Researchers from an international research team, led by the University of Cologne, “has succeeded in connecting several atomically precise graphene nanoribbons to form complex structures. The scientists have synthesized and spectroscopically characterized nanoribbon heterojunctions, and were able to integrate the heterojunctions into an electronic component. In this way, they have created a novel sensor that is highly sensitive to atoms and molecules.” -Graphene Info
The graphene nanoribbon heterojunctions were described by Dr. Boris Senkovskiy, a researcher from the Institute for Experimental Physics, as atomically precise nanoribbons, which allow for the creation of more complex heterostructures that act as tunneling barriers.
For more information, see this article by Graphene Info.