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.
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