Making Graphene Ribbons Semiconducting
Since its discovery, researchers have been working to find a way to make use of graphene in our electronics. This has been difficult though, as graphene is an electrical conductor and not a semiconductor, like silicon. Researchers at the University of Wisconsin, Milwaukee however have found that graphene nano-ribbons can become semiconductors, just by making them the right width.
Graphene is an atom-thick sheet of carbon and often worked with as a sheet, but other geometries can have special properties. As it turns out, nano-ribbons of graphene, which are typically conductors like larger sheets, can become semiconductors if they are three nanometers wide, or less. At such a small width, the electrons on one edge are able to interact with the atoms on the other, resulting in the sought-after semiconductor behavior.
Cutting the nano-ribbons that narrow is not easy though, especially as the edges have to possess the proper alignment. The researchers accomplished this with iron nanoparticles that catalyze a reaction between carbon and hydrogen atoms. Now the researchers are investigating other ways to change the properties of the nano-ribbons, by adding other atoms, such as oxygen to the edges, potentially making them act as a metal.