scholarly journals The Use of Gravity Filtration of Carbon Nanotubes from Suspension to Produce Films with Low Roughness for Carbon Nanotube/Silicon Heterojunction Solar Device Application

2020 ◽  
Vol 10 (18) ◽  
pp. 6415
Author(s):  
Tom S. L. Grace ◽  
Christopher T. Gibson ◽  
Jason R. Gascooke ◽  
Joseph G. Shapter
Keyword(s):  
Carbon Nanotube ◽  
Light Transmittance ◽  
Average Height ◽  
Vacuum Filtration ◽  
Force Microscopy ◽  
Atomic Force ◽  
Extended Area ◽  
Slow Filtration ◽  
Large Improvement ◽  
Single Walled Cnts

The morphology of carbon nanotube (CNT) films is an important factor in the performance of CNT/silicon (CNT/Si) heterojunction solar devices. Films have generally been prepared via vacuum filtration from aqueous suspensions. Whilst this enables strong films to be formed quickly, they are highly disordered on the micron scale, with many charge traps and gaps forming in the films. It has been previously established that lowering the filtration speed enables more ordered films to be formed. The use of slow gravity filtration to improve the morphology of CNT films used in the CNT/Si device is reported here. It was found that slow filtration causes significant macroscale inhomogeneity in the CNT films, with concentrated thick regions, surrounded by larger thinner areas. By using atomic force microscopy (AFM), scanning electron microscopy (SEM), and polarised Raman spectroscopy, it was determined that there was no large improvement in directional organisation of the CNTs on the microscale. However, the films were found to be much smoother on the microscale, with arithmetic and root mean square average height deviation values roughly 3 times lower for slow-filtered films compared to fast-filtered films. A comparison was performed with CNT-Si solar cells fabricated with both slow and fast-filtered single-walled CNTs (SWCNT) films. It was found that slow filtration can produce similar photovoltaic results with thinner films. The results demonstrate that film morphology, even without improved CNT alignment, can lead to significant improvement in device performance in some applications. However, slow filtration did not form films of uniform light transmittance over an extended area, causing an increase in the variation in performance between individual devices compared to fast-filtered films.

Modulation of carbon nanotube yield and type through the collective effects of initially deposited catalyst amount and MgO underlayer annealing temperature

MRS Advances ◽  
2018 ◽  
Vol 4 (3-4) ◽  
pp. 139-146
Author(s):  
Takashi Tsuji ◽  
Guohai Chen ◽  
Kenji Hata ◽  
Don N. Futaba ◽  
Shunsuke Sakurai
Keyword(s):  
Carbon Nanotube ◽  
Annealing Temperature ◽  
Catalyst Surface ◽  
Catalyst System ◽  
Forest Growth ◽  
Collective Effects ◽  
High Yield ◽  
Force Microscopy ◽  
Atomic Force ◽  
Fe Catalysts

ABSTRACTRecently, the millimetre-scale, highly efficient growth of single-wall carbon nanotube (SWCNT) forests from iron (Fe) catalysts has been reported through the annealing of the magnesia (MgO) underlayer. Here, we report the modulation of the CNT yield (height) and average number of CNT walls for a Fe/MgO catalyst system through the collective effects of initial Fe amount and MgO annealing temperature. Our results revealed the existence of a well-defined region for high yield SWCNT forest growth in the domain of deposited Fe thickness and MgO annealing temperature. Through topographic examinations of the catalyst surface using atomic force microscopy, we confirmed that our results stem from the collective effects of increased amounts of surface-bound Fe through the amount of deposition and suppression of Fe subsurface diffusion, together govern the amount of surface-bound catalyst. The combination of these mechanisms determined the final nanoparticle size, density, and stability and could explain the three distinctly defined regions: low yield SWCNT growth, high yield SWCNT growth, and high yield multiwall CNT growth. Furthermore, we explained the observed borders between these three regions.

Electrical tomography using atomic force microscopy and its application towards carbon nanotube-based interconnects

2012 ◽  
Vol 23 (30) ◽  
pp. 305707 ◽  
Author(s):  
A Schulze ◽  
T Hantschel ◽  
A Dathe ◽  
P Eyben ◽  
X Ke ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Carbon Nanotube ◽  
Electrical Tomography ◽  
Force Microscopy ◽  
Atomic Force

The Attachment of Carbon Nanotube on a Blunt AFM Tip Using Electric Fields

2004 ◽  
Author(s):  
Hyung Woo Lee ◽  
Soon Geun Kwon ◽  
Soo Hyun Kim ◽  
Yoon Keun Kwak ◽  
Chang Soo Han
Keyword(s):  
Carbon Nanotubes ◽  
Atomic Force Microscopy ◽  
Carbon Nanotube ◽  
Electric Fields ◽  
Low Cost ◽  
Reliable Technique ◽  
Force Microscopy ◽  
Atomic Force

We report a simple, low cost, reliable technique of making carbon nanotube (CNT) modified atomic force microscopy (AFM) tip. We used the dielectrophoresis and the electrophoresis to align and deposit carbon nanotubes on the end of the AFM tip. From the simulation and the various experiments, we obtained the optimal electric condition, 0.32Vpp/μm. Also, we found that the blunt shape of the tip’s apex is more effective than sharpened one. Through the experiments, we verified that the blunt shape is more effective over 50% than the sharpened one in the attachment of CNTs. By comparing the scanning results between the CNT modified tip and a normal AFM tip, we obtained the improvement in efficiency of 23%.

