Анотація:
Transmission of twenty-four carbon nanotube geometries to form twelve
intramolecular junctions between every two carbon nanotubes have been investigated
numerically. The twelve carbon nanotubes are zigzag and rest carbon nanotubes are
armchair forming three different kinds of intramolecular junctions named as
circumferential defective carbon nanotubes, grouped defective carbon nanotubes and
distributed defective carbon nanotubes. Electronic states joining carbon nanotubes form
Schottky diode that is analyzed using the tight-binding method. These quantum
transmissions through Schottky diodes have been compared among the different
defective carbon nanotubes and correlated with the pentagon and heptagon that formed in
the intramolecular junction. The transmission coefficient of conduction band always
simulated less than the transmission coefficient of valence band in each intramolecular
junction irrespective of the joining of carbon nanotubes in the Schottky diodes. The
maximum asymmetry of distributed defective carbon nanotubes in transmission is
observed more clearly than that for other two defective carbon nanotubes forming
Schottky diodes. It is interesting to note that the position of the localized states above and
below the Fermi energy level may be controlled with the distribution of the defect pairs
and the hexagons around the defects in the defected carbon nanotube.