Charge transfer at carbon nanotube–graphene van der Waals heterojunctions

Nanoscale ◽  
2016 ◽  
Vol 8 (26) ◽  
pp. 12883-12886 ◽  
Author(s):  
Yuanda Liu ◽  
Fengqiu Wang ◽  
Yujie Liu ◽  
Xizhang Wang ◽  
Yongbing Xu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Charge Transfer ◽  
Carbon Nanotube ◽  
Van Der Waals ◽  
Optoelectronic Devices ◽  
Low Dimensional ◽  
Low Dimensional Materials

Carbon nanotubes and graphene are two most widely investigated low-dimensional materials for photonic and optoelectronic devices.

Electrochemical Tuning of Single-Wall Carbon Nanotube Mat and Investigations on Actuator Mechanism

2004 ◽  
Vol 855 ◽  
Author(s):  
S. Gupta ◽  
M. Hughes ◽  
J. Robertson
Keyword(s):  
Carbon Nanotubes ◽  
Charge Transfer ◽  
Carbon Nanotube ◽  
Bond Length ◽  
Upper Bound ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon Nanotube ◽  
Single Wall Carbon ◽  
Electrochemical Tuning

ABSTRACTElectrochemical tuning of single-wall carbon nanotubes has been investigated using in situ Raman spectroscopy. We built a linear actuator from single-wall carbon nanotube mat and studied in several alkali metal (Li, Na, and K) and alkaline earth (Ca) halide solutions. The variation of bonding with electrochemical biasing was monitored using in situ Raman. This is since Raman can detect changes in C-C bond length: the radial breathing mode (RBM) at ∼190 cm−1 varies inversely with the nanotube diameter and the G band at ∼1590 cm−1 varies with the axial bond length. In addition, the intensities of both the modes vary significantly in a nonmonotonic manner pointing at the emptying/depleting or filling of the bonding and anti-bonding states - electrochemical charge injection. We discuss the variation of spectroscopic observables (intensity/frequency) of these modes providing valuable information on the charge transfer dynamics on the single-wall carbon nanotubes mat surface. We found the in-plane compressive strain (∼ -0.25%) and the charge transfer per carbon atom (fc ∼ -0.005) as an upper bound for the electrolytes used i.e. CaCl2. These results can be quantitatively understood in terms of the changes in the energy gaps between the one-dimensional van Hove singularities in the electron density of states arising possibly due to the alterations in the overlap integral of π bonds between the p orbitals of the adjacent carbon atoms. Moreover, the extent of variation of the absolute potential of the Fermi level or alternatively modification of band gap is estimated from modeling Raman intensity to be around 0.1 eV as an upper bound for CaCl2.

Photoconductivity Study of Modified Single-Wall Carbon Nanotube/ Oxotitanium Phthalocyanine

2007 ◽  
Vol 121-123 ◽  
pp. 631-636
Author(s):  
T. Li ◽  
X.B. Zhang ◽  
Y. Li ◽  
W.Z. Huang ◽  
X.Y. Tao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Charge Transfer ◽  
Carbon Nanotube ◽  
Chemical Modification ◽  
Single Wall Carbon Nanotubes ◽  
Charge Generation ◽  
Photoinduced Charge Transfer ◽  
Single Wall Carbon ◽  
Discharge Method ◽  
Photoinduced Charge

Single-wall Carbon nanotubes (SWNTs) bonded with dodecylamine groups were obtained by chemical modification. The modified SWNTs showed improved solubility in organic solvents. Both its chemical and aggregated structure was characterized by means of FTIR and TEM. The photoconductivity of oxotitanium phthalocyanine (TiOPc) doped with the modified SWNTs was investigated by xerographic photoinduced discharge method. The results showed that the photosensitivity of the double-layered photoreceptor composed of the SWNTs/TiOPc composite as charge generation material was higher than that of pristine TiOPc, and the sensitivity increased with the content of modified SWNTs in the composites. It is the photoinduced charge transfer between TiOPc and SWNTs that contributes to the improved photosensitivity of the modified SWNTs/TiOPc composites.

