Abstract
We investigated the mechanism of electron field emission in prestine short carbon nanotubes using ab-initio computation in isolated and periodic simulation cells. We computed the evolution of the wave functions using Time-Dependent Density Functional Theory, where we have utilized the Crank-Nicholson propagator. We found that in prestine carbon nanotubes, emitted charge tends emerge mostly from electrons that are concentrated at the nanotube tip region, unlike metallic tips. The charge beam concentrates into specific channel structures as the wave function approaches the anode. Nitrogen doping of carbon nanotubes improves emission, in line with experimental findings, and the nitrogen dopant closer to the nanotube tip produces optimal emission performance. However, the nitrogen dopant causes dispersion of the charge cloud, which might lead to wasting of the emission current. Boron doping either impedes field emission in nanotubes or produces minimal effect.
Department
Physics Department
Degree Name
MS in Physics
Graduation Date
6-1-2011
Submission Date
September 2010
First Advisor
El Sheikh, Salah
Second Advisor
Salem, Noha
Extent
NA
Document Type
Master's Thesis
Library of Congress Subject Heading 1
Carbon.
Library of Congress Subject Heading 2
nostructured materials.
Rights
The author retains all rights with regard to copyright. The author certifies that written permission from the owner(s) of third-party copyrighted matter included in the thesis, dissertation, paper, or record of study has been obtained. The author further certifies that IRB approval has been obtained for this thesis, or that IRB approval is not necessary for this thesis. Insofar as this thesis, dissertation, paper, or record of study is an educational record as defined in the Family Educational Rights and Privacy Act (FERPA) (20 USC 1232g), the author has granted consent to disclosure of it to anyone who requests a copy.
Institutional Review Board (IRB) Approval
Not necessary for this item
Recommended Citation
APA Citation
Tawfik, S.
(2011).Simulation of field emission from carbon nanotubes using time-dependent density functional theory and the effect of nitrogen and boron doping [Master's Thesis, the American University in Cairo]. AUC Knowledge Fountain.
https://fount.aucegypt.edu/etds/1285
MLA Citation
Tawfik, Sherif. Simulation of field emission from carbon nanotubes using time-dependent density functional theory and the effect of nitrogen and boron doping. 2011. American University in Cairo, Master's Thesis. AUC Knowledge Fountain.
https://fount.aucegypt.edu/etds/1285