Finland and the Netherlands jointly develop a new structure of atomic precision graphene nanoribbons

Basic electronic components such as diodes and tunnel barriers can be included in graphene nanoribbons with atomic precision. The work was carried out by the Aalto University of Finland and the University of Utrecht, the Netherlands, and the Delft University of Technology, with the aim of developing graphene electronics that work extremely fast. The research results were published in the journal Nature Communication.

Graphene has many interesting properties, and researchers around the world are looking for new ways to use graphene. Graphene itself does not have the ability to turn on or turn off current, and researchers are always looking for ways to solve this problem. Professor Peter Ligiros of Aalto University said: "We can produce graphene structures with atomic precision. By selecting certain precursors (molecules), we can encode circuit structures with extremely high precision."

Seamless integration

The electronic properties of graphene can be controlled by synthesizing graphene nanoribbons. Previous studies have shown that the electronic properties of a nanoribbon depend on its atomic width. A 5 atom wide nanoribbon is similar to a metal wire and has good electrical conductivity, but if two atoms are added, the nanobelt can become a semiconductor. Professor Ingmar Schwart of Utrecht University said: "We are able to seamlessly integrate 5 atom wide nanoribbons and 7 atom wide nanoribbons to produce a metal-semiconductor junction, which is the basic module of electronic components."

Surface chemistry

The researchers prepared an electronic graphene structure by chemical reaction. The researchers evaporate the precursor molecules onto the gold crystals, and the precursor molecules react with the gold crystals in a controlled manner to produce new compounds. "This technology is different from the electronic nanostructures currently fabricated on computer chips. For graphene, the accuracy of the structure is at the atomic level, and chemical methods may be the only effective method."

Electronic property

Researchers use advanced microscopic techniques to determine the electronic properties of new structures. Researchers can measure current through graphene nanoribbon devices, and the atomic structure of graphene nanoribbon devices is known. Professor Peter Ligiros said: "This is the first time we have prepared a tunnel barrier and know its exact atomic structure. Measuring the current through the device allows us to quantitatively compare theoretical and experimental values."