Ongoing Research
Projects
Frontier Carbon Materials • Nanowires,
Nanobelts, and Novel Nanostructures • Molecular
Electronics • Chemical and Biological
Sensors • Wide Band Gap Crystals
Frontier Carbon Materials
Carbon (C):
Boron Nitride (B-N):
Boron Carbon-Nitride (B-C-N):
Carbon Nitride (C-N): |
Nanotubes and new nanostructures
Thin films, nanotubes, and new nanostructures
Thin films, nanotubes, and new
nanostructures
Thin films, nanotubes, and new nanostructures |
The arrangement of carbon atoms differentiates a pencil lead from
a pricey jewel. Pencil lead consists of graphite where carbon atoms
are sp2 hybridized for three covalent bonds . In diamonds,
carbon atoms are sp3 hybridized for four bonds in a tetrahedral
configuration. Graphite is soft, semi-metallic, and dark (zero energy
band gap), while diamond is super-hard, insulating, and transparent
(band gap = 5.4 eV). In the past three decades, new carbon materials
like fullerenes, and carbon nanotubes (CNTs) have attracted tremendous
research interest and have led to a Nobel Prize. Clearly, the change
of bond hybridization and molecular packing among carbon atoms can
make very exciting new materials.
Materials within the B-C-N triangular zone offer new vistas for
materials research. They include thin films and nanostructures of
carbon, or compounds constructed of multiple elements using B, C
and N atoms: the smallest atoms that can form the strongest covalent
bonds in solids. These materials are commonly called frontier carbon
materials because of their flexibility to form various covalent bonds
like those in pure carbon solids. Clearly, the ability to control
bond hybridization, molecular packing, and composition of these materials
is important to create new materials. They could possibly be useful
for protective coatings, high-power electronics, and nanoscale devices:
indispensable materials for the advancement of science in the new
century.
In addition to investigating how to control the
arrangement of B, C, and N atoms, the functions of kinetic energy
of the growth species, potential energy of the growth species,
and the role of catalysts in controlling bonding between B, C, and
N atoms will be explored. The goal is to create new thin films and
nanostructures of boron nitride, carbon nitride and boron-carbon-nitride
with desired physical properties.
sp2 to sp3 phase transformation of BN films
sp2 to sp3 phase transformation of CN
films |
B-C-N fibrous nanostructures
Boron nitride nanotubes
Vertical bundles of boron nitride nanotubes |
Multiwalled carbon nanotubes
Multiwalled carbon nanotubes
Multiwalled carbon nanotubes |
Multiwalled carbon nanotubes
Bundle of single wall CNTs
Double wall CNTs
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