Researchers have developed a new fabrication process that allows for the precise creation of a graphene hybrid with potential uses in the electronic industry.
Ever since its discovery in 2004, graphene — the single layer of carbon atoms flaked off from a piece of everyday graphite pencil — has been big news. Among its many extraordinary properties is its conductivity, which at about 100 times that of copper triggered much excitement about what the material might do for electronics.
However, graphene has no band gap. So unlike silicon, its electrons are always on the move — not so useful for making transistors, which need to be able to switch on and off.
Now, scientists at Cornell University have come up with a new way of combining graphene with boron nitride to create a hybrid two-dimensional material that could be engineered to have this much sought-after band gap.
The trick is a two-step technique. First, the graphene is grown on a copper substrate, and then etched with conventional photolithography. Then boron nitride is grown on the etched areas using chemical vapour deposition.
Cheol-Joo Kim, a co-author of the study, told the Royal Society of Chemistry: "The two different regions can be laterally stitched together very well, forming mechanically stable atomic films. This means they are not just locally close to each other but they also form a heterojunction, opening possibilities to utilise interesting properties of the junction.
"We are excited that the structural and electrical properties of films were not degraded by the regrowth process after patterning for making heterojunctions, implying it can be employed for more complicated and necessary structures."