Broken symmetry, boundary conditions, and band-gap oscillations in finite single-wall carbon nanotubes

ABSTRACTWe report anisotropic optical absorption and saturable absorption (SA) properties of aligned single wall carbon nanotubes (SWNT) embedded in the mechanically stretched polyvinyl alcohol (PVA) film. Polarized absorption spectra of the film showed a strong anisotropy for the near-infrared band gap transition of semiconductor SWNT with a dichroic ratio of 7.4, indicating the good alignment of the embedded SWNT. The SA property of the band gap transition measured using a polarized femtosecond fiber laser showed a strong polarization angle dependence for the stretched film. When the polarization of light is parallel to the stretching direction, the absorption saturation of the stretched film became more efficient than that of the unstretched film because of the apparently stronger transition moment.

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(Invited) Evidence for Strong Electronic Correlations and Band-Gap Renormalization in Doped Single-Wall Carbon Nanotubes

ECS Meeting Abstracts ◽

10.1149/ma2016-01/8/678 ◽

2016 ◽

Keyword(s):

Carbon Nanotubes ◽

Band Gap ◽

Single Wall Carbon Nanotubes ◽

Electronic Correlations ◽

Single Wall Carbon

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Band-gap unification of partially Si-substituted single-wall carbon nanotubes

Physical Review B ◽

10.1103/physrevb.74.245417 ◽

2006 ◽

Vol 74 (24) ◽

Cited By ~ 8

Author(s):

Pavel V. Avramov ◽

Pavel B. Sorokin ◽

Alexander S. Fedorov ◽

Dmitri G. Fedorov ◽

Yoshihito Maeda

Keyword(s):

Carbon Nanotubes ◽

Band Gap ◽

Single Wall Carbon Nanotubes ◽

Single Wall Carbon

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Growth of semiconducting single-wall carbon nanotubes with a narrow band-gap distribution

Nature Communications ◽

10.1038/ncomms11160 ◽

2016 ◽

Vol 7 (1) ◽

Cited By ~ 52

Author(s):

Feng Zhang ◽

Peng-Xiang Hou ◽

Chang Liu ◽

Bing-Wei Wang ◽

Hua Jiang ◽

...

Keyword(s):

Carbon Nanotubes ◽

Band Gap ◽

High Performance ◽

Narrow Band ◽

Thin Film Transistor ◽

Diameter Distribution ◽

Single Wall Carbon Nanotubes ◽

Uniform Size ◽

Single Wall Carbon ◽

Cobalt Nanoparticle

Abstract The growth of high-quality semiconducting single-wall carbon nanotubes with a narrow band-gap distribution is crucial for the fabrication of high-performance electronic devices. However, the single-wall carbon nanotubes grown from traditional metal catalysts usually have diversified structures and properties. Here we design and prepare an acorn-like, partially carbon-coated cobalt nanoparticle catalyst with a uniform size and structure by the thermal reduction of a [Co(CN)6]3− precursor adsorbed on a self-assembled block copolymer nanodomain. The inner cobalt nanoparticle functions as active catalytic phase for carbon nanotube growth, whereas the outer carbon layer prevents the aggregation of cobalt nanoparticles and ensures a perpendicular growth mode. The grown single-wall carbon nanotubes have a very narrow diameter distribution centred at 1.7 nm and a high semiconducting content of >95%. These semiconducting single-wall carbon nanotubes have a very small band-gap difference of ∼0.08 eV and show excellent thin-film transistor performance.

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Temperature dependence of the optical excitation lifetime and band gap in chirality assigned semiconducting single-wall carbon nanotubes

Physical Review B ◽

10.1103/physrevb.74.121411 ◽

2006 ◽

Vol 74 (12) ◽

Cited By ~ 24

Author(s):

Ferenc Simon ◽

Rudolf Pfeiffer ◽

Hans Kuzmany

Keyword(s):

Carbon Nanotubes ◽

Temperature Dependence ◽

Band Gap ◽

Optical Excitation ◽

Single Wall Carbon Nanotubes ◽

Single Wall Carbon

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Effect of strain on the band gap and effective mass of zigzag single-wall carbon nanotubes: First-principles density-functional calculations

Physical Review B ◽

10.1103/physrevb.77.155434 ◽

2008 ◽

Vol 77 (15) ◽

Cited By ~ 33

Author(s):

S. Sreekala ◽

X.-H. Peng ◽

P. M. Ajayan ◽

S. K. Nayak

Keyword(s):

Carbon Nanotubes ◽

Band Gap ◽

Effective Mass ◽

First Principles ◽

Density Functional Calculations ◽

Density Functional ◽

Single Wall Carbon Nanotubes ◽

Single Wall Carbon

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Band-Gap Modulation and Kohn Anomalies in Two-Dimensional Graphite and Single-Wall Carbon Nanotubes

MRS Proceedings ◽

10.1557/proc-0963-q01-06 ◽

2006 ◽

Vol 963 ◽

Author(s):

Georgii Samsonidze ◽

Eduardo B. Barros ◽

Hyungbin Son ◽

Riichiro Saito ◽

Gene Dresselhaus ◽

...

Keyword(s):

Carbon Nanotubes ◽

Band Gap ◽

Graphene Sheet ◽

Phonon Mode ◽

Single Wall Carbon Nanotubes ◽

Two Dimensional ◽

Phonon Modes ◽

Single Wall Carbon ◽

Electron Phonon Coupling ◽

Band Gap Modulation

ABSTRACTThe electron-phonon coupling in two-dimensional graphite (graphene sheet) and metallic single-wall carbon nanotubes (SWNTs) is analyzed. In the graphene sheet the G-band phonon mode induces oscillations of the Fermi points, while the G′-band phonon mode opens a dynamical (oscillating with the phonon frequency) band gap, and accordingly, both phonon modes exhibit Kohn anomalies. Similarly, truly metallic armchair SWNTs undergo Peierls transitions driven by the G−- and G′-band phonon modes both of which open a dynamical band gap. In addition, the dynamical band gap induces a non-linear dependence of the phonon frequencies on the doping level and gives rise to strong anharmonic effects in the graphene sheet and metallic SWNTs.

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