Magnified experimental and simulated scanning tunnelling microscopy images of
the molecule used (maleimide derivative-BCM) network on graphene. Credit: INRS.
An
international research team involving Professor Federico Rosei of the Institut
national de la recherche scientifique (INRS) has demonstrated a novel process
to modify the structure and properties of graphene. This chemical reaction,
known as photocycloaddition, modifies the bonds between atoms using ultraviolet
light. The results of the study were recently published in the prestigious
journal Nature Chemistry.
Graphene
has outstanding physical, optical and mechanical properties. For instance, it
is commonly used in the manufacture of transparent touch screens, in aerospace,
and in biomedicine. This material, however, has limited use in electronics.
"No
other material has properties similar to graphene, yet unlike semiconductors
used in electronics, it lacks a band gap. In electronics, this gap is a space
in which there are no energy levels that can be occupied by electrons. Yet it
is essential for interacting with light," explains Professor Federico
Rosei of INRS's Énergie Matériaux Télécommunications Research Centre.
"The
multidisciplinary group of researchers from Canada, China, Denmark, France and
the United Kingdom succeeded in modifying graphene so as to create a band gap.
Current research is rather fundamental but could have repercussions over the
next few years in optoelectronics, such as in the fabrication of photodetectors
or in the field of solar energy. These include the manufacture of high-performance
photovoltaic cells for converting solar energy into electricity, or the field
of nanoelectronics, for the extreme miniaturization of devices," says
Professor Rosei.
This
breakthrough is complementary to the results published in Nature Materials, in
May 2020, by an Italian-Canadian team of researchers under the supervision of
Professor Rosei.