SOME NOTES ON LOW-DIMENSIONAL ELASTIC THEORIES OF BIO- AND NANO-STRUCTURES

2010 ◽  
Vol 24 (23) ◽  
pp. 2403-2412 ◽  
Author(s):  
XIAO-HUA ZHOU
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Energy Density ◽  
Helix Angle ◽  
Dimensional Structure ◽  
One Dimensional ◽  
Nano Structures ◽  
Multi Walled Carbon Nanotubes ◽  
Low Dimensional ◽  
Walled Carbon Nanotubes

The shapes of DNA, carbon nanotube (CNT) and vesicle are determined by the minimum of their elastic energy. Two central results about the low-dimensional elastic structure are reported here. Firstly, if the energy density of a one-dimensional structure is only related to its curvature, we generally find that a helix solution with the helix angle θ = ±π/4 will have zero total energy. Secondly, with the fixed length and radii, the helical multi-walled carbon nanotubes (MWNTs) and DNA will have the lowest energy when the helix angle θ = ±π/3.

scholarly journals Image polaritons in van der Waals crystals

Nanophotonics ◽  
2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Sergey G. Menabde ◽  
Jacob T. Heiden ◽  
Joel D. Cox ◽  
N. Asger Mortensen ◽  
Min Seok Jang
Keyword(s):  
Van Der Waals ◽  
Mirror Image ◽  
Propagation Loss ◽  
Strong Light ◽  
New Class ◽  
Close Proximity ◽  
Matter Interaction ◽  
Light Matter Interaction ◽  
Low Dimensional ◽  
Low Dimensional Materials

Abstract Polaritonic modes in low-dimensional materials enable strong light–matter interactions and the manipulation of light on nanometer length scales. Very recently, a new class of polaritons has attracted considerable interest in nanophotonics: image polaritons in van der Waals crystals, manifesting when a polaritonic material is in close proximity to a highly conductive metal, so that the polaritonic mode couples with its mirror image. Image modes constitute an appealing nanophotonic platform, providing an unparalleled degree of optical field compression into nanometric volumes while exhibiting lower normalized propagation loss compared to conventional polariton modes in van der Waals crystals on nonmetallic substrates. Moreover, the ultra-compressed image modes provide access to the nonlocal regime of light–matter interaction. In this review, we systematically overview the young, yet rapidly growing, field of image polaritons. More specifically, we discuss the dispersion properties of image modes, showcase the diversity of the available polaritons in various van der Waals materials, and highlight experimental breakthroughs owing to the unique properties of image polaritons.

scholarly journals Buckling and Vibration of Carbon Nanotubes Embedded in Polyethylene Polymers

2012 ◽  
Vol 3 (2) ◽  
Author(s):  
Dai Shi ◽  
Quan Wang ◽  
Vijay K. Varadan ◽  
Wenhui Duan
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Molecular Mechanics ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Buckling Instability ◽  
Resonance Frequencies

The discovery of buckling instability and vibration of polyethylene (PE)/carbon nanotube (CNT) matrices is reported by molecular mechanics simulations. The buckling strains and the resonance frequencies are found to decrease with an increase in the number of polyethylene chains in the polyethylene/carbon nanotube matrices. The van der Waals forces between the polyethylene chains and the carbon nanotube in matrices are investigated to provide physical interpretations on the findings.

Study on the Morphology Properties of Carbon Nanotube/Polyaniline Composites Thin Film

2012 ◽  
Vol 569 ◽  
pp. 15-18
Author(s):  
Wen Ding ◽  
Vasileios Koutsos ◽  
Jin Hai Si ◽  
Zhong Xiao Song
Keyword(s):  
Thin Film ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Spin Coating ◽  
Optoelectronic Devices ◽  
Topographic Image ◽  
Interpenetrating Network ◽  
Force Microscopy ◽  
Atomic Force ◽  
Polyaniline Composites

Active layer’s morphologies properties are important for the optoelectronic devices. In this paper, the morphologies properties of the carbon nanotube/polyaniline composites thin film formed by spin coating were studied by the atomic force microscopy (AFM). The results showed that spin coating way greatly affects the thin film’s topographic image, carbon nanotubes’ concentration is the key that decide whether the interpenetrating network phase separation microstructure can be formed.

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