"Electronic properties of zig-zag carbon nanotubes : a first-principles" by Pavan Kumar Valavala

Date of Award

2008

Document Type

Master's Thesis

Degree Name

Master of Science in Physics (MS)

College, School or Department Name

Department of Physics

Advisor

Ranjit Pati

Co-Advisor

Gregory M Odegard

Abstract

Carbon nanotube (CNT) is a one dimensional (1-D) nanostructured material, which has been the focal point of research over the past decade for intriguing applications ranging from nanoelectronics to chemical and biological sensors. Using a first-principles gradient corrected density functional approach, we present a comprehensive study of the geometry and energy band gap in zig-zag semi-conducting (n,0) carbon nanotubes (CNT) to resolve some of the conflicting findings. Our calculations confirm that the single wall (n,0) CNTs fall into two distinct classes depending upon n mod 3 equal to 1 (smaller band gaps) or 2 (larger gaps). The effect of longitudinal strain on the band gap further confirms the existence of two distinct classes: for n mod 3 = 1 or 2, changing Eg by ~ ±110 meV for 1% strain in each case. We also present our findings for the origin of metallicity in multiwall CNTs.

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Physics Commons

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