The screening effect on field enhancement factor of the finite-length small radius single-walled carbon nanotubes

2009 ◽  
Vol 106 (1) ◽  
pp. 014301 ◽  
Author(s):  
W. S. Su ◽  
F. C. Chuang ◽  
T. H. Cho ◽  
T. C. Leung
Keyword(s):  
Carbon Nanotubes ◽  
Finite Length ◽  
Enhancement Factor ◽  
Field Enhancement ◽  
Single Walled Carbon Nanotubes ◽  
Field Enhancement Factor ◽  
Small Radius ◽  
Screening Effect ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

Confined water inside single-walled carbon nanotubes: Global phase diagram and effect of finite length

2011 ◽  
Vol 134 (24) ◽  
pp. 244501 ◽  
Author(s):  
Haruka Kyakuno ◽  
Kazuyuki Matsuda ◽  
Hitomi Yahiro ◽  
Yu Inami ◽  
Tomoko Fukuoka ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Phase Diagram ◽  
Finite Length ◽  
Single Walled Carbon Nanotubes ◽  
Confined Water ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes ◽  
Global Phase Diagram

EFFECTS OF NITROGEN SUBSTITUTIONAL DOPING ON THE ELECTRICAL PROPERTIES OF SMALL RADIUS (4, 0) SINGLE-WALLED CARBON NANOTUBES

2012 ◽  
Vol 27 (01) ◽  
pp. 1350003
Author(s):  
LI XIA ZHANG ◽  
JUAN ZHANG ◽  
QING YI SHAO
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Large Change ◽  
Single Walled Carbon Nanotubes ◽  
Small Radius ◽  
Single Walled Carbon ◽  
Large Dosage ◽  
Walled Carbon Nanotubes

By using the first-principles method based on density functional theory, we investigate the structural and electrical properties of the small radius (4, 0) single-walled carbon nanotubes (SWCNTs) in which one or more carbon atoms are substituted by one or more nitrogen (N) atoms. Results show that substitution of nitrogen alters the electrical properties and the global structure of the tube in some way. The conductivity of the metallic (4, 0) SWCNT weaken and an energy gap opens after doping nitrogen atoms. Meanwhile, the further research tells us that a large dosage concentration will bring a large change to the band structure for the SWCNTs.

Coalescence of parallel finite length single-walled carbon nanotubes by heat treatment

2013 ◽  
Vol 74 (3) ◽  
pp. 436-440 ◽  
Author(s):  
Xueming Yang ◽  
Fangwei Qiao ◽  
Xiaoxun Zhu ◽  
Pu Zhang ◽  
Dongci Chen ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Carbon Nanotubes ◽  
Finite Length ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

High-density metallic nanogap arrays for the sensitive detection of single-walled carbon nanotube thin films

2015 ◽  
Vol 178 ◽  
pp. 195-201 ◽  
Author(s):  
Hyeong-Ryeol Park ◽  
Seon Namgung ◽  
Xiaoshu Chen ◽  
Sang-Hyun Oh
Keyword(s):  
Carbon Nanotubes ◽  
Strong Field ◽  
Electromagnetic Coupling ◽  
Field Enhancement ◽  
Single Walled Carbon Nanotubes ◽  
Atomic Layer ◽  
Terahertz Waves ◽  
Single Walled Carbon ◽  
Bare Glass Substrate ◽  
Walled Carbon Nanotubes

We have investigated the extraordinary optical transmission of terahertz waves through an array of nanogaps with varying dimensions and periodicities, and used this platform to demonstrate terahertz sensing of a thin film of single-walled carbon nanotubes. We have used atomic layer lithography to fabricate periodic arrays of nanogap loops that have a gap size of 2 nm and a loop length of 100 μm (aspect ratio of 50 000). These sub-mm-scale loops of nanogaps can sustain terahertz electromagnetic resonances along the contour. We have characterized the transmission of terahertz waves through the nanogap arrays and investigated the influence of inter-gap electromagnetic coupling as the array periodicity shrinks from 100 μm to 4 μm. While the gaps occupy only 0.1% of the surface area, we have measured an amplitude (|E|) transmittance of over 50% due to the strong and broadband field enhancement inside the nanogaps. The absolute transmission through the 2 nm gaps along the rectangular loops can be boosted up to 25%, while it is only 1% for annular gaps with the same perimeter. Furthermore, the extremely tight field confinement and strong field enhancement near the 2 nm gap lead to 43% extinction of THz waves in a 10 nm-thick film of single-walled carbon nanotubes over the gaps. On the other hand, THz extinction by the same nanotube film on a bare glass substrate is only 2%. These nanogaps pave the way toward developing sensitive terahertz detectors for biological and chemical targets.

The Effects of Curvature, Relaxation and Mechanical Deformation on the Electronic Properties of Single-Walled Carbon Nanotubes

2008 ◽  
Author(s):  
Dong Qian ◽  
Qingjin Zheng
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Properties ◽  
Single Walled Carbon Nanotubes ◽  
Mechanical Deformation ◽  
Band Gaps ◽  
Coarse Grained ◽  
Small Radius ◽  
Single Walled Carbon ◽  
Curvature Effects ◽  
Walled Carbon Nanotubes

We present a framework based on coupling FEM/continuum method with quantum mechanical model for studying the effects of curvature, relaxation and mechanical deformation on the electronic properties of single-walled carbon nanotubes. The rehybridization and curvature effects, which are important for carbon nanotubes with both rotational and helical symmetries, is incorporated in the developed coarse grained model as an extension to the Bloch’s theorem. Based on extensive studies, we report the significant contribution of curvature-induced rehybridization, relaxation effect to the finite band gaps in small radius zigzag and chiral tubes that were predicted to be metallic (mod (n-m, 3) = 0) from the graphite-based models. Our calculation indicates the significant changes in the band gaps as linear functions of the applied tensile strain with the exception of armchair tubes. Transitions from metal to semi-conductor and vice versa are observed. Similar switch in conducting behavior is also present in the twisting case, while the band structures are observed to be insensitive to the applied bending. The deformation-band gap relation obtained in this work differs significantly with prior studies that use either phenomenological relations or empirical potentials for resolving the bond geometry. These differences highlight the importance of concurrent coupling.

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