Frequency Response of Carbon Nanotube Probes during Tapping Mode of Atomic Force Microscopy

2013 ◽  
Vol 378 ◽  
pp. 466-471
Author(s):  
Po Jen Shih ◽  
Shang Hao Cai
Keyword(s):  
Atomic Force Microscopy ◽  
Carbon Nanotube ◽  
Atomic Force Microscope ◽  
Frequency Response ◽  
Tapping Mode ◽  
Force Microscopy ◽  
Frequency Responses ◽  
Atomic Force ◽  
Frequency Drop ◽  
Atomic Force Microscope Measurement

The dynamic behaviors of carbon nanotube probes applied in Atomic Force Microscope measurement are of interest in advanced nanoscalar topography. In this paper, we developed the characteristic equations and applied the model analysis to solve the eigenvalues of the microcantilever and the carbon nanotube. The eigenvalues were then used in the tapping mode system to predict the frequency responses against the tip-sample separations. It was found that the frequency drop steeply if the separation was less than certain distances. This instability of frequency is deduced from the jump of microcantilever or the jump of the carbon nanotube. Various lengths and binding angles of the carbon nanotube were considered, and the results indicated that the binding angle dominated the frequency responses and jumps.

Surface and Interface Characterization of Ion Beam Re-crystallized Si

2002 ◽  
Vol 750 ◽  
Author(s):  
P. K. Sahoo ◽  
B. Satpati ◽  
S. Dey ◽  
P. V. Satyam ◽  
T. Som ◽  
...  
Keyword(s):  
Ion Beam ◽  
Amorphous Layer ◽  
Amorphous Structure ◽  
Average Height ◽  
Force Microscopy ◽  
Surface And Interface ◽  
Atomic Force ◽  
Nano Crystalline ◽  
Transmission Electron

ABSTRACTIn the present work we have studied efficacy of ion beam induced epitaxial crystallization (IBIEC) to recover amorphous layers (300 – 350 nm) produced by MeV Kr ions in Si(100) and studied the associated changes occurring on surface and interface of the recrystallized region. IBIEC experiments were carried out at sample temperatures in the range of 200 − 400°C using 1 MeV N+ ion beam. Rutherford backscattering-Channeling technique showed planar and gradual recovery of the amorphous layer as a function of temperature. Transmission electron microscopy measurements show good crystalline structure of the recovered region at 400°C while at lower temperatures nano-crystalline Si formation embedded in the amorphous structure is evident. The surface topography studied by atomic force microscopy shows development of islands after IBIEC. The rms roughness is around 0.5 nm and average height of the islands is found to be 1.8 nm. The observed epitaxial growth and the surface topographical features have been correlated.

Atomic Force Microscopy Studies of DNA-Wrapped Carbon Nanotube Structure and Binding to Quantum Dots

2008 ◽  
Vol 130 (32) ◽  
pp. 10648-10655 ◽  
Author(s):  
Jennifer F. Campbell ◽  
Ingrid Tessmer ◽  
H. Holden Thorp ◽  
Dorothy A. Erie
Keyword(s):  
Quantum Dots ◽  
Atomic Force Microscopy ◽  
Carbon Nanotube ◽  
Force Microscopy ◽  
Atomic Force

Dispersibility of Carbon Nanotubes

2007 ◽  
Vol 537-538 ◽  
pp. 161-168 ◽  
Author(s):  
T. Gábor ◽  
D. Aranyi ◽  
Katalin Papp ◽  
F.H. Kármán ◽  
Erika Kálmán
Keyword(s):  
Carbon Nanotubes ◽  
Atomic Force Microscopy ◽  
Carbon Nanotube ◽  
Polymer Composites ◽  
Ionic Surfactant ◽  
Geometrical Parameters ◽  
Stable Carbon ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dispersion Agent

Availability of a stable carbon nanotube suspension is a prerequisite for production of polymer composites with carbon nanotube as additives. In this work nanotube suspensions, which have been prepared from various nanotubes in different dispersion agents, were compared. Dispersibility of the samples was investigated by scanning electon microscopy and atomic force microscopy. Solution of a non-ionic surfactant was also used successfully as a new dispersion agent. Geometrical parameters of the carbon nanotubes were determined by using atomic force microscopy. Correlation was found between the dispersibility and the parameters of the nanotubes and relative permittivity of the different solvents.

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