UA Physicists Further Research That Could Revolutionize Electronics

Nov 30, 2017

The elements selenium and tellurium naturally crystallize as bundles of parallel atom chains. This research aims to isolate just one of these semiconducting atom chains, as seen at the bottom, for use in electronic and optical circuits.
Credit J. Matthew Grant / University of Arkansas

The University of Arkansas’s Department of Physics in Fayetteville has announced progress that could lead to a great reduction in the size of electronics. Assistant Professor Dr. Hugh Churchill spoke with KUAR’s Michael Hibblen to explain this development.

HUGH CHURCHILL: So the idea is that we were really inspired by a previous sort of wonder material that a lot of physicists and engineers and scientists all around the world have gotten excited about which is the two-dimensional material graphene; and, what makes graphene special is that it has a layered structure where it’s like a stack of sheets where the chemical bonds in the material are really strong in two directions, but they’re really weak in the third direction and that allows you to peal these layers off the sheets and it actually made it possible to isolate a single atomically thin sheet of carbon called graphene. And the realization that our team had is that there are also materials that, whereas graphene has strong bonds in two directions and weak bonds in the third direction. There are also materials that have weak bonds in two directions and strong bonds in only one direction, and so the inspiration was if you can peal apart graphene into sheets, maybe you could take this materials, and examples are the elements selenium and tellurium, maybe you could peal individual atom chains of these material off of the crystals of those materials.

MICHAEL HIBBLEN: And this has the potential to revolutionize electronics?

CHURCHILL: Right, so the way that information is processed inside all our computers and smart phones and everything else is by transporting electrons through wires. And, at this point, those wires are very tiny. They’re on the nanoscale. And so there has been a huge effort really over the last 50 years shrinking those semiconductor wires down smaller, smaller and smaller, but the sort of traditional techniques for doing that have sort of hit the end of the road, and so it’s not really possible to shrink silicone electronic devices significantly further. And so if there was a way to make a material that would have those wires just be a single atom in diameter, it would represent the smallest possible shrinking of these electronic devices and that’s really the idea. So that application will be very far in the future, but that’s one of the exciting motivations for us to pursue this direction and try to actually create this potential material.

HIBBLEN: And I understand it could also be beneficial for electronic devices that, say are surgically implanted in people.

CHURCHILL: That’s right. One of the interesting things about these materials is that basically, because they’re so small and thin, they’re also very flexible, so we expect that they’ll have very interesting mechanical properties. And if you want to have some electronic device that’s implanted in someone’s body for example, you don’t want to have a brick somewhat rigid semiconductor like silicon, which would be uncomfortable and, as joints move, could break. Instead, if you had an atomically thin and flexible material, it might allow for more possibilities in that direction.

HIBBLEN: And where does your research go next?

CHURCHILL: So really what we’ve done so far is to show that these materials that have weak bonds in two directions. We’ve shown that they can in fact be split apart in wires. We have not yet succeeded in producing a single… one isolated single atom chain, and so that’s really where our focus is right now – either by starting with a larger crystal and breaking it apart in various ways, which is the strategy that was successful for graphene, the two dimensional material, or we’re pursuing techniques to actually directly grow the single atom chains using other strategies where we build up the atom chain sort of one atom at a time along its links.

KUAR is licensed to the University of Arkansas at Little Rock, which is part of the UA System.