Semiconductors Made Of Graphene
October 1, 2012

Graphene-Based Superconductors Created By Norwegian Developers

redOrbit Staff & Wire Reports - Your Universe Online

Researchers at the Norwegian University of Science and Technology (NTNU) have developed a thinner, more flexible, less expensive type of semiconductor that uses graphene instead of silicon.

Typically, the silicon-based semiconductors used in commercial technology are "rigid, opaque, and about half a millimeter thick," according to Gizmag's Ben Coxworth. However, a new process developed by Dr. Helge Weman, Professor Bjørn-Ove Fimland, and colleagues from NTNU uses the transparent, highly conductive material comprised as a less expensive replacement.

"Graphene is the super thin, super strong, transparent, conductive, self-repairing material that's poised to revolutionize the future by not only by super-charging batteries but also by giving us flexible semiconductors," explains Gizmodo reporter Eric Limer. Coxworth adds that it is comprised of hexagonally-linked carbon atoms, just one atom thick, making it "simultaneously the thinnest material in existence yet also one of the strongest."

In order to create their semiconductors, Weman and Fimland grow crystallized nanowires from gallium and arsenic, Limer said. They begin by placing a graphene substrate inside a vacuum chamber, then bombarding it with gallium atoms so that they stick to the carbon sheets and clump together, matching the hexagonal patterns of the graphene on the underside, Coxworth noted.

Meanwhile, they add arsenic molecules into the mix, allowing them and additional gallium atoms to absorb into the previous gallium clumps, ultimately forming into crystals. The process repeats itself, and over time the crystals form into a nanowire, the Gizmag writer said. The finished product -- "a graphene substrate covered with an array of one-micrometer-tall gallium/arsenic nanowires, evenly distributed in a hexagonal layout" -- is completed after only a handful of minutes, he added.

Their findings have been published in the journal Nano Letters.

"We do not see this as a new product. This is a template for a new production method for semiconductor devices. We expect solar cells and light emitting diodes to be first in line when future applications are planned," Weman said in a statement, according to Dexter Johnson of ieee Spectrum.

"Companies like IBM and Samsung are driving this development in the search for a replacement for silicon in electronics as well as for new applications, such as flexible touch screens for mobile phones. Well, they need not wait any more," Johnson added. "Our invention fits perfectly with the production machinery they already have. We make it easy for them to upgrade consumer electronics to a level where design has no limits."