ORNL-UT Researchers Invent ‘Sideways’ Approach to 2-D Hybrid Materials
ORNL and UT researchers have invented a method to merge different 2-dimensional materials into a seamless layer. This colorized scanning tunneling microscope image shows a single-atom sheet composed of graphene (seen in blue) combined with hexagonal boron nitride (seen in yellow).Image Credit: Oak Ridge National Laboratory
Researchers at the Department of Energy’s Oak Ridge National Laboratory and the University of Tennessee, Knoxville have pioneered a new technique for forming a two-dimensional, single-atom sheet of two different materials with a seamless boundary. The study could enable the use of new types of 2-D hybrid materials in technological applications and fundamental research. By rethinking a traditional method of growing materials, the researchers combined two compounds -- graphene and boron nitride -- into a single layer only one atom thick. Graphene, which consists of carbon atoms arranged in hexagonal, honeycomb-like rings, has attracted waves of attention because of its high strength and electronic properties. “People call graphene a wonder material that could revolutionize the landscape of nanotechnology and electronics,” ORNL’s An-Ping Li said. “Indeed, graphene has a lot of potential, but it has limits. To make use of graphene in applications or devices, we need to integrate graphene with other materials.” The researchers first grew graphene on a copper foil, etched the graphene to create clean edges, and then grew boron nitride through chemical vapor deposition. Instead of conforming to the structure of the copper base layer as in conventional epitaxy, the boron nitride atoms took on the crystallography of the graphene.