Vacancy Defects in Graphene Can Migrate
Single atom vacancies were introduced into graphene using the Tandem Laboratory ion implanter by Tuan Thien Tran, researcher in Materials Physics group, Uppsala University. Further studies revealed that the vacancies were mobile. Photo: Anja Castensson
Direct experimental evidence now demonstrates that carbon vacancy defects in graphene can migrate over long distances.
The vacancies created by energetic ions from an ion beam implanter moved to areas outside the irradiated areas.
A recently published study by researchers at Uppsala university and Linköping university demonstrates that carbon vacancy defects in graphene can migrate over long distances.
These findings were obtained by creating single atom vacancies in graphene using the Tandem Laboratory ion implanter and analysing the effects with Transmission Electron Microscopy.
Migration of single vacancies
While most defects in graphene are generally immobile, the migration of single vacancies, particularly at room temperature, has remained a topic of debate due to the wide range of reported migration barriers.
In this study, researchers provide clear evidence that these vacancies can indeed migrate. The carbon vacancy defects were observed to move over long distances, and mobile surface contaminants appear to play a crucial role in assisting graphene in self-healing these defects.
The unique properties of graphene
Graphene is a single layer of carbon atoms arranged in a hexagonal lattice, and it is one of the strongest, lightest, and most conductive materials known. Single vacancies, gaps where one carbon atom should be, are a common type of defect. Understanding how defects behave in graphene is critical, as they can significantly influence its properties.
While defects are often seen as detrimental, they can also be leveraged to tailor graphene's properties for specific applications. In some cases, the controlled introduction of defects can enhance graphene's chemical reactivity or enable desirable electronic properties, such as bandgap tuning for semiconductor applications.
Länkar
The research was conducted by Tuan T. Tran, Per O. Å. Persson, Ngan Pham, Radek Holenak, and Daniel Primetzhofer at Uppsala University and Linköping University. Their findings were published in the nanoscience and nanotechnology journal Small in July 2025