Carbon nanotubes (CNT) can be metals or semiconductors, just
depending on their diameter and helicity. We design a variety of
two and three terminal junctions of metals and/or semiconductors
by introducing topological defects into interface where the
different tubes are joined.
We study energetics of these devices via quantum chemistry
calculations. We derive topological and chemical rules to
identify or design a variety of CNT devices. Some of our model
heterojunctions have been observed from more recent CNTs grown by
chemical vapor deposition experiments. We apply molecular
dynamics simulations to study the thermal and mechnical stability
of these devices.
We use quantum mechanics calculations to investigate
electronic structures and properties of some CNT devices that
have been proved to be energetically stable and chemically
accessible. We calculate the density of state (DOS) and
conducdence as functions of interface composition and geometry.
Based on our systymatic studies of chemical, thermal, mechanical
and electronic properties, we discuss the fabrication and
applications of the CNT electronic devices as transistors,
resonant tunneling diodes, electro-mechanical devices and
Dr. Jie Han, NASA Ames Research Center, Moffett Field, CA 94035,
ph: 415-604-4799 fax: 415-604-3957 email: email@example.com