Kansas State University researchers have made an advance in producing graphene quantum dots of controlled shape and size at large densities.
Vikas Berry, William H Honstead professor of chemical engineering, is said to have developed a process that uses a diamond knife to cleave graphite into graphite nanoblocks, which are precursors for graphene quantum dots. These nanoblocks are then exfoliated to produce ultra-small sheets of carbon atoms of controlled shape and size.
By controlling the size and shape, the researchers can control graphene’s properties over a wide range for varied applications, such as solar cells, electronics, optical dyes, biomarkers, composites and particulate systems. Their work has been published in Nature Communications.
‘The process produces large quantities of graphene quantum dots of controlled shape and size and we have conducted studies on their structural and electrical properties,’ Berry said in a statement.
While other researchers have been able to make quantum dots, Berry’s research team is claimed to make quantum dots with a controlled structure in large quantities, which may allow these optically active quantum dots to be used in solar cell and other optoelectronic applications.
‘There will be a wide range of applications of these quantum dots,’ Berry said. ‘We expect that the field of graphene quantum dots will evolve as a result of this work since this new material has great potential in several nanotechnologies.’
It has been known that because of the edge states and quantum confinement, the shape and size of graphene quantum dots dictate their electrical, optical, magnetic and chemical properties.
This work also shows proof of the opening of a band-gap in graphene nanoribbon films with a reduction in width. Furthermore, Berry’s team shows through high-resolution transmission electron micrographs and simulations that the edges of the produced structures are straight and relatively smooth.