Proceedings Article | 2 September 2011

Proc. SPIE. 8101, Carbon Nanotubes, Graphene, and Associated Devices IV

KEYWORDS: Semiconductors, Scattering, Metals, Constructive interference, Quantum dots, Electronic components, Heterojunctions, Nanoelectronics, Lead, Carbon nanotubes

Recently, one of the most significant topics in electronic devices is miniaturization. It has been a growing interest in
some mesoscopic systems such as quantum dots. The size of these quantum dots approaches to the atomic scale,
which contributes to interesting new behaviors. Understanding their properties is an important problem in the fields
of nano electronics. Here we study the transport properties of the single wall carbon nanotubes quantum dots.
Considering Carbon nanotube (2n,0)/1(n,n)/m(2n,0) quantum dot, we have investigated the effects of the
central cell size on the conductance of the system. By increasing the length of armchair carbon nanotube in metalmetal-
metal quantum dot m(12,0)/1(6,6)/m(12,0) , we have observed reduction in the conductance. In
semiconductor- metal- semiconductor quantum dots (8,0)/1(4,4)/m(8,0), increasing the length of armchair part
causes the scattering rate raising. For more than special length, due to the destructive and constructive interference
of the wave functions, the conductance gap oscillates near the Fermi energy. Therefore, by controlling on cell size
characteristics, it is possible to manipulate some efficient devices in nano-electronics.