A new study on decoupled graphene from the use of potassium bromide has been reported by physicists from the universities of Basel, Modena and Munich in the journal ACS Nano.
The flexibility, stability, and electrical conductivity of graphene has promising applications in electronics. However, one of the barriers is the damage caused to graphene due to electronic coupling on metallic surfaces. A new study has analysed how to achieve decoupled graphene using potassium bromide for results closer to pure graphene.
According to the University of Basel, Graphene is usually produced by chemical vapour deposition, a chemical reaction on metallic surfaces. This causes the graphene layer and the underlying metal to electronically couple which can diminish some of graphene’s electrical properties. To be used in electronics, the graphene has to transferred onto insulating substrates in a multistep process, which risks damage and contamination.
The study, titled “Altering the Properties of Graphene on Cu(111) by Intercalation of Potassium Bromide” and published in ACS this month, adds: “The catalytic growth on transition metal surfaces provides a clean and controllable route to obtain defect-free, monocrystalline graphene. However, graphene’s optical and electronic properties are diminished by the interaction with the metal substrate.”
What is electronic decoupling?
However, defect-free, pure graphene can be achieved by decoupling the graphene electrically from the metallic substrate without damage.
The University of Basel state that the use of potassium bromide on graphene on a copper surface results in electronic decoupling, which alters the electrical properties of the graphene, and achieves a result closer to pure graphene.
Closer to clean, defect-free graphene
The project supervisor Dr. Thilo Glatzel, who is a member of Meyer’s team, said:“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.”