compared to that of the current graphene-based materials," says study author Qitang Fan, from the University of Marburg.
The research was published in the journal Science.