New York, NYOctober 31, 2013Columbia Engineering researchers have experimentally demonstrated for the first time that it is possible to electrically contact an atomically thin two-dimensional (2D) material only along its one-dimensional (1D) edge, rather than contacting it from the top, which has been the conventional approach. With this new contact architecture, they have developed a new assembly technique for layered materials that prevents contamination at the interfaces, and, using graphene as the model 2D material, show that these two methods in combination result in the cleanest graphene yet realized. The study is published in Science on November 1, 2013.
"This is an exciting new paradigm in materials engineering where instead of the conventional approach of layer by layer growth, hybrid materials can now be fabricated by mechanical assembly of constituent 2D crystals," says Electrical Engineering Professor Ken Shepard, co-author of the paper. "No other group has been able to successfully achieve a pure edge-contact geometry to 2D materials such as graphene."
He adds that earlier efforts have looked at how to improve 'top contacts' by additional engineering such as adding dopants: "Our novel edge-contact geometry provides more efficient contact than the conventional geometry without the need for further complex processing. There are now many more possibilities in the pursuit of both device applications and fundamental physics explorations."
First isolated in 2004, graphene is the best-studied 2D material and has been the subject of thousands of papers studying its electrical behavior and device applications. "But in nearly all of this work, the performance of graphene is degraded by exposure to contamination," notes Mechanical Engineering Professor James Hone who is also a co-author of the study. "It turns out that the problems of contamination and electrical contact are linked. Any high-performance electronic materia
|Contact: Holly Evarts|