Nanotube process enabling new research avenues

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By Susan Kantor, ECE ILLINOIS
December 17, 2009

  • Carbon nanotubes and graphene are seen as future replacements for silicon as main material in semiconductors.
  • ECE Prof. Lyding has been researching these materails for their use in transistors.
  • Lyding developed a dry contact transfer process, which enables nanostructures of any sort to be placed on any surface.

Joseph W. Lyding
Joseph W. Lyding

In September, ECE Professor Joseph W. Lyding wrote an invited article, “Carbon Nanotubes: A Simple Approach to Superlattices,” for Nature Nanotechnology News & Views. In this article Lyding reviewed another article published in that same issue by a joint team of researchers from RIKEN and the University of Tokyo, who had based their work on a method developed in Lyding’s lab.

New nanomaterials, especially carbon nanotubes and graphene, are on the “semiconductor industry roadmap,” for replacing silicon as the main material for semiconductors. Lyding has been researching the properties of these materials and how they can be controlled to make transistors.  

“One of the things that has kind of evolved from this is that you really need to understand and control the properties of nanotubes and graphene at the atomic level,” Lyding said. “That’s one of the key aspects of this paper that I wrote.”

Lyding developed a dry contact transfer process, which enables nanostructures of any sort to be placed on any surface. For example, this enabled his group to study graphene on silicon with unprecedented detail, which was published in the March 2009 issue of Nature Materials.

“In a sense, it’s extremely simple, but it’s also powerful because there is no available technique to do this type of a deposition anywhere in scientific literature,” Lyding said. “People try all sorts of things that result in huge levels of contamination. If that’s the case, then you really can’t study the atomic-level details of what’s going on.”

But the work of Lyding and his research group enabled research across the world.

Researchers at RIKEN and the University of Tokyo were able to place carbon nanotubes onto an atomically clean silver surface. When carbon atoms in the nanotube lie directly over a silver atom, they were able to observe an interesting electronic modulation. This modulation could potentially be used for non-volatile memory-type information storage or as a switching element. 

Numerous processing steps that modify silicon are needed to make today’s silicon transistor devices. But using this technique, it seems to happen automatically by touching the atoms to each other.

“There’s a wide gap between a real technological application and where they are now, but at least being able to study this effect is something that’s been enabled by some of the background work that we’ve done,” Lyding said.

Carbon nanotubes and graphene, a flat sheet of carbon, have the potential to dramatically improve the speed of electronics.

“Any way to realize electronic function in these types of materials is highly sought after,” Lyding said.

Lyding was very pleased to be asked to write an article for Nature Nanotechnology News & Views. “It’s a big deal for us, especially for the students,” Lyding said.

Editor's note: media inquiries should be directed to Brad Petersen, Director of Communications, at bradp@illinois.edu or (217) 244-6376.

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