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Carbon Nanotube Based Molecular ElectronicsCarbon nanotubes and the nanotube heterojunctions have recently emerged as excellent candidates for nanoscale molecular electronic device components. Experimental measurements on the conductivity, rectifying behavior and conductivity-chirality correlation have also been made. While quasi-one dimensional simple heterojunctions between nanotubes with different electronic behavior can be generated by introduction of a pair of heptagon-pentagon defects in an otherwise all hexagon graphene sheet. Other complex 3- and 4-point junctions may require other mechanisms. Structural stability as well as local electronic density of states of various nanotube junctions are investigated using a generalized tight-binding molecular dynamics (GDBMD) scheme that incorporates non-orthogonality of the orbitals. The junctions investigated include straight and small angle heterojunctions of various chiralities and diameters; as well as more complex 'T' and 'Y' junctions which do not always obey the usual pentagon-heptagon pair rule. The study of local density of states (LDOS) reveal many interesting features, most prominent among them being the defect-induced states in the gap. The proposed three and four pointjunctions are one of the smallest possible tunnel junctions made entirely of carbon atoms. Furthermore the electronic behavior of the nanotube based device components can be taylored by doping with group III-V elements such as B and N, and BN nanotubes as a wide band gap semiconductor has also been realized in experiments. Structural properties of heteroatomic nanotubes comprising C, B and N will be discussed.
Document ID
20020051315
Document Type
Conference Paper
Authors
Srivastava, Deepak (NASA Ames Research Center Moffett Field, CA United States)
Saini, Subhash (NASA Ames Research Center Moffett Field, CA United States)
Menon, Madhu (Kentucky Univ. Lexington, KY United States)
Date Acquired
August 20, 2013
Publication Date
January 1, 1998
Subject Category
Electronics and Electrical Engineering
Meeting Information
Eleventh Red Sea Conference(Hurgada)
Funding Number(s)
PROJECT: RTOP 519-40-12
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.