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Graphenylene nanotubes : structure, electronic properties and potential applications Koch, Andrew Thomas
Abstract
The electronic properties of a new type of carbon nanotube, based on the graphenylene motif, are investigated using density functional and tight-binding methods. Analogous to conventional graphene-based carbon nanotubes, a two-dimensional graphenylene sheet can be “rolled” into a seamless cylinder in armchair, zigzag, or chiral orientations. The resulting nanotube can be described using the familiar (n,m) nomenclature and possesses four-, six-, and twelve-membered rings. Density functional theory-based geometry relaxations predict that graphenylene nanotubes, like their two-dimensional counterpart, exhibit three distinct bond lengths between carbon atoms, indicating a non-uniform electron distribution. The dodecagonal rings form pores, 3.3 Å in diameter in the two-dimensional case, which become saddle-shaped paraboloids in smaller-diameter graphenylene nanotubes. Electronic structure calculations in density functional theory predict zigzag graphenylene nanotubes to be small-band-gap semiconductors, with a generally decreasing band gap as the diameter increases. Interestingly, the calculations predict metallic characteristics for armchair graphenylene nanotubes with small diameters (< 2 nm), and semiconducting characteristics with a small band gap for armchair graphenylene nanotubes with larger diameters. Similar to conventional carbon nanotubes, graphenylene nanotubes with indices mod(n-m,3)=0 exhibit a band gap approximately equal to that of armchair graphenylene nanotubes with comparable diameters.
Item Metadata
Title |
Graphenylene nanotubes : structure, electronic properties and potential applications
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2015
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Description |
The electronic properties of a new type of carbon nanotube, based on the graphenylene motif, are investigated using density functional and tight-binding methods. Analogous to conventional graphene-based carbon nanotubes, a two-dimensional graphenylene sheet can be “rolled” into a seamless cylinder in armchair, zigzag, or chiral orientations. The resulting nanotube can be described using the familiar (n,m) nomenclature and possesses four-, six-, and twelve-membered rings. Density functional theory-based geometry relaxations predict that graphenylene nanotubes, like their two-dimensional counterpart, exhibit three distinct bond lengths between carbon atoms, indicating a non-uniform electron distribution. The dodecagonal rings form pores, 3.3 Å in diameter in the two-dimensional case, which become saddle-shaped paraboloids in smaller-diameter graphenylene nanotubes. Electronic structure calculations in density functional theory predict zigzag graphenylene nanotubes to be small-band-gap semiconductors, with a generally decreasing band gap as the diameter increases. Interestingly, the calculations predict metallic characteristics for armchair graphenylene nanotubes with small diameters (< 2 nm), and semiconducting characteristics with a small band gap for armchair graphenylene nanotubes with larger diameters. Similar to conventional carbon nanotubes, graphenylene nanotubes with indices mod(n-m,3)=0 exhibit a band gap approximately equal to that of armchair graphenylene nanotubes with comparable diameters.
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Genre | |
Type | |
Language |
eng
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Date Available |
2015-11-05
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Provider |
Vancouver : University of British Columbia Library
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Rights |
Attribution-NonCommercial-NoDerivs 2.5 Canada
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DOI |
10.14288/1.0167799
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2015-11
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Campus | |
Scholarly Level |
Graduate
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Rights URI | |
Aggregated Source Repository |
DSpace
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Rights
Attribution-NonCommercial-NoDerivs 2.5 Canada