Decoupled graphene thanks to potassium bromide

Potassium bromide molecules (pink) arrange themselves between the copper substrate (yellow) and the graphene layer (gray). This brings about electrical decoupling. © Department of Physics, University of Basel

Graphene consists of a layer of carbon atoms just one atom in thickness in a honeycomb pattern and is the subject of intensive worldwide research.

Thanks to its high level of flexibility, combined with excellent stability and electrical conductivity, graphene has numerous promising applications – particularly in electronic components.

Molecules for decoupling

Graphene is often produced via a chemical reaction on metallic surfaces in a process known as chemical vapor deposition. The graphene layer and the underlying metal are then electrically coupled, which diminishes some of the special electrical properties of graphene.

For use in electronics, the graphene has to be transferred onto insulating substrates in a multistep process, during which there is a risk of damage and contamination.

In order to obtain defect-free, pure graphene, it is therefore preferable to decouple the graphene electrically from the metallic substrate and to develop a method that allows easier transfer without damage.

The group led by Professor Ernst Meyer from the Department of Physics and the Swiss Nanoscience Institute (SNI) of the University of Basel is investigating ways of incorporating molecules between the graphene layer and the substrate after the chemical deposition process, which leads to this type of decoupling.

Altering electrical properties

In a study carried out by SNI doctoral student Mathias Schulzendorf, scientists have shown that potassium bromide is ideally suited to this. Potassium bromide is a soluble hydrogen bromide salt.

Unlike the chemically similar compound sodium chloride, potassium bromide molecules arrange themselves between the graphene layer and the copper substrate. This was demonstrated by researchers in a variety of scanning probe microscopy studies.

Calculations performed by colleagues at the University of Modena and Reggio Emilia (Italy) explain this phenomenon: It is more energetically advantageous for the system if potassium bromide molecules arrange themselves between the graphene and copper than if they are deposited on the graphene – as happens with sodium chloride.

The researchers have shown that the intermediate layer of potassium bromide alters the electrical properties of graphene – until they correspond to those expected for free graphene.

“Our work has demonstrated that the graphene and the underlying metal can be decoupled using potassium bromide, bringing us a key step closer to producing clean and defect-free graphene,” says project supervisor Dr. Thilo Glatzel, who is a member of Meyer’s team.

Dr. Thilo Glatzel, University of Basel, Department of Physics, Tel. +41 61 207 37 30, Email: thilo.glatzel@unibas.ch

Mathias Schulzendorf, Antoine Hinaut, Marcin Kisiel, Res Jöhr, Rémy Pawlak, Paolo Restuccia, Ernst Meyer, Maria Clelia Righi, and Thilo Glatzel
Altering the Properties of Graphene on Cu(111) by Intercalation of Potassium Bromide
ACS Nano (2019), doi: 10.1021/acsnano.9b00278

https://pubs.acs.org/doi/10.1021/acsnano.9b00278

Media Contact

lic. phil. Christoph Dieffenbacher Universität Basel

Weitere Informationen:

http://www.unibas.ch

Alle Nachrichten aus der Kategorie: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Zurück zur Startseite

Kommentare (0)

Schreib Kommentar

Neueste Beiträge

Cyanobacteria: Small Candidates …

… as Great Hopes for Medicine and Biotechnology In the coming years, scientists at the Chair of Technical Biochemistry at TU Dresden will work on the genomic investigation of previously…

Do the twist: Making two-dimensional quantum materials using curved surfaces

Scientists at the University of Wisconsin-Madison have discovered a way to control the growth of twisting, microscopic spirals of materials just one atom thick. The continuously twisting stacks of two-dimensional…

Big-hearted corvids

Social life as a driving factor of birds’ generosity. Ravens, crows, magpies and their relatives are known for their exceptional intelligence, which allows them to solve complex problems, use tools…

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close